Long-term Outcomes of Laparoscopic Resection of Gastric Gastrointestinal Stromal Tumors

Abstract and Introduction

Abstract

Objective: Gastric gastrointestinal stromal tumors (GISTs) are rare neoplasms that require excision for cure. Although the feasibility of minimally invasive resection of gastric GIST has been established, the long-term safety and efficacy of these techniques are unclear. We hypothesized that complete resection of gastric GISTs using a combination of laparoscopic or laparoendoscopic techniques results in low perioperative morbidity and an effective long-term control of the disease.
Methods: Between August 1996 and June 2005, 50 consecutive patients undergoing laparoscopic or laparoendoscopic resection of gastric GISTs were identified in a prospectively collected database. Outcome measures included patient demographics and outcomes, operative findings, morbidity, and histopathologic characteristics of the tumor. Patient and tumor characteristics were analyzed to identify risk factors for tumor recurrence.
Results: Fifty patients, mean age 60 years (range, 34-84 years), underwent 47 local and 3 segmental laparoscopic gastric resections. GI bleeding and dyspepsia were the most common symptoms. Mean tumor size was 4.4 cm (range, 1.0-8.5 cm) with the majority of the lesions located in the proximal stomach. Mean operative time was 135 minutes (range, 49-295 minutes), the mean blood loss was 85 mL (range, 10-450 mL), and the mean length of hospitalization was 3.8 days (range 1-10 days). There were no major perioperative complications or mortalities. All lesions had negative resection margins (range, 2-45 mm). Nine patients had 10 or more mitotic figures per 50 high power fields, while 11 had ulceration and/or necrosis of the lesion. At a mean follow-up of 36 months, 46 (92%) patients were disease free, 1 patient was alive with disease, 1 patient with metastases died of a cardiac event, and 2 (4%) patients died of metastatic disease. No local or port site recurrences have been identified. Patient age, tumor size, mitotic index, tumor ulceration, and necrosis were statistically associated with tumor recurrence. The presence of 10 or more mitotic figures per 50 high power fields was an independent predictor of disease progression (P = 0.006).
Conclusion: A laparoscopic approach to surgical resection of gastric GIST is associated with low morbidity and short hospitalization. As found in historical series of open operative resection, the tumor mitotic index predicts local recurrence. The long-term disease-free survival of 92% in our study establishes laparoscopic resection as safe and effective in treating gastric GISTs. Given these findings as well as the advantages afforded by minimally invasive surgery, a laparoscopic approach may be the preferred resection technique in most patients with small- and medium-sized gastric GISTs.

Introduction

Gastrointestinal stromal tumors (GISTs) represent a rare but distinct histopathologic group of intestinal neoplasms of mesenchymal origin.^[1] Historically, most of these tumors were classified as leiomyomas, leiomyoblastomas, and leiomyosarcomas due to the mistaken belief that they were of smooth muscle origin.^[1-3] However, with the advent of electron microscopy and immunohistochemistry, a pleuropotential intestinal pacemaker cell, the interstitial cell of Cajal, was identified as the origin of GISTs.^[4] These cells have myogenic and neurogenic architecture and are found within the myenteric plexus, submucosa, and muscularis propria of the gastrointestinal (GI) tract.^[4,5] The recent discovery and identification of the CD117 antigen, a c-kit proto-oncogene product, and CD34, a human progenitor cell antigen, in the majority of GIST have led to further delineation of the cellular characteristics of these neoplasms.^[6-8]

Although GIST tumors are found throughout the GI tract, the stomach is the site of occurrence in more than half of patients.^[2,3,9-11] The most common symptoms of gastric GISTs are GI bleeding and abdominal pain. However, most patients are asymptomatic and the lesions are discovered incidentally during an upper endoscopy performed for other reasons.^[12] Their metastatic potential is difficult to predict due to the lack of clear clinical or pathologic signs of malignancy other than obvious metastasis at surgery. In addition, local recurrence or distant metastasis may not present until years after the initial diagnosis.^[9] Surgical resection is required for cure of gastric GISTs. In the past, a 1- to 2-cm margin was thought to be necessary for an adequate resection.^[12,13] Recently, DeMatteo et al demonstrated that tumor size and not negative microscopic surgical margins determined survival.^[2] These findings support the local resection of GIST lesions, including both wedge and submucosal resections. Although the feasibility of minimally invasive resections of gastric GISTs has been established,^{[11,12,14-18]} it has been proposed that this approach be limited to lesions <2 cm.^[10,19] As a result, the long-term safety of the laparoscopic approach to gastric GISTs, especially for lesions >2 cm, is unclear. We hypothesized that complete resection of gastric GISTs using a combination of laparoscopic or laparoendoscopic techniques results in low perioperative morbidity and effective long-term control of the disease.