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

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).We retrospectively analyzed the data from 382 patients who received neoadjuvant CCRTx and esophagectomy for ESCC between 2003 and 2018.This study included 357 (93.4%) men, and the years median patient age was 63 (range 40~84 years). Overall, 69 (18.1%) patients received adjuvant chemotherapy, whereas 313 (81.9%) patients did not. The median follow-up period was 28.07 (interquartile range: 15.50-62.59) months. 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).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.