268P - Evaluating the efficacy of adjuvant capecitabine in triple-negative breast cancer patients with residual disease: A real-world evidence study

Background

In early breast cancer, residual disease after neoadjuvant chemotherapy is considered an important prognostic factor, especially for triple-negative breast cancer (TNBC) and HER2-positive patients. The CREATE-X study demonstrated a survival benefit of adjuvant capecitabine (adjC) for these patient groups, particularly in TNBC. Researchers have been trying to find the appropriate population for adjC as Real-World Evidence (RWE). However, RWE in the Asian population was lacking, and previous RWE studies were limited in number. In addition, these studies did not include patients who received neoadjuvant immunotherapy treatment, while the Keynote-522 trial demonstrated the benefit of immunotherapy in early TNBC. Therefore, we evaluated the advantages of adjC in non-pCR TNBC patient group by using RWD.

Methods

We conducted a retrospective analysis of 1,033 TNBC patients who received neoadjuvant treatment at Samsung Medical Center between 2018 and 2023, using de-identified, anonymous data from the institutional Clinical Data Warehouse. Among these patients, we identified 403 patients who received at least one cycle of adjC, while 36 received no adjuvant treatment. Residual Cancer Burden (RCB) classification were available for 399 patients. The primary outcome of the study was Disease-Free Survival (DFS). We conducted a survival analysis using Kaplan-Meier method.

Results

The median DFS has not yet been reached. The disease risk of the adjC group tended to be lower than that of the no adjuvant treatment group, but the difference was not statistically significant (Hazard ratio(HR), 0.52; p-value=0.083). At 36 months, 86% of patients in the adjC group were disease-free or alive, compared to 76% of patients in the no adjuvant treatment group. Compared to the RCB-I group (n=114, 28.4%), the HR for the RCB-II group (n=233, 58.5%) was 1.40, and the for the RCB-III group (n=52, 13.1%), it was 5.88 (p<0.0001). The DFS at 36 months was 90%, 89%, and 67% for the RCB-I, II, and III groups, respectively.

Conclusions

In this study, adjC demonstrated a potential survival benefit for non-pCR TNBC patients. Subgroup analysis based on RCB classification indicated a higher risk associated with higher RCB class.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

This study was supported by Future Medicine 2030 Project of the Samsung Medical Center [SMO1230451].

Disclosure

M.J. Kim: Financial Interests, Personal, Full or part-time Employment: Roche Korea. Y.H. Park: Financial Interests, Personal, Advisory Board: AstraZeneca, Pfizer, Roche, Novartis, MSD, Daiichi Sankyo; Financial Interests, Personal, Invited Speaker: AstraZeneca, Pfizer, Roche, Novartis, MSD; Financial Interests, Institutional, Other, Research Grant: AstraZeneca, Pfizer, Roche, MSD; Non-Financial Interests, Principal Investigator: AstraZeneca, Pfizer, Novartis, MSD, Lilly, Roche, Daiichi Sankyo. All other authors have declared no conflicts of interest.