Prevalence of hereditary breast/ovarian carcinoma risk in patients with a personal history of breast or ovarian carcinoma in a mammography population.

BACKGROUND: Identifying BRCA1 and BRCA2 mutation carriers is increasingly important as new management options show promise in decreasing morbidity and mortality in these women. The authors sought to determine the prevalence of family histories suggestive of a hereditary breast carcinoma syndrome in a cohort of patients with a personal history of breast and/or ovarian carcinoma presenting for mammography.
METHODS: The authors reviewed the family histories of all women with a history of breast or ovarian carcinoma presenting for mammography over a 37-week period. Using the Myriad model, the authors evaluated the prevalence of family histories with a > or = 10% risk of a BRCA1 or BRCA2 mutation.
RESULTS: During the period of the current study, 14,597 women completed a family history questionnaire. Of these women, 1764 had a personal history of breast or ovarian carcinoma, 86.6% had unilateral breast carcinoma, 4.6% had bilateral breast carcinoma, 8.2% had ovarian carcinoma, and 0.5% had both breast and ovarian carcinoma. Overall, 20.6% met the criteria for a > or = 10% risk of mutation according to the Myriad model. This incidence was higher among Ashkenazi women (47.3%) and among patients with a personal history of ovarian carcinoma (35.9%).
CONCLUSIONS: Application of the Myriad model to women with a personal history of breast and ovarian carcinoma suggested that approximately 1 in 5 of these women (20.6%) will have family histories suspicious for a genetic mutation. This risk was higher for Ashkenazi women and for those with a personal history of ovarian carcinoma. This prevalence was considerably higher than the rate reported among women with no personal history of cancer, and has significant implications for their management, as well as for the capacity for risk assessment and testing. (c) 2005 American Cancer Society.