CP-172 Tyrosine kinase inhibitors in the treatment of renal cell carcinoma in routine clinical practice

Background Administration of cytokines, such as interleukin 2 and interferon α, has been clinically proven since the 1980s, but today their use in clinical practice has decreased considerably due to the effectiveness of new target treatments, such as tyrosine kinase inhibitors (TKIs) that have shown greater clinical efficacy and a better tolerance profile. Purpose The aim of this study was to analyse the effectiveness of TKIs in treating renal cell carcinoma (RCC) in different treatment lines according to previously received treatment. Material and methods Retrospective observational study conducted between January and September 2015 in a tertiary care hospital. All patients with RCC treated with TKIs were included. The variables collected were demographics (age at baseline, sex), clinical (stage), pharmacological (drug, duration of treatment, cause of treatment order) and effectiveness (progression free survival (PFS), overall survival (OS)). The information sources used were clinical and prescription electronic records from which demographic, clinical, pharmacological and effectiveness variables were collected. Results 44 patients were included with a mean age of 63 years (68% male, 32% female); 2%, 43%, 9%, 18% and 28% were treated with sorafenib, sunitinib, axitinib, everolimus and pazopanib, respectively. 100% of patients had stage IV at the start of treatment. The average duration of treatment was 15.9 months. The causes of end of treatment were disease progression in 86% of patients, exitus in 9% and toxicity in 5%. 57.3% of patients received firstline TKI treatment, 8% after failure of cytokines, 29.7% after failure of another previous TKI and the remaining 5% after failure with cytokines and another TKI. Median PFS were 75.1, 7.9 and 23.3 months for patients previously treated with cytokines, pretreated with another TKI and after failure of prior therapy with cytokines and another TKI, respectively. In the same order, OS values were 83.2, 8.8 and 23.3 months. Conclusion Median PFS and OS were higher in the group of patients pretreated with cytokines than in patients receiving TKIs as firstline or after failure of another TKI. The difference found in favour of treatment with secondline TKIs after receiving cytokines compared with pretreatment with TKIs may be due to the possible emergence of resistance to TKIs by prior exposure to them. No conflict of interest.