Colonic Gastrointestinal Stromal Tumors Demonstrate Unique Biological Characteristics: A Retrospective, Propensity...

Colonic gastrointestinal stromal tumors (cGISTs) represent an exceptionally rare subtype of gastrointestinal stromal tumors (GISTs) and exhibit distinct clinicopathological features. Nonetheless, limited research has systematically assessed the prognostic differences between cGISTs and GISTs originating from other anatomical sites under comparable baseline and oncological conditions. Current prognostic stratification systems for GISTs have significant limitations in evaluating colonic subtypes.

A retrospective case-control study. Surgical cGIST cases (2012-2024) from 4 tertiary hospitals were analyzed, along with 676 contemporaneous gastric GISTs (gGISTs) controls. Additional individual patient data were extracted from published articles, reviews, letters, and comments identified through a systematic literature search. Propensity score matching (1:4) was performed to balance baseline variables before comparing survival outcomes.

Compared with gGISTs, cGISTs exhibited distinct clinicopathological characteristics, including older average age (P = .001), larger tumor diameter (P = .003), higher mitotic index (P = .007), and lower positive expression rates of CD117 (79.25% vs 98.81%, P < .001), CD34 (80.43% vs 98.81%, P < .001), and DOG-1 (76.67% vs 98.35%, P < .001). After propensity score matching successfully eliminated baseline differences, gGIST patients demonstrated superior survival outcomes, with higher 1-, 3-, and 5-year recurrence-free survival (RFS) rates of 100.0%, 98.76%, and 94.13%, compared with 95.50%, 86.69%, and 86.69% in matched cGIST cases. Similarly, gGIST patients showed higher 1-, 3-, and 5-year overall survival (OS) rates of 100.0%, 99.39%, and 97.06%, compared with 95.50%, 86.58%, and 82.45% in matched cGIST cases. Of note, the difference in OS was statistically significant (P = .04), whereas the difference in RFS did not reach significance (P = .31).

The cGISTs exhibit distinct clinicopathological characteristics and are associated with a significantly poorer prognosis compared with gGISTs. Therefore, diagnostic and therapeutic strategies for cGISTs warrant further exploration and refinement.