A phase II study of neoadjuvant chemotherapy with a modified FOLFOX6 regimen for locally advanced gastric cancer.

Abstract

81 Background: The aim of this study was to evaluate the efficacy and safety of neoadjuvant chemotherapy with the mFOLFOX6 regimen in gastric cancer patients. Methods: This study was a single-arm phase II study. 73 patients with histologically confirmed locally advanced gastric cancer (T2-T4 or N+) were enrolled. The patients were administered the mFOLFOX6 regimen for 3 cycles. Surgery was scheduled 3-4 weeks after the completion of the chemotherapy. Postoperative chemotherapy began 4 weeks after surgery, and the program choice was based on the results of patients’ clinical/pathological evaluations. Perioperative efficacy, toxicity, effects of surgery, postoperative observation, and prognosis were studied. Survival analysis was performed to identify the relationship between the response and outcome and to identify factors predictive of OS. Results: 73 patients received the neoadjuvant chemotherapy, and 67 (91.8%) completed all of the preoperative cycles, with grade 3-4 toxicity arising in 33.0%. Surgery was performed in 71 (97.3%) patients, and radical resection was achieved in 67 (91.8%) patients. Postoperative chemotherapy started in 63 (88.7%) patients. The radiology response rate of chemotherapy was 45.8%. Among the patients who underwent radical surgery, pT downstaging was observed in 22 (32.8%) patients and pN downstaging was observed in 17 (25.4%) patients. All of the patients showed different levels of histological regression of the primary tumour, with a ≥ 50% regression rate of 49.2% and a pCR rate of 3.0%. Univariate analysis identified factors that were associated with OS, including local tumour infiltration, Lauren classification, pre-chemotherapy N stage, ypTNM stage, and pathologic regression rate (GHR)( ≥ 2/3/ < 2/3, ≥ 50%/ < 50%). Multivariate analysis identified both ypTNM stage and Lauren classification as independent predictors of survival. Conclusions: The mFOLFOX6 regimen was very effective and well-tolerated as a neoadjuvant chemotherapy for locally advanced gastric cancer. The ypTNM stage could serve as an independent predictor of survival. GHR ≥ 50% / < 50% could be used as a surrogate marker to guide the selection of a postoperative chemotherapy regimen. Clinical trial information: NCT02226380.