Clinical and prognostic effects of adjuvant therapy on less advanced esophageal squamous cell carcinoma patients.

Background: This study aimed to clarify whether adjuvant therapy is suitable for less advanced esophageal squamous cell carcinoma (ESCC) patients postoperatively. Methods: Data from 973 patients were collected. The prognosis and clinicopathological traits of these patients were calculated in both the TNM I and IIA stages. Meanwhile, 2 separate nomograms were applied in terms of the variables with a multivariate P value <0.05 in the Cox proportional hazard regression model. Results: There were 471 and 502 patients in the I and IIA stage respectively; among all enrolled patients, 641, 130, 73, and 129 patients were in the no-treatment, chemotherapy, radiotherapy, and chemoradiotherapy groups, respectively. Adjuvant therapy was drawn as the independent prognostic factors for stage I (P=0.026; HR =1.081, 95% CI: 1.093, 1.308) and IIA patients (P<0.001; HR =0.788, 95% CI: 0.693, 0.896). Radiotherapy consistently obtained the best prognosis for patients when compared with the other 3 groups in the I and IIA stage. Patients in I stage had the worst prognosis after receiving chemoradiotherapy, and still, the small survival benefits of chemoradiotherapy were seen in patients of IIA stage. Two separate nomograms for the I and IIA stage were constructed. The C-index was 0.665 (95% CI: 0.569, 0.761) in the I stage and 0.645 (95% CI: 0.567, 0.723) in the IIA stage. Meanwhile, the calibration curves for predicting 3-year and 5-year survival for I and IIA patients agreed well with the actual observations. Conclusions: Among less advanced ESCC patients, adjuvant therapy was not only found to be an independent factor but also proved to be of importance in patient prognosis, and radiotherapy is recommended.