The Clinical Value of Chemotherapy Combined With Capecitabine in Triple-Negative Breast Cancer-A Meta-Analysis

Does the Dose of Standard Adjuvant Chemotherapy Affect the Triple-negative Breast Cancer Benefit from Extended Capecitabine Metronomic Therapy? An Exploratory Analysis of the SYSUCC-001 Trial

Purpose

Results from studies of extended capecitabine after the standard adjuvant chemotherapy in early stage triple-negative breast cancer (TNBC) were inconsistent, and only low-dose capecitabine from the SYSUCC-001 trial improved disease-free survival (DFS). Adjustment of the conventional adjuvant chemotherapy doses affect the prognosis and may affect the efficacy of subsequent treatments. This study investigated whether the survival benefit of the SYSUCC-001 trial was affected by dose adjustment of the standard adjuvant chemotherapy or not.

Patients and Methods

We reviewed the adjuvant chemotherapy regimens before the extended capecitabine in the SYSUCC-001 trial. Patients were classified into "consistent" (standard acceptable dose) and "inconsistent" (doses lower than acceptable dose) dose based on the minimum acceptable dose range in the landmark clinical trials. Cox proportional hazards model was used to investigate the impact of dose on the survival outcomes.

Results

All 434 patients in SYSUCC-001 trial were enrolled in this study. Most of patients administered the anthracycline-taxane regimen accounted for 88.94%. Among patients in the "inconsistent" dose, 60.8% and 47% received lower doses of anthracycline and taxane separately. In the observation group, the "inconsistent" dose of anthracycline and taxane did not affect DFS compared with the "consistent" dose. Moreover, in the capecitabine group, the "inconsistent" anthracycline dose did not affect DFS compared with the "consistent" dose. However, patients with "consistent" taxane doses benefited significantly from extended capecitabine (P=0.014). The sufficient dose of adjuvant taxane had a positive effect of extended capecitabine (hazard ratio [HR] 2.04; 95% confidence interval [CI] 1.02 to 4.06).

Conclusion

This study found the dose reduction of adjuvant taxane might negatively impact the efficacy of capecitabine. Therefore, the reduction of anthracycline dose over paclitaxel should be given priority during conventional adjuvant chemotherapy, if patients need dose reduction and plan for extended capecitabine.

Role and efficacy of capecitabine in the anthracycline-free regimen in breast cancer patients: a systematic review and meta-analysis

PURPOSE

Capecitabine has extensive utilization in the treatment of diverse solid tumors, and its efficacy has been substantiated. Its oral administration and minimal toxicity in clinical practice render it advantageous. Nevertheless, uncertainty remains regarding whether capecitabine can substitute anthracycline drugs in chemotherapy regimens to achieve a lower risk of anthracycline-induced degradation. Consequently, we conducted a meta-analysis of randomized controlled trials (RCTs) to assess the potential of capecitabine as a replacement for anthracycline drugs in chemotherapy regimens for breast cancer.

METHODS

We systematically searched PubMed, Embase, Web of Science, and the Cochrane Controlled Trials Register (CENTRAL) to retrieve eligible studies published before July 18, 2023. Two independent reviewers extracted relevant data from the included studies using a pre-established data extraction form. The primary endpoints of interest encompassed overall survival (OS) and progression-free survival (PFS) for postoperative adjuvant therapy, as well as pathological complete response (PCR) following neoadjuvant therapy. Adverse events were considered as secondary outcomes. The statistical analysis was performed using Revman 5.4.1.

RESULTS

A total of six studies involving 2348 breast cancer patients were deemed eligible according to the selection criteria. The pooled meta-analysis revealed that there were no statistically significant differences observed in the primary outcomes of overall survival (OS) (HR 1.06, 95% CI 0.88-1.28) and progression-free survival (PFS) (HR 1.10, 95% CI 0.90-1.34) across the four postoperative adjuvant chemotherapy trials, as well as in the two neoadjuvant chemotherapy trials with respect to the primary outcome of pathological complete response (PCR) (OR 1.65, 95% CI 0.93-2.95) when comparing regimens containing anthracycline drugs to those without. In terms of adverse events, the probability of experiencing diarrhea (OR 3.94, P = 0.004) and hand-foot syndrome (OR 10.89, P = 0.004) was significantly higher in the capecitabine group, attributable to the drug characteristics. Conversely, the likelihood of developing neutropenia (OR 0.50, P = 0.03) was higher in the anthracycline group.

CONCLUSIONS

According to the current evidence, there was no statistically significant difference in the primary outcomes when capecitabine was substituted for anthracycline drugs. Thus, capecitabine can be regarded as a feasible alternative in the subset of patients who necessitate the exclusion of anthracyclines.