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.