Resections for Wild-type GISTs Should Be Restricted to Initial Procedures

Among patients with wild-type gastrointestinal stromal tumors (GISTs), there was no improvement in event-free survival with more extensive or serial resections, suggesting that resections for this disease be restricted to the initial procedure, according to a study published in the Journal of Clinical Oncology.¹

Wild-type GISTs, which lack KIT or PDGFRA mutations, are unique subtypes of GIST that are most common among children. There are, however, limited studies evaluating the impact of staging variables and resections on clinical outcome.

To determine the effect of staging variables, extent of resection, and repeat resection of tumors on event-free survival, researchers analyzed data from 76 patients with wild-type GIST who underwent resection for their disease. All patients were treated at a wild-type GIST clinic that was established by the National Cancer Institute in 2008.

At a median follow-up of 4.1 years, the overall event-free survival was 72.6% at 1 year, 57.6% at 2 years, 23.7% at 5 years, and 16.3% at 10 years postoperatively.

Patients with metastatic disease (adjusted hazard ratio [aHR], 2.3; 95% CI, 1.0-5.1; P = .04) and those with greater than 5 mitoses per 50 high-power fields (aHR, 2.5; 95% CI, 1.1-6.0; P = .03) had about a 2 times higher risk of disease progression or recurrence.

There was no significant impact of negative microscopic resection margins (aHR, 0.9; 95% CI, 0.4-2.2; P = .86) or type of gastric resection (P = .67) on event-free survival.

Repeated resection following the initial resection was significantly associated with reduced postoperative event-free survival (P < .01).

These findings suggest that disease progression or recurrence may be more closely related to tumor biology than surgical management. The authors therefore concluded that subsequent resections after the initial procedure for wild-type GISTs be performed only to eliminate symptoms such as obstruction or bleeding.

Reference

1. Weldon CB, Madenci AL, Boikos SA, et al. Surgical management of wild-type gastrointestinal stromal tumors: A report from the National Institutes of Health Pediatric and Wildtype GIST Clinic. J Clin Oncol. 2016 Dec 28. doi: 10.1200/JCO.2016.68.6733 [Epub ahead of print]