[Is Adjuvant Chemotherapy Necessary after R0 Resection for pCR or ypStage I Patients with Gastric Cancer ?]

Neoadjuvant chemotherapy(NAC)followed by surgery and palliative chemotherapy for unresectable advanced gastric cancer followed by conversion surgery are currently under investigation in clinical trials and are attractive therapeutic alternatives. We examined the relationship between ypStage and prognosis among patients with gastric cancer who underwent surgery following preoperative chemotherapy and evaluated the necessity of adjuvant chemotherapy in patients with pCR or ypStage I gastric cancer. Sixty-one patients received chemotherapy followed by surgery from 2006 to 2014 in Osaka National Hospital. For preoperative chemotherapy, 41 patients received NAC, and 20 patients received palliative chemotherapy. Five (8.2%)patients with pCR, ypStage I A, and Stage I B disease(n=2, 1, and 2, respectively), 3 of whom received adjuvant chemotherapy and 2 of whom did not, were all alive without recurrence after a median follow-up of 3 years and 6 months. The overall survival for patients from each ypStage in the preoperative chemotherapy group was comparable with that for each ypStage in the surgery without preoperative chemotherapy group during the same period. Discontinuation of adjuvant chemotherapy and intense follow-up is a treatment option after R0 resection for patients with gastric cancer who achieve pCR or downstaging to ypStage I .