Education and cancer incidence in a rural population in south India.

BACKGROUND: Population-based studies describing the association between education and cancer incidence has not yet been reported from India. METHODS: Information on the educational attainment of 4417 cancer cases aged 14 years and above, diagnosed during 2003-2006 in Dindigul district, Tamil Nadu, India, was obtained from the Dindigul Ambilikkai Cancer Registry, which registers invasive cancer cases by active methods from 102 data sources. Population distribution by 5-year age groups and for four educational levels namely no education, education 12 years, was obtained from census data. Standardized rate ratios based on age-standardized rates were calculated to study cancer risks for different educational levels. RESULTS: Men and women with no education had higher overall cancer incidence rates compared to the educated population. The risk of cervix, mouth, esophagus, stomach and lung cancers were inversely associated with higher levels of education whereas a high incidence of breast cancer was observed with increasing educational levels. The standardized rate ratio of cervical cancer 0.32 (95% CI: 0.19-0.52) and of breast cancer was 6.08 (95% CI: 1.81-20.48) for women with more than 12 years of education compared to those with no education. There was paucity of cases in the highest education level for most cancers. CONCLUSION: With more and more women in rural India becoming educated, one could foresee breast cancer becoming more frequent even in rural areas of India in future.

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

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 Münster 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.

International uveal melanoma incidence trends in view of a decreasing proportion of morphological verification.

The introduction of eye-preserving therapies for uveal melanoma in the 1970s complicates time trend analyses of the uveal melanoma incidence because the proportion of morphologically verified uveal melanoma has been decreasing over the decades. We carried out incidence trend analyses, based on data from internationally accredited population-based cancer registries throughout the world that take missing data on topography, morphology and basis of diagnosis of eye tumours into account. We selected incidence data of cancer registries that were included in Cancer Incidence In 5 Continents, Volumes VI-VIII covering a registration period of at least 15 years (usually 1983 to 1997) and classified each eye cancer as morphologically verified uveal melanoma, clinically diagnosed uveal melanoma, uveal melanoma identified as DCO case (Death certificate only), possibly uveal melanoma, other eye tumour or unclassifiable eye tumour and calculated age-standardized incidence rates by 3-year calendar periods using the World Standard Population as the reference. The uveal melanoma incidence decline in the United States SEER Caucasian population is due mainly to an incidence decline in the early registration period (from 1974-76 to 1986-88). The data from France and Italy suggest a recent increase in incidence. Uveal melanoma diagnosed clinically increasingly contribute to the overall uveal melanoma incidence over time. Combining all registries, the proportion of morphologically verified uveal melanoma decreased from 82% in 1983-87 to 75% in 1993-97. Uveal melanoma incidence rates remained quite stable during the period 1983-97. The interpretation of uveal melanoma incidence trends is complicated by missing data on topography within the eye, morphology and basis of diagnosis.