Showing papers by "Cancer Epidemiology Unit published in 1997"

Melanoma and sun exposure: an overview of published studies.

Abstract: To assess the association between the incidence of cutaneous melanoma; intermittent, occupational and total sun exposure; and history of sunburn at different ages, we conducted a systematic review using results of all published case-control studies which have assessed incident melanoma, sun exposure and sunburn. Twenty-nine studies contributed data on sun exposure and 21 on sunburn. Overall, there was a significant positive association (odds ratio [OR] = 1.71) for intermittent exposure, a significantly reduced risk for heavy occupational exposure (OR = 0.86) and a small, marginally significant excess risk for total exposure (OR = 1.18). There was a significantly increased risk with sunburn at all ages or in adult life (OR = 1.91) and similarly elevated relative risks for sunburn in adolescence (OR = 1.73) and in childhood (OR = 1.95). There was significant heterogeneity with all of these estimates except that of all ages or adult sunburn. These results show the specificity of the positive association between melanoma risk and intermittent sun exposure, in contrast to a reduced risk with high levels of occupational exposure. The association with sunburn also is likely to reflect intermittent exposure; the results do not suggest any strong relationship to age at sunburn. These associations are similar to those reported for basal cell skin cancer but different from those reported for squamous cell cancer. The mechanisms by which intermittent exposure increases risk, while other patterns of exposure do not, remain to be elucidated.

A case-control study of diet and prostate cancer.

Abstract: We interviewed 328 men diagnosed with prostate cancer before the age of 75 years and 328 age-matched population controls. The principal hypotheses were that risk would increase with a high intake of total or saturated fat and would decrease with a high intake of carotene (beta-carotene equivalents) or lycopene. We also examined the associations of other nutrients and foods with risk. There was no evidence for an association between fat intake and risk, although the average fat intake was high and the range of fat intakes was narrow (medians of lower and upper thirds of percentage of energy from fat among controls were 34.3% and 42.9% respectively). Risk was lower in subjects with higher carotene intake: odds ratios 0.65 (95% CI 0.45-0.94) and 0.76 (0.53-1.10) in the middle and upper thirds of carotene intake respectively (P for trend = 0.150). Lycopene was not associated with risk. Among 13 other nutrients examined, the odds ratios in the top third of intake were below 0.8 for: potassium, 0.74 (0.51-1.09; P for trend = 0.054); zinc, 0.73 (0.49-1.08; P for trend = 0.126); iodine, 0.75 (0.51-1.11; P for trend = 0.077); vitamin B6 food only, 0.77 (0.53-1.12; P for trend = 0.077); and vitamin B6 including supplements, 0.70 (0.48-1.03; P for trend = 0.029). Among 18 foods examined, statistically significant associations were observed for: garlic as food, > or = 2/week vs never, 0.56 (0.33-0.93); garlic including supplements, > or = 2/week vs never, 0.60 (0.37-0.96); baked beans, > or = 2/week vs or = 5/week vs < or = 3/month, 0.35 (0.13-0.91). This study does not support the hypothesis that fat increases risk and is equivocal in relation to carotene. The possible relationships of vitamin B6, garlic, beans and peas with risk for prostate cancer should be further investigated.

A prospective study of endogenous serum hormone concentrations and breast cancer risk in post-menopausal women on the island of Guernsey.

Abstract: The associations between serum concentrations of oestradiol, testosterone and sex hormone-binding globulin (SHBG) and risk of breast cancer in post-menopausal women were investigated in a prospective study on the island of Guernsey. Sixty-one women who developed breast cancer an average of 7.8 years after blood collection were matched for age, year of blood collection and number of years post-menopausal with 179 control subjects. Women using exogenous hormones at the time of blood collection were excluded from the study. Women who subsequently developed breast cancer had a 29% higher geometric mean oestradiol concentration than control women (P = 0.004). The odds ratio for breast cancer in the top third compared with the lowest third of the oestradiol concentration distribution was 5.03 (95% confidence interval 2.02-12.49, P for trend < 0.001). Adjusting for testosterone and SHBG concentrations did not substantially alter the odds ratio for oestradiol. Although testosterone and SHBG concentrations were associated with breast cancer risk, the concentrations of these hormones were correlated with those of oestradiol; the associations were not statistically significant after adjusting for oestradiol concentration. These data provide evidence that serum oestradiol concentrations in post-menopausal women may have a substantial effect on breast cancer risk.

Endogenous estrogen and postmenopausal breast cancer: a quantitative review

Abstract: This paper systematically reviews the results from epidemiologic studies investigating the hypothesis that breast cancer risk inpostmenopausal women increases with increasing concentrations of estradiol in blood and with increasing urinary estrogen excretion rates. Data from 29epidemiologic studies of endogenous hormones and postmenopausal breast cancer were used. The ratio of the average estrogen concentration in the women with breast cancer to that in the women without breast cancer (and its 95 percent confidence interval [CI]) was calculated for each study, and the results were summarized by calculating weighted averages of the log ratios. In six prospective studies of serum estradiol concentration, 329 women who subsequently developed breast cancer had, overall, a 15 percent (CI = 6-24percent, P = 0.0003) higher mean concentration of estradiol in their blood than the 1,105 women who remained free of cancer. The results of these prospective studies did not differ significantly from each other(chi-squared for heterogeneity = 8.7; degrees of freedom = 5; P > 0.1).Similar differences in mean estrogen levels were seen in the case-control studies which reported either estradiol concentrations in the blood or urinary estrogen excretion. However, the case-control studies showed significant heterogeneity among their results. The data from the prospective studies strongly suggest that breast cancer risk in postmenopausal women is associated with relatively high concentrations of endogenous estradiol.

Dietary determinants of ischaemic heart disease in health conscious individuals

Abstract: Objective To investigate dietary determinants of ischaemic heart disease (IHD) in health conscious individuals to explain the reduced risk in vegetarians, and to examine the relation between IHD and body mass index (BMI) within the normal range. Design Prospective observation of vegetarians, semi-vegetarians, and meat eaters for whom baseline dietary data, reported weight and height information, social class, and smoking habits were recorded. Subjects 10 802 men and women in the UK aged between 16 and 79, mean duration of follow up 13.3 years. Main outcome measures Death rate ratios for IHD and total mortality in relation to dietary and other characteristics recorded at recruitment (reference category death rate = 100). Results IHD mortality was less than half that expected from the experience reported for all of England and Wales. An increase in mortality for IHD was observed with increasing intakes of total and saturated animal fat and dietary cholesterol—death rate ratios in the third tertile compared with the first tertile: 329, 95% confidence interval (CI) 150 to 721; 277, 95% CI 125 to 613; 353, 95% CI 157 to 796, respectively. No protective effects were observed for dietary fibre, fish or alcohol. Within the study, death rate ratios were increased among those in the upper half of the normal BMI range (22.5 to Conclusions In these relatively health conscious individuals the deleterious effects of saturated animal fat and dietary cholesterol appear to be more important in the aetiology of IHD than the protective effect of dietary fibre. Reduced intakes of saturated animal fat and cholesterol may explain the lower rates of IHD among vegetarians compared with meat eaters. Increasing BMI within the normal range is associated with increased risk of IHD. The results have important public health implications.

The use of quality of life data in clinical practice

Abstract: A large amount of quality of life (QoL) information has been and is being collected in the oncology setting but it is unclear how such data influence decisions about the management of individual patients. A questionnaire designed specifically for the study was mailed to 260 senior oncologists to investigate how QoL data are being used outside the context of cancer clinical trials; replies were received from 154 (59%). Approximately 80% believed QoL information should be collected prior to the commencement of treatment, but less than 50% actually did so. Similarly, less than 50% assessed QoL as a method of monitoring the responses to treatment even when the treatment goal was palliation. The barriers to collecting such data were time and resource constraints, perceived lack of an appropriate instrument and a belief that QoL assessments were unnecessary. Other than making a subjective assessment based on examination and history, 73 (47%) used either standardized questionnaires or a system derived in their unit to assess the QoL of their patients. Given an appropriate instrument the majority believed that QoL data could be collected on a routine basis. The main barriers to collecting QoL data are logistic and the challenge remains to develop a method of collecting and analysing QoL information in a manner which enhances decision making.

Clinical course during the 1st year after diagnosis in ulcerative colitis and Crohn's disease. Results of a large, prospective population-based study in southeastern Norway, 1990-93.

Abstract: Background: The clinical course and prognosis in ulcerative colitis (UC) and Crohn's disease (CD) have been described in many studies, mostly retrospective Such studies are hampered by problems such as inclusion over a long time period, proper definitions, incomplete case records, and outdated methods of diagnosis In a prospective study we identified 846 patients with inflammatory bowel disease (IBD) over a 4-year period from 1990 to 1993 Uniform diagnostic and therapeutic strategies were used as a basis for later assessment of the short-term clinical course in different subgroups of UC and CD and analysis of potential risk factors for relapse or surgery Methods: At the time of follow-up, a mean of 162 months after diagnosis, 496 UC patients and 232 CD patients, altogether 98%, were available for evaluation A colonoscopy was performed in 88% (410 of 465) of the UC patients attending a clinical examination and in 76% (164 of 216) of the CD patients Results: Eleven patients with UC and five patients

The epidemiology of non-Hodgkin's lymphoma: comparison of nodal and extra-nodal sites.

Abstract: International population-based cancer incidence data, coded according to the International Classification of Diseases for Oncology (WHO, 1990), were used to describe geographical patterns of incidence of extra-nodal non-Hodgkin's lymphomas. Incidence data from the USA were also used to describe age and sex distribution of lymphomas at different extranodal sites. The percentage of all non-Hodgkin's lymphomas coded as being of extra-nodal origin is between 25% and 35% in most countries, with the stomach, skin and small intestine being the most common extra-nodal sites. In general, the pattern of incidence rates for extra-nodal lymphomas tends to reflect that of other lymphomas. For example, the age incidence curve of each site-specific extra-nodal lymphoma is similar to that of nodal lymphomas, and in countries where total lymphoma incidence is high the incidence of lymphomas at each extra-nodal site also tends to be relatively high. Although specific factors are known to increase the risk of lymphomas at certain anatomical sites, these data suggest that the aetiology of extra-nodal lymphomas is not entirely independent from that of nodal lymphomas.

Cancer incidence in a cohort of human immunodeficiency virus seroconverters

Abstract: BACKGROUND In addition to Kaposi's sarcoma and non-Hodgkin's lymphomas, it has been postulated that human immunodeficiency virus (HIV) infection may increase the risk of other cancers. The aim of the current study was to compare incidence rates of cancer among individuals who seroconverted for HIV infection with the rates in the general population of Italy. METHODS This study is part of an ongoing cohort investigation conducted by the HIV Italian Seroconversion Study Group. The study has enrolled 1255 individuals (906 males and 349 females) between the ages of 20 and 49 years who are at risk for HIV infection and have had a documented negative HIV test followed by a positive test. For each individual, the midpoint in time between the negative and positive tests was used to estimate the seroconversion date. The person-years at risk for cancer were then computed from the midpoint date to the last follow-up date or to death, and the number of cases of cancer observed in the cohort was compared with the expected number, based on rates among the general population of the same age and gender. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were computed. RESULTS A total of 58 cases of cancer were observed in the cohort. In comparison with rates in the general population, Kaposi's sarcoma was 1051 times more frequent, and non-Hodgkin's lymphomas were 157 times more frequent. Hodgkin's disease was observed in 3 men (i.e., 38 times more often in the cohort of HIV seroconverters [95% CI, 8-111]), in particular among homosexual men (SIR = 103). One woman developed stomach carcinoma. CONCLUSIONS The findings of the current incidence study are in agreement with previous studies showing excesses of Kaposi's sarcoma and non-Hodgkin's lymphomas in HIV-positive individuals. In addition, the findings suggest an association of HIV infection with Hodgkin's disease. Whether Hodgkin's disease in HIV-infected individuals should be considered an AIDS-defining illness is a question that is worthy of attention. Cancer 1997; 79:1004-8. © 1997 American Cancer Society.

Comparison of the site distribution of melanoma in new zealand and canada

Abstract: A comparison of the site distribution of cutaneous malignant melanoma in New Zealand and Canada was performed. This series deals with 41,331 incident cases registered between 1968 and 1990 and is the largest to date to evaluate the influence of age and gender on the site distribution of melanoma. Site-specific, age-standardized rates per unit surface area and relative tumour density were assessed by gender and country and differences compared with statistical techniques adapted to this context. The age-standardized rates for all sites were higher in New Zealand than in Canada, the ratio being 3.2 for men and 3.8 for women. Occurrence of melanoma was denser for chronically than intermittently exposed sites in both New Zealand and Canada. The highest incidence rate per unit area was for the ears in men which was more than 5 times the rate for the entire body in each country. For each gender, melanomas were relatively commoner on the trunk and the face in Canada, and on the lower limbs in New Zealand. The variations in the site distribution were similar in each country and consistent with the effect of differential patterns of sun exposure between genders. Our results show that the levels of risk of melanoma between phenotypically comparable populations exposed to different amount of UV radiation vary in a site-specific manner, especially for intermittently exposed sites. This suggests that both environmental conditions and lifestyle factors influence the site distribution of melanoma in these two populations.

The epidemiology of epithelial ovarian cancer: a review

Abstract: Banks E, Beral V, Reeves G. The epidemiology of epithelial ovarian cancer: a review. Int J Gynecol Cancer 1997; 7: 425–438. This paper presents a review of the scientific literature investigating the epidemiology of epithelial ovarian cancer. Epithelial ovarian cancer is an important cause of cancer death among women in industrialized countries, and incidence increases with age. It is more common among women of low parity and among those with a family history of the disease. Oral contraceptive use, hysterectomy, oophorectomy, and sterilization have all been shown to protect against epithelial ovarian cancer, while the role of other reproductive and environmental factors, such as infertility, fertility drugs and hormone replacement therapy, is less clear. The evidence to date is discussed in this review.

Sinonasal cancer and occupation. Results from the reanalysis of twelve case-control studies

Abstract: A pooled reanalysis of twelve case-control studies on sinonasal cancer and occupation from seven countries was conducted in order to study associations with occupations other than wood- and leather-related occupations. The pooled data set included a total of 930 cases (680 men and 250 women) and 3,136 controls (2,349 men and 787 women). All the studies included a detailed occupational history for cases and controls. Each job was coded using the same classifications for occupation and industry. Two approaches were used in the analysis: systematic analysis of occupations; a priori analysis using a preestablished list of occupations and industries. The results confirmed associations observed in several studies not included in this analysis. For agricultural workers, significant excesses were observed for squamous cell carcinoma among women (OR = 1.69) and men (OR = 3.72 for ten years or more of employment as an orchard worker), and adenocarcinomas among men (OR = 2.98 for ten years or more of employment). Associations with textile occupations were observed for adenocarcinoma among women (OR = 2.60) and squamous cell carcinoma among men (OR = 5.09 for fiber preparers, 3.01 for bleachers). Elevated risks for both histologic types were observed among men employed in food manufacturing (OR = 3.25, adenocarcinoma), or as food preservers (OR = 13.9, squamous cell carcinoma), and among men employed as cooks (OR = 1.99, squamous cell carcinoma). A positive association with squamous cell carcinoma was observed for male transport equipment operators (OR = 1.21), and also with adenocarcinoma for male motor-vehicle drivers (OR = 2.50). A number of other associations were observed in the systematic analysis. Am. J. Ind. Med. 31:153–165, 1997. © 1997, Wiley-Liss Inc.

Gastric cancer, gastritis and plasma vitamin C: Results from an international correlation and cross-sectional study

Abstract: Low intake of foods rich in vitamin C is associated with an increased risk of gastric cancer, and geographic variation in average vitamin C intake, therefore, could explain some of the wide international variation in gastric cancer rates. This multicentre study investigated the relationships between plasma levels of vitamin C, as an indicator of vitamin C intake, and gastric cancer rates, markers of gastritis and other socio-demographic variables. Fasting plasma samples from about 1,400 individuals from 9 centres in 7 countries worldwide were assayed for total vitamin C using a fluorometric assay. There was no association between average plasma vitamin C levels and either gastric cancer mortality or incidence rates in the populations studied. Therefore, variation in fasting plasma vitamin C levels, as an indicator of consumption of vitamin C, does not appear to explain any of the wide geographic variation in gastric cancer rates. Furthermore, there was no association between plasma vitamin C levels and Helicobacter pylori infection, low serum levels of pepsinogen A (as a marker of severe chronic atrophic gastritis) or the presence of DNA adducts in blood leukocyte DNA. Multivariate models showed that fasting plasma vitamin C levels were associated positively with female sex, higher levels of education, never having smoked and increasing height and negatively with number of cigarettes smoked per day and increasing weight. This suggests not only that gender and tobacco smoking, in particular, are important predictors of plasma vitamin C levels but also that their effects are consistent throughout the developed world.

Observations on the prevention of cleft palate in dogs by folic acid and potential relevance to humans.

Abstract: Folic acid has been shown to prevent neural tube defects in humans, but its effects on other defects is unknown. In a consistent breeding programme of Boston terrier dogs started in 1974, folic acid supplementation (5 mg/day) was introduced in 1981. The frequency of cleft palate fell from 9/51 (17.6%) without folic acid to 8/191 (4.2%) after its introduction, giving a reduction of 76% (95% confidence limits 42%-90%, p = 0.003).

Malignant mesothelioma of the pleura. The reproducibility of the immunohistological diagnosis.

Abstract: The reproducibility of the histopathological diagnosis of pleural malignant mesothelioma (MM), after supplementing routine H&E stain by immunohistochemistry (IH) in 77 cases of original diagnoses of MM, was assessed by examining interobserver variation between five pathologists. A battery of commercial antibodies (cytokeratins, vimentin, HMFG-2, anti Leu-M1 [CD15], BerEP4, B72.3 [TAG-72], carcinoembyonic antigen), considered to be useful in enhancing diagnostic accuracy, was used. The number of definitively classified tumors (accepted MM plus rejected MM) increased from 57 on H&E stain to 60 after IH, with 59 (76.6%) cases being accepted as true MM. Based on IH, the chance-adjusted interobserver agreement was poor (kappa w = 0.29) and lower than that observed on previous H&E alone. The intraobserver agreement for four of the five pathologists was rather good (kappa w = 0.54-0.56). The inter- and intraobserver concordance was higher in accepting than excluding the cases as MM. A larger number of cases were classified by all reviewers as mixed or sarcomatous variants after IH. In the interpretation of each immunostain, kappa values ranged from 0.19 for B72.3 to 0.62 for HMFG-2, which were respectively the least and the most consistently interpreted immunostains. The information additionally contributed by IH did not seem to change the pathologists' diagnoses very much in comparison with those made by routine H&E stain. Until highly specific and sensitive probes for the positive identification of MM become available, a careful scrutiny of routinely stained preparations still remains the most rewarding component of the diagnostic pathway.

Head and neck cancer in the South West of England: influence of socio-economic status on incidence and second primary tumours

Abstract: This study examined possible links between the incidence of head and neck squamous cell carcinoma (HNSCC) and social deprivation. Data on all HNSCC registered between 1985 and 1991 in the South West of England were collected. Excluding tumours of the lip and skin there were 1570 cases, 72% in males. Of these, 1467 were identified as first primary tumours. Corrected chi-squared tests, accepting significance at the 5% level, were used to examine the association of socio-economic status (Carstairs index) with incidence at different sites. Overall, the incidence of HNSCC was higher in the socially deprived group. In males, the most deprived group had a significantly higher incidence of oral carcinoma than all other groups (P<0.05), whereas the incidence of laryngeal carcinoma showed a gradual rise with increasing deprivation. In females, where numbers were relatively low, the trend remained, but was less clear. In total, seventy-two (4.9%) cases went on to develop a second primary, of which 35% were in the lung and 13% in the bladder. Socio-economic status did not affect the development of a second primary tumour. The association of HNSCC with carcinoma of the bladder is a new finding.

The excess of childhood leukaemia near Sellafield: a commentary on the fourth COMARE report

Abstract: Problems in investigating disease clusters are illustrated by the latest (fourth) report of the Committee on Medical Aspects of Radiation in the Environment (COMARE) on the excess of leukaemia and non-Hodgkin lymphoma among young people living near the Sellafield nuclear installation in West Cumbria, England. COMARE found no evidence that exposure to radiation could account for this excess and examined alternative explanations. The Report discusses inter alia the hypothesis that these diseases have an infective aetiology promoted by population mixing and considers the relevance of such mixing to the Sellafield area. It concludes that infection cannot be the sole explanation for the excess of cases, implying that some other causative factor (possibly radiation) must also be operating. This conclusion is, however, largely the result of arbitrarily concentrating attention on the village of Seascale (where the excess had initially been observed) rather than the entire vicinity of Sellafield, the putative cause of the excess. This well known pitfall exaggerates the significance of the Seascale excess. The Report then contrasts the magnitude of this excess in Seascale with those in much larger study areas away from Sellafield that were chosen (independently of leukaemia data) because of their relevance to population mixing; but this is not a comparison of like with like. When the Report does consider an area that includes Sellafield, the area chosen is so large (over 700 sq miles) as to `dilute out' localised excesses. COMARE underestimates the special factors that would account, under the infection hypothesis, for the unusually large excess in Seascale, and pays insufficient attention to other communities near Sellafield which may have been affected by population mixing.

Epidemiology - A human germ project?

Abstract: A few weeks ago,Nature reported the sequence of Helicobacter pylori, which is present in up to one in three people and causes peptic ulcers. But many other chronic diseases or cancers are also thought to be caused by infectious agents. Weight is now lent to this theory by two studies that link coronary heart disease to the bacterium Chlamydia pneumoniae, and the implications of these findings are discussed.