EVALUATION OF THE ROLE OF POSTMASTECTOMY RADIOTHERAPY IN WOMEN WITH ONE TO THREE POSITIVE AXILLARY NODES WITH EXTRACAPSULAR INVASION

Abstract

Background: There is insufficient evidence to suggest the routine use of postmastectomy radiotherapy (PMRT) in women with T1-T2 breast carcinoma and 1-3 positive lymph nodes with extracapsular invasion (ECI). PURPOSE: To determine whether PMRT after adjuvant chemotherapy will reduce the risk of loco-regional recurrence (LRR) and thus improve survival, in this group of patients. Patients and methods: Between May 2004 and December 2006, 64 women with pathologic T1-T2 breast carcinoma and 1-3 positive nodes with ECI, and who had undergone modified radical mastectomy and received adjuvant chemotherapy, were randomized to PMRT (group A, n=32) or no adjuvant radiotherapy (group B, n=32). Loco-regional radiotherapy schedule was 50 Gy in 25 fractions over 5 weeks. The median Follow-up period was 50 months (range, 35-66). Results: The two treatment groups were well balanced with respect to the known prognostic factors. Out of 64 patients, 53% were < 45 years, 75% had more than one positive node with ECI 56% had stage T2, 61% had lymphovascular invasion, 31% were negative estrogen receptor and 23% had histologic grade 3. LRR rates were 12.5% and 25% of patients in group A and group B, respectively (P < 0.05). The estimated 5-year disease free survival rates were 81% and 68% of patients in group A and group B, respectively (P > 0.05). The 5-year overall survival rates were 96% and 93% of patients in group A and group B, respectively (P > 0.05). Univariate analysis failed to show any impact of prognostic factors on local recurrence free survival, distant metastasis free survival or overall survival. Three patients in group A and one in group B developed grade-3 lymphodema. None of the patients have developed radiation pneumonitis, brachial plexopathy or cardiac events. Conclusion: In women with T1-T2 breast carcinoma and 1-3 positive lymph nodes with ECI, significantly lower LRR was observed with PMRT than without adjuvant radiotherapy. Further trials with larger number of patients and longer follow-up periods are needed to optimize loco-regional control and potentially improve survival in this group of patients, Key words: Breast cancer, Post-mastectomy radiotherapy, 1-3 positive nodes, Extracapsular invasion