The Role of Adjuvant Chemoradiotherapy Over Radiotherapy After R0 Resection for Stage II-III Esophageal Squamous Cell Carcinoma

Purpose: This study compared the effectiveness and safety of postoperative concurrent chemoradiotherapy (POCRT) containing paclitaxel (PTX) and cisplatin (DDP) with postoperative radiotherapy (PORT) after R0 resection for stage II-III thoracic esophageal squamous cell carcinoma (TESCC). Materials and Methods: After propensity score matching (PSM) analysis, 87 TESCC patients treated with PORT were matched 1:1 to 87 patients who received POCRT between July 2012 and December 2018. Radiotherapy was delivered at a dose of 200 cGy per day to a total dose of 5000 cGy. Concurrent chemotherapy consisted of DDP (25 mg/m(2)) for 3 days plus PTX (135 mg/m(2)) on day 1 every 3 weeks. Results: Patient- and disease-related characteristics were well-balanced between the two groups. The median overall survival (OS) and disease-free survival (DFS) times were 39.2 and 31.0 months, respectively. The 5-year OS and DFS rates were 31.9% and 19.1% in the PORT group and 45.1% and 35.1% in the POCRT group, respectively. Statistical significance was demonstrated by comparing OS and DFS (P=0.022 and 0.016, respectively). Additionally, subgroup analysis revealed that in node positive TESCC patients, the POCRT group was significantly different from the PORT group regarding OS and DFS (P=0.049 and 0.039, respectively). POCRT decreased distant metastasis over PORT (P=0.044) with manageable toxicities. Multivariate analysis revealed that aside from factors associated with tumor stages, treatment modality was another strong prognostic factor for both OS and DFS (P=0.015 and 0.010, respectively). Conclusion: Stage II-III TESCC patients could benefit from POCRT with manageable toxicities. Future well-designed prospective studies are highly warranted to confirm the findings in our report.