Treatment burden of robotic gastrectomy for locally advanced gastric cancer (LAGC): a single western experience

Background This study compares standard of care (SOC) open and robotic D2-gastrectomy for locally advanced gastric cancer (LAGC) in the Western context of low disease prevalence, reduced surgical volume, and neoadjuvant chemotherapy (NAC). We hypothesized that robotic gastrectomy (RG) after NAC reduces treatment burden for LAGC across multiple outcome domains vs. SOC. Methods Single institution, interrupted time series comparing SOC (2008-2013) for LAGC (T2-4Nany/TanyN+) vs. NAC + RG (2013-2018). Treatment burden was a composite metric of narcotic consumption, oncologic efficacy, cumulative morbidity, and 90-day resource utilization. Predictors were evaluated via multivariate modeling. Learning curve analysis was done using CUSUM. Results After exclusions, 87 subjects with equivalent baseline characteristics, aside from male sex, were treated via SOC (n=55) or NAC + RG (n=32). All four domains of treatment burden were significantly reduced in the NAC + RG cohort compared to SOC (P=0.003). The odds ratio for excess treatment burden in the NAC/RG was 0.23 (95% CI: 0.07-0.72, P=0.0117) vs. SOC upon multivariable modeling, whereas the extent of resection (total/subtotal), tumor size, T-stage, sex, and early learning curve had no effect. Differences in treatment burden persisted in subgroup analysis for NAC (n=51). Conclusions NAC + RG was associated with decreased treatment burden relative to SOC for LAGC. Frequencies of unfavorable hospitalization, adverse oncological outcomes, major morbidity, and narcotic consumption all decreased in this interrupted time series.