The Role of Adjuvant Chemotherapy after Neoadjuvant Chemoradiotherapy Followed by Surgery in Patients with Esophageal Squamous Cell Carcinoma

PURPOSE: This study aimed to investigate the efficacy of adjuvant chemotherapy after neoadjuvant chemoradiotherapy (CCRTx) followed by surgery in patients with esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS: We retrospectively analyzed the data from 382 patients who received neoadjuvant CCRTx and esophagectomy for ESCC between 2003 and 2018. RESULTS: This study included 357 (93.4%) men, and the years median patient age was 63 (range, 40 to 84 years). Overall, 69 patients (18.1%) received adjuvant chemotherapy, whereas 313 patients (81.9%) did not. The median follow-up period was 28.07 months (interquartile range, 15.50 to 62.59). The 5-year overall survival (OS) and disease-free survival were 47.1% and 42.6%, respectively. Adjuvant chemotherapy did not improve OS in all patients, but subgroup analysis revealed that adjuvant chemotherapy improved the 5-year OS in patients with ypT+N+ (24.8% vs. 29.9%, p=0.048), whereas the survival benefit of adjuvant chemotherapy was not observed in patients with ypT0N0, ypT+N0, or ypT0N+. Multivariable analysis revealed that ypStage and adjuvant chemotherapy (hazard ratio, 0.601; p=0.046) were associated with OS in patients with ypT+N+. Freedom from distant metastasis was marginally different according to the adjuvant chemotherapy (48.3% vs. 41.3%, p=0.141). CONCLUSION: Adjuvant chemotherapy after neoadjuvant therapy followed by surgery reduces the distant metastasis in ypT+N+ ESCC patients, thereby improving the OS. The consideration could be given to administration of adjuvant chemotherapy to ypT+N+ ESCC patients with tolerable conditions.