Family History of Cancer, Oral Contraceptive Use, and Ovarian Cancer Risk

Abstract

The use of oral contraceptives has been shown to reduce the risk of ovarian cancer in women with a BRCA1 or BRCA2 genetic mutation. This study was conducted to determine if oral contraceptives give the same protection to women with a family history of ovarian cancer but whose genetic predisposition to ovarian cancer is unknown. The study population was drawn from the hospital records of 39 hospitals in three northeastern states. Seven hundred sixty-seven women aged 20 to 69 years, who were treated for ovarian cancer at these hospitals from May 1994 to July 1998 were interviewed in detail for family history and personal information. A group of control subjects, 1367 women aged 65 to 69 years at risk for ovarian cancer but without disease, was recruited from Health Care Financing Administration lists and similarly interviewed. Women who had multiple relatives with ovarian cancer, a relative with early onset of ovarian cancer, or a mother or a sister with ovarian cancer were described as having a positive family history. Among the study subjects, serous cell tumors were the most common (47%), followed by endometrioid (18%), mucinous (15%), clear cell (8%), undifferentiated (7%), and mixed/others (5%). The tumors were invasive in 80% of the women and borderline in 20%.