During the last 2 decades, the proportion of early gastric cancers (EGCs) has increased continuously from 24.8% to nearly 50% [17
]. Given that the prognosis of EGC is excellent, attention is being focused on the QoL of these patients after the operation. For this reason, laparoscopic gastrectomy has emerged as an alternative treatment option for EGC and many studies have reported early safety results and the short-term benefits of that procedure. However, most of the reports on laparoscopic gastrectomy are retrospective and the randomized controlled trials that are available have many limitations such as being non-multicenter trials, having small sample sizes, generating conflicting results, etc. [2
]. To our knowledge, the present study will be the first large-scale randomized controlled trial that assesses the long-term outcomes of laparoscopic surgery for gastric cancer.
Although there is solid evidence supporting the shortterm efficacy of laparoscopic gastrectomy for EGC, there is little information about its long-term efficacy. The Japanese Laparoscopic Surgery Study Group reported a multicenter study of the oncologic outcomes after laparoscopic gastrectomy for EGC in Japan [20
]. In total, 1,294 patients underwent laparoscopic gastrectomy. The 5-year disease-free survival rates were 99.8%, 98.7%, and 85.7% for stage IA, IB, and II disease, respectively. The median follow-up period was 36 months. In Korea, Song et al. [11
] retrospectively reviewed multicenter data to assess the timing and patterns of disease recurrence. In a 41-month follow-up, the incidence of disease recurrence was 1.6% in patients with EGC and 13.4% in patients with advanced gastric cancer. Advanced T-classification and lymph node metastasis were risk factors for recurrence. The authors concluded that the long-term oncologic outcomes of laparoscopic gastrectomy were satisfactory and similar to those of open gastrectomy. Moreover, a single-center study by Hwang et al. [21
] of 197 patients who underwent laparoscopic gastrectomy revealed that the actual 3 years disease-free survival rates for EGC and AGC were 98.8% and 79.1%, respectively. In addition, when the single-center study of Pak et al. [22
] examined the long-term oncologic outcomes of 714 consecutive laparoscopic gastrectomies for gastric cancer, the 5-year relapse-free survival rates were 95.8%, 83.4%, and 46.4% for stage I, II, and III disease, respectively while the 5-year overall survival rates were 96.4%, 83.1%, and 50.2%, respectively. The independent risk factors for recurrence were T stage and N stage. For survival, age, T stage, and N stage were statistically independent prognostic factors. The authors concluded that laparoscopic gastrectomy for gastric cancer had acceptable long-term oncologic outcomes that were comparable to those of conventional open surgery.
To date, seven randomized controlled trials have compared laparoscopic gastrectomy with open gastrectomy for gastric cancer. In all trials, LADG was compared to ODG [2
]. Six of the trials only enrolled patients with clinically diagnosed EGC. One of the trials reported a 5-year follow-up of 59 patients with EGC or AGC; 29 underwent open subtotal gastrectomy, and 30 underwent laparoscopic resection [2
]. The 5-year overall survival rates for open gastrectomy and laparoscopic gastrectomy were 55.7% and 58.9%, respectively, while the 5-year disease-free survival rates of the two groups were 54.8% and 57.3%, respectively. The authors concluded that laparoscopic radical subtotal gastrectomy for distal gastric cancer is a feasible and safe oncological procedure supported by long-term results similar to those obtained with an open surgery. Currently, the Gastric Cancer Surgical Study Group of the Japan Clinical Oncology Group (JCOG 0912) and the KLASS group (KLASS 01) are conducting multi-institutional prospective randomized controlled phase III trials to compare laparoscopic gastrectomy with open gastrectomy. A separate phase III study for evaluating the feasibility of laparoscopic surgery in advanced gastric cancer is also underway in Korea (KLASS 02).
In summary, large multicenter randomized controlled trials are still required to determine whether there are significant and quantifiable differences between laparoscopic gastrectomy and open gastrectomy. The KLASS 01 trial is the first large multicenter randomized controlled clinical trial that will investigate whether laparoscopic surgery can improve patient QoL without compromising overall survival. The findings from this trial have the potential to change clinical practice in treating EGC.