Alaina J. Kessler, MD, MPH1; Natalie S. Berger, MD1; Lauren K. Margetich, MD1; Erin L. Moshier, MS2; and Paula Klein, MD1,2
1Icahn School of Medicine at Mount Sinai, New York, NY.
2The Mount Sinai Hospital, New York, NY.
Capecitabine has been shown to prolong overall survival in patients with triple-negative breast cancer (TNBC) with residual disease after neoadjuvant chemotherapy based on the CREATE-X study (UMIN000000843). The starting dose of capecitabine in CREATE-X was 1250 mg/m2 twice per day on days 1 through 14 every 3 weeks. Fluoropyrimidine toxicity is higher in the United States compared with East Asia. The goal of this study was to evaluate the tolerance of capecitabine at a US urban clinic treating predominantly non-Asian patients.
Materials and Methods
We performed a retrospective chart review of patients with TNBC with residual disease from June 1, 2017, to June 1, 2020. Distributions of categorical variables were compared between capecitabine dosing groups using the χ2/Fisher’s exact test, as appropriate. All statistical analyses were conducted using SAS version 9.4 (SAS Institute).
A total of 32 patients who met criteria were included (average [SD] age, 52.5 [9.6] years). Eight patients (25%) were Hispanic/Latinx, 11 (34.4%) were White, 10 (31.3%) were African American, and 2 (6.3%) were Asian. At diagnosis, 4 patients (12.5%) had clinical stage I disease, 16 (50.0%) had stage II disease, and 12 (37.5%) had stage III disease. Of the 16 patients (50.0%) prescribed capecitabine 1250 mg/m2, 5 patients (31.3%) completed 8 cycles, all requiring dose reductions. Of the 283 patients in the CREATE-X study treated with this dose, 37.8% completed capecitabine treatment with the planned dose compared with 0% of patients in our cohort; 36.7% completed treatment with dose reduction compared with 31.3% in our cohort; and 25.4% discontinued treatment compared with 25.0% in our cohort. Of the 14 patients (43.8%) in our cohort prescribed the US standard dosing of 1000 mg/m2, 4 patients (28.6%) completed 8 cycles with 1 patient requiring dose reductions. Four of the 14 patients (28.6%) discontinued capecitabine due to intolerance. The most common adverse events were hand-foot syndrome (62.5%), nausea (46.9%), and diarrhea (34.4%).
When compared with the study population in CREATE-X, no patients in our cohort tolerated 8 cycles of capecitabine 1250 mg/m2 whereas 3 of 4 (75%) patients tolerated 8 cycles of capecitabine at 1000 mg/m2. This treatment dose was not studied in CREATE-X. Trials in metastatic disease comparing these 2 doses demonstrated similar efficacy with less toxicity. Further studies are warranted in this curative-intent population.