Outcome of treatment for breast cancer patients with chest wall recurrence according to initial stage: Implications for post-mastectomy radiation therapy

Purpose: The impact of postmastectomy radiation therapy (PMRT) on overall survival (OS) for patients with Stage II breast cancer with 1-3 positive lymph nodes is controversial. We sought to compare the outcome of salvage treatment for patients with chest wall recurrence (CWR) according to initial disease stage to shed light on the potential benefit of PMRT in specific subgroups of patients. Methods: We retrospectively reviewed information concerning 96 patients with CWR who were not previously treated with PMRT. The patients were divided according to their initial extent of disease: T1-T2N0 (Group 1), T1-T2 with 1-3 positive lymph nodes (Group 2), and T3-T4 or ≥4 positive lymph nodes (Group 3). The OS and distant metastasis-free survival (DMFS) from the time of CWR were compared using the method of Kaplan and Meier, and a Cox regression model was used for a multivariate analysis. Results: Group 1 had an improved OS and DMFS compared with Group 2 and Group 3 (p < 0.001), but there were no differences in OS or DMFS between Group 2 and Group 3 (p = 0.250 and p = 0.492, respectively). The respective 5-year rates for the three groups were as follows: OS 79.9% vs. 41.9% vs. 29.1%; DMFS 75.2% vs. 33.6% vs. 25.9%. Conclusions: Breast cancer patients with T1-T2N0 breast cancer who develop a CWR have a significantly better outcome than those with lymph node-positive disease. Patients with T1-T2 tumors and one to three positive lymph nodes have a similar outcome after CWR as those with larger tumors or more than four positive lymph nodes. These data should be considered when weighing the risks and benefits of PMRT for patients with Stage II breast cancer with one to three positive lymph nodes.