Active surveillance for clinical complete responders after chemoradiotherapy for oesophageal squamous cell carcinoma

Background: Guidelines on the treatment of oesophageal squamous cell carcinoma (SCC) recommend neoadjuvant chemoradiotherapy plus surgery or definitive chemoradiotherapy. The aim of this study was to evaluate the outcome of patients with a cCR after chemoradiotherapy who underwent active surveillance. Methods: Patients with oesophageal SCC who were treated with chemoradiotherapy between January 2016 and June 2022 were identified from an institutional database. Survival and recurrence of patients with a cCR who underwent active surveillance were compared with those of patients who underwent planned surgery. Survival was calculated according to the Kaplan-Meier method and compared between groups using the log rank test. Results: The 37 patients who underwent active surveillance were older and tumours were more often located in the middle/upper-third of the oesophagus than in the surgery group of 57 patients. Median follow-up was 28.1 (i.q.r. 17.2-47.1) months for the active surveillance group and 20 (12.9-39.1) months for the surgery group. Overall survival was comparable between the two groups, with 3-year survival rates of 50 (95% c.i. 31 to 67) and 59 (40 to 73)% for the active surveillance and surgery groups respectively (P = 0.55). Three-year progression-free survival for patients who underwent active surveillance was better than in the surgery group: 70 (43 to 85) versus 58 (40 to 72)% (P = 0.02). Overall and progression-free survival was comparable between patients in the active surveillance group and 23 patients in the surgery group who had a pCR (ypT0 N0). The overall recurrence rate was comparable between the groups: 7 of 37 (19.4%) in active surveillance group versus 16 of 49 (32.6%) in surgery group (P = 0.26). Locoregional recurrence was noted more often in the active surveillance group and systemic recurrence in the surgery group. Conclusion: Active surveillance is feasible and safe for patients with oesophageal SCC who have a cCR after chemoradiotherapy.