Robotic Versus Laparoscopic Distal Gastrectomy With D2 Lymphadenectomy for Locally Advanced Gastric Cancer

This study is an investigator-initiated, randomized, controlled, parallel group, and non-inferiority trial comparing robot-assisted gastrectomy with D2 nodal dissection for locally advanced gastric cancer patients with laparoscopic procedure.

Since the first case of laparoscopy-assisted distal gastrectomy was reported in 1994, the number of patients undergoing the laparoscopic procedure has gradually increased. The latest Japanese gastric cancer treatment guideline recommends laparoscopic gastrectomy (LG) as an optional treatment for cStage I gastric cancer (GC). Based on the experience of early GC, most experienced surgeons have applied the laparoscopic procedure in patients with locally advanced gastric cancer (AGC). According to the results of large-scaled retrospective studies and ongoing randomized controlled trials (RCTs), LG treating AGC can gain better short-term outcomes and comparable long-term oncologic results.

To minimize the limitations of laparoscopic surgery, robot systems have been introduced to treat GC providing technical advantages. Though the feasibility and safety of robotic gastrectomy (RG) have been well accepted, the benefits of RG remain controversial. A recent meta-analysis including eleven studies of 3503 patients demonstrated that RG indicated potentially favorable outcomes in terms of blood loss compared with LG. Furthermore, it has been confirmed that robotic system could provide an advantage over LG in the dissection of the N2 area lymph nodes, especially around the splenic artery area. Our previous study demonstrated that the RG had less intraoperative blood loss and more lymph nodes dissection compared with the laparoscopic procedure. However, the only prospective study reported that RG is not superior to LG in terms of perioperative surgical outcomes. Nevertheless, the following subgroup analysis found that patients with GC undergoing D2 lymph node dissection can benefit from less blood loss when a robotic surgery system is used. Take together, RG with D2 nodal dissection may be superior laparoscopic surgery in terms of blood loss and retrieved lymph nodes. However, lack of high-level evidence-based medical researches, we can't drew a conclusion that patients with AGC may benefit from RG with D2 nodal dissection.

With regard to a new surgical approach, oncologic safety has attracted more attention. Although some retrospective studies have demonstrated that RG with lymphadenectomy for GC had non-inferior oncologic outcome relative to LG, there is no prospective RCT to evaluate the long-term outcomes of RG. Therefore, the Chinese Robotic Gastrointestinal Surgery Study (CRASS) Group launched a multicenter prospective RCT to verify the short-term and long-term outcomes of RG in AGC. The primary objective of this study is to assess whether robot-assisted distal gastrectomy is comparable to laparoscopic approach in terms of long-term oncologic outcomes without compromising relapse-free survival. The secondary research objectives are to compare robotic and laparoscopic approach in terms of morbidity, mortality, quality of life, cost-effectiveness, and overall survival.

Eligibility Criteria:
Inclusion Criteria:

1. Pathologically proven gastric adenocarcinoma.
2. Tumor located in the lower third of the stomach, and is possible to be curatively resected by subtotal gastrectomy.
3. Preoperative stage of cT2-4aN0-3M0 according to American Joint Committee on Cancer/Union for International Cancer Control 8th edition
4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
5. American Society of Anesthesiology (ASA) score of class I to III
6. Patients who freely give informed consent to participate in the clinical study

Exclusion Criteria:

1. Previous upper abdominal surgery (except laparoscopic cholecystectomy)
2. Previous gastric resection (gastrectomy, endoscopic mucosal resection, or endoscopic submucosal dissection)
3. Gastric cancer-related complications (complete obstruction or perforation)
4. Enlarged or bulky regional lymph node diameter larger than 3 cm based on preoperative imaging
5. Previous neoadjuvant chemotherapy or radiotherapy for gastric cancer
6. Patients diagnosed with other malignancy within 5 years
7. Severe mental disorder
8. Unstable angina or myocardial infarction within the past 6 months
9. Cerebrovascular accident within the past 6 months
10. Severe respiratory disease (FEV1\< 50%)
11. Continuous systemic steroid therapy within 1 month before the study
12. Pregnant or breast-feeding women