MINIMALLY INVASIVE SURGERY FOR GASTRIC ADENOCARCINOMA IS ASSOCIATED WITH BETTER SHORT-TERM OUTCOMES WITHOUT COMPROMISE IN LONG TERM AND ONCOLOGICAL OUTCOMES

Introduction: Utilization of minimally invasive surgery (MIS) for gastric adenocarcinoma has increased consistently. This study investigates the impact of perioperative outcomes on receiving adjuvant chemotherapy and MIS versus open gastrectomy in gastric adenocarcinoma.

Patient and methods: National cancer database (NCDB) 2020 was used as the data source. Patients who underwent curative-intent surgery for gastric adenocarcinoma were included. Selection criteria were known stage, size, comorbidities, grade, lymphovascular invasion, type of surgery, approach, conversion information, margin status, neoadjuvant and adjuvant treatment, hospital stay, readmission, 30-day and 90-day mortality, complete follow-up, type of institution, and hospital gastric surgery case volume. Only patients with complete data were included. Binary logistic regression was used for 30- and 90-day mortality, readmission, and margin status. Linear regression models were used for hospital stay and lymph node yield. Kaplan-Meier survival analysis and Cox regression models were used to identify the impact of MIS surgery on survival.

Results: 23765 patients met the criteria with complete data; 39.6% were female. 28.3% underwent MIS, and 71.7% underwent open gastrectomy. Median hospital stay was 8 days for MIS and 9 days for open gastrectomy groups. Linear regression model was significant favoring MIS (beta -0.207, p<0.001). 30-day mortality was 2.3% MIS and 3.5% open (OR 0.325, p=0.041), 90-day mortality was 5.1% MIS and 7.2% open (OR 0.478 p=0.036). R1 margin rate was 9.9% MIS and 12.9% open (p=<0.001), Lymph node yield was 16 for MIS, and 17 open (p=0.83) Unplanned readmission rate was 6.1% MIS and 7.1% open (p=0.02). Rate of receiving adjuvant chemotherapy were 31.2% for MIS and 29.3% for open (p=0.031), time to AC was 51 days vs 53 days (p=0.872). Cox regression models showed no difference in survival between MIS and open approaches (p=0.25, HR 0.82).

Conclusion: This retrospective analysis shows that MIS approach for adenocarcinoma is feasible. MIS approach is associated with shorter hospital stay, less readmissions, possibly better 30- and 90-day mortality rates, similar margin status, and no compromise in long-term oncological outcomes. Ultimately, to conclusively show the impact of MIS on these tumors, randomized control trials are needed.