Identifying women at high risk for invasive breast cancer at the time of screening mammography.

Abstract

6 Background: Most mammography centers collect reproductive, family, and environmental data on patients presenting for screening mammograms. These data, if entered into a Gail Model Risk Assessment Tool, can help identify those patients at increased risk. These patients can then be referred to high-risk centers that will focus on risk-reduction strategies. Methods: This study is an observational prospective cohort of 1,000 women presenting for mammographic screening or diagnostic evaluation at mammography clinics affiliated with a single institution. Women at the time of their mammogram were asked to fill out a standard intake sheet by the institutional clinic. These data sheets were gathered and Gail model risk scores were calculated. Women with a 5-year risk of invasive breast cancer of 1.7% or greater were identified. Patients with a history of breast cancer or who underwent diagnostic mammography were excluded. A high risk subgroup was identified and risk factors were analyzed. Women at particularly high risk ( ≥ 3.4% or double the 5-year risk) were analyzed separately. Results: Of 1,000 women screened, 366 had ≥ 1.7% 5-year risk of invasive breast cancer. 26% (96) of these women were under 60 years old while 74% (270) were ≥ 60 years old. Among the latter group, 19.6% (53) were found to have ≥ 3.4% of developing invasive cancer. In these women with double the 5-year risk, 96.2% had a family history of breast cancer and 92.4% had a prior biopsy. Similarly, in women under 60, greater than half were high risk secondary to a prior biopsy or family history. Conclusions: 1/3 of patients who receive annual screening are at high risk for breast cancer. These patients can be identified from data routinely obtained at the time of screening mammography. Many were found to be at increased risk due to a strong family history or prior biopsy. Mammography centers may be the ideal setting in which to alert these patients of their risk and refer them to high risk centers for genetic counseling and consideration of chemoprevention.