Educational inequalities in cancer incidence in Turin, Italy.

The objective of this study was to investigate the relationship between cancer incidence and socioeconomic status, and to examine the temporal trends in social inequalities in cancer risk. Educational differentials in the incidence of cancer (25 sites) among adult residents of Turin (Italy) were examined using data from the Turin Longitudinal Study and the Piedmont Cancer Registry. The relationship between cancer incidence and educational level was evaluated over three 5-year periods between 1985 and 1999 using Poisson models. An estimated 17% of malignancies among men in the low-educational group were attributable to education, whereas women with a low educational level were slightly protected. Less-educated men had higher risks of upper aero-digestive tract, stomach, lung, liver, rectal, bladder, central nervous system and ill-defined cancers, and lower risks of melanoma, kidney and prostate cancers. Women with lower educational levels were at higher risk of stomach, liver and cervical cancers, whereas they were less likely to be diagnosed with melanoma, ovarian and breast cancers. For most sites, the educational gradient in risk did not vary substantially over time. The educational inequalities in cancer incidence observed in this cohort appear similar in magnitude and direction to socioeconomic inequalities found in other Western countries; for some cancer sites results partly differ from the results of other studies, and require further investigation. A thorough understanding of the relative burden of well-documented causes of social inequalities in cancer risk is essential to address preventive measures and to direct future research on unexplained social differences.