Current status and challenges in sentinel node navigation surgery for early gastric cancer

Determining the precise extent of sentinel basins during laparoscopic gastrectomy for early gastric cancer

PURPOSE

By analyzing sentinel basin dissection (SBD) data from the SEntinel Node ORIented Tailored Approach (SENORITA) trial, we sought to determine the precise extent of the sentinel basin (SB) without a tracer.

MATERIALS AND METHODS

This study investigated SB length in patients (n = 25) who underwent laparoscopic SBD for early gastric cancer (EGC) in the SENORITA trial. SB length along the greater curvature (GC) and lesser curvature (LC) was measured intraoperatively before performing SBD.

RESULTS

In all 25 cases, along the LC of the stomach, the lengths of the SB were 3.7 cm [2.0-5.0] (median [min-max]) proximally and 3.0 cm [2.3-5.5] distally; along the GC side, the lengths of the SB were 6.8 cm [3.5-11.0] proximally and 7.0 cm [3.8-9.5] distally from the tumors. The SB length at the GC or LC side was not significantly different between subgroups categorized by tumor depth, size, and longitudinal location. When tumors were located at the anterior wall of the stomach, the length of the proximal SB (10.0 cm [9.0-11.0]) at the GC side was the longest. In cases with several sentinel lymph nodes (SLNs), the lengths of the SB at the GC side were significantly longer than those with fewer SLNs. However, the lengths of the SB were similar on the LC side regardless of the number of SLNs.

CONCLUSIONS

This pilot study had some limitations of a small number of enrolled patients, the lack of research on the specific station of SLNs, and the inaccurate indication for sentinel node navigation surgery (SNNS) without tracer. Nevertheless, the present study which reported the extents of SBs might be the first step towards simplifying procedures in laparoscopic SNNS for stomach preservation in EGC.

Recent Advances in Sentinel Node Navigation Surgery for Early Gastric Cancer

Maintaining the postoperative quality of life (QOL) while ensuring curability without overtreatment is important in the treatment of early gastric cancer. Postoperative QOL is anticipated to be maintained through minimally invasive function-preserving gastrectomy in early gastric cancer. The concept of the sentinel lymph node (SN) basin is essential to maintain the curability of early gastric cancer using minimally invasive function-preserving gastrectomy. However, additional resection after surgery is difficult to perform in gastric cancer. Thus, the SN basin theory is important. Recently, a multicenter randomized phase III trial in South Korea (SENORITA trial) proved that laparoscopic sentinel node navigation surgery (LSNNS) for stomach preservation results in better postoperative QOL compared with standard gastrectomy in patients with early gastric cancer. LSNNS contributes to patients' QOL based on the concept that curability is not impaired. A multicenter nonrandomized phase III trial is ongoing in Japan, and oncologic safety is expected to be demonstrated. LSNNS has been established as a treatment option for selected patients with early gastric cancer, and its application will become widespread in the future.

Recent updates and current issues of sentinel node navigation surgery for early gastric cancer

With the increase in the incidence of early gastric cancer (EGC), several endoscopic and laparoscopic approaches, such as endoscopic submucosal dissection and function-preserving gastrectomy, have been accepted as standard treatments. Sentinel node navigation surgery (SNNS) is an ideal surgical option for preservation of most parts of the stomach and consequent maintenance of normal gastric function to improve quality of life in patients with EGC. Although many previous studies and clinical trials have demonstrated the safety and feasibility of the sentinel node concept in gastric cancer, the clinical application of SNNS is debatable. Several issues regarding technical standardization and oncological safety need to be resolved. Recently several studies to resolve these problems are being actively performed, and SNNS might be an important surgical option in the treatment of gastric cancer in the future.

Laparoscopic sentinel node navigation surgery versus laparoscopic gastrectomy with lymph node dissection for early gastric cancer: short-term outcomes of a multicentre randomized controlled trial (SENORITA)

BACKGROUND

Sentinel node navigation surgery reduces the extent of gastric and lymph node dissection, and may improve quality of life. The benefit and harm of laparoscopic sentinel node navigation surgery (LSNNS) for early gastric cancer is unknown. The SENORITA (SEntinel Node ORIented Tailored Approach) trial investigated the pathological and surgical outcomes of LSNNS compared with laparoscopic standard gastrectomy (LSG) with lymph node dissection.

METHODS

The SENORITA trial was an investigator-initiated, open-label, parallel-assigned, non-inferiority, multicentre RCT conducted in Korea. The primary endpoint was 3-year disease-free survival. The secondary endpoints, morbidity and mortality within 30 days of surgery, are reported in the present study.

RESULTS

A total of 580 patients were randomized to LSG (292) or LSNNS (288). Surgery was undertaken in 527 patients (LSG 269, LSNNS 258). LSNNS could be performed according to the protocol in 245 of 258 patients, and a sentinel node basin was detected in 237 (96·7 per cent) Stomach-preserving surgery was carried out in 210 of 258 patients (81·4 per cent). Postoperative complications occurred in 51 patients in the LSG group (19·0 per cent) and 40 (15·5 per cent) in the LSNNS group (P = 0·294). Complications with a Clavien-Dindo grade of III or higher occurred in 16 (5·9 per cent) and 13 (5·0 per cent) patients in the LSG and LSNNS groups respectively (P = 0·647).

CONCLUSION

The rate and severity of complications following LSNNS for early gastric cancer are comparable to those after LSG with lymph node dissection. Registration number: NCT01804998 ( http://www.clinicaltrials.gov).