Timing of surgery after neoadjuvant chemotherapy for gastric cancer: Impact on outcomes.

ABSTRACT

AIM: To evaluate whether the neoadjuvant chemotherapy (NACT)-surgery interval time significantly impacts the pathological complete response (pCR) rate and long-term survival. METHODS: One hundred and seventy-six patients with gastric cancer undergoing NACT and a planned gastrectomy at the Chinese PLA General Hospital were selected from January 2011 to January 2017. Univariate and multivariable analyses were used to investigate the impact of NACT-surgery interval time (< 4 wk, 4-6 wk, and > 6 wk) on pCR rate and overall survival (OS). RESULTS: The NACT-surgery interval time and clinician T stage were independent predictors of pCR. The interval time > 6 wk was associated with a 74% higher odds of pCR as compared with an interval time of 4-6 wk (P = 0.044), while the odds ratio (OR) of clinical T3vs clinical T4 stage for pCR was 2.90 (95%CI 1.04-8.01, P = 0.041). In Cox regression analysis of long-term survival, post-neoadjuvant therapy pathological N (ypN) stage significantly impacted OS (N0vs N3 HR = 0.16, 95%CI 0.37-0.70, P = 0.015; N1vs N3 HR = 0.14, 95%CI 0.02-0.81, P = 0.029) and disease-free survival (DFS) (N0vs N3 HR = 0.11, 95%CI 0.24-0.52, P = 0.005; N1vs N3 HR = 0.17, 95%CI 0.02-0.71, P = 0.020). The surgical procedure also had a positive impact on OS and DFS. The hazard ratio of distal gastrectomy vs total gastrectomy was 0.12 (95%CI 0.33-0.42, P = 0.001) for OS, and 0.13 (95%CI 0.36-0.44, P = 0.001) for DFS. CONCLUSION: The NACT-surgery interval time is associated with pCR but has no impact on survival, and an interval time > 6 wk has a relatively high odds of pCR.