Survival Analysis of Elderly Patients Over 65 Years Old With Stage Ii/iii Gastric Cancer Treated With Adjuvant Chemotherapy After Laparoscopic D2 Gastrectomy: a Retrospective Cohort Study

Background: The benefits of adjuvant chemotherapy for elderly patients (age >65) with gastric cancer (GC) remain unknown because elderly patients are underrepresented in most clinical trials. To evaluate the effectiveness and complications of adjuvant chemotherapy in elderly patients (>65 years of age) after laparoscopic D2 gastrectomy. Methods: This was a retrospective cohort study of elderly patients (>65 years) with stage II/III GC who underwent curative laparoscopic D2 gastrectomy between 2004 and 2018. The patients were divided as surgery alone and surgery plus adjuvant chemotherapy (chemo group). The overall survival (OS), disease-free survival (DFS), circulating tumor cells (CTCs), chemotherapy duration, and toxicity were examined. Results: There were 270 patients included: 169 and 101 in the surgery and chemo groups, respectively. There were ten (10/101) and six (6/101) patients with grade 3+ non-hematological and hematological adverse events. The 1-/3-/5-year OS rates of the surgery group were 72.9%/51.8%/48.3%, compared with 90.1%/66.4%/48.6% for the chemo group (log-rank test: P=0.018). For stage III patients, the 1-/3-/5-year OS rates of the surgery group were 83.7%/40.7%/28.7%, compared with 89.9%/61.2%/43.6% for the chemo group (log-rank test: P=0.015). Adjuvant chemotherapy was significantly associated with higher OS (HR=0.568, 95%CI: 0.357-0.903, P=0.017) and DFS (HR=0.511, 95%CI: 0.322-0.811, P=0.004) in stage III patients. CTC >0 had no significant impact on the benefits of adjuvant chemotherapy on OS and DFS. Conclusions: This study suggested that adjuvant chemotherapy significantly improves OS and DFS for elderly patients with stage III GC after D2 laparoscopic gastrectomy, with a tolerable adverse event profile.