Showing papers by "Donald Maxwell Parkin published in 2006"

The global health burden of infection-associated cancers in the year 2002.

Abstract: Several infectious agents are considered to be causes of cancer in humans. The fraction of the different types of cancer, and of all cancers worldwide and in different regions, has been estimated using several methods; primarily by reviewing the evidence for the strength of the association (relative risk) and the prevalence of infection in different world areas. The estimated total of infection-attributable cancer in the year 2002 is 1.9 million cases, or 17.8% of the global cancer burden. The principal agents are the bacterium Helicobacter pylori (5.5% of all cancer), the human papilloma viruses (5.2%), the hepatitis B and C viruses (4.9%), Epstein-Barr virus (1%), human immunodeficiency virus (HIV) together with the human herpes virus 8 (0.9%). Relatively less important causes of cancer are the schistosomes (0.1%), human T-cell lymphotropic virus type I (0.03%) and the liver flukes (0.02%). There would be 26.3% fewer cancers in developing countries (1.5 million cases per year) and 7.7% in developed countries (390,000 cases) if these infectious diseases were prevented. The attributable fraction at the specific sites varies from 100% of cervix cancers attributable to the papilloma viruses to a tiny proportion (0.4%) of liver cancers (worldwide) caused by liver flukes.

The evolution of the population-based cancer registry

Abstract: The idea of recording information on all cancer cases in defined communities dates from the first half of the twentieth century, and there has been a steady growth in the number of such cancer registries since. Originally, they were concerned primarily with describing cancer patterns and trends. Later, many were able to follow up the registered patients and calculate survival. In the last 20 years the role of registries has expanded further to embrace the planning and evaluation of cancer control activities, and the care of individual cancer patients. This Review looks at the current status of cancer registration practice and use from an international perspective, mindful that the registration of cancer has expanded into a global activity.

Spectrum of cancers among HIV-infected persons in Africa: The Uganda AIDS-Cancer Registry Match Study

Abstract: Although more than 25 million people in sub-Saharan Africa have human immunodeficiency virus (HIV) infection, little is known regarding their cancer risk. We investigated cancer risk among persons with HIV/AIDS in Uganda using record-linkage. We linked records of 12,607 HIV-infected persons attending The AIDS Support Organization (TASO) in Kyadondo County from October 1988 through December 2002 to the Kampala Cancer Registry. We calculated standardized incidence ratios (SIRs) to identify increased cancer risks in the early (4-27 months after TASO registration), late (28-60 months), or combined (4-60 months) incidence periods. We identified 378 cancers (181 prevalent, 197 incident) among TASO participants. Of incident cancers, 137 (70%) were AIDS-defining cancers. Risk was increased in the early-incident period, compared to the general population, for the AIDS-defining cancers: Kaposi sarcoma (SIR 6.4, 95%CI 4.8-8.4), non-Hodgkin lymphoma (6.7, 1.8-17), and cervical carcinoma (2.4, 1.1-4.4). These three cancers were also increased in the combined periods. Risks of five non-AIDS-defining cancers were increased in the combined periods: Hodgkin lymphoma (5.7, 1.2-17) and cancers of the conjunctiva (SIR 4.0; 1.5-8.7), kidney (16, 1.8-58), thyroid (5.7, 1.1-16), and uterus (5.5, 1.5-14). Cancers of the breast, nasopharynx, and lung were increased either in the early or late incident periods only. Among 407 children, seven cancers were observed, of which five were Kaposi sarcoma. The application of a record-linkage design in Africa broadens the repertoire of epidemiological tools for studying HIV-infected populations. We confirm the increased risks of AIDS-defining cancers and report increased risks of a few non-AIDS-defining cancers.

Outcome of screening by clinical examination of the breast in a trial in the Philippines

Abstract: The value of screening by Clinical Examination of the Breast (CBE) as a means of reducing mortality from breast cancer (BC) is not established. The issue is relevant, as CBE may be a suitable option for countries in economic transition, where incidence rates are on the increase but limited resources do not permit screening by mammography. Our aims were to assess whether mass screening by CBE carried out by trained para-medical personnel is feasible in an urban population of a low-income country, and its efficacy in reducing BC mortality. Our study was designed as a randomised controlled trial of the effect on BC mortality of 5 annual CBE carried out by trained nurses. The target population was women aged 35-64 years, resident in 12 municipalities of the National Capital Region of Manila, Philippines. The units of randomization were the 202 health centres (HC) within the selected municipalities. During 1995 nurses and midwives were recruited and trained in performing CBE. The first round of screening took place in 1996-1997. The intervention however showed a refractory attitude of the population with respect to clinical follow-up and was discontinued after the completion of the first screening round. Cases of breast cancer occurring in the study population during 1996-1999 were identified by the 2 local population-based registries. In the single screening round 151,168 women were interviewed and offered CBE, 92% accepted (138,392), 3,479 were detected positive for a lump and referred for diagnosis. Of these only 1220 women (35%) completed diagnostic follow-up, whereas 42.4% actively refused further investigation even with home visits, and 22.5% were not traced. Of 53 cases that occurred among screen-positive women in the 2 years after CBE only 34 were diagnosed through the intervention. Eighty cases occurred among screen-negative women. The test sensitivity for CBE repeated annually was 53.2%. The actual sensitivity of the programme was 25.6% and positive predictive value 1%. Screen-detected cases were non-significantly less advanced than the others. Previous studies have shown that most breast cancer cases in the Philippines present at advanced stages and have an unfavourable outcome. Although CBE undertaken by health workers seems to offer a cost-effective approach to reducing mortality, the sensitivity of the screening programme in the real context was low. Moreover, in this relatively well-educated population, cultural and logistic barriers to seeking diagnosis and treatment persist and need to be addressed before any screening programme is introduced.

Trends in the incidence of cancer in Qidong, China, 1978-2002.

Abstract: A population-based cancer registry was established in Qidong, Jiangsu Province, China, in 1972, and the trends in incidence rates of the major cancer sites have been analyzed for a 25-year period, 1978–2002. Five-year age-specific rates, crude incidence rates, world age-standardized rates (ASR), percent change (PC) and annual percent change (APC) were calculated using annual data on population size, and estimates of its age structure. The indices of histological verification of diagnosis, death certificate only and proportion of mortality to incidence were employed for assessing the registration quality. A total of 51,933 incident cases of cancer were registered in Qidong from years 1978 to 2002, with a male-to-female sex ratio of 1.9:1. Crude incidence increased markedly over the 25-year period (PC and APC of +55.6% and +2.1%, respectively), but ASR showed a slight decrease (−0.4% in males, and −0.3% in females), indicating that the major part of this is due to population ageing. The leading cancer sites in rank were liver (average ASR = 50.8 per 100,000), stomach (26.7), lung (22.7), colon-rectum (8.9), oesophagus (7.4) and breast (5.4). Cancers of liver, lung, colon-rectum and female breast all showed increases in incidence during the study period, with APCs (ASR) of +0.1%, +1.7% and +1.4% for males, and +0.2%, +0.9%, +1.9% and +1.1% for females, while the cancers of stomach (APC: −3.2% in male, and −2.4% in female) and cervix (APC: −4.7%) showed notable declines. Examination of age-specific rates showed declining trends in the younger generations for liver cancer, but increases for cervix cancer. The results underline the increasing importance of cancer as a cause of mortality and morbidity in a population that is ageing and undergoing profound changes in socioeconomic development and lifestyle. The cancers of high lethality that have been common in the Chinese population (liver, stomach, oesophagus) are showing some evidence of decline, at least in younger generations, but they remain major problems. At the same time, the cancers associated with economically “developed” societies—lung, colon-rectum and female breast—are showing increases. The population-based cancer registry is an indispensable tool for providing data for planning and evaluation of programmes for cancer control in all societies. © 2006 Wiley-Liss, Inc.

Time trends,estimates and projects for breast cancer incidence and mortality in China

Abstract: Objective Using comprehensive available data on women breast cancer in China, to describe the mortality trends from late 1970s, estimate and project the profile in 2000 and 2005, and to aim to provide a reference for clinic, basic research and prevention and control strategy making for breast cancer in China. Methods Using Joinpoint model, the mortality trends were analyzed on the basis of routine surveillance data. Combining with the data from the second national mortality survey and several cancer registries, using the log-linear model （based on Poisson distribution）, the breast cancer profile in 2000 and 2005 were estimated and projected. Results Although there was a slight decline in mortality between early 1970s and 1990s, the age-specific mortality rates among young and middle age women increased dramatically which followed a continuing increase trend on both rates and absolute numbers, in both urban and rural areas in recent 15 years. Compared with 2000, there are 470 thousands more new breast cancer cases and 130 thousands more deaths from breast cancer in 2005. Conclusion Due to the double effects of both increasing risk factors and population growth and ageing, breast cancer will be one of the most extensively increasing cancers in Chinese women. The prevention and control of breast cancer will be of great emphasis for future cancer control strategy in China. Key words: Women,China; Breast cancer; Mortality trends; Estimation; Prediction; Mortality

Human papillomavirus and cervical cancer from a prospective study in Khon Kaen, Northeast Thailand.

Abstract: The risk of developing carcinoma of the cervix in women infected with human papillomavirus (HPV) was estimated in a nested case-control analysis of 33 cancers (invasive and in situ) and 113 controls, matched by age and sex, from an ongoing cohort study of lifestyle and cancer in a rural population of Northeast Thailand. Oncogenic HPV types were present in 10.8% of control women and in 31/33 of the carcinoma cases, corresponding to an odds ratio of 130.6 (95% CI 11.7–1457.0). There was no significant difference in risk between prevalent cancer cases (diagnosed less than 3 months after HPV testing) and incident cases (diagnosed an average of 2.1 years later). HPV 16 and 18 were the most prevalent oncogenic HPV types present. The results confirm that some two of three of cervical cancer cases in this population of Northeast Thailand are caused by HPV 16 and 18.

Population-based incidence estimates of uveal melanoma in Germany. Supplementing cancer registry data by case-control data.

Abstract: Valid incidence rates of uveal melanoma (UM) from German population-based cancer registries are currently not available due to under-reporting. We conducted two case-control studies on UM at a reference centre for eye tumours and show the influence on population-based incidences of UM when data from case-control studies are linked with a cancer registry. The first case-control study (1996-1998) recruited 13 UM cases aged 35-74 years and the second case-control study (2002-2003) recruited 20 UM cases aged 20-74 residing within the population covered by the Munster Cancer Registry. After record linkage, age-truncated and standardized (World Standard Population) incidences with and without the record linkage were compared. Incidence rates based on routine cancer registration increased by a factor of 1.7 (1996-1998, age group 35-74 years) and 3.7 (2002-2003, age group 20-74 years) after record linkage with the case-control data. The supplemented age-standardized incidence of UM is 8.6 per million (20-74 years, 2002-2003) compared with the unsupplemented incidence of 2.3 per million. UM unknown to the registry were less often morphologically verified than those known to the registry. Cancer registries relying on pathology reports underestimate UM incidences if eye-preserving treatments are introduced. Close co-operation between cancer referral centres and cancer registries can substantially improve the completeness of registration.

Calculating age-adjusted cancer survival estimates when age-specific data are sparse: an empirical evaluation of various methods.

Abstract: We evaluated empirically the performance of various methods of calculating age-adjusted survival estimates when age-specific data are sparse. We have illustrated that a recently proposed alternative method of age adjustment involving the use of balanced age groups or age truncation may be useful for enhancing calculability and reliability of adjusted survival estimates.

BK virus and cancer in Uganda.

Abstract: As part of an epidemiological study of cancer in Uganda, we investigated the titre of antibodies against BK virus among 821 people with different cancer types and benign tumours. Among study participants, 790 were considered seropositive for anti-BK virus antibodies and all analyses were conducted on transformed data. The mean optical density (a measure of antibody titre) for all patients combined (including the 31 who were considered seronegative) was 1.03 (standard error 0.01), but was 5% higher in women than in men (P=0.05), and 8% higher among HIV seropositive than seronegative people (P= 0.002). Otherwise, there were few consistent associations between anti-BK virus antibodies and any social and lifestyle factor investigated. Differences in the mean optical density for each cancer type were estimated using multivariate analysis of variance with adjustment for sex, age group and HIV serostatus, using all other patients as controls. The mean optical density was about 17% lower among those with oral cancer (optical density 0.86, standard error 0.06; P=0.01, based on 30 patients) and about 20% higher among those with prostate cancer (optical density 1.22, standard error 0.09; P=0.01, based on 11 cases) than among all other patients combined. The number of cases of each cancer was too small to exclude the possibility of these findings arising by chance. No other cancer site or type was significantly associated with low, or with high anti-BK virus antibody titres.