Background: After an initial diagnosis of breast cancer, the risk of contralateral breast cancer is approximately 0.5% per year. Annual mammography is recommended to identify local recurrences and contralateral new primaries. Because the sensitivity of mammography tends to be lower in younger women, we conducted a retrospective review of the method of detection and pathologic stage of metachronous contralateral primary breast cancers according to age at diagnosis in a cohort of breast cancer patients.
Methods: The Henrietta Banting Database contains information on cases of breast cancer diagnosed at Women's College Hospital from 1987 to 2004. From among 1992 women in the database, 71 patients were identified who were initially diagnosed before age 60 and who subsequently developed a contralateral breast cancer. Medical records were obtained for 53 of the 71 patients.
Results: Of the 53 contralateral cancers, 33 (62%) were detected by mammography, including 4 in 16 patients (25%) diagnosed before age 50 and 29 in 37 patients (78%) diagnosed at age 50 or older (p ≤ 0.001).
Conclusions: Mammography has poor sensitivity for the surveillance of contralateral breast cancer in early-onset breast cancer patients. Other imaging modalities should be evaluated in this setting.
Keywords: Breast cancer; contralateral cancer; detection; mammography; surveillance.