Neoadjuvant chemotherapy in older patients with gastric cancer undergoing surgery: a population-based cohort study

Background: In trials evaluating perioperative chemotherapy for gastric cancer, which serve as the basis for treatment guidelines, patients are selected. The generalizability of these trial findings to older patients is uncertain. Methods: This population-based retrospective cohort study compared the survival outcomes of patients ≥ 75 years with gastric adenocarcinoma treated with or without neoadjuvant chemotherapy between 2015 and 2019. Additionally, the percentage of patients < 75 years and ≥ 75 years who did not proceeded to surgery after receiving neoadjuvant chemotherapy were examined. Results: A total of 1995 patients, of whom 1249 aged < 75 years and 746 aged ≥ 75 years, were included. In the group of patients ≥ 75 years, 275 patients received neoadjuvant chemotherapy and 471 patients were directly scheduled for gastrectomy. Patients ≥ 75 years treated with or without neoadjuvant chemotherapy differed significantly from one and another in characteristics. Overall survival of patients ≥ 75 years treated with or without neoadjuvant chemotherapy was not significantly different (median 34.9 vs. 32.3 months; P = 0.506), also after adjusting for potential confounders (HR 0.87; P = 0.263). Of patients ≥ 75 years who received neoadjuvant chemotherapy, 43 (15.6%) did not proceed to surgery compared to 111 (8.9%) patients < 75 years (P < 0.001). Conclusion: Patients ≥ 75 years treated with or without chemotherapy were highly selected, and overall survival was not significantly different between both groups. Nonetheless, the proportion of patients who did not proceed to surgery following neoadjuvant chemotherapy was higher in patients ≥ 75 years compared to patients < 75 years. Therefore, neoadjuvant chemotherapy should be considered with more caution in patients ≥ 75 years, while identifying those who may benefit.