Endometrial cancer in the family-cancer database

Endometrial cancer was studied in the Swedish Family-Cancer Database, updat ed in 1999 to cover individuals born after 1934 with their biological paren ts, totaling 9.6 million persons, Cancer data were obtained from the Swedis h Cancer Registry from 1958 to 1996 and included over 20,000 cases of endom etrial cancer. Seventy-six families were identified in which both the mothe r and the daughter had endometrial cancer, giving a familial standardized i ncidence ratio (SIR) of 3.19 for daughters and 2.78 for mothers. The risk d epended inversely on the age at diagnosis, and the risk was almost 10 in da ughters who were diagnosed before age 50 when their mothers were also diagn osed before that age. The discordant cancer site that associated with endom etrial cancer between the two generations was colon, with a SIR of 1.44-1.6 8, However, when the maternal endometrial cancer was diagnosed before age 5 0, increased SIRs were observed in daughters or sons for rectal, pancreatic , nervous system, breast, and ovarian cancers. Second cancers were followed in females diagnosed with endometrial cancer, and the highest overall risk s were observed for ovarian and connective tissue cancers; colorectal cance rs were also clearly in excess. Among the other family members of the 76 fa milies in which both mother and daughter were affected with endometrial can cer, there were 11 cases of colorectal cancer. When a sister was affected i n such families, the SIR of endometrial cancer was 31.40, and the median di agnostic age was several years lower than in endometrial cancer families in which no colorectal cancers were found. Many of these families may have he reditary nonpolyposis colorectal carcinoma syndrome. However, the risk of e ndometrial cancer was increased even in families presenting no colorectal c ancers.