Sentinel lymph node and skip metastases in gastric cancer: a prospective study.

Background/aims: The aim of the present study was to investigate localization and distribution of sentinel lymph node (SLN) in gastric cancer and influenced factors of skip metastasis.

Methodology: Eighty-nine cases with solitary or single station metastatic lymph nodes (LNs) among 779 gastric cancer patients were included in this study. D2 or D2+ lymph node dissection with total or distal gastrectomy had been performed. The location of SLNs and characteristics were analyzed retrospectively.

Results: Seventy-one patients (79.8%) had SLNs at the first level of the regional LN group and 18 cases (20.2%) had skip metastases SLNs. NO.7 (44.4%) and NO.8a (27.8%) were the most common sites of skip metastases. Multivariate analysis identified the differentiated degree of tumor as the only significant influenced factor of skip metastases (p=0.031). The number of metastatic SLNS was significantly greater in advanced gastric cancer patients (2.4 ± 1.4) than early gastric cancer patients (1.5 ± 0.9) (pT4 vs. pT1, p=0.002; pT4 vs. pT2, p=0.014; pT3 vs. pT1, p=0.018).

Conclusions: The differentiated degree of gastric cancer is the most important influenced factor of skip metastases and NO.7 and NO.8a are the most important N2 LN stations that should be observed when lymphadenectomy is performed.