Treatment Results and Prognostic Factors of Early Breast Cancer Treated with a Breast Conserving Operation and Radiotherapy

Background: The purpose of this study was to analyze the prognostic factors affecting local control and survival rates for patients with early breast cancer who received breast conserving treatment (BCT) and to find out the optimal treatment according to their risk factors. Methods: From October 1994 to December 2001, 605 patients with 611 stage I and II breast cancers received BCT, and the results were analyzed retrospectively. BCT consists of breast conserving surgery and whole breast irradiation. All the patients underwent lumpectomy or quad-rantectomy. Axillary lymph node dissection or sentinel lymph node biopsy was performed in 608 cases (99.5%). The radiation dose to the whole breast was 50.4 Gy over 5 weeks with a 1.8 Gy daily fraction and with boost doses of 9–14.4 Gy administered to the tumor bed. Adjuvant chemotherapy was performed in most of the patients with axillary lymph node metastasis or tumors larger than 1 cm. The median follow-up period was 47 months. Results: Local relapse, regional relapse and distant metastasis occurred in 15 (2.5%), 16 (2.6%) and 43 patients (7.1%), respectively. The 5-year overall survival, local-relapse-free survival, distant-metastasis-free survival and disease-free survival rates were 95.3%, 97.2%, 91.3% and 88.5%, respectively. On multivariate analysis, age (P = 0.02), number of involved axillar