The impact of histology on recurrence patterns in esophageal cancer treated with definitive chemoradiotherapy

To assess the impact of histology on recurrence patterns and survival outcomes in patients with esophageal cancer (EC) treated with definitive chemoradiotherapy (CRT).We analyzed 590 consecutive EC patients who received definitive CRT from 1998 to 2014, including 182 patients (30.8%) with squamous cell carcinoma (SCC) and 408 (69.2%) with adenocarcinoma. Recurrence pattern and timing, survival, and potential prognostic factors were compared.After a median follow-up time of 58.0months, the SCC group demonstrated a comparable locoregional recurrence rate (42.9% vs. 38.0%, P=0.264) but a significantly lower distant failure rate (27.5% vs. 48.0%, P<0.001) than adenocarcinoma group. No significant difference was found in overall survival or locoregional failure-free survival between groups, whereas the SCC group was associated with significantly more favorable recurrence-free survival (P=0.009) and distant metastasis-free survival (P<0.001). The adenocarcinoma group had higher hematogenous metastasis rates of bone, brain, and liver, whereas the SCC group had a marginally higher regional recurrence rate. Among patients who received salvage surgery after locoregional recurrence, no significant difference in survival was found between groups (P=0.12).The patterns and sites of recurrence, survival outcomes, and prognostic factors were significantly different between esophageal SCC and adenocarcinoma.