Lower tolerated dose of adjuvant capecitabine seen in several TNBC patients

Many patients with triple-negative breast cancer (TNBC) have a lower tolerated dose of capecitabine relative to the recommended adjuvant dose, a study has shown.

In the CREATE-X trial, adjuvant capecitabine was found effective in improving survival in high-risk TNBC patients. However, the recommended dose is generally not well tolerated by the US population, according to the researchers.

This single-centre retrospective study was performed to analyse dosing patterns in an ethnically diverse cohort to better characterize tolerability and inform future dosing guidelines. The researchers assessed the safety and tolerability of adjuvant capecitabine treatment in TNBC patients.

Relative dose intensity (RDI) across eight cycles, the primary endpoint, was investigated along with subgroup analyses based on age, race, BMI, and initial dose. Capecitabine-related side effects and survival were the secondary endpoints.

Sixty-seven patients who completed adjuvant capecitabine at the University of Chicago Medicine (UCM) between January 2017 and November 2022 met the eligibility criteria. The mean RDI across eight treatment cycles was 60.2 percent (95 percent confidence interval, 0.554‒0.650).

The RDI of TNBC patients was significantly lower than those in the CREATE-X trial (0.602 vs 0.787; p<0.001). No statistically significant difference was observed in average RDI across eight cycles for patients stratified by age, race, BMI, or initial starting dose.

In terms of safety, the most common adverse event was hand-foot syndrome (73 percent), followed by diarrhoea (27 percent) and fatigue (22 percent). This safety profile supported that found in prior studies.

“Acknowledging the limitations of our single-centre analysis, RDI was not significantly affected by age, race, BMI, or initial starting dose,” the researchers said.