Family history and the risk of endometrial cancer.

The association between a family history of endometrial, breast and ovarian cancer and the risk of endometrial cancer was analyzed on the basis of data from a case-control study conducted in northern Italy between 1983 and 1993. A total of 726 histologically confirmed endometrial-cancer patients (median age 61) admitted to a network of general and teaching hospitals in the Greater Milan area were interviewed. The controls were 2,123 women (median age 59), admitted for acute, non-neoplastic, non-hormone-related diseases to the same network of hospitals where the cases had been identified, with admission diagnoses unrelated to any of the known or suspected risk factors for endometrial cancer. Among cases, 37 (5.1%) reported a history of endometrial cancer in first-degree relatives. The corresponding figure among controls was 77 (3.6%). In comparison with women with no family history of endometrial cancer, the odds ratio (OR) of endometrial cancer was 1.5 (95% CI [confidence interval], 1.0-2.3) in women with a history of endometrial cancer in first-degree relatives. No relation emerged between endometrial cancer and a family history of breast or ovarian cancer. These results suggest that a family history of endometrial cancer increases the risk of contracting the same disease. However, the proportion of cases attributable to this factor was small: less than 1% of endometrial cancers in this population were attributable to familial (and hence potentially genetic) factors.