The efficacy and safety of definitive concurrent chemoradiotherapy for non‐operable esophageal cancer

OBJECTIVE: To report outcomes and toxicity in patients who received definitive concurrent chemoradiation (DCCRT) for non‐operable esophageal cancer (EC) in the modern era, and to identify markers of overall and disease‐free survival (OS/DFS). METHODS: We conducted a retrospective cohort study of patients with unresectable EC who received DCCRT at our institution between 1/2008 and 1/2019. Descriptive statistics were used to report disease‐control outcomes and CTCAE v4.0–5.0 toxicities. Univariable and multivariable Cox regression, and stepwise regression were used to identify associations with survival. RESULTS: At a median follow‐up of 19.5 months, 130 patients with adenocarcinoma (AC) (62%) or squamous cell carcinoma (SCC) (38%) were evaluable (Stage II‐III: 92%). Patients received carboplatin/paclitaxel (75%) or fluorouracil‐based (25%) concurrent chemotherapy. Median total RT dose was 50.4 Gy (range, 44.7–71.4 Gy) delivered in 28 fractions (24–35). Locoregional and distant recurrence occurred in 30% and 35% of AC, and 24% and 33% of SCC, respectively. Median OS and DFS were 22.9 and 10.7 months in AC, and 25.7 and 20.2 months in SCC, respectively. On stepwise regression, tumor stage, feeding tube during DCCRT, and change in primary tumor PET/CT SUVmax were significantly associated with OS and DFS. Most severe toxicities were acute grade 4 hematologic cytopenia (6%) and radiation dermatitis (1%). Most common acute grade 3 toxicities were hematologic cytopenia (35%), dysphagia (23%), and anorexia (19%). CONCLUSIONS: Treatment of non‐operable EC with DCCRT has acceptable toxicity and can provide multi‐year disease control for some patients, even in AC. Continued follow‐up and investigation in large studies would be useful.