Detection of gastric cancer cells in the blue lymph node and lymphaticus under sentinel lymph node biopsy using dye technique alone.

Background/aims: We investigated whether or not there are cancer cells in the blue node (BN) and the sentinel lymphaticus (SL), which is detected using sentinel node biopsy (SNB).

Methodology: Patent blue (1%) is injected submucosally into 4 to 5 different sites at 1 mL per site around the primary tumor. Blue-stained lymphatics and lymph nodes can be seen by turning over the greater omentum and lesser omentum extraperitoneally. If blue nodes or lymphaticus are found, biopsy is performed at this point. The study was conducted in 14 patients (11 males and 3 females, mean age 65.7 y/o) with a preoperative diagnosis of T1 tumor invasion and NO that there is no lymph node metastasis. Informed consent was obtained from the patients for SNB after patent blue staining and investigation of CEAmRNA and CK20mRNA.

Results: Of the 14 patients in whom BN and SL were identified, 1 (7.1%) had positive CEAmRNA and positive CK20mRNA of SL.

Conclusion: Our present study shows the possibility for the existence of cancer cells in the lymphaticus from the tumor to BN. We should avoid the cut of lymphaticus when we perform gastrectomy.