SENTINEL LYMPH NODES AND LYMPHATIC BASIN BY THE DYE-GUIDED METHOD IN EARLY GASTRIC CANCER BASED ON IMMUNOHISTOCHEMICAL ANALYSIS OF MICROMETASTASES

Abstract

To elucidate the value of sentinel nodes (SN) navigation surgery by dye-guided method in early gastric cancer (EGC), we investigated the micrometastasis in lymph nodes (LN) dissected for EGC with immunohistochemical technique (IHC). Totally 257 SNs were obtained from 57 EGC patients who underwent conventional distal gastrectomy with SN identification by dye method. These LNs were analyzed with IHC using anticytokeratin antibodies (CAM5.2). LN metastases newly detected by IHC were defined as micrometastasis of a wide sense, which were classified into two categories : tumor cell microinvolvement (TCM) was one individual CAM5.2-positive cell ; and tumor cluster (TC) was clusters of two or more tumor cells. In mucosal cancer, TCM was detected in one patients, 2.9% (1/34). In SM cancer, TCM or TC were detected in 14 patients, 60.9% (14/23). SNs were deteced in 57 of 57 (100%) patients, the sensitivity of the SN as an indicator of lymph node micrometastasis was 60%, and overall diagnostic accuracuy was 89.5%. The sensitivity of the sentinel lymphatic basin (SB) as an indicator was as good as 86.7%, and the overall diagnostic accuracuy was 96.5%, which suggests the superiority of SB to SN as an indicator in SNNS for EGC. SB as an indicator will enable us to perform safer limited surgery.