Evaluation of hereditary risk in a mammography population

BRCA1 and BRCA2 mutations significantly increase a women's lifetime risk of breast and ovarian cancer. Because several management options have shown promise in decreasing morbidity and mortality for these women, identifying potential mutation carriers is increasingly important. We have developed a large-scale method to collect family histories in a population of unaffected women presenting for mammography. We then applied current risk-assessment models to determine the prevalence of women at risk for hereditary breast and ovarian cancer.

We performed a retrospective review of family histories using data collected on all unaffected women presenting for mammography over a 14-week period. The Claus, Myriad II, and Hartmann models for hereditary risk assessment were applied to the survey results.

The questionnaire was completed by 5736 women, 695 of whom were excluded because of a personal history of breast or ovarian cancer. Family histories of the remaining 5041 women were evaluated. Totals of 5.9%, 5.2%, and 3.3% of patients, respectively, met criteria for increased risk according to the Hartmann, Myriad II, and Claus models, corresponding to 3.5, 3.1, and 1.9 patients per day. Although 9.2% of patients met criteria for >/=1 model, only 1.4% met criteria for all 3.

Application of available models to a screening population classifies a larger than expected number of women at high risk for a BRCA1 or BRCA2 mutation. New approaches to risk assessment and counseling are needed to apply our knowledge of hereditary risk to a broad population in a practical manner.