Postmastectomy radiation and survival in patients with breast cancer

Abstract

To analyze the impact of postmastectomy radiotherapy on locoregional control and overall survival in patients with carcinoma breast. Between 1995 and 2000, 688 patients of carcinoma breast were analyzed. Out of these, 608 received postmastectomy radiotherapy and 80 patients were not given any radiation therapy. At a median follow-up of 67 months, the outcomes studied were locoregional recurrence (LRR), distant metastases, disease-free survival (DFS) and overall survival (OS) using univariate and multivariate analyses. The frequency of LRR with or without distant metastases was 8.5%, and distant metastases was seen in 18.7% of patients. On univariate analyses, factors affecting LRR were age < 40 years (0.019), tumor stage ( P = 0.001 ), grade ( P = 0.027 ), pathological nodal status ( P ), deep resection plane (0.041), ER/PR status ( P = 0.032 ) and postmastectomy radiation therapy (PMRT) ( P ). DFS rate was 69% at 5 years. Factors affecting distant metastases were age < 40 years (0.005), tumor stage ( P ), grade ( P = 0.0007 ), pathological nodal status ( P ), extra capsular extension (ECE) ( P = 0.002 ), hormonal therapy ( P ) and PMRT ( P ). The OS rate was 81% at 5 years. Factors affecting OS were tumor stage ( P ), grade ( P = 0.0001 ), pathological nodal status ( P ), ECE ( P = 0.002 ) ER/PR status ( P = 0.008 ), hormonal therapy ( P = 0.001 ) and PMRT ( P = 0.004 ). On multivariate analysis, factors affecting LRR were age ( P = 0.001 ), tumor stage ( P = 0.021 ), deep resection plane (0.003), ECE ( P = 0.022 ) and PMRT ( P = 0.047 ). Factors affecting distant metastases were menopause ( P = 0.044 ), grade ( P = 0.012 ), ECE ( P = 0.017 ) and PMRT ( P = 0.012 ). Factors affecting OS were menopausal status ( P = 0.017 ), tumor stage ( P = 0.029 ), pathological nodal status ( P = 0.011 ) and PMRT ( P = 0.002 ). PMRT improves LRR as well as OS in patients with carcinoma breast. Other factors of prognostic importance were menopausal status, tumor stage and pathological nodal status.