BACKGROUND: Trastuzumab-based chemotherapy is the standard first-line treatment for patients with HER2-positive advanced or metastatic gastric cancer (GC). However, evidence on real-world outcomes according to the chemotherapy backbone remains limited. METHODS: A total of 2,399 patients with GC treated with trastuzumab-based chemotherapy were analyzed, 486 patients were treated with trastuzumab/5-fluorouracil/cisplatin (HFP) and 1,913 patients were treated with trastuzumab/capecitabine/cisplatin (HXP). Time to subsequent treatment (TST) and overall survival (OS) were analyzed according to the type of chemotherapy backbone. RESULTS: With a median follow-up of 10.5 months, the median TST was 6.08 months 95% confidence interval (CI) 5.65-6.60 in the HFP group and 8.02 months (95% CI 7.72-8.57) in the HXP group (p < 0.0001). The median OS was 9.89 months (95% CI 8.94-10.87) for the HFP group and 13.27 months (95% CI 12.75-14.00) for the HXP group (p < 0.0001). Specifically, HXP followed by trastuzumab and capecitabine maintenance (HXP-HX) demonstrated the best outcomes with median TST of 13.44 months (95% CI 12.52-15.61) and median OS of 22.18 months (95% CI 20.83-24.44) compared with HXP followed by trastuzumab maintenance (HXP-H) and HXP alone (both p < 0.0001), which were also significant in multivariable analysis. CONCLUSIONS: HXP-HX showed the best survival outcomes for patients with locally advanced unresectable, or metastatic HER2-positive GC based on real-world big data analysis of the ToGA regimen, suggesting that HXP-HX is recommended over HXP-H. In the current immunotherapy era for HER2-positive GC, the potential role of capecitabine maintenance as part of combination strategies should be interpreted cautiously and warrants further investigation.
Kim et al. (Fri,) studied this question.