OCCURRENCE OF CERTAIN MULTIPLE PRIMARY CANCERS IN FEMALES

This study was designed to ascertain whether a woman with a single primary cancer of the breast or genital organs has an increased, decreased, or unchanged risk of developing a second primary cancer of the genital organs or digestive system. The investigation dealt with 19,394 patients of known age with cancer of the breast and 18,317 patients of known age with cancer of the genital organs. These patients were admitted to a Connecticut hospital between the years 1935 and 1962, inclusive. Survival experience was converted to person-years of observation, and the expected number of second primary cancers by site was calculated according to person-years of observation and age-, sex-, and site-specific incidence rates. The expected number of second primary malignancies obtained was then compared with the observed number, and a 50% or greater excess of observed- over-expected second primary cancer was found for the following sets of sites: This study indicates 1) a need to carry out careful follow-up screening of females with cancer of the breast or genital organs for early detection of second primary cancers, and 2) a possible common etiology (perhaps hormonal) for cancer of the breast, genital organs, and large intestine in females. © 1969, Oxford University Press.