(PM P36) Should Ascites be a Contraindication to Laparoscopic HIPEC in Gastric Cancer?

Introduction: Laparoscopic hyperthermic intraperitoneal chemotherapy (LS-HIPEC) is safe in patients with gastric adenocarcinoma, but has shown limited success in improving overall survival. Thus, we examined factors associated with improved survival and resection.

Methods: Prospectively collected data for all patients undergoing LS-HIPEC between June 2014 and November 2018 was analyzed for associations with survival and resection using uni- and multivariate logistic regression, Cox proportional hazards models, and Kaplan-Meier survival functions.

Results: Seventy-one patients underwent LS-HIPEC procedures for stage IV gastric adenocarcinoma. 43(61%) received a 2-drug protocol with mitomycin C and cisplatin, while 27(39%) were treated with 3 drugs: mitomycin C, cisplatin, and paclitaxel. There were no statistically significant demographic or oncologic differences between groups. The 3-drug group had lower radiation therapy use (58%vs15%,p<0.01). On univariate analysis, high histologic grade (Cox hazard ratio [HR],2.68,p<0.01), gross carcinomatosis (HR,2.34,p=0.03), and ascites (HR,3.55,p<0.01) were associated with shorter median survival. Gastrectomy was associated with improved overall survival (HR,0.32,p<0.01). On multivariate analysis of all significant univariate factors, only ascites was associated with worse overall survival (HR,3.17];p<0.01). 17(38%) patients without ascites went on to resection, while no patients with ascites were able to proceed to resection (p<0.01).

Conclusion: We did not demonstrate a benefit for 3-drug LS-HIPEC over the 2-drug regimen on short-term follow-up. The presence of ascites is a newly described prognostic factor. Given the high rate of ascites upon initial laparoscopy, we hope this will assist in identifying patients unlikely to proceed to resection and are good candidates for novel therapeutic approaches or clinical trials.