Sentinel node biopsy for cT1 and cT2a gastric cancer

Aims To evaluate the feasibility and accuracy of sentinel node (SN) biopsy for gastric cancer. Patients and methods One hundred patients with gastric cancer diagnosed as cT1 (n=80) or cT2a (n=20) were enrolled. Indocyanine green-stained SNs were analysed by hematoxylin and eosin staining (n=100) and by cytokeratin immunohistochemistry (n=50). Results SNs were identified in 94 of the 100 patients and the mean number of SNs was 4.4 (range, 1—12). Of these 94 patients, 14 patients had lymph node metastases. Two patients with T1 and one patient with T2 had metastases in non-SNs alone by hematoxylin and eosin staining (diagnostic accuracy =97.3% in T1 and 95.0% in T2). All three patients with a false negative result had a tumour, which was more than 4 cm in size and signet ring cell histology. In two of them, the tumour was located at lesser curvature. By immunohistochemical staining, three patients with T1 and one patient with T2 were found to have lymph node micrometastases in non-SNs alone among 45 patients (diagnostic accuracy =92.1% in T1, 85.7% in T2). Conclusion SN biopsy using indocyanine green can be performed rapidly and easily with a high detection rate and accuracy in patients with T1 gastric cancer. However, it should be performed with caution for large tumours with a signet ring cell histology located at lesser curvature due to the possibility of a false negative result.