RISK FOR BREAST AND COLORECTAL CANCERS SUBSEQUENT TO CANCER OF THE ENDOMETRIUM IN A POPULATION-BASED CASE SERIES

The purpose of this study was to estimate the relative risk of breast and colorectal cancers in women who were previously diagnosed with end ometrial cancer. This study was conducted using a population-based coh ort of 2347 women diagnosed with invasive cancer of the endometrium be tween January 1, 1984, and December 31, 1995 in Orange County, Califor nia. Only women with a diagnosis of invasive endometrial cancer at age 80 years old or below were included in the analysis (N = 2170). In th is same cohort, metachronous and synchronous breast and colorectal can cers were ascertained and the risk of developing one or the other type of neoplasm was compared to the expected number of cases derived from cancer incidence in California by age, 1988-1992. We found a statisti cally increased risk of breast cancer as a second primary, while the o bserved incidence in colorectal risk did not reach statistical signifi cance. The association between endometrial cancer and breast and possi bly colorectal cancer indicates the importance of common etiologies fo r these cancers. (C) 1997 Academic Press.