Failure identification of metastasis and non-sentinel lymph node metastasis in early gastric cancer

In the realm of sentinel lymph node navigation surgery for cancer patients, the intraoperative pathological examination of sentinel lymph nodes is of paramount importance in delineating the extent of surgical intervention. This study aimed to analyze the feasibility of frozen section of sentinel lymph node in early gastric cancer.

A retrospective analysis of data prospectively collected was undertaken from a tertiary hospital. Patients with early gastric cancer were treated by sentinel lymph node biopsy followed by lymph node dissection. Primary outcome variables were the failure rate of frozen section identification and the incidence of metastasis in non-sentinel lymph nodes.

Of the 238 patients who underwent sentinel lymph node pelvic dissection, 30 were identified as having lymph node metastasis upon permanent pathological examination. Thirteen patients exhibited macrometastasis confirmed in both frozen and formalin-fixed and paraffin-embedded (FFPE) sections. Patients with negative sentinel lymph nodes in frozen sections but evidence of micrometastasis in FFPE sections did not experience lymph node recurrence during the follow-up period. In instances where tumor-positive lymph nodes were identified in frozen sections, metastasis in non-sentinel lymph nodes was detected in the paraffin blocks (8.3%, 2/24).

The single-section hematoxylin and eosin staining method proves efficacious in detecting macrometastatic tumors through intraoperative pathological examination. Should the frozen section result be definitively negative, sentinel basin dissection can be executed with safety. Conversely, in the absence of such confirmation, the standard surgical approach is advisably pursued.