Clinical outcomes of first-line nivolumab plus chemotherapy in patients aged ≥ 75 years with unresectable advanced or recurrent gastric cancer: a retrospective study

Abstract Background Older patients with unresectable advanced or recurrent gastric cancer remain underrepresented in clinical trials of immune checkpoint inhibitors. This study assessed the clinical feasibility of first-line nivolumab plus chemotherapy in patients aged ≥ 75 years treated at our institutions. Methods This retrospective study included 82 patients with HER2-negative unresectable advanced or recurrent gastric cancer who received first-line nivolumab-containing chemotherapy between January 2022 and February 2025. Patients were divided into two groups: those aged < 75 years ( n = 52) and those aged ≥ 75 years ( n = 30). The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and adverse events (AEs). Results Patients aged ≥ 75 years more frequently had comorbidities, hypertension, and initial dose reductions. Median follow-up was 27.7 months in the < 75 years group and 24.3 months in the ≥ 75 years group. Median PFS was 7.2 months in the < 75 years group and 5.6 months in the ≥ 75 years group ( P = 0.779). Median OS was 12.5 and 13.3 months, respectively ( P = 0.852). No significant differences were observed in ORR, DCR, or AEs between the two groups. Conclusions These findings suggest that first-line nivolumab plus chemotherapy may represent a clinically feasible treatment option for selected patients aged ≥ 75 years with HER2-negative, unresectable, advanced or recurrent gastric cancer. Nevertheless, given the limited sample size, these results should be interpreted with caution and should not be construed as evidence of equivalent efficacy or safety between age groups.