P109 GEOGRAPHICAL DIFFERENCES IN RESECTION RATES ASSOCIATED WITH SURVIVAL IN SWEDEN-IS SURGERY UNDERUSED?
Abstract Aim To investigate associations between resection rates and survival in esophageal and gastroesophageal junctional cancer. Background & Methods Surgical resection is the mainstay of curative treatment for cancer in the esophagus and the gastroesophageal junction. Merely about one third of these patients undergo resectional surgery although proportions vary. We set out to study differences in resection rates by county and their influence, if any, on survival. A national cohort of patients with esophageal- and gastroesophageal junctional cancer, diagnosed 2006-2015, was set up by cross linking several national registries. The annual resection rate of each geographical county was calculated and divided into three groups (low, middle and high). Survival was analyzed with a Cox proportional hazards model including resection rate, sex, age, year of diagnosis, clinical TNM status, relevant comorbidities, neoadjuvant treatment as well as proportion intended curative oncological treatment. Results 6532 patients were diagnosed during the study period whereof 1733 (26.3 %) underwent open or endoscopic resectional surgery. 860 (49.6%) patients received neoadjuvant treatment. In the studied decade, rates ranged from 21% to 33% in the 21 counties. Overall mean survival after diagnosis was 8.1, 9.9 and 12.1 months in the low, middle and high-resection rate groups respectively. In the multivariate Cox analysis, higher resection rate was associated with improved survival (HR 0.87, 95% CI 0.84-0.90, p<0.001). Conclusion In this national population-based cohort study, patients undergoing treatment in counties with higher resection rates had an associated improved survival. Local underuse of the surgical modality cannot be excluded.