Concurrent Selective Lymph Node Radiotherapy and S-1 Plus Cisplatin for Esophageal Squamous Cell Carcinoma: A Phase II Study

Abstract

Background: The efficacy, toxicity, and patterns of failure of esophageal squamous cell carcinoma (ESCC) treated with selective lymph node (SLN) conventional fraction radiotherapy (CFRT) and S-1 plus cisplatin (CDDP) were evaluated.

Patients and methods: 67 Patients with clinical stage II-IVa ESCC were enrolled. The total dose of SLN CFRT was 60 Gy in 30 fractions over 6 weeks. The first course of radiation covered the primary and metastatic regional tumors and high-risk lymph nodal regions, given at 2 Gy/fraction for a dose of 40 Gy. In the second course, CFRT was delivered to the boost volume for an additional 20 Gy in 10 days, using 2 Gy/fraction. Two cycles of chemotherapy were given at the beginning of radiotherapy. CDDP at 25 mg/m²/day was given on days 1-3 and days 22-24, and S-1 at 80 mg/m²/day on days 1-14 and days 22-35. Patients achieving objective response after concurrent chemoradiotherapy underwent two additional cycles of chemotherapy.

Results: The objective response rate (ORR) was 82.5%. Grade 3 or 4 toxicities included leukopenia (23.8%), neutropenia (14.3%), thrombocytopenia (14.3%), hemoglobin (4.8%), gastrointestinal (12.7%), skin (1.6%), and esophagus fistula (1.6%). One patient died of severe pneumonia, and two died of late toxicity because of esophagus fistula. With median follow-up of 32 months, the overall survival (OS) and progression-free survival (PFS) at 1 year and 2 years were 81.0% and 73.0%, and 63.5% and 49.2%, respectively.

Conclusions: SLN RT concurrent with S-1 plus CDDP may represent a better strategy for treatment of ESCC patients.