SRS196 - Identifying hospital volume thresholds in oesophagogastric cancer surgery: a population-based cohort study using a nationwide registry

Background Increasing hospital operative volume is associated with improved outcomes in oesophagogastric cancer surgery, but definitions of ‘high-volume’ vary widely. This study examined the relationship between operative volume and 90-day mortality and examined whether a minimum threshold for a ‘high-volume’ unit could be defined. Methods Patients in England and Wales who underwent surgery with curative-intent for oesophagogastric cancer from 2016–2022 were identified using data from the National Oesophagogastric Cancer Audit. A multivariable restricted cubic spline model evaluated the relationship between hospital operative volume and adjusted 90-day mortality. A volume threshold was derived using a point of maximal change (PMC) method. Results Across 34 hospitals, 11 806 patients underwent surgery: 7905 for oesophageal and 3901 for gastric cancer. 76% were male, and the median age was 67 years-old (IQR 60–73). Overall, 376 patients (3.2%) died within 90 days of surgery. Median annual hospital volume was 65 cases (range 11–149). Increasing operative volume was associated with reduced adjusted 90-day mortality (P = 0.03). The PMC identified a threshold of 71 cases per year; 5368 (45.5%) patients underwent surgery at hospitals meeting this threshold. Treatment at high-volume hospitals (≥71 cases/year) was associated with significantly lower 90-day mortality (adjusted odds ratio 0.75, 95% c.i. 0.60–0.92; P = 0.007). Conclusions Avoiding low hospital operative volume could improve short-term survival after oesophagogastric cancer surgery. A threshold of 71 cases per year appears to minimise the risk of postoperative mortality but fewer than a quarter of hospitals met this benchmark each year.