Longer Time Interval from Neoadjuvant Chemoradiation to Surgery is Associated with Poor Survival for Patients Without Clinical Complete Response in Oesophageal Cancer.

BACKGROUND: The optimal interval between neoadjuvant therapy and oesophagectomy for oesophageal cancer remains controversial. METHODS: Patients with locally advanced oesophageal squamous cell carcinoma (ESCC) who received neoadjuvant chemoradiotherapy followed by oesophagectomy between June 2017 and December 2020 were prospectively enrolled and retrospectively analysed. Patients were divided into two groups: timely (group A; < 10 weeks) and delayed (group B; ≥ 10 weeks) surgery groups. Survival was the primary outcome, and tumour response and post-operative complications were the secondary outcomes. RESULTS: Overall, 224 patients were recruited; 116 patients (51.8%) underwent timely surgery within 10 weeks (group A), and 108 patients (49.2%) underwent delayed surgery over 10 weeks (group B) after chemoradiotherapy. In patients with clinical complete response (cCR), two groups had no significant difference of survival benefit (P = 0.618). However, in patients without cCR, delayed surgery was associated with poor survival (P = 0.035) and cancer progression (P = 0.036). A total of 40 patients (34.5%) in group A and 54 patients (50.0%) in group B achieved pCR (P = 0.019). pCR rates were significantly different across the four groups and increased over time (P = 0.006). CONCLUSIONS: Patients with a prolonged time interval from neoadjuvant chemoradiation to surgery had higher pCR rates. For patients with cCR to neoadjuvant chemoradiation, the time interval to surgery can be safely prolonged for at least 10 weeks. However, for patients with non-cCR to neoadjuvant chemoradiation, delayed surgery is associated with poor survival, and surgery should be performed within 10 weeks of neoadjuvant chemoradiation.