Patterns of Relapse after Definitive Chemoradiotherapy in Stage II/III (Non-T4) Esophageal Squamous Cell Carcinoma

The purpose of this study was to investigate the utility of surveillance after definitive chemoradiotherapy (dCRT) in patients with squamous cell carcinoma.Patients who underwent dCRT for stage II/III (excluding T4) esophageal squamous cell carcinoma were analyzed. First failures following complete response were classified into luminal relapse (LR), regional relapse (RR), distant metastasis (DM), new cancer diagnosed by esophagogastroduodenoscopy (NC-E), and new cancer other than NC-E (NC-O). We focused on LR, RR, and NC-E, and analyzed their frequency, timings and survival outcomes after local treatments.Among 302 patients treated with dCRT, 204 achieved complete response. The number of patients who recurred with LR, RR, DM, NC-E, and NC-O were 28 (14% of 204), 13 (6%), 39 (19%), 34 (17%), and 16 (8%). Ninety-three percent of LRs were diagnosed within 3 years after dCRT, and all RRs were diagnosed within 2 years. Annual odds of NC-E did not decrease over time. Twenty-three patients with LR, 6 with RR, and 32 with NC-E underwent local treatment, and their median overall survivals were 49.2, 19.5, and 108.9 months.Surveillance with esophagogastroduodenoscopy may be important in the first 3 years after dCRT to detect LR and to detect NC-E beyond 3 years.