Long term overall survival (OS) in patients with primary metastatic kidney cancer: An analysis of 1468 patients from the Austrian National Cancer Registry (ANCR).

Abstract

489 Background: The introduction of thyrosinkinase inhibitors (TKI) changed the treatment of metastatic kidney cancer fundamentally. To elaborate the potential impact of TKI therapies, we studied trends in OS for patients with primary metastatic kidney cancer between 1998 and 2014 in Austria. Methods: All patients with primary metastatic kidney cancer aged ≥18 years, diagnosed from 1998-2009 were derived from the ANCR (n=2134). Patients diagnosed from 2004-2006 (n=316) were excluded (transition period of systemic therapies). To evaluate differences in OS between patients treated in preTKI-era and TKI-era, two periods were defined: 1998-2003 (before the introduction of Sunitinib in Austria, P1; n=926) and 2006-2009 (P2; n=542). Follow-up was complete until December 31st, 2014. OS rates were estimated by using the Kaplan-Meier method. The Cox proportional hazard model was used to calculate hazard ratios (HR). Results: A total 1468 patients was included in the analysis. The median age of the study population was 70 yrs (sd ±12) and did not differ between the two eras. The incidence of T1 tumors increased from 6.6% in P1 to 10% in P2 while T4 tumors decreased from 15% to 6.5% (p<0.001). Surgery rate remained stable at 48% (p=0.14). Five-year OS for patients undergoing surgery slightly increased from 16% in P1 to 20% in P2, although not significant (p=0.11). For patients without surgery 5-year OS improved from 4.3% in P1 to 7.9% in P2 (p=0.02). Apart from surgery, survival gain was observed for younger patients (<75 yrs) of 4% (p=0.04) and for T3/T4 tumors of 7% (p=0.008). The risk of death (HR) for patients treated in the TKI-era was reduced compared to the preTKI-era (HR 0.83, 95% CI 0.74-0.93) adjusted for sex, age, T-stage, and surgery. Survival advantage for patients undergoing surgery remained significant (HR: 0.50, 95% CI 0.45-0.57) after adjustment for TKI-era, sex, age, and T-stage. Conclusions: Patients with primary metastatic kidney cancer treated in the TKI era show improved OS compared to the cytokine era. Most benefit was observed in non-surgical patients, younger patients, and for T3/T4 disease. Surgery remains as an important therapy for additional survival benefit.