Longer interval between neoadjuvant chemoradiotherapy and surgery is associated with improved pathological response, but does not accurately estimate survival in patients with resectable esophageal cancer

Neoadjuvant chemoradiotherapy (nCRT) has been shown to reduce tumor burden and achieve tumor regression in patients with esophageal cancer (ESC). However, the most beneficial time interval between the administration of nCRT and surgery remains unclear. Therefore, the aim of the present study was to explore the association of the duration of time between nCRT and surgery with the prognosis of patients with ESC. Patients with ESC who received nCRT following surgical resection (n=161) were reviewed and divided into the prolonged time interval group (time interval >= 66 days) and the short time interval group (time interval <66 days), according to the median value. Subsequent analysis revealed that the prolonged time interval group achieved a higher pathological complete response (pCR) rate compared with the short time interval group (49.4 vs. 26.3%; P=0.003). Furthermore, multivariate logistic regression analysis showed that it was possible to independently estimate a higher pCR rate based on a prolonged time interval (odds ratio, 2.131; P=0.042). However, no association between a prolonged time interval and disease-free survival (DFS) was detected using Kaplan-Meier curves (P=0.252) or multivariate Cox regression (P=0.607) analyses. Similarly, no association was identified between a prolonged time interval and overall survival (OS; P=0.946) based on Kaplan-Meier curve analysis, and subsequent multivariate Cox regression analyses showed that the time interval also failed to independently estimate OS (P=0.581). Moreover, female sex (P=0.001) and a radiation dose >= 40 Gy (P=0.039) served as independent factors associated with a higher pCR rate, and the pCR rate was an independent predictor of favorable DFS (P=0.002) and OS (P=0.015) rates. In conclusion, the present study revealed that a prolonged time interval from nCRT to surgery was associated with a higher pCR rate, but it failed to estimate the survival profile of patients with ESC.