Postoperative extended-volume external-beam radiation therapy in high-risk esophageal cancer patients: a prospective experience

BACKGROUND AND PURPOSE: Extended-volume external-beam radiation therapy (rt) following esophagectomy is controversial. The present prospective study evaluates the feasibility of extended-volume rt treatment in high-risk esophagectomy patients with a cervical anastomosis receiving postoperative combined chemoradiation therapy. PATIENTS AND METHODS: From 2001 to 2006, 15 patients with resected esophageal cancer were prospectively accrued to this pilot study to evaluate the adverse effects of extended-volume rt. Postoperative management was carried out at London Regional Cancer Program. Eligibility criteria were pathology-proven esophageal malignancy (T3–4, N0–1), disease amenable to surgical resection, and esophagectomy with or without resection margin involvement. Patients with distant metastases (M1) and patients treated with previous rt were excluded. All 15 study patients received 4 cycles of 5-fluorouracil–based chemotherapy. External-beam rt was conducted using conformal computed tomography planning, with multi-field arrangement tailored to the pathology findings, with coverage of a clinical target volume encompassing the primary tumour bed and the anastomotic site in the neck. The radiation therapy dose was 50.40 Gy at 1.8 Gy per fraction. The rt was delivered concurrently with the third cycle of chemotherapy. The study outcomes—disease-free survival (dfs) and overall survival (os)—were calculated by the Kaplan–Meier method. Treatment-related toxicities were assessed using the U.S. National Cancer Institute’s Common Toxicity Criteria. RESULTS: The study accrued 10 men and 5 women of median age 64 years (range: 48–80 years) and TNM stages T3N0 (n = 1), T2N1 (n = 2), T3N1 (n = 11), and T4N1 (n = 1). Histopathology included 5 adenocarcinomas and 10 squamous-cell carcinomas. Resection margins were clear in 10 patients. The median follow-up time was 19 months (range: 3.5–53.4 months). Before radiation therapy commenced, delay in chemotherapy occurred in 20% of patients, and dose reduction was required in 13.3%. During the concurrent chemoradiation therapy phase, 20% of the patients experienced chemotherapy delay, and 6.6% experienced dose reduction. No patient experienced treatment-related acute and chronic esophagitis above grade 2. Disease recurred in 40% of the patients (6/15), and median time to relapse was 24 months. No tumour recurred at the anastomotic site. The median dfs was 23 months, and the median os was 21 months. CONCLUSIONS: Extended-volume external-beam rt encompassing the tumour bed and the anastomotic site is feasible and safe for high-risk T3–4, N0–1 esophageal cancer patients after esophagectomy.