Clinical Aspects of Sentinel Lymph Node Biopsy in Gastric Cancer

Abstract

Forty percent of patients with gastric cancer are node negative, so they have an unnecessarily extended lymph node dissection with a higher rate of morbidity and mortality. Successful sentinel lymph node (SLN) mapping may help to reduce the number of extended lymphadenectomy. Sentinel lymph node biopsy (SNB) is indicated in patients with T1 or T2 tumors; primary lesions < than 4 cm in diameter; and clinical N0 gastric cancer. The injection method and selection of tracers for SLN mapping in gastric cancer remain controversial. However, the use of dual tracer and in cases with non-palpable lesions, the submucosal marking method is recommended. The identification rate and sensitivity are the highest in time performing SLN biopsy after dye injection ≥15 min, the number of SLNs ≥5 and application of the basin dissection. The cardinal problem in the SNB concept is the intraoperative false negative rate, the combination of hematoxylin-eosin and immunohistochemical staining has the highest sensitivity of intraoperative pathologic detection by frozen tissue sections.The application of SNB has a beneficial side effect, as it significantly increased the number of harvested LN and the ratio of the number of the harvested LN per time, although an extensive surgical experience is necessary for application of SNB concept. If the SLN contains tumor deposit(s), extended dissection is warranted, but if findings are negative, the patient could be spared additional complications associated with extended dissection. Finally, the SNB could be suitable for tumors following endoscopic resection and could represent a new era of sentinel node navigation surgery in early gastric cancer. However, the clinical application of SLN biopsy should be limited to the patients of cT1N0M0 gastric cancer within the confines of prospective randomized trial.