Prognostic factors for survival of patients with esophageal squamous cell carcinoma following radiotherapy

Background: Prognostic factor is desperately needed to help predict outcomes of patients with esophageal cancer treated by radiotherapy. Materials and Methods: We retrospectively analyzed the probable prognostic factors which could be attained easily through general clinical examinations and imaging parameters without surgical approaches. General clinical features included sex, age, smoking, anemia, lesion location and radiation field. Imaging parameters included the lesion length defined by esophageal barium swallow and lesion characteristics on CT imaging, such as lymph nodes metastasis, volume of the primary lesion (GTV-E), the volume of positive lymph nodes (GTV-LN), and the total gross tumor volume (GTV-T = GTV-E + GTVLN). Results: The 3-year overall survival rate was 20.3%, with a median follow-up of 31.2 months (range: 8-54 months) for patients who were still alive. On univariate analysis, anemia, lesion location, lesion length by barium esophagogram, computed tomography imaging characteristics including lymph nodes metastasis, GTV-E, GTV-LN, GTV-T were prognostic for overall survival. By multivariate analysis, only anemia [hazard ratio (HR) 0.51, 95% CI 0.30-0.84, P = 0.02] and the GTV-T (HR 0.78, 95% CI 0.62-0.95, P = 0.01) were independent prognostic factors for survival. Conclusion: We recommend that GTV-T and anemia could be the best predictors for survival of ESCC patients who treated by 3D-CRT or IMRT.