Level of education and the risk of cancer in Sweden.

It is well known that certain cancers have shown clusteringin educational and socioeconomic groups, but recent comprehensive data on clustering by education are limited. We determined standardized incidence ratios (SIRs), adjusted for several variables, for cancer among men and women in six educational groups based on the Swedish Family-Cancer Database. People were identified with a certain educational background in the census of year 1970; the comparison group was the largest group, those with <9 years of education. Cancers were followed from years 1971 to 1998. Total cancer risks did not differ much, but at individual sites, the trend was significant, either increasing or decreasing over all educational groups (for 27 of 29 male and 28 of 31 female cancers). University graduates had a decreased risk of tobacco-, alcohol-, and genital infection-related cancers, but male graduates had an excess of colon, prostate, squamous cell skin, nervous system cancer, and melanoma. Male graduates showed a low SIR of 0.50 for stomach cancer and a high SIR of 1.89 for melanoma; female graduates showed a low SIR of 0.43 for lung and cervical cancer and a high SIR of 1.57 for melanoma. The overall weighted population attributable fraction for educational level was 13.8% for men and 16.7% for women, and it was highest, >50%, for stomach cancer in both genders and for cervical and anal cancer in women.