No Improvement in Event-Free Survival Reported With More Extensive or Serial Resections in Wild-Type GIST
Findings from the National Institutes of Health Pediatric and Wildtype Gastrointestinal Stromal Tumors (GISTs) Clinic, reported in the Journal of Clinical Oncology by Weldon et al, indicate that more extensive or serial resections are not associated with improvement in event-free survival in patients with wild-type GISTs. These tumors lack KIT and PDGFRA mutations and predominantly affect younger patients.
The analysis included 76 patients undergoing initial resection of wild-type GISTs at the Wildtype GIST Clinic, established in 2008. Patients had a median age at diagnosis of 21.0 years, with 47% aged < 18 years at diagnosis.
Factors Affecting Event-Free Survival
Median follow-up was 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 after surgery. On multivariate analysis, risk of disease progression or recurrence was significantly increased among patients with metastatic disease (adjusted hazard ratio [AHR] = 2.28, P = .04) and those with > 5 mitoses per 50 high-powered fields (AHR = 2.54, P = .03); no effect of negative microscopic resection margins was observed (AHR = 0.9, P = .86).
There was no significant association between the extent of initial gastric resection (anatomic vs partial-wedge) and event-free survival (P = .67) and no significant difference in the rate of local recurrence after initial anatomic gastric resection (0 of 8, 0%) vs nonanatomic gastric resection (2 of 9, 22%; P = .47). Among all patients, each subsequent resection after initial resection was significantly associated with decreasing postoperative event-free survival (P < .01). Overall, five patients (6%) have died since initial clinic enrollment in 2008.
The investigators concluded: “[Wild-type] GIST is an indolent disease, and most patients survive with disease progression. We found no improvement in [event-free survival] with more extensive or serial resections. Disease progression or recurrence may be more closely related to tumor biology than surgical management. These data suggest that resections for [wild-type] GISTs be restricted to the initial procedure and that subsequent resections be performed only to address symptoms such as obstruction or bleeding.”
Christopher B. Weldon, MD, PhD, of Boston Children’s Hospital, Harvard Medical School, is the corresponding author of the Journal of Clinical Oncology article.
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