Does Post Mastectomy Radiotherapy Reduce Loco-Regional Recurrence Rates in all Clinical Stages of Breast Cancer Following a Complete Pathological Response to Neoadjuvant Chemotherapy? A Systematic Review and Meta-Analysis of the Literature

Abstract

The role of post-mastectomy radiotherapy (PMRT) has not been qualified in contemporary cohorts that have achieved complete pathological response (pCR) following neoadjuvant chemotherapy (NAC). This systematic review evaluated loco-regional recurrence (LRR) rates following PMRT for patients with pCR or pathologically lymph node negative disease (ypN0) after NAC. We identified seven papers that described LRR in 415 patients with pCR following NAC. Pooled analysis demonstrated clear benefit of PMRT on LRR (OR: 0.2 [95% CI: 0.06–0.58; p = 0.003]) and this was most pronounced in stage III/IV disease (OR: 0.12 [95% CI: 0.04–0.44; p = 0.0012]), as well as of benefit in ypN0 disease. PMRT appears to be effective in reducing LRR following pCR or ypN0 in advanced breast cancer but requires further investigation.