Prognosis After Laparoscopic Gastrectomy in Patients with Pathological Stage II or III Gastric Cancer Who Were Preoperatively Diagnosed with Clinical Stage I: Propensity Score Matching Analysis of a Multicenter Dataset.

BACKGROUND: Laparoscopic gastrectomy (LG) is a standard approach for patients with clinical stage I gastric cancer in East Asia; however, following surgery, these patients may be pathologically diagnosed with stage II or III cancer. The prognosis of patients with gastric cancer migration from clinical stage I to pathological stage II or III after LG has not been completely clarified. METHODS: To compare the prognosis following LG and open gastrectomy (OG) in patients with pathological stage II or III gastric cancer who were preoperatively diagnosed with stage I cancer, we conducted a retrospective analysis using a multicenter dataset comprising details of 3480 patients who underwent gastrectomy between 2010 and 2014 at nine participating institutions. We used propensity score matching to reduce selection bias. RESULTS: After propensity score matching, 146 patients were finally selected. There were no significant differences in the number of dissected lymph nodes. Morbidity rates, length of postoperative hospital stay, and time between surgery and initiation of adjuvant chemotherapy were comparable between the two groups. Moreover, there were no significant differences in the overall, disease-specific, and relapse-free survival rates between the LG and OG groups. The LG group tended to have more patients with hematogenous recurrence, whereas the OG group tended to have more patients with peritoneal recurrence. CONCLUSIONS: Our multicenter dataset analysis indicated that the prognosis of patients with gastric cancer migration from clinical stage I to pathological stage II or III was independent of the surgical approach.