PURPOSE S-1 is a standard postoperative adjuvant chemotherapy for patients with stage II or III gastric cancer in Asia. Neoadjuvant or perioperative strategies dominate in Western countries, and docetaxel has recently shown significant survival benefits when combined with other standard regimens in advanced cancer and perioperative settings. PATIENTS AND METHODS This randomized phase III study was designed to prove the superiority of postoperative S-1 plus docetaxel over S-1 alone for R0 resection of pathologic stage III gastric cancer. The sample size of 1,100 patients was necessary to detect a 7% increase in 3-year relapse-free survival as the primary end point (hazard ratio, 0.78; 2-sided α = .05; β = .2). RESULTS The second interim analysis was conducted when the number of events reached 216 among 915 enrolled patients (median follow-up, 12.5 months). Analysis demonstrated the superiority of S-1 plus docetaxel (66%) to S-1 (50%) for 3-year relapse-free survival (hazard ratio, 0.632; 99.99% CI, 0.400 to 0.998; stratified log-rank test, P < .001), and enrollment was terminated as recommended by the independent data and safety monitoring committee. Incidences of grade 3 or greater adverse events, particularly neutropenia and leukopenia, were higher in the S-1 plus docetaxel group, but all events were manageable. CONCLUSION Addition of docetaxel to S-1 is effective with few safety concerns in patients with stage III gastric cancer. The present findings may also be applicable in countries in which perioperative adjuvant chemotherapy or chemoradiation is not standard.
Background
Predictive factors of nivolumab treatment response in patients with gastric cancer (GC) remain unclear.
Methods
In this retrospective cohort study, tissue specimens of patients with unresectable or recurrent GC and prior or scheduled treatment with nivolumab as third-line or higher therapy between September 2017 and February 2019 were collected from 23 institutions. The tumour-positive score (TPS) and combined positive score (CPS) of PD-L1 expression and mismatch repair (MMR) were analysed by immunohistochemistry. Associations between clinicopathological factors and tumour-response rate, hyperprogressive disease (HPD) rate and survival were assessed.
Results
Of 200 eligible patients, 143 had measurable lesions. The response and HPD rates were 17.5% and 22.1%, respectively. The response rate was significantly higher in patients with performance status (PS) 0–1 (P = 0.026), non-peritoneal metastasis (P = 0.021), PD-L1 TPS ≥ 1 (P = 0.012), CPS ≥ 5 (P = 0.007) or ≥ 10 (P < 0.001) or MMR deficiency (P < 0.001). The HPD rate was significantly higher in patients with PS 2–3 (P = 0.026), liver metastasis (P < 0.001) and CPS < 10 (P = 0.048). Multivariate analysis revealed that CPS (P = 0.001) and MMR (P = 0.002) were independent prognostic factors of progression-free survival, as well as liver metastasis (P < 0.001), peritoneal metastasis (P = 0.004) and CRP (P < 0.001).
Conclusions
PD-L1 CPS and MMR could be useful biomarkers for nivolumab treatment efficacy in GC.
Clinical trial registration
UMIN000032164.
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