Purpose: For esophageal cancer patients with a clinical complete response (cCR) after standard-dose radiotherapy with concurrent chemotherapy, data on the survival outcomes and recurrence patterns remain scarce. To evaluate the impact of dose escalation on overall survival for this subset of patients, we carried out the current investigation.
Materials and methods: Medical records of 80 esophageal cancer patients with a cCR after standard-dose radiotherapy with concurrent chemotherapy at our center from 2010 to 2014 were allocated into the standard-dose group (50.4 Gy, observation group) or the radiation dose-escalation group (59.4 Gy, control group). In this cohort study, we compared the outcomes between the 2 groups.
Results: There were no differences in patient characteristics between the 2 groups. The median recurrence-free survival and overall survival times for all patients were 38 and 54 months, respectively. Patients in the control group had significantly better 5-year recurrence-free survival rate (12% vs 0%, p=0.019) and 5-year overall survival rate (42.8% vs 21.0%, p=0.028) than the observation group. Additionally, local control rate was significantly higher in the control group (p=0.04), and ~60% of treatment failures were local failures even for patients achieving cCR after chemoradiotherapy. There were no significant differences in treatment-related toxicities between the groups.
Conclusion: The results of the current study suggest that for esophageal cancer patients with a cCR after standard-dose radiotherapy with concurrent chemotherapy, those with dose-escalated radiotherapy showed significantly better local control, recurrence-free survival, and overall survival than patients receiving 50.4 Gy radiotherapy.
Keywords: esophageal squamous cell carcinoma, radiotherapy, survival outcome, recurrence patterns