P79: Impact of Tumor Size and Management on Survival in Gastric GIST

Thursday, March 23, 2023

9:41 AM – 9:46 AM

Location: SSO HUB Pan-Tumor Zone: CRS, HPB, Pan-Tumor & Upper GI

Poster Presenter(s)

Kristen E. Rhodin, MD

General Surgery Resident
Duke University Medical Center
Durham, North Carolina, United States

Disclosure(s): No financial relationships to disclose

Author(s)

Kristen E. Rhodin, MD

General Surgery Resident
Duke University Medical Center
Durham, North Carolina, United States

Disclosure(s): No financial relationships to disclose
Alex Bartholomew, MD (he/him/his)

General Surgery Resident
Duke University Medical Center, North Carolina, United States

Disclosure information not submitted.
TH

Thomas C. Howell, MD

General Surgery Resident
Duke University Medical Center, United States

Disclosure information not submitted.
EK

Elishama Kanu, MD

General Surgery Resident
Duke University Medical Center, United States

Disclosure information not submitted.
Sabran Masoud, MD (he/him/his)

General Surgery Resident
Duke University Medical Center, United States

Disclosure information not submitted.
Michael E. Lidsky, MD

Assistant Professor of Surgery
Duke University
Durham, North Carolina, United States

Disclosure information not submitted.
DN

Daniel P. Nussbaum, MD

Assistant Professor of Surgery
Duke University Medical Center, United States

Disclosure information not submitted.
Dan Blazer, III, MD

Associate Professor of Surgery
Duke University Medical Center
Durham, North Carolina, United States

Disclosure(s): No financial relationships to disclose

Disclosure(s):

Kristen E. Rhodin, MD: No financial relationships to disclose

Dan Blazer, MD, III: No financial relationships to disclose

Introduction: National Comprehensive Cancer Network (NCCN) guidelines recommend endoscopic and radiographic surveillance for gastric gastrointestinal stromal tumors (GIST) less than 2 cm without high-risk features; however, level 1 evidence supporting these recommendations is lacking. Herein, we aimed to characterize tumor size and long-term survival outcomes in patients with gastric GIST undergoing observation and surgical resection.

Methods: The National Cancer Database (NCDB) was queried for gastric GIST ≤10 cm diagnosed from 2010-2017. Patients with metastatic disease, those undergoing endoscopic resection, surgical resection > 90 days from diagnosis, or with missing survival were excluded. Patients were stratified by management strategy—observation vs surgical resection. The primary outcome was overall survival (OS) and examined with Kaplan-Meier and multivariable Cox proportional hazards methods. Subgroup analyses were conducted on tumors < 1 cm, 1-2 cm, and ≥2 cm in size.

Results: Altogether, 8,629 patients were identified: 2,235 (25.9%) patients undergoing observation and 6,394 (74.1%) patients receiving surgical resection. In the overall cohort, patients undergoing surgical resection had a survival advantage (86.8% vs 71.8% 5-year OS, p< 0.0001). On subgroup analysis of patients with tumors less than 1 cm, there was no significant difference in survival based on management (Figure A). However, patients with tumors 1-2 cm and ≥2 cm in size had improved survival with surgical resection (Figure B and C). This survival advantage was preserved in multivariable analysis (HR 0.62, 95% CI 0.41-0.94, p=0.03; HR 0.75, 95% CI 0.63-0.88, p< 0.001, respectively).

Conclusions: While patients with gastric GISTs less than 1 cm in size had comparable survival with observation compared to surgical resection, this NCDB analysis suggests that patients with tumor size ≥1 cm may benefit from upfront surgical resection rather than observation.

Learning Objectives:

Upon completion, participant will be able to understand pathophysiology of gastrointestinal stromal tumors (GIST)
Upon completion, participant will be able to differentiate management for gastric GIST from other gastric cancers
Upon completion, participant will be familiar with management strategies for small gastric GIST