Design: International multicentre retrospective cohort, 17 centres
Population: 2,905 patients after neoadjuvant CROSS or FLOT and oesophagectomy
Primary outcome: Overall survival by leak severity
Effect: Type III leak HR 1.51 (95% CI 1.04 to 2.18); median OS 33.9 vs 69.3 months

The ALES cohort included 2,905 patients who had oesophagectomy after CROSS or FLOT neoadjuvant therapy at 17 high-volume European centres, 2018 to 2023. Leaks were graded by the Esophagectomy Complications Consensus Group definition.

425 patients (14.6%) leaked. Leaks nearly doubled pulmonary complications (46.8% vs 26.7%). Type III leaks — those needing surgical reintervention — were associated with higher 90-day mortality (12.3% vs 4%), shorter median survival (33.9 vs 69.3 months) and, after adjustment, an HR for death of 1.51 (1.04 to 2.18). Leaks managed conservatively or endoscopically showed no survival penalty. Leak patients received adjuvant therapy less often.

The message is that the modern endoscopic rescue era has changed what a leak means: most no longer shorten survival, but those that reach the operating theatre still do.

Grade every leak by the ECCG definition in the notes.
Pursue early endoscopic control where feasible to avoid reoperation.
Plan for adjuvant therapy after recovery from a leak; it was given less often.
Watch closely for pulmonary complications in any patient with a leak.

Why it matters

It separates leaks that change prognosis from those that do not, which reframes counselling and follow-up.

The statistics, in plain English

An HR of 1.51 means about 50% higher risk of death at any time for patients with a reoperated leak, after adjusting for measured factors. The interval runs from 1.04 to 2.18, so the true excess could be small. Patients who need reoperation are also sicker, which adjustment may not fully capture.