Surgical resection with negative margins without lymphadenectomy has been the treatment of choice of gastric GISTs up to now. Histologically, a 1 to 2 cm margin has been thought to be necessary for adequate resection[9, 10]. However, more recently, DeMatteo et al. said that tumor size and negative microscopic surgical margins did not determine the survival. It is therefore accepted that the surgical goal should be complete resection with gross negative margins only[3, 11]. Given this, wedge resection has been advocated by many investigators for the majority of gastric GISTs[3, 10, 11]. Currently, gastric GISTs are viewed as a good indication for laparoscopic resection. Moreover, the development of laparoscopic stapling devices and surgical techniques has made laparoscopic wedge resection an attractive alternative to conventional open surgery. In this study, laparoscopic surgery has been performed with an annually increasing tendency, and wedge resection was more commonly advocated. This shows that laparoscopic wedge resection has become the mainstay of treatment for gastric GIST.
Recent reports from the National Comprehensive Cancer Network (NCCN) GIST Task Force and the GIST Consensus Conference under the auspices of The European Society for Medical Oncology (ESMO) state that laparoscopic or laparoscopic-assisted resection may be used for small gastric GISTs (that is, those < 2 cm in size). However, Ronellenfitsch et al. stated that the tumor size did not determine the feasibility of laparoscopic wedge resection, and the location of the gastric GISTs did not directly affect the indication for laparoscopic wedge resection. Whereas Yang et al. reported on the performance of laparoscopic wedge resection for tumors less than 6 cm in diameter, Ronellenfitsch et al. and Huguet et al. reported its feasibility for tumors bigger than 10 cm in diameter. The Japanese clinical practice guidelines for GIST suggest that laparoscopic resection of gastric GISTs smaller than 5 cm appears safe when performed by a skillful surgeon who is thoroughly familiar with the neoplastic characteristics of gastric GISTs. Before 2005, in our institute we performed open surgery for tumors bigger than 5 cm and for those located at the cardia. As our experience has increased, we have been performing laparoscopic surgery on tumors smaller than 10 cm regardless of their location.
We classified the 38 patients who had large tumors (5 to 10 cm) into those who received laparoscopic versus open surgery. Although there were statistically significant differences in age, tumor size, and tumor location, we thought that these variables were not considered to be factors that were comparable between laparoscopic and open surgery. From the point of view of the merit of laparoscopic surgery, the length of hospitalization was statistically shorter in laparoscopic surgery than in open surgery. Moreover, the operation time was shorter in laparoscopic surgery, although there was no statistical difference. In terms of survival rates, there were no statistical differences in overall and disease-free survival rates, although the survival graphs appeared to be different.
In the case of gastric GISTs bigger than 10 cm, surgeons were concerned about the operative methods of laparoscopic versus open surgery. The merits of laparoscopic surgery included lesser degree of pain, smaller wound size, shorter hospital stay, and earlier recovery. However, in order to safely retrieve a mass bigger than 10 cm, a larger wound incision was needed, as in open surgery. Moreover, laparoscopic surgical techniques became more difficult in cases with bigger gastric GISTs, and there was a possibility that tumor cells would spread due to the rupture of the capsules. Therefore, with bigger tumors, special attention should be paid to the prevention of capsular rupture. It should also be emphasized that careful laparoscopic evaluation of the tumor size, and its characteristics in terms of the possibility of capsular rupture during further manipulations, should be performed, giving timely conversion to the open method whenever necessary. In our series, for the prevention of tumor spread during laparoscopic surgery, we tried to grasp the stomach and normal tissues around the tumor. In our study, there were seven patients with tumors bigger than 10 cm, three of whom underwent laparoscopic surgery, while four underwent open surgery. In addition, there were no capsular ruptures in the three patients who had laparoscopic surgery.
The recurrence rate after surgery in reported series ranges from 17 to 24%[17, 18]. In recurrent gastric GISTs, some reports demonstrated that a combination of surgery and targeted therapy may reduce the development of recurrence or decrease the risk of disease progression[19, 20]. Although most of our patients who underwent surgical resection were at very low, or low malignant potential (74/104, 71.2%), we had a lower recurrence rate in our series compared to other reports[17, 18]. We experienced five cases (5/104, 4.8%) of recurrence, with a median follow-up time of 49.3 months (range, 8.4 to 164.4 months) after surgical resection for gastric GISTs. Three patients underwent reoperation, and two were treated with imatinib mesylate. Unfortunately, none of the patients responded to imatinib mesylate, and two patients who underwent surgical management are currently living.
Although this was a retrospective research study of laparoscopic and open surgery for gastric GIST, and large tumors 5 to 10 cm in size, and although it was not a case-matched study of laparoscopic and open surgery, it provides a basic guideline to determine the size-related indication for laparoscopic surgery for gastric GIST. A prospective randomized controlled study of tumors larger than 5 cm is necessary.