The Safety of the Dissection of Lymph Node Stations 5 and 6 in Pylorus-Preserving Gastrectomy

This study was intended to examine the safety of possibly incomplete dissection of lymph node stations (LNS) 5 and 6 in pylorus-preserving gastrectomy (PPG) for gastric cancer. We reviewed the medical information from 1802 gastric cancer patients who underwent curative gastrectomy and whose lymph nodes were topographically classified according to LNS between March 2003 and December 2008. We divided the patients who underwent subtotal gastrectomy into 2 groups according to the distance between the distal resection margin (DRM) and primary tumor: those with a distance of < 6 cm (the < 6 DRM group) and those with a distance of a parts per thousand yen6 cm (the a parts per thousand yen6 DRM group). We analyzed the lymph node metastasis rate to LNS 5 and 6 according to T stage and the location. The number of retrieved lymph nodes according to LNS was compared between subtotal gastrectomy (STG) and PPG. The metastasis rate to LNS 5 was very rare in a parts per thousand yen6 DRM group: T1a, 0% (0 of 105); T1b, 0.9% (1 of 113); and T2a, 0% (0 of 56), although the number of retrieved LNS 5 was significantly lower in PPG than in STG. The metastasis rate to LNS 6 in the a parts per thousand yen6 DRM group was significantly lower than in the < 6 DRM group, but higher than that of LNS 5: T1a, 0% (0 of 107); T1b, 1.8% (2 of 114); and T2a, 3.6% (2 of 56). The number of retrieved LNS 6 was not significantly different between STG and PPG. PPG seems to be safe for early gastric cancer located a parts per thousand yen5 cm from the pylorus in terms of LNS 5 and 6.