Prognostic Factors Affecting the Outcome of Salvage Radiotherapy for Isolated Locoregional Recurrence After Mastectomy

Abstract

To evaluate the prognostic factors affecting the outcome of salvage radiotherapy for isolated locoregional recurrence after mastectomy. Between May 1988 and April 2002, 65 breast cancer patients underwent radiotherapy as a component of salvage treatment for isolated locoregional recurrence after mastectomy. The sites of failure were as follows: chest wall in 37 patients, regional lymph nodes (LNs) in 23 patients, and combined chest wall and LNs in 5 patients. None of the patients had previously been treated with radiation. Thirty-nine patients had surgical resection, and 55 patients received systemic chemotherapy and/or hormonal therapy for recurrent disease. In 51 cases (78.5%), the chest wall and ipsilateral regional lymphatics including supraclavicular, axillary, and internal mammary LNs were irradiated. Median dose was 50.4 Gy (range: 50-71.5). Median duration of follow-up was 52 months (range: 2-206). The 5-year overall survival rate was 48.1%. On multivariate analysis, patients without initial nodal involvement had better overall survival (P = 0.0118). The 5-year locoregional progression-free survival rate was 69.8%, and time to recurrence (>36 months vs. < or =36 months) had an influence on the outcome with borderline significance (P = 0.0775). The 5-year distant metastasis-free survival rate was 42.1%. Lack of systemic therapy after recurrence (P = 0.0089) and age <50 years at recurrence (P = 0.0145) were significant prognostic factors predicting poor distant metastasis-free survival. Radiotherapy for isolated locoregional relapse after mastectomy achieved locoregional control in about two-thirds of patients. Major pattern of failure was distant relapse, and systemic therapy is warranted to prevent secondary dissemination.