Clinicopathological features and prognosis of colonic gastrointestinal stromal tumors: evaluation of a pooled case series

Background Due to the extremely rare incidence, data about colonic GISTs are limited. Therefore, aim of the present study was to explore clinicopathological characteristics and prognosis of colonic GISTs. Patients and Methods Colonic GISTs cases were obtained from our center and from case report and clinical studies extracted from MEDLINE. Clinicopathological features and survivals were analyzed. Results There were 79 colonic GISTs patients with a female predominance. The median age was 66 years (range 0.17-84). The median tumor size was 5.8 cm (range 0.5-29). The most common location was sigmoid colon (45.8%), followed by transverse colon (19.5%). The majority of colonic GISTs were high risk (70.8%). Mitotic index was correlated with gender (P = 0.002) and tumor size (P = 0.005), and tumor location was correlated with age (P = 0.017). The five year DFS and DSS were 57.4% and 61.6%, respectively. Mitotic index and NIH risk classification were associated with prognosis of colonic GISTs. However, mitotic index was the only independent risk factor. The distribution of tumor size and NIH risk classification were significantly different between colonic and gastric GISTs (both P = 0.000). The DFS and DSS of colonic GISTs were significantly lower than that of gastric GISTs (P = 0.012 and P = 0.002, respectively). Conclusions The most common location for colonic GISTs was sigmoid colon. Most tumors were high risk. Mitotic index was the only independent risk factor for prognosis of colonic GISTs. Colonic GISTs differ significantly from gastric GISTs in respect to clinicopathological features. The prognosis of colonic GISTs was worse than that of gastric GISTs.