Disscussion and analysis of the effect of adjuvant radiotherapy after neoadjuvant chemotherapy for stage T1-2N1M0 breast cancer

Abstract

Objective To evaluate the effects and significance of adjuvant radiotherapy after neoadjuvant chemotherapy on local recurrence (LR) rate in patients with stage T1-2N1M0 breast cancer. Methods Clinical data were collected from patients with stage T1-2N1M0 breast cancer who were admitted to our hospital and treated with neoadjuvant chemotherapy from 2005 to 2010. The clinical outcomes in those patients were analyzed after treatment with adjuvant radiotherapy. A total of 144 patients with a median age of 45 years (23-72 years) were enrolled as subjects. Results In the 144 patients, 30 patients (21%) who had pathological complete response (pCR) in primary breast tumor and axillary lymph node received adjuvant radiotherapy; 10 out of 45 patients who had pCR in axillary lymph node alone did not receive adjuvant radiotherapy; 6 out of 69 patients who still had axillary lymph node metastasis after treatment did not receive adjuvant radiotherapy; all of the rest received adjuvant radiotherapy. In all patients, the median follow-up time was 88 months; 46 patients (32%) had relapse and metastasis. The 5-year LR rate was 3.0% in patients with pCR. In patients with pCR in axillary lymph node metastasis after neoadjuvant chemotherapy, there was no significant difference in the 5-year LR rate between patients treated with and without radiotherapy (7% vs. 16%, P=0.181). In patients with axillary lymph node metastasis after neoadjuvant chemotherapy, there was also no significant difference in the 5-year LR rate between patients treated with and without radiotherapy (15.9% vs. 33.3%, P=0.267). In all patients, those with pCR had significantly longer disease-free survival (DFS) time than those without pCR (P=0.017). Conclusions Patients with pCR to neoadjuvant chemotherapy have longer DFS time than those without pCR. The LR rate is relatively lower in patients with pCR undergoing adjuvant radiotherapy. Patients with pCR in axillary lymph node metastasis do not benefit from postoperative adjuvant radiotherapy. However, adjuvant radiotherapy is helpful in patients with axillary lymph metastasis after neoadjuvant chemotherapy who have high LR rates Key words: Breast neoplasms/neoadjuvant chemotherapy; Pathological complete response; Breast neoplasms/adjuvant radiotherapy