Prolonged interval between neoadjuvant chemoradiotherapy and esophagectomy does not benefit the outcome in esophageal cancer: a systematic review and meta-analysis.

Whether a prolonged interval between neoadjuvant chemoradiotherapy (nCRT) and esophagectomy could benefits conditions such as rectal cancer, still remains unknown. We therefore performed the current study to evaluate the influence of the interval between nCRT and esophagectomy on the clinical outcomes in patients with esophageal cancer. PubMed and Embase were searched to identify eligible cohort studies. The primary outcome was five-year overall survival (OS), and secondary outcomes included the incidence of anastomotic complications, perioperative mortality, pathologic complete response (pCR) rate, positive circumferential resection margin (CRM) rate, and R0 resection rate. A random-effects model was used for all meta-analyses irrespective of heterogeneity. Ten cohort studies with 2383 patients were included. Overall, the pooled estimate revealed that the prolonged interval has no impact on five-year OS (odds ratio (OR) 0.87, 95% CI 0.66 to 1.14, P = 0.30), with low heterogeneity (PH = 0.78, I2 = 0%). However, it was associated with an increased risk of anastomotic complication (OR 1.71, 95% CI 1.15 to 2.54, P = 0.008), with no effect on perioperative mortality (OR 1.20, 95% CI 0.79 to 1.83, P = 0.40). Additionally, the prolonged interval failed to increase the pCR rate (OR 1.02, 95% CI 0.78 to 1.33, P = 0.89). Even worse, it was correlated with a decreased R0 resection rate (OR 0.60, 95% CI 0.41 to 0.88, P = 0.009) and increased positive CRM rate (OR 2.20, 95% CI 1.44 to 3.36, P < 0.001). This study suggests that the prolonged interval between nCRT and esophagectomy fails to result in better outcomes, and in fact, could worsen clinical outcomes, with increasing anastomotic complications, and undermine resection completeness. However, this conclusion should be treated with caution because of the limitations of retrospective cohort study and substantial clinical heterogeneity. (The study was registered at PRESPERO as CRD42016048210).