Is the benefit of using adjuvant capecitabine in patients with residual triple-negative breast cancer related to pathological response to neoadjuvant chemotherapy?

Abstract

Background Triple-negative-breast-cancer (TNBC) has a poor prognosis if pathologic complete response (pCR) cannot be achieved after receiving neoadjuvant chemotherapy (NAC). The group of patients that benefit most from adjuvant capecitabine remains unclear. Materials and Methods We collected data from 218 consecutive patients who had previously received NAC and operated for TNBC from eight cancer centers. Data of 160 patients without PCR was included in the statistical analysis. Pathologic response to NAC was defined into two groups as having good-pathologic response (MillerPayneGrading (MPG) IV-III) or poor-pathologic response (MPG I-II). The histopathological characteristics of patients were compared in regard to adjuvant capecitabine usage. Results Univariate-analysis revealed that age, histological subtype, clinical stage, size of tumor, number of lymph-nodes, menopausal status, pathological T and N stage, were significantly different between two groups. In multivariate-analysis, menopausal status (p=0.043) and residual tumor size (p<0.001) were found to be independent prognostic factors for pathological response. The hazard ratio for disease recurrence and death in the poor responsive group with adjuvant capecitabin was 2.94 (95% confidence interval (CI), 1.21 to 7.10; p=0.016) and 4.080 (95% CI, 1.22 to 13.64; p=0.022) respectively. DFS (p=0.58) and OS (p=0.89) improvements with adjuvant capecitabine were not demonstrated in good response groups. Conclusion This multicenter study suggested that only the poor responsive group to NAC achieved benefit from adjuvant capecitabine. Postmenopausal status and residual tumor size were related to poor prognosis.