Breast-conserving surgery following radiation therapy of 50 Gy in Stages I and II carcinoma of the breast: The experience at one institute in Japan

This study evaluated the results of breast-conserving therapy experienced in one institute. A total of 217 breasts in 215 patients with clinical stages I and II breast cancer undergoing breast-conserving therapy between August 1991 and December 1999 were included. The actuarial 5-year local recurrence-free survival, disease-free survival and overall survival rates were 97.4%, 88.5% and 92.5%, respectively. Microscopic margins were negative in 176 (81.1%) of the total breasts and positive in 41 (18.9%). There were no differences in the age at operation, tumor size, clinical stage, lymph node status, estrogen receptor status, or distance from tumor to nipple between patients with positive surgical margins and with negative surgical margins. During the follow-up period, local recurrence occurred in seven patients. Local recurrence was significantly less frequent in patients with surgical margin-negative tumors than those with surgical margin-positive tumors, and also in ER-positive tumors than ER-negative or ER-unknown tumors. There was no difference in overall survival between patients with and without breast-recurrence. Using multivariate analysis, the surgical margin was determined to be an independent predictive factor for local recurrence in the conserved breast. Nodal status and ER status were independent prognostic factors, but local recurrence did not have an independent negative impact on survival. We conclude that microscopic surgical margin is the most important factor associated with local recurrence in the conserved breast among patients treated with breast-conserving surgery and radiation therapy of 50 Gy. Local recurrence however, has no adverse effect on survival of patients.