Real-world effectiveness and safety of adjuvant capecitabine in triple-negative breast cancer (TNBC) patients with residual disease following neoadjuvant chemotherapy.

543 Background: The presence of residual disease in triple-negative breast cancer (TNBC) after neoadjuvant chemotherapy is associated with high recurrence risk and poor prognosis. The CREAT-X study demonstrated improved recurrence risk and survival outcomes with adjuvant capecitabine in this population [1]. We previously reported long-term outcomes in nonmetastatic TNBC, but the population is unselected, and the impact of adjuvant capecitabine is not assessed in the Indian scenario [2]. Methods: This single-center retrospective study included TNBC patients with residual disease after neoadjuvant chemotherapy treated between January 2020 and December 2024 with adjuvant capecitabine. Baseline clinicopathological characteristics were analyzed descriptively. Survival outcomes were assessed using the Kaplan–Meier method, and recurrence-free survival (RFS) and overall survival (OS) were estimated. Factors associated with survival outcomes were evaluated using univariate and multivariate Cox proportional hazards regression models. Results: Among 1548 patients diagnosed with Stage I-III TNBC, 1044 patients treated with neoadjuvant therapy underwent surgery; 671 patients had residual disease, out of which 315 patients who received adjuvant capecitabine were included in this retrospective analysis. The majority were premenopausal (66.3%), were older than 40 years (59.7%), and had stage III residual disease (71.4%). At a median follow-up of 25 months, the 2-year overall survival (OS) was 79.6%, with a median OS of 49.7 months. The 2-year recurrence-free survival (PFS) was 49.3%, with a median RFS of 23.9 months. On univariate analysis, higher nodal status (P < 0.001) and advanced stage (P < 0.05) were significantly associated with inferior RFS, while higher nodal status was also associated with inferior OS (P < 0.05). Multivariate analysis confirmed nodal status as an independent predictor of poor survival (P < 0.01). Conclusions: Adjuvant capecitabine demonstrated poor outcomes in our TNBC patients with residual disease compared to the randomized study; nodal status independently predicted poorer outcomes, emphasizing risk stratification and prospective validation. References: Toi M, Lee SJ, Lee ES, Ohtani S, Im YH, Im SA, Park BW, Kim SB, Yanagita Y, Takao S, Ohno S. Abstract S1-07: a phase III trial of adjuvant capecitabine in breast cancer patients with HER2-negative pathologic residual invasive disease after neoadjuvant chemotherapy (CREATE-X, JBCRG-04). Cancer Research. 2016 Feb 15; 76(4_Supplement): S1-07. Bajpai J, Kashyap L, Vallathol DH, Das A, Singh M, Pathak R, Rath S, Sekar A, Mohanta S, Reddy A, Joshi S. Outcomes of non-metastatic triple negative breast cancers: Real-world data from a large Indian cohort. The Breast. 2022 Jun 1;63:77-84. Clinical trial information: CTRI/2026/01/101798 .