Although colonic and rectal gastrointestinal stromal tumors (GISTs) are often regarded as different entities with different histopathological characteristics, demography, and treatment, there appears to be no significant difference between the 2 in overall long-term survival after propensity score matching (PSM), according to a recently published study in the journal Frontiers in Surgery.
Rectal and colonic are 2 of the rarest subtypes of GISTs, which are more frequently present in the stomach or the small intestine. From an embryological point of view, the rectum and colon are 2 very different structures. Therefore, it is not surprising that many studies have revealed significant differences between the 2 regarding characteristics such as clinical course, biological hallmarks, and metastasis patterns.
However, due to their low incidence, there are no studies that compare the clinical and histopathological characteristics of rectal and colonic GISTs. In this study, the authors aimed to summarize the main differences between the GIST subtypes, with the purpose of providing evidence for future clinical management.
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The retrospective study used a multicenter database including several of the biggest hospitals in China. It included patients with either rectal or colonic GIST who underwent surgery. Overall survival was defined as the primary outcome measure. The study included over 300 patients treated between 2012 and 2022.
Regarding demographic data, patients with colonic GIST were more likely to be over 60 years of age than those with rectal GIST. Nonetheless, men were more likely than women to have either tumor.
In terms of tumor size and mitotic activity, results showed that patients with colonic GIST were more likely than patients with rectal GIST to have a tumor over 10 cm in diameter. The most common size for both subtypes was between 5 cm and 10 cm. Similarly, it was noted that colonic GISTs had, on average, a higher mitotic rate than rectal GISTs.
Considering the previous findings, it is not surprising that patients with colonic GISTs were more likely to receive adjuvant therapy, the authors noted. However, patients with rectal GIST were more likely to receive neoadjuvant therapy, probably due to the anatomical characteristics of the rectum, they continued.
Although data showed that patients with rectal GIST had better overall survival before PSM, there was no significant difference between the entities in overall survival after PSM.
“Randomized controlled trials with a larger sample size are needed to compare the differences between the two groups,” the authors concluded.
Li C, Lu Y, Zhang M, et al. Clinicopathological features and prognosis of colonic and rectal gastrointestinal stromal tumors: a propensity score matching analysis. Front Surg. Published online October 21, 2022. doi:10.3389/fsurg.2022.968585