Volume-outcome relation in palliative systemic treatment of metastatic oesophagogastric cancer.

INTRODUCTION: Palliative systemic therapy has been shown to improve survival in metastatic oesophagogastric cancer. Administration of palliative systemic therapy in metastatic oesophagogastric cancer varies between hospitals. We aimed to explore the association between the annual hospital volume of oesophagogastric cancer patients and survival.

METHODS: Patients diagnosed in the Netherlands between 2005 and 2013 with metastatic oesophagogastric cancer were identified in the Netherlands Cancer Registry. Patients were attributed according to three definitions of high volume: (1) high-volume incidence centre, (2) high-volume treatment centre and (3) high-volume surgical centre. Independent predictors for administration of palliative chemotherapy were evaluated by means of multivariable logistic regression analysis, and multivariable Cox proportional hazard regression analysis was performed to assess the impact of high-volume centres on survival.

RESULTS: Our data set comprised 4078 patients with metastatic oesophageal cancer, and 5425 patients with metastatic gastric cancer, with a median overall survival of 20 weeks (95% confidence interval [CI] 19-21 weeks) and 16 weeks (95% CI 15-17 weeks), respectively. Patients with oesophageal cancer treated in a high-volume surgical centre (adjusted hazard ratio [HR] 0.80, 95% CI 0.70-0.91) and a high-volume treatment centre (adjusted HR 0.88, 95% CI 0.78-0.99) exhibited a decreased risk of death. For gastric cancer, patients treated in a high-volume surgical centre (adjusted HR 0.83, 95% CI 0.74-0.92) had a superior outcome.

CONCLUSION: Improved survival in patients undergoing palliative systemic therapy for oesophagogastric cancer was associated with treatment in high-volume treatment and surgical centres. Further research should be implemented to explore which specific factors of high-volume centres are associated with improved outcomes.