Abstract 1432P
Background
In China, esophageal cancer is one of the most common cancers and the third cause of cancer-related death. Surgery is the main treatment approach. However, the 5-year survival rate of surgical resection alone is 30% and local recurrence and lymph node metastasis are the main causes of failure. Theoretically, postoperative radiotherapy has the effect to kill the subclinical lesions. However, the results of the clinical studies are controversial.
Methods
This trial initiated in 2014. Patients who underwent a radical transthoracic resection with negative margins within 3 months and histologically confirmed as esophageal squamous cell carcinoma (pT3-4 or N+, M0 according to AJCC 7th) were eligible for this study. Radiotherapy was delivered with total dose of 40Gy in 20 fractions using 3D technique. CTV included tumor bed, anastomosis site, bilateral supraclavicular region, all mediastinal lymph node site, left gastric and celiac trunk lymph node site.The primary endpoint was 2-year local control rate.The secondary endpoint was overall survival (OS) and adverse events.
Results
The median follow-up was 48 months. In 70 patients, 17 patients died. 2 year-local control rate is 67.29%. Median LRFS was 39 months. The 1-, 2-, 3 and 4-year LRFS were 81.18%, 59.43%, 53.63%, 50.74%. Median OS was 57months. The 1, 2, 3 and 4-year OS rate were 92.75%, 69.57%, 60.87%, 53.47%. Median DFS was 36 months. 1, 2, 3, and 4-year DFS were 78.28%, 56.19%, 50.00% and 46.78%, respectively. Median DMFS was 46.19 months. Locoregional recurrence was found in 40%, most in mediastinal lymph node region, followed by anastomosis , celiac lymph node region. 25.7% was found hematogenous recurrence. Lung was the most frequent metastasis site. No late AE occurred. Incidences of acute grade 3 hematological toxicity including 5.7% leukopenia and 1.4% neutropenia. In term of acute grade 3 nonhematological toxicity, nausea and vomiting were the most frequent AE followed by radiation induced pneumonitis.
Conclusions
This study proves that the dose distribution of large-field radiation is feasible. It provides a basis for further exploration of higher dose large-field radiation and combined chemotherapy.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Fudan University Shanghai Cancer Center.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.