AGE AT ONSET OF OVARIAN-CANCER IN WOMEN WITH A STRONG FAMILY HISTORY OF OVARIAN-CANCER

Objective. To determine whether women with a strong family history of ovarian cancer develop ovarian cancer at a younger age than the genera l population, and to determine if the age at onset of ovarian cancer i n families with multiple cases of ovarian cancer is progressively youn ger with successive generations.Methods. Using a large voluntary famil ial ovarian cancer registry, 90 probands were identified whose grandmo thers had developed ovarian cancer and for whom the age at onset was k nown. The distribution of age at onset of ovarian cancer in the grandm others was compared to the expected distribution based on data from th e Surveillance Epidemiology End Results (SEER) project. In addition, 1 31 families were identified for whom complete pedigrees were available and in whom 3 or more family members had developed ovarian cancer. Ov arian cancer-free survival curves were constructed for each aggregate generation (using the probands as the reference generation) utilizing the Kaplan-Meier method. Results. Among the 90 grandmothers, 18 from f amilies with 3 or more cases of ovarian cancer had a distribution of a ge of onset that was younger than expected (P = 0.02). However, the di stribution of age at onset among the 72 grandmothers from families wit h only 2 cases of ovarian cancer was not significantly different from that expected based on the SEER data (P = 0.18). Among the 131 familie s with 3 or more cases of ovarian cancer, the probands' daughters deve loped ovarian cancer at a younger age than the probands (P = 0.018), p robands developed ovarian cancer at a younger age than their mothers ( P = 0.0008), and the probands' mothers developed ovarian cancer at a y ounger age than the probands' grandmothers (P = 0.0038). Conclusions. Ovarian cancer patients from families with 3 or more cases of ovarian cancer tend to develop their cancer at a younger than expected age. Th is is consistent with the phenomenon known as anticipation. (C) 1997 A cademic Press.