Recent advances in sentinel node navigation for gastric cancer: A paradigm shift of surgical management

Abstract

The sentinel node (SN) is defined as the first draining node from the primary lesion and it has proven to be a good indicator of the metastatic status of regional lymph nodes in solid tumors. In the past 5 years, the validity of SN concept for gastric cancer has been demonstrated by a number of single institutional studies. Using a dual tracer method as the optimal procedure, the radio-guided method allows us to confirm the complete harvest of SNs by gamma probing, while the dye procedure enables us to perform real time observation of the lymphatic vessels. From previous reports, clinically staged T1N0 gastric cancer seems to be a good entity on which to try to change the therapeutic approach based on SN biopsy. At present, two large scale prospective multicenter trials are on-going in Japan. To overcome some remaining issues, such as limited sensitivity of intra-operative diagnosis of metastasis, and technical difficulty in laparoscopic SN detection, further technical and instrumental developments will be required. During this transitional phase, focused lymph node dissection targeted to sentinel lymphatic basins and modified resection of the stomach is an acceptable approach. Although there are several remaining issues, SN navigation should provide a paradigm shift for the surgical management of early gastric cancer in near future.

Novel surgical approach based on the sentinel node concept in patients with early gastric cancer

“…SN are defined as the first lymph nodes to receive lymphatic flow from primary tumor sites. Many investigators have already demonstrated the clinical utility of sentinel node navigation surgery (SNNS) for patients with gastric cancer,7, 8, 9, 10, 11 and the current technical procedures for SNNS have been gradually advancing over time. Furthermore, intraoperative methods have been developed for the accurate diagnosis of lymph node metastasis, including micrometastasis 12.…”

Animal model for training in sentinel lymph node biopsy of the stomach through combined methods

“…There have been initiatives that use SLNB in humans for gastric cancer aimed to indicating more economic lymphadenectomies and gastric resections 15,18,19,24,25 , and this conduct is currently becoming accepted in global clinical practice 9,11,26 , especially after the recommendation of the Japanese multicenter trial on the use of SLNB in early gastric cancer (T1 or T2, N0, M0) 27 .…”

“…In the last decade, SLNB has also been carried out for cases of early gastric cancer 5,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] .…”

“…However, the stomach has characteristics that make SLNB difficult, such as the existence of a multi-directional lymphatic drainage system, the presence of skip metastasis [9][10][11] and an average identification of sentinel nodes of more than two per individual 5,9,16,[12][13][14][15] .…”

“…However, they have limitations, such as their small sample size 9,11 , high cost, and large sentimental humanistic appeal, especially when dogs are involved. Also, for the establishment of an experimental model, it is necessary to take into consideration the characteristics of the animal and its similarities to humans [29][30][31]35 .…”