Real-world data on adjuvant capecitabine after standard neoadjuvant chemotherapy for triple negative breast cancer.

Objective: Neoadjuvant chemotherapy (NACT) has become the standard of care for patients with triple-negative breast cancer (TNBC) with tumors > 1 cm or positive axillary nodes. Pathologic complete response (pCR) has been used as an endpoint to select patients for treatment scaling. This study aimed to examine the benefit of adding adjuvant capecitabine for TNBC patients who did not achieve pCR after standard NACT in a real-world scenario.

Methods: This retrospective cohort study included all patients with TNBC who underwent NACT between 2010 and 2020. Clinicopathological data were obtained from the patient records. Univariate and multivariate analyses were conducted at the 5 years follow-up period.

Results: We included 153 patients, more than half of whom had stage III (58.2%) and high-grade tumors (60.8%). The overall pCR rate was 34.6%, and 41% of the patients with residual disease received adjuvant capecitabine. Disease-specific survival (DSS) among the patients who achieved pCR was significantly higher (p<0.0001). Residual disease after NACT was associated with detrimental effects on DSS. In this cohort, we did not observe any survival benefit of adding adjuvant capecitabine for patients with TNBC subjected to NACT who did not achieve pCR (p=0.52).

Conclusion: Our study failed to demonstrate a survival benefit of extended capecitabine therapy in patients with TNBC with residual disease after NACT. More studies are warranted to better understand the indication of systemic treatment escalation in this scenario.