A multicenter non-randomized phase III study of sentinel node navigation surgery for early gastric cancer.

4076 Background: Sentinel node navigation surgery (SNNS) has the potential to minimize the extent of gastrectomy, thereby improving quality of life (QOL) after surgery for patients with early gastric cancer (GC). This prospective, multicenter, non-randomized, phase III study aims to evaluate the long-term outcomes of SNNS for early GC. Methods: A total of 13 institutions enrolled clinically diagnosed primary T1N0M0 gastric cancer patients with a single lesion (≤40 mm) and without previous endoscopic treatment. Sentinel nodes (SNs) were identified using dye and radioisotope tracers, then subjected to intraoperative rapid pathology. Patients with negative SN metastasis underwent individualized surgery consisting of limited stomach resection and SN basin dissection, while those with positive SN metastasis underwent standard gastrectomy with D2 lymph node dissection. The primary endpoint was five-year relapse-free survival (RFS). The secondary endpoints were overall survival (OS), SN detection rate, diagnostic accuracy for SNs, SN distribution, and the distribution of metastatic and non-SNs. Postoperative QOL was also assessed. RFS was assessed in the full analysis set (FAS), excluding patients who did not undergo intraoperative SN biopsy and pathological assessment during surgery. The data cutoff date for the analysis was May 31, 2025. Clinical trial information: jRCTs031180432. Results: A total of 187 patients were enrolled from May 2014 to May 2020. Of the 180 patients in FAS, 62.2% were male. The median (range) age was 64 (27–85). cT1a/cT1b was 18.3%/81.7%, respectively. The median follow-up time was 60.2 months (range: 9.0–62.8). The 5-year RFS rate (95% CI) was 95.6% (91.43–98.06). Since the lower boundary of the 95% CI exceeded the predefined threshold of 90%, the study met its primary endpoint. Events for RFS included one recurrence and three non-cancer deaths. SNs were identified in all patients, and LN metastasis was detected in 17 patients (9.4%) during surgery. Finally, 143 patients (79.4%) underwent individualized surgery consisting of limited stomach resection and SN basin dissection. The 5-year RFS rate (95% CI) for this cohort was 96.5% (92.03 - 98.86). There was no mortality after surgery. Conclusions: SNNS for early GC has been shown to be non-inferior to standard gastrectomy, with an acceptable toxicity profile. SNNS represents a promising alternative as a potential new standard treatment for early GC. Clinical trial information: jRCTs031180432 .