Clinical analysis of chemoradiation sequence for early breast cancer patients with conserving surgery

Abstract

Objective To investigate the prognostic factors affecting early breast cancer patients with conserving surgery and discuss the influences of chemoradiation sequence on treatment efficacy. Methods We retrospectively analyzed 191 cases of early breast cancer after breast conservation surgery in the second hospital of Dalian medical university, from January 1, 2006 to December 31, 2015. According to the treatment order, they were divided into radiotherapy group, chemotherapy group and sandwich group. There were 32 patients in the radiotherapy group, 107 patients in the chemotherapy group, and 52 patients in the sandwich group. The sandwich group was treated with chemotherapy-radiotherapy-chemotherapy. The factors were analyzed independently from the patients' age, menopausal status, pathology type, tumor size (T1, T2), axillary lymph node, molecular type of breast cancer, the interval between surgery and radiation, vascular tumor emboli. Regression model was used to find the risk factors of early stage breast cancer patients with conserving surgery. The 5-year LRR and 5-year OS was compared among radiotherapy-first group, chemotherapy-first group, the sandwich group in patients with high risk factors, and the factors associated with the prognosis of patients were analysed. Results The Multivariate Cox Regression model showed that tumor size, axillary lymph node, vascular tumor emboli, the interval between surgery and radiation were independent risk factors associated with 5-year OS. Among patients with T1 and T2 stage in radiotherapy-first group, chemotherapy-first group, sandwich group, there was no statistical difference in 5-year LRR or 5-year OS (P>0.05). Among patients with N0 stage in radiotherapy first group, chemotherapy first group, sandwich group, 5-year LRR were not statistically different (P>0.05). For patients with N1 stage in chemotherapy-first group and the sandwich group 5-year LRR were with statistical difference(χ2=4.813, P=0.028). OS were without statistical difference (P>0.05). In patients with vascular tumor emboli in radiotherapy-first group, chemotherapy-first group, the sandwich group, 5-year LRR were without statistical difference (5.3%, 9.2%, vs. 18.1%, P>0.05), OS were statistically different (61.5%, 90.1% vs. 87.2%, χ2=6.282, P=0.043). For patients without vascular tumor emboli, there was no statistical difference in 5-year LRR (P>0.05). For patients started radiation within 6 months after surgery in radiotherapy-first group, chemotherapy-first group, the sandwich group, 5-year LRR were without statistical difference (P>0.05). However, patients in chemotherapy-first group the time interval surgery and radiation ≤6 months vs. >6 months 5-year LRR was 5.2% and 14.1% (χ2=4.886, P=0.027), 5-year OS were 96.9% and 85.7% (χ2=5.758, P=0.038). Conclusions Clinical treatment is based on individualized options. For patients with negative axillary lymph nodes, but high risk factors for local recurrence, radiotherapy may be performed firstly. For high-risk patients with axillary lymph node metastasis or vascular tumor embolus, chemotherapy should be started early and radiotherapy may be followed, but not more than 6 months. Key words: Early breast cancer breast; Conservation surgery; Sequence of radiotherapy and chemotherapy