Long-term Results of Breast-conserving Surgery and Radiation Therapy in Early Breast Cancer

Abstract

Purpose: To evaluate the long-term results after breast-conserving surgery and radiation therapy in early breast cancer in terms of failure, survival, and cosmesis. Materials and Methods : One hundred fifty-four patients with stage I and II breast cancer were treated with conservative surgery plus radiotherapy between January 1992 and December 2002 at the Keimyung University Dongsan Medical Center. According to TNM stage, 93 patients were stage I, 50 were IIa, and 11 were IIb. The affected breasts were irradiated with 6 MV photons to 50.4 Gy i n 28 fractions over 5.5 weeks with a boost irradiation dose of 10∼16 Gy to the excision site. Chemotherapy was administered in 75 patients and hormonal therapy in 92 patients with tamoxifen. Follow-up periods were 13∼179 months, with a median of 92.5 months. Results : The 5- and 10-year overall survival rates were 97.3% and 94.5%, respectively. The 5- and 10-year disease-free survival (5YDFS and 10YDFS, respectively) rates were 92.5% and 88.9%, respectively; the ultimate 5YDFS and 10YDFS rates after salvage treatment were 93.9% and 90.2%, respectively. Based on multivariate analysis, only the interval between surgery and radiation therapy (≤6 weeks vs. ＞6 weeks, p=0.017) was a statistically significant prognostic factor for DFS. The major type of treatment failure was distant failure (78.5%) and the most common distant metastatic site was the lungs. The cosmetic results were good-to-excellent in 96 patients (80.7%). Conclusion : Conservative surgery and radiation for early stage invasive breast cancer yielded excellent survival and cosmetic results. Radiation therapy should be started as soon as possible after breast-conserving surgery in patients with early breast cancer, ideally within 6 weeks.