Showing papers in "International Journal of Cancer in 2005"

Trends in incidence and prognosis for head and neck cancer in the United States: A site-specific analysis of the SEER database

Abstract: Despite recent advances in the diagnosis and treatment of head and neck cancer, there has been little evidence of improvement in 5-year survival rates over the last few decades. To determine more accurate trends in site-specific outcomes as opposed to a more general overview of head and neck cancer patients, we analyzed the site-specific data collected in the Surveillance, Epidemiology, and End Results-SEER Public-Use Database 1973-1999. Based on the selection criteria, 96,232 cases were evaluated for trend analysis in incidence, clinical stage, treatment and 5-year survival. During the period 1973-1999, site-specific incidence rates for head and neck cancer changed significantly. Site-specific analysis of survival from 1974-1997 showed significant improvements in 5-year survival rates for cancers of the nasopharynx, oropharynx and hypopharynx (38.1% to 56.7% for nasopharynx, p < 0.001; 36.3% to 49.1% for oropharynx, p = 0.001 and 28.3% to 33.3% for hypopharynx, p = 0.015). The prognosis for early-stage salivary gland cancer during 1983-1997 and late-stage larynx cancer during 1974-1997 also demonstrated improvement (82.7% to 88.5%, p = 0.012 and 22.2% to 38.3%, p = 0.013, respectively). On the other hand, the prognosis for regional stage oral cavity cancer as well as early-stage larynx cancer patients declined during 1983-1997 (49.2% to 43.8%, p = 0.032 and 82.3% to 74.3%, p = 0.002, respectively). Site-specific changes in treatment and staging were also noted. Site-specific analysis allows for a more accurate description of incidence, staging, treatment, and prognostic trends for head and neck cancer.

International lung cancer trends by histologic type: Male:female differences diminishing and adenocarcinoma rates rising

Abstract: Lung cancer rates have peaked among men in many areas of the world, but rates among women continue to rise. Most lung cancers are squamous cell carcinoma, small cell carcinoma, or adenocarcinoma; trends vary according to type. We compiled population-based morphology-specific incidence data from registries contributing to the International Agency for Research on Cancer (IARC) databases. Unspecified cancers and carcinomas were reallocated based on a registry, time period, sex and age group-specific basis. Where available, data from several registries within a country were pooled for analysis. Rates per 100,000 person-years for 1980-1982 to 1995-1997 were age-adjusted by the direct method using the world standard. Squamous cell carcinoma rates among males declined 30% or more in North America and some European countries while changing less dramatically in other areas; small cell carcinoma rates decreased less rapidly. Squamous and small cell carcinoma rates among females generally rose, with the increases especially pronounced in the Netherlands and Norway. In contrast, adenocarcinoma rates rose among males and females in virtually all areas, with the increases among males exceeding 50% in many areas of Europe; among females, rates also rose rapidly and more than doubled in Norway, Italy and France. Rates of all lung cancer types among women and adenocarcinoma among men continue to rise despite declining cigarette use in many Western countries and shifts to filtered/low-tar cigarettes. Renewed efforts toward cessation and prevention are mandatory to curb the prevalence of cigarette smoking and to reduce lung cancer rates eventually.

Microvesicles derived from activated platelets induce metastasis and angiogenesis in lung cancer.

Abstract: The role of platelets in tumor progression and metastasis has been recognized but the mechanism of their action remains unclear. Five human lung cancer cell lines (A549, CRL 2066, CRL 2062, HTB 183, HTB 177) and a murine Lewis lung carcinoma (LCC) cell line (for an in vivo model of metastasis) were used to investigate how platelet-derived microvesicles (PMV), which are circular fragments shed from the surface membranes of activated platelets, and exosomes released from platelet alpha-granules, could contribute to metastatic spread. We found that PMV transferred the platelet-derived integrin CD41 to most of the lung cancer cell lines tested and stimulated the phosphorylation of mitogen-activated protein kinase p42/44 and serine/threonine kinase as well as the expression of membrane type 1-matrix metalloproteinase (MT1-MMP). PMV chemoattracted 4 of the 5 cell lines, with the highly metastatic A549 cells exhibiting the strongest response. In A549 cells, PMV were shown to stimulate proliferation, upregulate cyclin D2 expression and increase trans-Matrigel chemoinvasion. Furthermore, in these cells, PMV stimulated mRNA expression for angiogenic factors such as MMP-9, vascular endothelial growth factor, interleukin-8 and hepatocyte growth factor, as well as adhesion to fibrinogen and human umbilical vein endothelial cells. Intravenous injection of murine PMV-covered LLC cells into syngeneic mice resulted in significantly more metastatic foci in their lungs and LLC cells in bone marrow than in control animals injected with LCC cells not covered with PMV. Based on these findings, we suggest that PMV play an important role in tumor progression/metastasis and angiogenesis in lung cancer.

Prospective study of risk factors for esophageal and gastric cancers in the Linxian general population trial cohort in China.

Abstract: Esophageal cancer incidence and mortality rates in Linxian, China are among the highest in the world. We examined risk factors for esophageal squamous cell carcinoma (ESCC), gastric cardia cancer (GCC), and gastric noncardia cancer (GNCC) in a population-based, prospective study of 29,584 adults who participated in the Linxian General Population Trial. All study participants completed a baseline questionnaire that included questions on demographic characteristics, personal and family history of disease, and lifestyle factors. After 15 years of follow-up, a total of 3,410 incident upper gastrointestinal cancers were identified, including 1,958 ESCC, 1,089 GCC and 363 GNCC. Cox proportional hazard models were used to estimate risks. Increased age and a positive family history of esophageal cancer (including ESCC or GCC) were significantly associated with risk at all 3 cancer sites. Additional risk factors for ESCC included being born in Linxian, increased height, cigarette smoking and pipe smoking; for GCC, male gender, consumption of moldy breads and pipe smoking; and for GNCC, male gender and cigarette smoking. Protective factors for ESCC included formal education, water piped into the home, increased consumption of meat, eggs and fresh fruits and increased BMI; for GCC, formal education, water piped into the home, increased consumption of eggs and fresh fruits and alcohol consumption; and for GNCC, increased weight and BMI. General socioeconomic status (SES) is a common denominator in many of these factors and improving SES is a promising approach for reducing the tremendous burden of upper gastrointestinal cancers in Linxian.

High‐throughput protein expression analysis using tissue microarray technology of a large well‐characterised series identifies biologically distinct classes of breast cancer confirming recent cDNA expression analyses

Abstract: Recent studies on gene molecular profiling using cDNA microarray in a relatively small series of breast cancer have identified biologically distinct groups with apparent clinical and prognostic relevance. The validation of such new taxonomies should be confirmed on larger series of cases prior to acceptance in clinical practice. The development of tissue microarray (TMA) technology provides methodology for high-throughput concomitant analyses of multiple proteins on large numbers of archival tumour samples. In our study, we have used immunohistochemistry techniques applied to TMA preparations of 1,076 cases of invasive breast cancer to study the combined protein expression profiles of a large panel of well-characterized commercially available biomarkers related to epithelial cell lineage, differentiation, hormone and growth factor receptors and gene products known to be altered in some forms of breast cancer. Using hierarchical clustering methodology, 5 groups with distinct patterns of protein expression were identified. A sixth group of only 4 cases was also identified but deemed too small for further detailed assessment. Further analysis of these clusters was performed using multiple layer perceptron (MLP)-artificial neural network (ANN) with a back propagation algorithm to identify key biomarkers driving the membership of each group. We have identified 2 large groups by their expression of luminal epithelial cell phenotypic characteristics, hormone receptors positivity, absence of basal epithelial phenotype characteristics and lack of c-erbB-2 protein overexpression. Two additional groups were characterized by high c-erbB-2 positivity and negative or weak hormone receptors expression but showed differences in MUC1 and E-cadherin expression. The final group was characterized by strong basal epithelial characteristics, p53 positivity, absent hormone receptors and weak to low luminal epithelial cytokeratin expression. In addition, we have identified significant differences between clusters identified in this series with respect to established prognostic factors including tumour grade, size and histologic tumour type as well as differences in patient outcomes. The different protein expression profiles identified in our study confirm the biologic heterogeneity of breast cancer and demonstrate the clinical relevance of classification in this manner. These observations could form the basis of revision of existing traditional classification systems for breast cancer.

Renal cell carcinoma in relation to cigarette smoking: Meta-analysis of 24 studies

Abstract: Renal cell carcinoma (RCC) accounts for 3% of adult deaths from cancer. The risk factors for its development are still under intense investigation. Although tobacco smoke is a risk factor, the data are inconsistent and the extent of the increased risk is unclear. Estimates from 19 case-control and 5 cohort studies were used. The case-control reports included 8,032 cases and 13,800 controls; the cohort estimates were based on 1,457,754 participants with 1,326 cases of RCC. The relative risk (RR) for RCC for ever smokers as compared to lifetime never smokers was 1.38 (95% confidence interval [CI] = 1.27-1.50). The RR for male smokers was 1.54 (95% CI = 1.42-1.68) and for female smokers was 1.22 (95% CI = 1.09-1.36). For men and women there was a strong dose-dependent increase in risk. Ever smoker men who had smoked 1-9, 10-20 or 21 or more cigarettes/day had a RR of 1.60 (95% CI = 1.21-2.12), 1.83 (95% CI = 1.30-2.57), or 2.03 (95% CI = 1.51-2.74), respectively. For women, the relative risks were 0.98 (95% CI = 0.71-1.35), 1.38 (95% CI = 0.90-2.11), or 1.58 (95% CI = 1.14-2.20), respectively. The advantages of smoking cessation were confirmed by a reduction in RR for those who had quit smoking for >10 years as compared to those who had quit for 1-10 years. Inhaled tobacco smoke is clearly implicated in the etiology of RCC, with a strong dose-dependent increase in risk associated with numbers of cigarettes smoked per day and a substantial reduction in risk for long-term former smokers.

Anthocyanin‐ and hydrolyzable tannin‐rich pomegranate fruit extract modulates MAPK and NF‐κB pathways and inhibits skin tumorigenesis in CD‐1 mice

Abstract: Chemoprevention has come of age as an effective cancer control modality; however, the search for novel agent(s) for the armamentarium of cancer chemoprevention continues. We argue that agents capable of intervening at more than one critical pathway in the carcinogenesis process will have greater advantage over other single-target agents. Pomegranate fruit extract (PFE) derived from the tree Punica granatum possesses strong antioxidant and antiinflammatory properties. Pomegranate fruit was extracted with acetone and analyzed based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and found to contain anthocyanins, ellagitannins and hydrolyzable tannins. We evaluated whether PFE possesses antitumor-promoting effects. We first determined the effect of topical application of PFE to CD-1 mice against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced conventional markers and other novel markers of skin tumor promotion. We found that topical application of PFE (2 mg/mouse) 30 min prior to TPA (3.2 nmole/mouse) application on mouse skin afforded significant inhibition, in a time-dependent manner, against TPA-mediated increase in skin edema and hyperplasia, epidermal ornithine decarboxylase (ODC) activity and protein expression of ODC and cyclooxygenase-2. We also found that topical application of PFE resulted in inhibition of TPA-induced phosphorylation of ERK1/2, p38 and JNK1/2, as well as activation of NF-kappaB and IKKalpha and phosphorylation and degradation of IkappaBalpha. We next assessed the effect of skin application of PFE on TPA-induced skin tumor promotion in 7,12-dimethylbenz(a)anthracene-initiated CD-1 mouse. The animals pretreated with PFE showed substantially reduced tumor incidence and lower tumor body burden when assessed as total number of tumors per group, percent of mice with tumors and number of tumors per animal as compared to animals that did not receive PFE. In TPA-treated group, 100% of the mice developed tumors at 16 weeks on test, whereas at this time in PFE-treated group, only 30% mice exhibited tumors. Skin application of PFE prior to TPA application also resulted in a significant delay in latency period from 9 to 14 weeks and afforded protection when tumor data were considered in terms of tumor incidence and tumor multiplicity. The results of our study provide clear evidence that PFE possesses antiskin-tumor-promoting effects in CD-1 mouse. Because PFE is capable of inhibiting conventional as well as novel biomarkers of TPA-induced tumor promotion, it may possess chemopreventive activity in a wide range of tumor models. Thus, an in-depth study to define active agent(s) in PFE capable of affording antitumor-promoting effect is warranted.

Penile cancer: importance of circumcision, human papillomavirus and smoking in in situ and invasive disease.

Abstract: Few population-based case-control studies have assessed etiologic factors for penile cancer. Past infection with high-risk human papillomavirus (HPV) is a known risk factor for penile cancer; however, few previous studies have related the HPV DNA status of the tumor to potential demographic and behavioral risk factors for the disease or evaluated whether in situ and invasive penile cancer share risk factors. Little information is available on the role and timing of circumcision in the etiology of penile cancer. We conducted a population-based case-control study in western Washington state that included 137 men diagnosed with in situ (n = 75) or invasive (n = 62) penile cancer between January 1, 1979, and December 31, 1998, and 671 control men identified through random digit dialing. Cases and controls were interviewed in person and provided peripheral blood samples. Case and control blood samples were tested for antibodies to HPV16 and HSV-2, and tumor specimens from cases were tested for HPV DNA. Men not circumcised during childhood were at increased risk of invasive (OR = 2.3, 95% CI 1.3-4.1) but not in situ (OR = 1.1, 95% CI 0.6-1.8) penile cancer. Approximately 35% of men with penile cancer who had not been circumcised in childhood reported a history of phimosis compared to 7.6% of controls (OR = 7.4, 95% CI 3.7-15.0). Penile conditions such as tear, rash and injury were associated with increased risk of disease. Among men not circumcised in childhood, phimosis was strongly associated with development of invasive penile cancer (OR = 11.4, 95% CI 5.0-25.9). When we restricted our analysis to men who did not have phimosis, the risk of invasive penile cancer associated with not having been circumcised in childhood was not elevated (OR = 0.5, 95% CI 0.1-2.5). Cigarette smoking was associated with a 4.5-fold risk (95% CI 2.0-10.1) of invasive penile cancer. HPV DNA was detected in 79.8% of tumor specimens, and 69.1% of tumors were HPV16-positive. The proportion of HPV DNA-positive tumors did not vary by any risk factors evaluated. Many risk factors were common for both in situ and invasive disease. However, 3 factors that did not increase the risk for in situ cancer proved significant risk factors for invasive penile cancer: lack of circumcision during childhood, phimosis and cigarette smoking. The high percentage of HPV DNA-positive tumors in our study is consistent with a strong association between HPV infection and the development of penile cancer regardless of circumcision status. Circumcision in early childhood may help prevent penile cancer by eliminating phimosis, a significant risk factor for the disease.

Breast cancer risk in relation to different types of hormone replacement therapy in the E3N‐EPIC cohort

Abstract: Most epidemiological studies have shown an increase in breast cancer risk related to hormone replacement therapy (HRT) use. A recent large cohort study showed effects of similar magnitude for different types of progestogens and for different routes of administration of estrogens evaluated. Further investigation of these issues is of importance. We assessed the risk of breast cancer associated with HRT use in 54,548 postmenopausal women who had never taken any HRT 1 year before entering the E3N-EPIC cohort study (mean age at inclusion: 52.8 years); 948 primary invasive breast cancers were diagnosed during follow-up (mean duration: 5.8 years). Data were analyzed using multivariate Cox proportional hazards models. In this cohort where the mean duration of HRT use was 2.8 years, an increased risk in HRT users compared to nonusers was found (relative risk (RR) 1.2 [95% confidence interval 1.1–1.4]). The RR was 1.1 [0.8 –1.6] for estrogens used alone and 1.3 [1.1–1.5] when used in combination with oral progestogens. The risk was significantly greater (p <0.001) with HRT containing synthetic progestins than with HRT containing micronized progesterone, the RRs being 1.4 [1.2–1.7] and 0.9 [0.7–1.2], respectively. When combined with synthetic progestins, both oral and transdermal/percutaneous estrogens use were associated with a significantly increased risk; for transdermal/percutaneous estrogens, this was the case even when exposure was less than 2 years. Our results suggest that, when combined with synthetic progestins, even short-term use of estrogens may increase breast cancer risk. Micronized progesterone may be preferred to synthetic progestins in short-term HRT. This finding needs further investigation. 2004 Wiley-Liss, Inc.

Folate intake and colorectal cancer risk: a meta-analytical approach.

Abstract: Adequate consumption of folate may reduce the risk of colorectal cancer. We performed a meta-analysis of 7 cohort and 9 case-control studies that examined the association between folate consumption and colorectal cancer risk. In cohort studies, the association between folate consumption and colorectal cancer risk was stronger for dietary folate (folate from foods alone; relative risk for high vs. low intake = 0.75; 95% CI = 0.64-0.89) than for total folate (folate from foods and supplements; relative risk for high vs. low intake = 0.95; 95% CI = 0.81-1.11) and there was no significant heterogeneity between studies. There was significant heterogeneity between case-control studies. These results offer some support for the hypothesis that folate has a small protective effect against colorectal cancer but confounding by other dietary factors cannot be ruled out.

Gastrointestinal stromal tumors in Iceland, 1990–2003: The Icelandic GIST study, a population-based incidence and pathologic risk stratification study

Abstract: Gastrointestinal stromal tumor (GIST) is a newly defined clinical and pathologic entity. This study examines the whole population-based incidence of GIST as well as pathologic risk stratification schemes. All patients diagnosed in Iceland with a gastrointestinal mesenchymal tumor over the years 1990-2003 were evaluated with an immunohistochemical panel including staining for c-kit. The age-adjusted incidence of GIST was calculated. Size, mitotic rate per 50 HPF and various other pathologic parameters were evaluated. Each tumor was categorized into 1 of 4 recently defined NIH risk stratification categories. Fifty-seven of the mesenchymal gastrointestinal tumors were positive for c-kit and therefore categorized as GIST. The annual incidence for the study period is 1.1 per 100,000. The median age of patients was 65.8 years and median tumor size was 4.6 cm. Only 2 of 35 gastric tumors fall into the NIH high-risk category while half of the nongastric tumors (11 of 22) fall into this high-risk category. Eight of the 57 tumors (14%) metastasized, 7 of which were nongastric. The positive predictive value for malignant behavior of the high-risk category is 46%. The negative predictive value of low- and very-low-risk NIH category is 100%. Pathologic predictors of malignant behavior are tumor size, mitotic rate, mucosal disruption, necrosis and high cellularity. Nongastric GISTs are clearly at much higher risk of a malignant behavior than gastric GISTs. This population-based GIST study estimates the incidence of GISTs at 1.1 per 100,000 and furthermore supports the NIH consensus categories for the prediction of malignant behavior of GISTs.

Serial killing of tumor cells by cytotoxic T cells redirected with a CD19-/CD3-bispecific single-chain antibody construct

Abstract: Certain bispecific antibodies exhibit an extraordinary potency and efficacy for target cell lysis by eliciting a polyclonal T-cell response. One example is a CD19-/CD3-bispecific single-chain antibody construct (bscCD19xCD3), which at femtomolar concentrations can redirect cytotoxic T cells to eliminate human B lymphocytes, B lymphoma cell lines and patient-derived malignant B cells. Here we have further explored the basis for this high potency. Using video-assisted microscopy, bscCD19xCD3 was found to alter the motility and activity of T cells from a scanning to a killing mode. Individual T cells could eliminate multiple target cells within a 9 hr time period, resulting in nuclear fragmentation and membrane blebbing of target cells. Complete target cell elimination was observed within 24 hr at effector-to-target cell ratios as low as 1:5. Under optimal conditions, cell killing started within minutes after addition of bscCD19xCD3, suggesting that the rate of serial killing was mostly determined by T-cell movement and target cell scanning and lysis. At all times, T cells remained highly motile, and no clusters of T and target cells were induced by the bispecific antibody. Bystanding target-negative cells were not detectably affected. Repeated target cell lysis by bscCD19xCD3-activated T cells increased the proportion of CD19/CD3 double-positive T cells, which was most likely a consequence of transfer of CD19 from B to T cells during cytolytic synapse formation. To our knowledge, this is the first study showing that a bispecific antibody can sustain multiple rounds of target cell lysis by T cells.

Detection of epithelial ovarian cancer using 1H‐NMR‐based metabonomics

Abstract: Currently available serum biomarkers are insufficiently reliable to distinguish patients with epithelial ovarian cancer (EOC) from healthy individuals. Metabonomics, the study of metabolic processes in biologic systems, is based on the use of (1)H-NMR spectroscopy and multivariate statistics for biochemical data generation and interpretation and may provide a characteristic fingerprint in disease. In an effort to examine the utility of the metabonomic approach for discriminating sera from women with EOC from healthy controls, we performed (1)H-NMR spectroscopic analysis on preoperative serum specimens obtained from 38 patients with EOC, 12 patients with benign ovarian cysts and 53 healthy women. After data reduction, we applied both unsupervised Principal Component Analysis (PCA) and supervised Soft Independent Modeling of Class Analogy (SIMCA) for pattern recognition. The sensitivity and specificity tradeoffs were summarized for each variable using the area under the receiver-operating characteristic (ROC) curve. In addition, we analyzed the regions of NMR spectra that most strongly influence separation of sera of EOC patients from healthy controls. PCA analysis allowed correct separation of all serum specimens from 38 patients with EOC (100%) from all of the 21 premenopausal normal samples (100%) and from all the sera from patients with benign ovarian disease (100%). In addition, it was possible to correctly separate 37 of 38 (97.4%) cancer specimens from 31 of 32 (97%) postmenopausal control sera. SIMCA analysis using the Cooman's plot demonstrated that sera classes from patients with EOC, benign ovarian cysts and the postmenopausal healthy controls did not share multivariate space, providing validation for the class separation. ROC analysis indicated that the sera from patients with and without disease could be identified with 100% sensitivity and specificity at the (1)H-NMR regions 2.77 parts per million (ppm) and 2.04 ppm from the origin (AUC of ROC curve = 1.0). In addition, the regression coefficients most influential for the EOC samples compared to postmenopausal controls lie around delta3.7 ppm (due mainly to sugar hydrogens). Other loadings most influential for the EOC samples lie around delta2.25 ppm and delta1.18 ppm. These findings indicate that (1)H-NMR metabonomic analysis of serum achieves complete separation of EOC patients from healthy controls. The metabonomic approach deserves further evaluation as a potential novel strategy for the early detection of epithelial ovarian cancer.

Metalloproteinases and their inhibitors in tumor angiogenesis.

Abstract: Angiogenesis is the process by which new blood vessels are formed from preexisting vasculature. It is an essential feature of the female reproductive cycle, embryonic development and wound repair. Angiogenesis has also been identified as a causal or contributing factor in several pathologies, including cancer, where it is a rate-limiting step during tumor progression. Matrix metalloproteinases (MMPs) are a family of soluble and membrane-anchored proteolytic enzymes that can degrade components of the extracellular matrix (ECM) as well as a growing number of modulators of cell function. Several of the MMPs, in particular the gelatinases and membrane-type 1 MMP (MT1-MMP), have been linked to angiogenesis. Potential roles for these proteases during the angiogenic process include degradation of the basement membrane and perivascular ECM components, unmasking of cryptic biologically relevant sites in ECM components, modulation of angiogenic factors and production of endogenous angiogenic inhibitors. This review brings together what is currently known about the functions of the MMPs and the closely related ADAM (a disintegrin and metalloproteinase domain) and ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) families in angiogenesis and considers how this information might be useful in manipulation of the angiogenic process, with a view to constraining tumor progression.

Role of smoking in global and regional cancer epidemiology: current patterns and data needs

Abstract: Although smoking is widely recognized as a major cause of cancer, there is little information on how it contributes to the global and regional burden of cancers in combination with other risk factors that affect background cancer mortality patterns. We used data from the American Cancer Society's Cancer Prevention Study II (CPS-II) and the WHO and IARC cancer mortality databases to estimate deaths from 8 clusters of site-specific cancers caused by smoking, for 14 epidemiologic subregions of the world, by age and sex. We used lung cancer mortality as an indirect marker for accumulated smoking hazard. CPS-II hazards were adjusted for important covariates. In the year 2000, an estimated 1.42 (95% CI 1.27-1.57) million cancer deaths in the world, 21% of total global cancer deaths, were caused by smoking. Of these, 1.18 million deaths were among men and 0.24 million among women; 625,000 (95% CI 485,000-749,000) smoking-caused cancer deaths occurred in the developing world and 794,000 (95% CI 749,000-840,000) in industrialized regions. Lung cancer accounted for 60% of smoking-attributable cancer mortality, followed by cancers of the upper aerodigestive tract (20%). Based on available data, more than one in every 5 cancer deaths in the world in the year 2000 were caused by smoking, making it possibly the single largest preventable cause of cancer mortality. There was significant variability across regions in the role of smoking as a cause of the different site-specific cancers. This variability illustrates the importance of coupling research and surveillance of smoking with that for other risk factors for more effective cancer prevention.

Characterization of human PA2.26 antigen (T1α–2, podoplanin), a small membrane mucin induced in oral squamous cell carcinomas

Abstract: We report the full cDNA sequence encoding the human homologue of murine PA2.26 (T1alpha-2, podoplanin), a small mucin-type transmembrane glycoprotein originally identified as a cell-surface antigen induced in keratinocytes during mouse skin carcinogenesis. The human PA2.26 gene is expressed as 2 transcripts of 0.9 and 2.7 kb in several normal tissues, such as the placenta, skeletal muscle, heart and lung. Using a specific polyclonal antibody raised against a synthetic peptide of the protein ectodomain, PA2.26 was immunohistochemically detected in about 25% (15/61) of human early oral squamous cell carcinomas. PA2.26 distribution in the tumours was heterogeneous and often restricted to the invasive front. Double immunofluorescence and confocal microscopy analysis showed that PA2.26 colocalized with the membrane cytoskeleton linker ezrin at the surface of tumour cells and that its presence in vivo was associated with downregulation of membrane E-cadherin protein expression. Ectopic expression of human PA2.26 in HeLa carcinoma cells and immortalized HaCaT keratinocytes promoted a redistribution of ezrin to the cell edges, the formation of cell-surface protrusions and reduced Ca(2+)-dependent cell-cell adhesiveness. These results point to PA2.26 as a novel biomarker for oral squamous cell carcinomas that might be involved in migration/invasion.

CTLA‐4 is constitutively expressed on tumor cells and can trigger apoptosis upon ligand interaction

Abstract: CTLA-4 (CD152) is a cell surface receptor that behaves as a negative regulator of the proliferation and the effector function of T cells. We have previously shown that CTLA-4 is also expressed on neoplastic lymphoid and myeloid cells, and it can be targeted to induce apoptosis. In our study, we have extended our analysis and have discovered that surface expression of CTLA-4 is detectable by flow cytometry on 30 of 34 (88%) cell lines derived from a variety of human malignant solid tumors including carcinoma, melanoma, neuroblastoma, rhabdomyosarcoma and osteosarcoma (but not in primary osteoblast-like cultures). However, by reverse transcriptase-PCR, CTLA-4 expression was detected in all cell lines. We have also found, by immunohistochemistry, cytoplasmic and surface expression of CTLA-4 in the tumor cells of all 6 osteosarcoma specimens examined and in the tumour cells of all 5 cases (but only weakly or no positivity at all in neighbouring nontumor cells) of ductal breast carcinomas. Treatment of cells from CTLA-4-expressing tumor lines with recombinant forms of the CTLA-4-ligands CD80 and CD86 induced apoptosis associated with sequential activation of caspase-8 and caspase-3. The level of apoptosis was reduced by soluble CTLA-4 and by anti-CTLA-4 scFvs antibodies. The novel finding that CTLA-4 molecule is expressed and functional on human tumor cells opens up the possibility of antitumor therapeutic intervention based on targeting this molecule.

Thymoquinone induces apoptosis through activation of caspase-8 and mitochondrial events in p53-null myeloblastic leukemia HL-60 cells

Abstract: Thymoquinone (TQ), the major biologically active component isolated from a traditional medicinal herb, Nigella sativa Linn, is a potential chemopreventive and chemotherapeutic compound Despite the promising antineoplastic activities of TQ, the molecular mechanism of its pharmacologic effects is poorly understood Here, we report that TQ exhibits antiproliferative effect, induces apoptosis, disrupts mitochondrial membrane potential and triggers the activation of caspases 8, 9 and 3 in myeloblastic leukemia HL-60 cells The apoptosis induced by TQ was inhibited by a general caspase inhibitor, z-VAD-FMK; a caspase-3-specific inhibitor, z-DEVD-FMK; as well as a caspase-8-specific inhibitor, z-IETD-FMK Moreover, the caspase-8 inhibitor blocked the TQ-induced activation of caspase-3, PARP cleavage and the release of cytochrome c from mitochondria into the cytoplasm In addition, TQ treatment of HL-60 cells caused a marked increase in Bax/Bcl2 ratios due to upregulation of Bax and downregulation of Bcl2 proteins These results indicate that TQ-induced apoptosis is associated with the activation of caspases 8, 9 and 3, with caspase-8 acting as an upstream activator Activated caspase-8 initiates the release of cytochrome c during TQ-induced apoptosis Overall, these results offer a potential mechanism for TQ-induced apoptosis in p53-null HL-60 cancer cells

Cancer risk among statin users: a population-based cohort study.

Abstract: Hydroxymethylglutaryl-CoA reductase inhibitors (statins) have been linked with potential chemopreventive effects; however, the data are conflicting. We conducted a population-based cohort study using data from the Prescription Database of North Jutland County and the Danish Cancer Registry for the period 1989-2002. In a study population of 334,754 county residents, we compared overall and site-specific cancer incidence among 12,251 statin users (> or =2 prescriptions) with cancer incidence among nonusers and users of other lipid-lowering drugs (n = 1,257). Statistical analyses were based on age-standardization and Poisson regression analysis, adjusting for age, gender, calendar period and use of NSAIDs, hormone replacement therapy and cardiovascular drugs. We identified 398 cancer cases among statin users during a mean follow-up period of 3.3 years (range 0-14 years). The age- and gender-standardized incidence rates of cancer overall were 596 per 100,000 person-years among statin users, 645 per 100,000 person-years among nonusers and 795 per 100,000 person-years among users of other lipid-lowering drugs. Adjusted rate ratios for cancer overall among statin users were 0.86 (95% CI, 0.78-0.95) compared to nonusers and 0.73 (95% CI, 0.55-0.98) compared to users of other lipid-lowering drugs. No significantly increased or decreased rate ratios were observed for any of the studied site-specific cancers (liver, colorectum, lung, breast, prostate, female genital organs and lymphatic and haematopoietic tissue), but most estimates tended to be less than 1.0. Stratification by duration of follow-up or number of prescriptions revealed no clear trends. In summary, individuals prescribed statins experienced a slightly reduced cancer incidence compared to population controls of nonusers and users of other lipid-lowering drugs. Larger and longer-term studies are needed to determine the potentially protective effect of statin use on cancer development.

C‐Met overexpression in node‐positive breast cancer identifies patients with poor clinical outcome independent of Her2/neu

Abstract: Receptor tyrosine kinases play an important role in malignant transformation of epithelial cells by activating signal transduction pathways important for proliferation, invasion and metastasis. In a pilot study (n = 40), we evaluated expression of the c-Met and Her2/neu receptor tyrosine kinases and the c-Met ligand hepatocyte growth factor/scatter factor (HGF/SF) in primary breast cancers and their lymph node metastases using both conventional immunohistochemistry and confocal immunofluorescence. Neither c-Met and HGF/SF nor Her2/neu expression correlated with established prognostic factors such as age, lymph node involvement, estrogen receptor (ER), progesterone receptor (PR), tumor size, or grade. Both staining methods confirmed a significant correlation between c-Met overexpression and a high risk of disease progression. Furthermore, among tumors with c-Met overexpression, only 50% also overexpress Her2/neu, thus identifying a subset of patients with aggressive disease in addition to Her2/neu. Median disease-free survival in patients with c-Met overexpressing tumors was 8 months compared to 53 months when c-Met expression was low (p = 0.037; RR = 3.0). This significant impact of c-Met on tumor aggressiveness independent of Her2/neu was also confirmed by multivariate analysis. In conclusion, the role of c-Met expression as a prognostic variable and consequently as an interesting target for novel therapeutic approaches deserves further analysis in a larger cohort of patients.

Frequent promoter hypermethylation and low expression of the MGMT gene in oligodendroglial tumors.

Abstract: Allelic losses on the chromosome arms 1p and 19q have been associated with favorable response to chemotherapy and good prognosis in anaplastic oligodendroglioma patients, but the molecular mechanisms responsible for this relationship are as yet unknown. The DNA repair enzyme O 6 -methylguanine DNA methyltransferase (MGMT) may cause resistance to DNA-alkylating drugs commonly used in the treatment of anaplastic oligodendrogliomas and other malignant gliomas. We report on the analysis of 52 oligodendroglial tumors for MGMT promoter methylation, as well as mRNA and protein expression. Using sequencing of sodium bisulfite-modified DNA, we determined the methylation status of 25 CpG sites within the MGMT promoter. In 46 of 52 tumors (88%), we detected MGMT promoter hypermethylation as defined by methylation of more than 50% of the sequenced CpG sites. Real-time reverse transcription-PCR showed reduced MGMT mRNA levels relative to non-neoplastic brain tissue in the majority of tumors with hypermethylation. Similarly, immunohistochemical analysis showed either no or only small fractions of MGMT positive tumor cells. MGMT promoter hypermethylation was significantly more frequent and the percentage of methylated CpG sites in the investigated MGMT promoter fragment was significantly higher in tumors with loss of heterozygosity on chromosome arms 1p and 19q as compared to tumors without allelic losses on these chromosomes arms. Taken together, our data suggest that MGMT hypermethylation and low or absent expression are frequent in oligodendroglial tumors and likely contribute to the chemosensitivity of these tumors.

Overexpression of hypoxia-inducible factor HIF-1α predicts early relapse in breast cancer: Retrospective study in a series of 745 patients

Abstract: Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor that is involved in tumour growth and metastasis by regulating genes involved in response to hypoxia. HIF-1alpha protein overexpression has been shown in a variety of human cancers, but only 2 studies have documented the prognostic relevance of HIF-1alpha expression in breast cancer. The aim of our study was to determine accurately the impact of HIF-1alpha expression on prognosis in a large series (n = 745) of unselected patients with invasive breast cancer in terms of overall survival, local recurrence and distant metastasis risk. HIF-1alpha expression was investigated using immunohistochemical assays on frozen sections, and correlated with patients' outcome (median follow-up = 13.5 years). Univariate (Kaplan-Meier) analysis showed that high levels of HIF-1alpha expression (cutoff = 10%) significantly correlated with poor overall survival (p = 0.019). HIF-1alpha expression correlated with high metastasis risk among the whole group of patients (p = 0.008). Multivariate analysis (Cox model) showed that the HIF-1alpha predictive value was independent of other current prognostic indicators. Moreover among node negative ones, HIF-1alpha expression was also significantly predictive of metastasis risk (p = 0.03) and of relapse (p = 0.035). All the data suggest that HIF-1alpha is associated with a worse prognosis in patients with invasive breast carcinoma. Furthermore HIF-1alpha immunodetection may be considered as a potential indicator for selecting patients who could benefit from specific therapies interfering with HIF-1alpha pathway.

Epidemiology of testicular cancer: an overview.

Abstract: Testicular cancer is a rare disease, accounting for 1.1% of all malignant neoplasms in Canadian males. Despite the low overall incidence of testicular cancer, it is the most common malignancy among young men. The incidence rate of testicular cancer has been increasing since the middle of the 20th century in many western countries. However, the etiology of testicular cancer is not well understood. A search of the peer-reviewed literature was conducted to identify important articles for review and inclusion in this overview of the epidemiology of testicular cancer. Most of the established risk factors are related to early life events, including cryptorchidism, carcinoma in situ and in utero exposure to estrogens. Occupational, lifestyle, socioeconomic and other risk factors have demonstrated mixed associations with testicular cancer. Although there are few established risk factors for testicular cancer, some appear to be related to hormonal balance at various life stages. Lifestyle and occupational exposures occurring later in life may play a role in promoting the disease, although they are not likely involved in cancer initiation. In addition to summarizing the current epidemiologic evidence on risk factors for testicular cancer, we suggest future research directions that may elucidate the etiology of testicular cancer.

Frequent genetic and biochemical alterations of the PI 3-K/AKT/PTEN pathway in head and neck squamous cell carcinoma.

Abstract: We investigated the status of the PI 3-kinase/AKT/PTEN signaling pathway in a series of 117 head and neck squamous cell carcinomas (HNSCC) in a search for molecular alterations in genes/proteins with potential prognostic value. For this purpose, PIK3CA and AKT2 gene amplification was assessed by multiplex and Quantitative Real-Time PCR. Protein expression of AKT, p-AKT, p110alpha and PTEN was determined by Western blot. PTEN allelic loss was evaluated by microsatellite analysis. PTEN-exon 5 was screened for point mutations by PCR-SSCP. Homozygous deletions were determined by multiplex PCR. PIK3CA gene was amplified in 43/117 (37%) fresh tumor samples, a frequency that did not differ from that found in archival premalignant tissues: 15/38 (39%); 12/40 (30%) fresh tumors harbored AKT2 gene amplification. AKT was found activated in 6/36 (17%) fresh tumor samples, when compared to their normal tissue counterparts. Of these 6 cases, 1 showed p110alpha overexpression and 5 displayed PTEN protein downregulation. Neither allelic loss (found in 11/77 informative cases) nor point mutations or homozygous deletions accounted for the reduced PTEN protein expression observed in our tumor series. The histologically normal mucosa of 4 patients displayed some of the molecular alterations analyzed. Dysregulation of the PI 3-K/AKT/PTEN pathway might contribute to early HNSCC tumorigenesis and might constitute a potential clinical target. Overall, 17/36 (47%) cases showed at least 1 of the molecular alterations studied here, which makes the PI 3-kinase-initiated signaling pathway one of the most frequently altered in HNSCC.

Nuclear or cytoplasmic expression of survivin: what is the significance?

Abstract: Growing evidence suggests that survivin expression in cancer cell nuclei may represent an important prognostic marker to predict disease outcome for cancer patients. Current reports in this research area, however, are inconsistent and propose opposing conclusions regarding the significance and prognostic value of survivin nuclear expression. The aim of our study is to review and discuss the data reported in the original publications. We have also provided new experimental data to support our view regarding the possible reasons for the observed inconsistencies in the literature. This would alert researchers to pay attention to potential pitfalls in the determination of nuclear or cytoplasmic expression of survivin for the future.

Randomized trial of dietary fiber and Lactobacillus casei administration for prevention of colorectal tumors.

Abstract: The epidemiologic evidence that dietary fiber protects against colorectal cancer is equivocal. No large-scale clinical study of the administration of Lactobacillus casei has been reported. We examined whether dietary fiber and L. casei prevented the occurrence of colorectal tumors. Subjects were 398 men and women presently free from tumor who had had at least 2 colorectal tumors removed. Subjects were randomly assigned to 4 groups administered wheat bran, L. casei, both or neither. The primary end point was the presence or absence of new colorectal tumor(s) diagnosed by colonoscopy after 2 and 4 years. Among 380 subjects who completed the study, 95, 96, 96 and 93 were assigned to the wheat bran, L. casei, both and no treatment groups, respectively. Multivariate adjusted ORs for occurrence of tumors were 1.31 (95% CI 0.87–1.98) in the wheat bran group and 0.76 (0.50–1.15) in the L. casei group compared to the control group. There was a significantly higher number of large tumors after 4 years in the wheat bran group. The occurrence rate of tumors with a grade of moderate atypia or higher was significantly lower in the group administered L. casei. No significant difference in the development of new colorectal tumors was observed with administration of either wheat bran or L. casei. However, our results suggest that L. casei prevented atypia of colorectal tumors. ' 2005 Wiley-Liss, Inc.

Red meat consumption and risk of cancers of the proximal colon, distal colon and rectum: The Swedish Mammography Cohort

Abstract: Although there is considerable evidence that high consumption of red meat may increase the risk of colorectal cancer, data by subsite within the colon are sparse. The objective of our study was to prospectively examine whether the association of red meat consumption with cancer risk varies by subsite within the large bowel. We analyzed data from the Swedish Mammography Cohort of 61,433 women aged 40-75 years and free from diagnosed cancer at baseline in 1987-1990. Diet was assessed at baseline using a self-administered food-frequency questionnaire. Over a mean follow-up of 13.9 years, we identified 234 proximal colon cancers, 155 distal colon cancers and 230 rectal cancers. We observed a significant positive association between red meat consumption and risk of distal colon cancer (p for trend = 0.001) but not of cancers of the proximal colon (p for trend = 0.95) or rectum (p for trend = 0.32). The multivariate rate ratio for women who consumed 94 or more g/day of red meat compared to those who consumed less than 50 g/day was 2.22 (95% confidence interval [CI] 1.34-3.68) for distal colon, 1.03 (95% CI 0.67-1.60) for proximal colon and 1.28 (95% CI 0.83-1.98) for rectum. Although there was no association between consumption of fish and risk of cancer at any subsite, poultry consumption was weakly inversely related to risk of total colorectal cancer (p for trend = 0.04). These findings suggest that high consumption of red meat may substantially increase the risk of distal colon cancer. Future investigations on red meat and colorectal cancer risk should consider cancer subsites separately.

Potential anticancer activity of tanshinone IIA against human breast cancer.

Abstract: Tanshinone IIA is a derivative of phenanthrene-quinone isolated from Danshen, a widely used Chinese herbal medicine. It has antioxidant properties and cytotoxic activity against multiple human cancer cell lines, inducing apoptosis and differentiation of some human cancer cell lines. Our purpose was to confirm its anticancer activity on human breast cancer in vitro and in vivo and to elucidate the mechanism of its activity. Human breast cancer cells were tested in vitro for cytotoxicity, colony formation inhibition, BrdU incorporation and gene expression profiling after treatment with tanshinone IIA. Seven nude mice bearing human breast infiltrating duct carcinoma orthotopically were tested for anticancer activity and expression of caspase-3 in vivo by s.c. injection of tanshinone IIA at a dose of 30 mg/kg 3 times/week for 10 weeks. Tanshinone IIA demonstrated a dose- and time-dependent inhibitory effect on cell growth (IC50 = 0.25 microg/ml), and it significantly inhibited colony formation and BrdU incorporation of human breast cancer cells. Oligonucleotide microarray analysis identified 41 upregulated (1.22%) and 24 downregulated (0.71%) genes after tanshinone IIA treatment. Upregulated genes were involved predominantly in cycle regulation, cell proliferation, apoptosis, signal transduction and transcriptional regulation; and downregulated genes were associated mainly with apoptosis and extracellular matrix/adhesion molecules. A 44.91% tumor mass volume reduction and significant increase of casepase-3 protein expression were observed in vivo. Our findings suggest that tanshinone IIA might have potential anticancer activity on both ER-positive and -negative breast cancers, which could be attributed in part to its inhibition of proliferation and apoptosis induction of cancer cells through upregulation and downregulation of multiple genes involved in cell cycle regulation, cell proliferation, apoptosis, signal transduction, transcriptional regulation, angiogenesis, invasive potential and metastatic potential of cancer cells. ADPRTL1 might be the main target at which tanshinone IIA acted.

Anti-proliferative and proapoptotic effects of (-)-epigallocatechin-3-gallate on human melanoma: possible implications for the chemoprevention of melanoma.

Abstract: Melanoma accounts for only about 4% of all skin cancer cases but most of skin cancer-related deaths. Standard systemic therapies such as interferon (IFN) have not been adequately effective in the management of melanoma. Therefore, novel approaches are needed for prevention and treatment of this disease. Chemoprevention by naturally occurring agents present in food and beverages has shown benefits in certain cancers including nonmelanoma skin cancers. Here, employing 2 human melanoma cell lines (A-375 amelanotic malignant melanoma and Hs-294T metastatic melanoma) and normal human epidermal melanocytes (NHEM), we studied the antiproliferative effects of epigallocatechin-3-gallate (EGCG), the major polyphenolic antioxidant present in green tea. EGCG treatment was found to result in a dose-dependent decrease in the viability and growth of both melanoma cell lines. Interestingly, at similar EGCG concentrations, the normal melanocytes were not affected. EGCG treatment of the melanoma cell lines resulted in decreased cell proliferation (as assessed by Ki-67 and PCNA protein levels) and induction of apoptosis (as assessed cleavage of PARP, TUNEL assay and JC-1 assay). EGCG also significantly inhibited the colony formation ability of the melanoma cells studied. EGCG treatment of melanoma cells resulted in a downmodulation of anti-apoptotic protein Bcl2, upregulation of proapoptotic Bax and activation of caspases -3, -7 and -9. Furthermore, our data demonstrated that EGCG treatment resulted in a significant, dose-dependent decrease in cyclin D1 and cdk2 protein levels and induction of cyclin kinase inhibitors (ckis) p16INK4a, p21WAF1/CIP1 and p27KIP1. Our data suggest that EGCG causes significant induction of cell cycle arrest and apoptosis of melanoma cells that is mediated via modulations in the cki-cyclin-cdk network and Bcl2 family proteins. Thus, EGCG, alone or in conjunction with current therapies, could be useful for the management of melanoma. © 2004 Wiley-Liss, Inc.

Independent and combined effects of alcohol intake, tobacco smoking and betel quid chewing on the risk of esophageal cancer in Taiwan

Abstract: A multicenter case-control study was conducted in northern and southern Taiwan to clarify the independent and combined effects of alcohol intake, tobacco smoking and betel quid chewing on the risk of esophageal cancer. A total of 513 patients with newly diagnosed and histopathologically confirmed squamous cell carcinoma of the esophagus and 818 gender, age and study hospital-matched controls were included. We found a significant dose-response relationship between the duration and intensity of consumption of the 3 substances and the development of this neoplasm in this site. Although the amount of alcohol consumed had a stronger effect on the risk of esophageal cancer than the number of years it was consumed, however, the number of years one smoked had a stronger effect on the risk than the amount of cigarettes consumed. The strongest risk factor of esophageal cancer was alcohol intake, with highest risk (OR = 13.9) being for those who consumed more than 900 g/day-year. Combined exposure to any 2 of 3 substances brought the risks up to 8.8-19.7 fold and, to all 3 substances, to 41.2-fold. A multiplicative interaction effect for alcohol drinkers who smoked on cancer risk was detected, whereas an additive interaction effect was found among drinkers who chewed. The combined effect of all 3 substances accounted for 83.7% of the attributable fraction of contracting esophageal cancer in this population. In conclusion, these results suggest that the intensity and the length of time alcohol and tobacco are used play different roles in the etiology of esophageal cancer. Alcohol separately interacts with tobacco and betel quid in a differently synergistic way in determining the development of this site of cancer.