Pretreatment clinical stage predicts locoregional recurrence in patients with esophageal cancer who achieved a complete clinical response to chemoradiotherapy

Objective: Definitive chemoradiotherapy (dCRT) represents a curative nonsurgical treatment option for patients with esophageal cancer. However, tumor recurrence is common after dCRT, even when clinical complete response (cCR) is achieved. Here, we investigated the timing, patterns, and risk factors for recurrence in patients with esophageal squamous cell carcinoma (ESCC) who achieved cCR following dCRT. Methods: We retrospectively examined the clinical records of patients with ESCC who achieved cCR following dCRT between 2001 and 2014. Locoregional recurrence (LR) was defined as a recurrence occurring in the esophageal lumen and/or locoregional lymph nodes. Recurrences at any other sites were considered as distant recurrences (DRs). Results: A total of 102 patients who achieved cCR were included. After a mean follow-up of 54.5 months, 51 patients developed recurrences (34 LRs, 6 combined LR and DR, and 11 DRs). The cumulative 1-, 3-, and 5-year recurrence rates were 35%, 46%, and 50%, respectively. The mean time to recurrence for the 40 patients with LRs (including LRs plus LRs/DRs) was significantly shorter (281.4 days) compared with that of patients with DRs (643.6 days; P =.006), with 95% of the former being diagnosed within 2 years. Multivariate Cox regression analysis identified pretreatment clinical stage III as the only independent risk factor for LR (hazard ratio, 2.732; 95% confidence interval; 1.063-7.020; P =.037). Conclusions: Disease recurrence occurs in 50% of ESCC patients who achieve cCR following dCRT, with LR being the most common pattern. Advanced pretreatment clinical stage is an independent risk factor for LR.