Centralization of gastric cancer surgery-impact on treatment strategies and survival-a national population-based cohort study.

Background: Centralized surgery care improves curative resection outcomes in rare malignancies. Less is known about the secondary effects of such centralization on all patients, including patients receiving palliative treatment or no tumor treatment. This population-based cohort study aimed to evaluate the effects of centralization on survival and treatment decision in all patients with gastric cancer in Sweden between 2006 and 2016.

Methods: All patients diagnosed with gastric cancer, including cardia cancer Siewert III, were identified using the National Registry for Esophageal and Gastric Cancer in Sweden. Patients diagnosed at a local hospital performing low-volume curative gastric cancer surgery before centralization were compared with patients in the same communities after curative cases were referred elsewhere. Survival differences were determined using multivariate Cox regression models, and the probability of curative care was determined using multivariate logistical regression.

Results: A total of 4547 patients diagnosed at 49 hospitals were included, among which 28 hospitals stopped performing curative gastric cancer surgery during the study period. After centralization, 8 hospitals performed curative gastric cancer surgery, and the median overall survival (OS) increased from 7.9 to 9.1 months. The resection rates decreased from 36% to 30%. Treatment recommendations performed at multidisciplinary cancer conferences increased from 23% to 80%, and any active tumor treatment (curative and palliative) recommendation increased from 68% to 73%. No significant difference in treatment strategy or time to surgery was observed among the groups. No difference in OS was observed among the groups.

Conclusion: During the centralization of gastric cancer surgery, survival, multidisciplinary treatment decisions, and active treatment increased, with no detrimental effects on populations outside the major centers' primary uptake areas.