Concurrent chemo-radiotherapy following neoadjuvant chemotherapy in locally advanced breast cancer

BACKGROUND Despite broad advances in multimodal treatment of locally advanced breast cancer (LABC), 30 to 40% of patients develop loco-regional relapse. The aim of this study was to analyze in a retrospective manner the effectiveness of concurrent chemo-radiotherapy (CCRTh) after neoadjuvant chemotherapy (NCT) in patients with LABC. METHODS One hundred twelve patients with LABC (stage IIB-IIIB) were treated with NCT (5-fluorouracil 500 mg/m2, doxorubicin 50 mg/m2, and cyclophosphamide 500 mg/m2 (FAC), or doxorubicin 50 mg/m2 and cyclophosphamide 500 mg/m2 (AC) IV in four 21-day courses) followed by CCRTh (60 Gy breast irradiation and weekly mitomycin 5 mg/m2, 5-fluorouracil 500 mg/m2, and dexamethasone 16 mg, or cisplatin 30 mg/m2, gemcitabine 100 mg/m2 and dexamethasone 16 mg), and 6-8 weeks later, surgery and two additional courses of FAC, AC, or paclitaxel 90 mg/m2 weekly for 12 weeks, and in case of estrogen-receptor positive patients, hormonal therapy. RESULTS Stages IIB, IIIA and -B were 21.4, 42.9, and 35.7%, respectively. Pathological complete response (pCR) in the breast was 42% (95% CI, 33.2-50.5%) and, 29.5% (95% CI, 21.4-37.5%) if including both the breast and the axillary nodes. Multivariate analysis showed that the main determinant of pCR was negative estrogen-receptor status (HR=3.8; 95% CI, 1.5-9; p=0.016). The 5-year disease-free survival (DFS) was 76.9% (95% CI, 68.2-84.7%). No relationship between pCR and DFS was found. Multivariate analysis demonstrated that the main DFS determinant was clinical stage (IIB and IIIA vs. IIIB, HR=3.1; 95% CI, 1.02-9.74; p=0.04). Only one patient had local recurrence. Five-year overall survival was 84.2% (95% CI, 75-93.2%). The toxicity profile was acceptable. CONCLUSION This non-conventional multimodal treatment has good loco-regional control for LABC. Randomized clinical trials of preoperative CCRTh following chemotherapy, in patients with LABC are warranted.