What question did this study set out to answer?

The aim is to identify factors influencing relative dose intensity of capecitabine in triple negative breast cancer patients post-neoadjuvant treatment.

April 5, 2026

Abstract 6645: Practice patterns impacting relative dose intensity of adjuvant capecitabine among triple negative breast cancer patients with residual disease following neoadjuvant chemotherapy.

Key Points

The aim is to identify factors influencing relative dose intensity of capecitabine in triple negative breast cancer patients post-neoadjuvant treatment.
Retrospective analysis of patients with triple negative breast cancer from 2016 to 2023.
Inclusion of patients with residual disease receiving adjuvant capecitabine.
Assessment of factors like prescribing schedule, tumor characteristics, and previous treatments.
45 patients had RDI≤66% while only 9 patients reached RDI≥92%.
A 7-day prescribing schedule significantly reduced the ability to achieve RDI >66% (p=0.0234).
No significant differences were found in invasive disease-free survival (iDFS) or overall survival (OS) based on RDI percentiles, but higher RDI groups showed trends towards improved outcomes.

Abstract

Abstract Background: This study aims to identify real-world practice pattern factors in capecitabine prescribing and assess which factors lead to higher relative dose intensity (RDI) to help address the variability in dosing strategies that limits the ability to assess the real-world effectiveness of adjuvant capecitabine. Methods: This institutional retrospective study involved patients diagnosed with triple negative breast cancer from 1/1/2016 to 12/31/2023 who had residual disease following neoadjuvant chemotherapy and received ≥1 dose of adjuvant capecitabine. Our objective was to examine factors that influence the achievement of an RDI 66%, with standard dosing based on a total of 8 cycles of capecitabine over 21-day cycles. Factors included radiation therapy, dose reductions, prescribing schedule, age, race, tumor grade, nodal status, tumor size, residual cancer burden, lymphovascular invasion, and neoadjuvant pembrolizumab 67-92, 66% (p=0.0234). When examining univariate iDFS, no statistically significant difference was noted between RDI percentiles (p=0.667) but a trend towards improved iDFS was noted among higher RDI groups. The 5-year iDFS was 78.4% for RDI≤66, 77.9% for RDI67-92, 93-100. Similarly for OS, no statistically significant difference was noted between RDI percentiles (p=0.395), but a trend towards improved OS was noted when RDI exceeded 66%. The 5-year OS was 82.1% for RDI≤66, 92.7% for RDI67-92, 92-100. Conclusion: Real world practice patterns can differ, but the implementation of weekly capecitabine dosing frequency has been shown in this study to significantly influence the ability to achieve higher RDI values. While no statistical difference in iDFS or OS was noted, a trend towards worsening outcomes was recorded for those with an RDI≤66%. Citation Format: Andrea House, Pratik Thakur, Blair Hoeting, Ruth Johnson, Brittany Sandoval, Julie Stephens, Daniel G. Stover, Sagar Sardesai, Tanun Jitwatcharakomol, Sasha Beyer, Arya M. Roy, Nerea Lopetegui-Lia, Dionisia M. Quiroga, Ashley P. Davenport, Gilbert Bader, Nicole O. Williams, Robert Wesolowski, Margaret E. Gatti-Mays, Kai C. Johnson, . Practice patterns impacting relative dose intensity of adjuvant capecitabine among triple negative breast cancer patients with residual disease following neoadjuvant chemotherapy abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6645.

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