Angiotensin system inhibitors and outcome of sunitinib treatment in patients with metastatic renal cell carcinoma: A retrospective examination

Background: Sunitinib is a standard treatment for metastatic renal cell carcinoma. Angiotensin system inhibitors, including angiotensin converting enzyme inhibitors and angiotensin II receptor blockers, are widely used in hypertension, kidney disease and heart failure. Data suggests that they may inhibit tumourigenesis. Aims: To study the effect of angiotensin system inhibitors on sunitinib treatment outcome in metastatic renal cell carcinoma. Methods: We performed a retrospective study of an unselected cohort of patients with metastatic renal cell carcinoma who were treated with sunitinib. Patients were divided into angiotensin system inhibitors users (group 1) and non-users (group 2). The effect of angiotensin system inhibitors on objective response, time to disease progression and overall survival, was tested with adjustment for known confounding risk factors through logistic regression model and Cox regression model. Results: Between 2004 and 2010, 127 patients with metastatic renal cell carcinoma were treated with sunitinib, 44 group 1 and 83 group 2. The groups were balanced regarding known clinicopathologic prognostic factors. Objective response was partial response/stable disease 86% versus 72% and progressive disease 14% versus 28% (p = 0.07) in group 1 versus 2, respectively. Median progression free survival was 13 versus 6 months (HR 0.537, p = 0.0055), and median overall survival 30 versus 23 months (HR 0.688, p = 0.21), in favour of group 1. Conclusions: Angiotensin system inhibitors may improve the outcome of sunitinib treatment in metastatic renal cell carcinoma. This should be investigated prospectively, and if validated applied in clinical practise and clinical trials.