Early-stage bilateral breast cancer treated with breast-conserving surgery and definitive irradiation: the University of Pennsylvania experience.

PURPOSE: To determine whether patients with early-stage bilateral breast cancer can be treated with definitive irradiation following breast-conserving surgery with acceptable survival, local control, complications, and cosmesis. METHODS AND MATERIALS: During the period 1977-1992, 55 women with Stage 0, I, or II concurrent (n = 12) or sequential (n = 43) bilateral breast cancer were treated with definitive irradiation following breast-conserving surgery. The records of these 55 patients with 110 treated breasts were reviewed for tumor size, histology, pathologic axillary lymph node status, first and overall site(s) of failure, and adjuvant chemotherapy or hormonal therapy. Curves for survival, local control, and regional control were determined. Cosmetic outcome, complication rates, and matching technique were analyzed. The median total radiation dose delivered was 64 Gy (range 42-72) using tangential whole-breast irradiation followed by an electron or iridium implant boost. The tangential fields were matched with no overlap in 40 patients (73%); there was overlap on skin of up to 4 cm in 14 patients (25%); and the matching technique was unknown in 1 patient (2%). The median follow-up for the 12 women with concurrent bilateral breast cancer was 4.0 years. The median follow-up for the other 43 women with sequential cancer was 9.3 and 4.9 years, respectively, after the first and second cancers. RESULTS: For the overall group of 55 patients, the 5- and 10-year overall survival rates were 96% and 94%, respectively, after treatment of the first cancer, and 96% and 92%, respectively, after treatment of the second cancer. The 5- and 10-year actuarial relapse-free survival rates were 90% and 75%, respectively, after treatment of the first cancer, and 83% and 72%, respectively, after treatment of the second cancer. For the 110 treated breast cancers, the 5- and 10-year actuarial local failure rates were 5% and 15%, respectively. Complication rates were: 28% breast edema, 8% arm edema, 4% pneumonitis, 3% cellulitis, 1% rib fracture, and 1% brachial plexopathy; no patient developed matchline fibrosis. For patients with a minimum of 3 years of relapse-free follow-up, the rate of excellent or good cosmetic outcome for 104 treated breasts was 85%. CONCLUSION: Definitive irradiation after breast-conserving surgery is technically feasible for selected patients with concurrent or sequential early-stage bilateral breast cancer. Survival, local control, complication rates, and cosmetic outcomes appear comparable to historical reports of breast conservation treatment for unilateral disease. Bilateral definitive breast irradiation after breast-conservation surgery should be considered an acceptable alternative treatment to bilateral mastectomy for selected patients with concurrent or sequential early-stage bilateral breast cancer.