Evaluation of the Role of Postmastectomy Radiotherapy in Women with One to Three Positive Auxillary Nodes with Extracapsular Invasion

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 2010 and December 2015, 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 less than 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 less than 0.05). The estimated 5-year disease free survival rates were 81 % and 68 % of patients in group A and group B, respectively (P greater than 0.05). The 5-year overall survival rates were 96 % and 93 % of patients in group A and group B, respectively (P greater than 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 lymphedema. 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 a 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.