Prognosis and failure patterns of esophageal squamous cell carcinoma patients undergoing selective lymph node irradiation

Objective To investigate the prognosis and failure mode of patients with esophageal squamous cell carcinoma receiving selective lymph node irradiation (ENI). Methods A total of 179 eligible patients with esophageal squamous cell carcinoma were retrospectively analyzed. The prognostic value of tumor-related factors, the influencing factors of short-term curative effect and prognosis of patients, and the single and multi factor indexes of affecting the overall survival rate (OS), progression free survival rate (PFS) and recurrence of patients were analyzed.SPSS 19.0 software was used for statistical analysis. Results The 1, 3- and 5-year OS of the whole group were 77.1%, 40.1% and 26.0%, respectively, and 1-, 3- and 5-year PFS were 62.6%, 30.6%, and 20.3%, respectively. Multivariate analysis showed that hoarseness, cN stage, cTNM stage, GTV-transverse diameter (GTV-D) and GTV-volume/length (GTV-V/L) were independent factors affecting OS (P<0.05). The sonar, cTNM staging, and short-term efficacy were independent factors affecting PFS (P<0.05). Recurrence occurred in 75 patients (41.9%) in the whole group, and 61 patients (34.1%) had distant metastases. Among them, 9 patients (10.6%) had both recurrence and distant metastasis. Of the 75 patients with recurrence, 64(85.3%) had simple esophageal recurrence, 4(5.3%) had lymph node recurrence, and 7 (9.3%) had both. Recurrence occurred in 18 of the 63 patients who achieved CR after treatment. Only 2 patients had lymph node recurrence. Logistic multivariate analysis showed that the surrounding tissue/organ invasion, GTV-D and short-term were independent factors affecting the recurrence rate (P<0.05). Conclusions ENI is feasible in patients with esophageal squamous cell carcinoma, and the main mode of failure is esophageal recurrence. Pre-treatment sonar, larger GTV-D and GTV-V/L, more advanced clinical stage and poorer short-term efficacy are indicators of poor prognosis, while the peripheral tissue involvement, GTV-D and short-term efficacy are the independent factors that influence failure. Key words: Esophageal neoplasms/esophageal squamous cell carcinoma; Intensity modulated conformal radiotherapy; Elective nodal irradiation; Prognosis; Failure mode