Treatment and overall survival (OS) in metastatic renal cell carcinoma (mRCC): A Swedish population-based study (2000–2008).

Abstract

389 Background: This retrospective register study assessed OS in all mRCC patients in Sweden diagnosed before (2000–2005) and after (2006–2008) the introduction of targeted therapies, plus factors and treatment options influencing OS. Methods: Three Swedish national health registers were used: the Swedish Cancer register (diagnosis and death), the National Patient Register (in-/out-patient data), and the Swedish Prescribed Drug Register. From 2000-2008, 3,243 patients were identified with mRCC; 602 were recorded as receiving 1st-line treatment. Cox proportional hazards regression analysis, including estimation of adjusted OS, was used in three models with the covariates: diagnosis period, age, gender, institution size, nephrectomy status, geographic region (all models); mRCC treatments, defined as any tyrosine kinase inhibitor (TKI; Model 1; n=417); sunitinib (SU), sorafenib (SO), and interferon-alfa (IFN-α) in the 1st-line setting (Model 2; n=602 [SU=244, SO=110, IFN-α=248]); and variations of these drugs as 1st- and 2nd-line treatment sequences (Model 3; n=602). Results: Amongst mRCC patients diagnosed from 2006–2008 compared with 2000–2005, median adjusted OS was 16.1 vs. 10.9 months, respectively (HR=0.76, 95% CI: 0.69, 0.83; P<0.001). In all three models, factors independently associated with significantly improved OS included female gender, large institution, and prior nephrectomy. Prescription of any TKI (Model 1: HR=0.82, 95% CI: 0.73, 0.93; P=0.002) and 1st-line SU treatment (Model 2: HR=0.79, 95% CI: 0.67, 0.94; P=0.007) were associated with significantly improved OS compared with other or no treatments. A similar significant improvement in OS was also confirmed for patients treated with SU only in Model 3; however, due to a low number of observations, the model had insufficient statistical power to be appropriate for all sequences. Conclusions: An improved OS for mRCC patients was demonstrated for the period 2006-2008 compared with 2000-2005. Although the observed survival advantage is multifactorial in origin, contribution of targeted therapies is highly probable. Of the drugs studied, given design limitations, only SU was associated with improved OS.