Long-term clinical outcomes and prognosis after definitive radiotherapy for patients with cervical esophageal squamous cell carcinoma: a single-institution retrospective study

Background: Definitive radiotherapy has become a more common treatment for cervical esophageal squamous cell carcinoma (CESCC), but data about long-term clinical outcomes is still relatively sparse. The purpose of this study was to describe long-term clinical outcomes after definitive radiotherapy for CESCC, and identify the prognostic factors influencing these outcomes.Methods: We retrospectively analyzed all patients who received definitive radiotherapy for CESCC at our institution between 2006 and 2014. The overall survival (OS) rate, locoregional failure-free survival (LRFFS) rate, and toxicities were retrospectively evaluated during long-term follow-up. Univariate and multivariate analyses were performed to identify prognostic factors.Results: A total of 120 patients were included for analysis. The median prescribed radiation dose for the gross tumor and metastatic lymph nodes was 60 Gy. Elective nodal irradiation (ENI) was performed on 99 patients (83%); 90 patients (75%) received concurrent chemotherapy. The OS rates were 22.7% at 5 years and 14.9% at 8 years. The LRFFS rates at 3, 5, and 8 years were 27.5%, 21.7%, and 15.0%, respectively. The univariate analysis suggested that N classification and non-regional lymph node metastasis (M1Lym) status were independent risk factors for overall survival (P<0.01). A dose of more than 60 Gy didn't have a statistically significant influence in the multivariate analysis, although a total dose of more than 60 Gy was associated with improved survival in the univariate analysis. Concurrent chemotherapy was not associated with OS or LRFFS time in the univariate or multivariate analysis. A total of 74 patients (61.7%) experienced locoregional treatment failure. The most commonly documented acute toxicities were grade 1 and grade 2 toxicities in 61 patients (50.8%). There were 2 patients diagnosed with hypothyroidism as a late toxicity event. Conclusions: Definitive radiotherapy is a reasonable curative treatment option with laryngopharyngeal preservation for CESCC patients. Radical treatments for lymph node metastases may improve the OS and LRFFS times. Monitoring for thyroid function may be warranted during long-term follow-up.