Importance of a personal history of breast cancer as a risk factor for the development of subsequent breast cancer: Results from screening breast MRI

OBJECTIVE. The purposes of this study were to assess the importance of a personal history of breast cancer as a risk factor for patients referred for screening breast MRI and to evaluate the importance of this risk factor compared with family history. MATERIALS AND METHODS. A retrospective review of screening breast MRI performed from 2004 to 2012 included a total of 702 patients, 465 of whom had undergone annual MRI and 237 of whom had undergone MRI every 6 months as part of a research protocol. RESULTS. Of the patients screened, 208 had a personal history of breast cancer, and 345 had a family history as the sole risk factor. An additional 97 patients had both risk factors. The absolute risk for detection of breast cancer at screening MRI among patients with a personal history of cancer was 2.8% (95% CI, 0.6-5.2%). The absolute risk for patients with a strong family history of cancer was 2.0% (95% CI, 0.5-3.5%). The relative risk for detection of breast cancer given a personal history was 1.42 (95% CI, 0.48-4.17) compared with family history. The relative risk when both risk factors were present compared with having only a family history was 3.04 (95% CI, 1.05-8.86). CONCLUSION. A personal history of breast cancer is an important risk factor for the development of subsequent breast cancer. Given the results, consideration should be given to MRI screening of patients with a personal history of breast cancer.