Postoperative adjuvant therapy for resectable thoracic esophageal squamous cell carcinoma: a retrospective analysis of 426 cases

The aim of this study was to evaluate the value of postoperative adjuvant therapy for resectable thoracic esophageal squamous cell carcinoma (ESCC) in China. We retrospectively analyzed 426 eligible patients seen between October 2007 and November 2011. Specifically, we assessed clinicopathological characteristics and the disease-free and overall survival rates. Of the 426 patients, 272 cases underwent surgery alone, and 154 cases received postoperative adjuvant therapy (67 cases with radiotherapy, 57 cases with chemotherapy, and 30 cases with simultaneous chemoradiotherapy). The median follow-up time was 48.0 months (23.0-72.0 months), and the median survival time was 48.4 months (1.0-72.0 months). We found a significant difference between the surgery-alone and adjuvant therapy groups in the status of lymph node (LN) metastasis (N stage; P < 0.01), but there were no differences between the two groups with regard to other clinicopathological characteristics, including age, sex, lesion location, T stage, differentiation grades, surgery approach, or average number of LN dissections. The 5-year disease-free survival (DFS) rates of the surgery-alone and adjuvant therapy groups were 48.9 and 37.1 %, respectively (P < 0.001); no significant difference was found in 5-year overall survival (OS) rate between the two groups (P > 0.05). A stratification analysis based on N stage suggested that the 5-year DFS and OS rates were similar in N0-N3 subgroups (P > 0.05), except that patients with surgery alone had a higher 5-year DFS than those with postoperative adjuvant therapy in N0 subgroup (P = 0.013). Our data suggest that patients with resectable thoracic ESCC may not benefit from postoperative adjuvant therapy. Further prospective studies are required to elucidate the utility of postoperative adjuvant therapy and to standardize individualized treatments for resectable ESCC.