Outcome of breast cancer patients with chest wall recurrence: 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. When these patients develop a chest wall recurrence (CWR), OS is dependent on the success of salvage treatment. The objective of this study was to compare the outcome after CWR for three groups of patients divided according to their initial extent of disease: T1-T2NO (Group 1), T1-T2 with 1-3 positive lymph nodes (Group 2), and T3-T4 or S4 positive lymph nodes (Group 3). Methods: We retrospectively reviewed the clinical and pathologic information of 96 patients with CWR who were not previously treated with PMRT. The OS and distant metastasis-free survival (DMFS) from the time of CWR were compared for the three groups of patients using the method of Kaplan and Meier. A multivariate analysis for these endpoints was performed using a Cox regression model. Results: Group 1 had an improved OS and DMFS compared to Group 2 and Group 3 (P < 0.001). This difference remained significant on multivariate analysis. There was no difference 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: OS79.9% vs. 41.9% vs. 29.1%; DMFS- 75.2% vs. 33.6% vs. 25.9%. Conclusion: Breast cancer patients with T1-2 tumors and 1-3 positive lymph nodes have a similar outcome after CWR as those with larger tumors or S4 positive lymph nodes. Conversely, patients with T1-T2NO breast cancer who develop a CWR have a significantly better outcome.