Surgical management of gastric gastrointestinal stromal tumors: Comparison of outcomes for open and laparoscopic resection

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are common mesenchymal tumors of the GI tract (80%). However, they represent only 0.1 to 3% of all gastrointestinal malignancies¹. These are the tumors that start as leiomyoma and leiomyosarcoma. What is now known as a GIST used to be called a gastrointestinal smooth muscle tumor. A landmark research by Mazur and Clark 1983 recognized that these tumors are biologically and clinically distinct entities, and coined the term GIST². They found that the histological origins of these tumors are the interstitial cells of Cajal, specialized pacemaker nerve cells of the sympathetic nervous system that drive the rhythmic, peristaltic activity of the intestinal smooth muscles and are necessary for digestion². The behavior of GISTs is driven by gain of function KIT gene mutations in 80-85% of cases and platelet-derived growth factor receptor alpha (PDGFRA) gene mutation in about 10% of cases¹. Wild-type (WT) GISTs exhibit no detectable KIT or PDGFRA mutations and have alternate pathways for pathogenesis³. Primary GISTs commonly arise in the stomach (50% to 70%), followed by small intestine in 25% to 35% cases. Primary extra-gastrointestinal GISTs (eGISTs) in omentum or mesentery are rare (<10%) and have a more aggressive clinical course compared with similar-sized gastric counterparts³. The aim of this study was to evaluate the outcomes of patients undergoing surgery for gastric GISTs at a single institution. Two cohorts undergoing laparoscopic excision or open conventional resection were compared. Intraoperative and post-operative parameters were reviewed and oncological outcomes were evaluated.

MATERIAL AND METHODS

This retrospective record-based study was carried out in the department of general and minimally invasive, Sher-i-Kashmir Institute of Medical Sciences, over 8 years. After obtaining ethical clearance from the Institutional Ethical Committee, a total of 35 subjects were included in our study. All of these patients consented to having their data used for this study. After institutional review board approval, we used medical records from wards and the medical record department to collect data on these patients. All the patients who underwent resection for primary gastric GIST in the Department of General and minimal invasive surgery (MIS) between January 2016 and May 2023 were included. Age, sex, tumor location, tumor size, and pathological results were systematically collected. Surgical parameters, including the type of surgery, operating time, length of hospital stay, and postoperative complications were analyzed. Patients were followed up every two weeks for the first month, every three months for the first year, and every six months during the second year after surgery. Patient demographic and tumor characteristics between the groups were compared by the Chi-square test. Statistical analysis was carried out with SPSS version 10.

RESULTS

A total of 35 patients were included. The mean age was 58 years (ranging from 15-75years). Males (62.9%) outnumbered females (37.2%). The maximum number 23/35 (65.7%) patients with gastric GISTs had small tumors. The tumors varied from 2 to 13 cm in size [Table 1].

The dominant symptom was GI bleeding (20/35), followed by incidental asymptomatic finding (6/35). Twelve patients (34.3%) had malena, 8 (22.9%) had hemetemesis, 5 (14.2%) had anemia, 2 (5.7%) patients had abdominal pain, 1(2.9%) had gastric outlet obstruction, and 1(2.9%) had an incidental finding of asymptomatic abdomen mass. Six (17.1%) patients were asymptomatic and diagnosed incidentally. Four (11.5%) patients had tumors located at the GE junction, 20 (57.1%) at the body of the stomach, and 11 (31.4%) had tumors located at the antrum of the stomach. Five (14.2%) patients had endophytic submucosal lesions, 20 (57.2%) had exophytic, and 10 (28.6%) had both exophytic and endophytic components.

Laparoscopic resection was conducted on 25 (71.4%) patients, and 10 (28.6%) patients had open surgery. Five (14.3%) were subjected to laparoscopic transgastric excision. There were no oncological differences in open and laparoscopic resection (p-value >0.5). The mean operative time in laparoscopic and open resection was 110 and 114 minutes. The difference was statistically not significant (p value> 0.5). The laparoscopic group had a lower rate of overall complications (0.04% vs. 50%, P= 0.02). The hospital stay and post-operative complications were significantly lower in laparoscopic resection than in open conventional surgery (p value< 0.05) [Table 2]. According to the National Health Institute classification, 11 (31.4%) were categorized into very low risk, 15 (42.9%) low risk, 6 (17.1%) intermediate risk, and 3 (8.6%) patients had high-risk tumors. 6 (17.1%) patients were subjected to adjuvant imatinib therapy. None of our patients had recurrence during follow-up and there was no mortality.

DISCUSSION

GISTs constitute 1-3% of all gastrointestinal tumors⁴, and 50% are in the stomach⁴, followed by the small bowel, rectum, and colon. The incidence of GISTs varies according to geographical area, and the overall incidence is estimated to be 7–15 cases per 1 million people per year^5,6. About 6000 new cases per year are diagnosed and treated in the United States⁷.

Development of GISTs, in most cases, is a result of a gain of function mutation and subsequent activation of tyrosine kinase proteins⁷. Most of the stomach GISTs are small and asymptomatic and hence remain unnoticed. Many GISTs are diagnosed incidentally at endoscopy, and some present with non-specific gastric symptoms. GISTs are typically submucosal tumors, and the overlying mucosa often remains intact on pathological and imaging assessment. If the overlying mucosa ulcerates, the patient may present with bleeding and anemia. Surgery involving local resection with macroscopically negative margins remains the standard, preferred, and definitive curative treatment of primary non-metastatic GISTs⁸. Routine lymphadenectomy is not necessary since GISTs rarely metastasize to the lymph nodes. Resection can be done with conventional open or laparoscopic techniques. The study evaluates demographic, clinicopathological, and surgical outcomes of patients of gastric GISTs undergone surgical resection.

In this study, unlike the similar prevalence of men and women, males (62.9%) outnumbered females (37.1%). Although GIST can develop at any age, 80% of these were reported in middle-aged and elderly people (mean age, 64-69 years) in literature⁹. The mean age in this study was 58 years (ranging from 15-75 years)

Besides the other factors, tumor size is one of the most relevant prognostic factors indicating the aggressive behavior of a gastric GIST¹⁰. In our study, the maximum number (65.7%) of patients with Gastric GISTs had small tumors less than 5 cm, hence had favorable outcomes. Small gastric GISTs are more likely to be asymptomatic and diagnosed incidentally during investigation for a different purpose or during surgery. Some grow intramurally and present exophytic or endophytic masses; others may ulcerate and bleed, and a significant number of patients may present with non-specific symptoms of early satiety, abdominal pain, anemia, and swelling^11,12. Fifty percent of gastric GISTs present with overt or occult gastrointestinal bleeding^{11, 12}. The dominant symptom in our study was GI bleeding (20/35), followed by incidental asymptomatic findings (6/35). Five (14.2%) patients had endophytic submucosal lesions, 20 (57.1%) had exophytic, and 10 (28.6%) had both exophytic and endophytic components.

The majority of primary GISTs occur in the body of the stomach, accounting for 70% to 80% of cases, while those located at the esophagogastric junction contribute 5.8% to 13.5% of the total incidence^13–15. In our study, four (11.4%) patients had tumors located at the GE junction, 20 (57.1%) at the body of the stomach, and 11 (31.4%) had tumor located at the antrum of the stomach.

The first laparoscopic resection was reported by Lukaszczyk et al. in 1992¹⁶. Over the past few decades now, laparoscopic resection of gastric GISTs has become a widely accepted technique, offering several advantages, including early recovery, fewer postoperative complications, improved cosmesis, and shorter hospital stays¹⁷. For GISTs located in the body of the stomach, both endophytic and exophytic masses can be addressed through either laparoscopic or open wedge resection. Laparoscopic exogastric wedge resection is the mostly used technique for gastric GISTs^18,19. However, when GISTs are located at the gastroesophageal junction or the pylorus, wedge resection becomes challenging due to the risk of causing stenosis at inlet and outlet of stomach respectively. In such cases, transgastric resection is an alternative approach advocated, which has been found safe and provide good oncological outcomes²⁰. In the current study 25 (71.4%) patients underwent laparoscopic resection, and 10 (28.5%) had open surgery. Five (14.2%) were subjected to laparoscopic transgastric excision. There were no oncological differences in open and laparoscopic resection (p-value >0.5). The mean operative time in laparoscopic and resection were 110 and 114 minutes, respectively. The difference was statistically not significant (p value> 0.5). The laparoscopic group had a lower rate of overall complications (0.04% vs. 50%, P= 0.02). The hospital stay and post-operative complications were significantly lower in laparoscopic resection than in conventional surgery (p value< 0.05). Laparoscopic surgery offers complication rates, shorter hospitalizations, and comparable oncological outcomes to open surgery for patients with gastric GIST²¹.

CONCLUSION

Gastric GIST are rare neoplasms traditionally treated with complete surgical resection. Laparoscopic surgery now enables curative resections while preserving function, offering similar oncological benefits. Laparoscopic transgastric resection is particularly effective for GIST near the GE junction and pylorus, providing better visualization of the lesion and control of the surgical margins.