The Incidence of Gastrointestinal Stromal Tumors in Obese Patients—A Large Single Center Experience

Incidental GIST in Patients Undergoing Bariatric Surgery: A Systematic Review of Incidence and Management

BACKGROUND

There has been a rapid increase in prevalence of obesity, and bariatric surgery is the most effective treatment to reduce all-cause mortality. Gastrointestinal stromal tumors (GISTs) comprise approximately 1% of GI tumors and are the most commonly encountered incidental tumor at the time of bariatric surgery. They have a reported prevalence of approximately 0.5%; however, there are no established guidelines for incidental GISTs.

METHODS

This study performed a systematic literature search using PubMed to identify 100 articles from 2005 to 2023 on incidental GIST tumors found during bariatric operations.

RESULTS

Total prevalence of GISTs was 0.54% with an average size of 7.04 mm. Management of these lesions should prioritize negative margins with the least invasive resection. Tumors able to be resected without alteration to bariatric surgery should be managed with a complete wedge resection prioritizing negative margins. In tumors where resection requires alteration to bariatric surgical plan, the decision to proceed with resection and alteration of bariatric surgical plan should be made only if previous discussions have been made with patient. Lastly, if resection of the GIST precludes the ability to perform the bariatric procedure, consideration to resect the GIST with the goal of negative margins should be prioritized with a plan to discuss future bariatric procedures after.

CONCLUSION

The goal of this paper is to remind bariatric surgeons to be aware of GISTs and provide the possible approaches to management.

Histopathological Examination of 404 Sleeve Gastrectomy Specimens at a Large UK Center and Systematic Review of the Published Literature

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) specimens are histologically analyzed to identify incidental pathologies. However, no guidelines recommend routine histology. This study evaluates the clinical utility of LSG sample analysis and if incidental diagnoses have a significant clinical impact.

METHODS

A single high-volume UK bariatric unit retrospectively gathered LSG data covering a 9-year period. All specimens were sent for histological analysis. Where incidental diagnoses were identified, patient records were reviewed to assess any clinical management alterations. A systematic review (2013-2023) was performed, exploring rates of incidental pathologies post-LSG. Publications were stratified into those performing routine pre-operative endoscopy, or not, and results compared to present data.

RESULTS

From 01/06/2013 to 12/12/2022, 404 patients underwent LSG. 365/404 (90.4%) had no pathology on histopathological analysis. Seven (1.7%) appeared macroscopically abnormal, with histology identifying 3 polyposis and 1 each of GIST, pernicious anaemia, sarcoidosis and gastritis. Ten (2.48%) appeared macroscopically normal but had incidental pathology. All patient management remained unchanged. Twenty-two (5.44%) were H. pylori positive. Forty-eight publications within wider literature reviewed LSG specimen histology. Fifteen, including 9662 patients undergoing pre-operative endoscopy, found pathological diagnoses in 0.5% and 1 malignancy. Thirty-three studies reporting 17,008 patients without pre-operative endoscopy identified pathologies in 0.45% and 7 malignancies.

CONCLUSION

There is little clinical utility in analyzing macroscopically normal gastric samples following LSG. The potential financial and environmental savings from limiting this practice are of great importance to worldwide bariatric teams. The authors recommend selectively sending LSG specimens only if abnormal gastric mucosa is identified when examining the extracted specimen.

Incidence and Survival Outcomes of Gastrointestinal Stromal Tumors

Importance

The incidence of gastrointestinal stromal tumors (GISTs) increased after the implementation of GIST-specific histology coding in 2001, but updated data on trends and survival are lacking.

Objective

To examine the evolving epidemiology of GISTs in major organ sites.

Design, Setting, and Participants

This descriptive, population-based cohort study used nationally representative data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program, including the SEER-22 and SEER-17 registries. Data were from evaluated patients aged 20 years or older with GISTs diagnosed between January 1, 2000, and December 31, 2019. Analyses were last updated on October 29, 2023.

Main Outcomes and Measures

Organ site-specific trends in age-standardized incidence rates and annual percent changes (APCs) in rates were estimated by race and ethnicity and, when possible, by sex, age, and primary indicator. Multivariable Cox proportional hazards regression models were used to examine racial and ethnic differences in overall and GIST-specific survival by site.

Results

The SEER-22 and SEER-17 datasets contained 23 001 and 12 109 case patients with GISTs, respectively. Patients in the SEER-22 registry had a mean (SD) age of 64 (13) years and 51.3% were men. With regard to race and ethnicity, 9.7% of patients were Asian or Pacific Islander, 12.3% were Hispanic, 19.6% were non-Hispanic Black, and 57.7% were non-Hispanic White. Overall incidence rates of GISTs in the SEER-22 cohort increased substantially over time for all organ sites but the colon (APCs: esophagus, 7.3% [95% CI, 4.4% to 10.2%]; gastric, 5.1% [95% CI, 4.2% to 6.1%]; small intestine, 2.7% [95% CI, 1.8% to 3.7%]; colon, -0.2% [95% CI, -1.3% to 0.9%]; and rectum, 1.9% [95% CI, 0.1% to 3.8%]). There were similar increasing trends by age groups (<50 vs ≥50 years), sex, race and ethnicity, and primary indicator for gastric and small intestine GISTs. Increases were mainly restricted to localized stage disease. Patients in the SEER-17 cohort had a mean (SD) age of 64 (14) years and 51.9% were men. With regard to race and ethnicity, 13.3% of patients were Asian or Pacific Islander, 11.6% were Hispanic, 17.8% were non-Hispanic Black, and 56.6% were non-Hispanic White. Non-Hispanic Black individuals had higher overall mortality for esophageal (adjusted hazard ratio [HR], 6.4 [95% CI, 2.0 to 20.3]) and gastric (adjusted HR, 1.4 [95% CI, 1.2 to 1.5]) GISTs compared with non-Hispanic White individuals. Asian or Pacific Islander individuals also had higher overall mortality for esophageal GISTs (adjusted HR, 5.6 [95% CI, 1.5 to 20.2]). Results were similar for GIST-specific survival.

Conclusions and Relevance

In this cohort study using SEER data, the incidence of GISTs in major organ sites increased in the last 2 decades among several population groups. These findings suggest that additional studies are warranted to identify risk factors, because histologic reclassification and higher availability of endoscopy and imaging do not fully explain these unfavorable incidence trends. Prevention efforts are needed to reduce the substantial survival disparities among racial and ethnic minoritized populations.

Can Incidental Gastric GISTs During Bariatric Surgeries Change the Primary Plan of Surgery? A Single Team Experience and a Systematic Review of Literature

As bariatric surgeries (BS) increase, more incidental findings are liable to be discovered. Incidental gastric gastrointestinal stromal tumors (GISTs) during BS can be found in around 0.7% of the cases. In this article, we have performed a systematic review of the literature and added our data to those of the review to review a conceptual treatment strategy to both improve patient outcomes and decrease the risk of overall cancer. With the rise of new bariatric techniques, we have proposed a new classification to BS to enhance our description of the treatment strategy.