Recent studies indicated that individuals who are morbidly obese demonstrated higher incidences of gastrointestinal stromal tumors (GISTs) than the general population, according to a study published in Medicina.

Upon further investigation among individuals with obesity who underwent laparoscopic sleeve gastrectomies (LSGs), the incidence rate of GISTs was 0.31%. These GISTs were proven to be low-risk with no recurrence by the time of follow-up.

The patients with GISTs were significantly older than the remaining patients with a mean age of 50.2 years (P =.03) and a mean preoperative body mass index of 43.3 kg/m2. None of the GISTs were larger than 7 mm and they were located in the fundus of the stomach (80%) and in the pylorus (20%). They were all extramurally located which makes it hard to diagnosis without surgery.

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While the overall prevalence of GISTs in the general population is around 0.006% to 0.0015%, the higher incidence rate of 0.31% among patients with obesity in this study also correlated with findings from a meta-analysis. These findings reported an incidence rate of GISTs for patients with obesity undergoing bariatric surgery as 0.45%.

“The major pathways in which obesity promotes tumorigenesis include hyperinsulinemia/insulin resistance and [insulin-like growth factor-I] abnormalities; sex hormone factors deriving from ectopic fat deposition; microenvironment and cellular disorders; disruption of circadian rhythms and dietary nutrients; altered intestinal microbiome and mechanic factors in obesity,” the authors said.

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They also observed an association between GISTs and ghrelin. The authors emphasized the importance of the surgeon’s awareness of incidental GISTs during LSGs.

Researchers prospectively enrolled 1564 patients who underwent bariatric surgery via LSG. Following LSG, each stomach resection sample underwent histopathological assessments to determine GIST presence. Five patients (3 men and 2 women) out of the 1564 patients had GISTs.

The investigators retrospectively collected data on tumor size, location, type, and mitotic index for tumor risk classification. They also recorded patient demographics including gender, age, body mass index, and comorbidities.

They then conducted postoperative surveys 1 month after the operation and every subsequent 6 months to assess progression-free survival. A limitation was that the study was only from a single center and the accurate diagnosis of GISTs depended on the pathology department.


Dowgiałło-Gornowicz N, Sztaba K, Lech P, Botulińska A, Michalik M. The incidence of gastrointestinal stromal tumors in obese patients—a large single center experience. Medicina. 2021;57(11):1242. doi:10.3390/medicina57111242