SOCIOECONOMIC-STATUS AND BREAST-CANCER SURVIVAL IN THE SOUTHEASTERN NETHERLANDS, 1980-1989

Socioeconomic differences in breast cancer survival in the southeaster n Netherlands between 1980 and 1989 were studied (n = 3928), as was th e impact of prognostic factors (stage at diagnosis, morphology, and tr eatment) on such differences. An area-based measure of socioeconomic s tatus (SES) in five groups, based on the postcode of residence at the time of diagnosis, was used. In univariate analyses the relative survi val rate was used to correct for causes of death other than breast can cer. The measure of outcome in multivariate analyses was the hazard ra tio. The results of both univariate and multivariate analyses suggeste d a small survival advantage for the higher SES groups. In a model wit h follow-up period, SES and age, the hazard ratios with 95% confidence intervals (CI) for SES groups from high to low were: 1.00, 1.06 (0.84 -1.33), 1.04 (0.86-1.26), 1.15 (0.96-1.38), 1.18 (0.99-1.42). After a correction for stage at diagnosis, differences in survival were reduce d substantially. Morphology and treatment were not important explanato ry factors of the SES survival association. We conclude that small soc ioeconomic differences in breast cancer survival exist in The Netherla nds and that stage at diagnosis is the most important determinant of s uch differences.