Fuhrman grade and concomitant bisphosphonates as additional prognostic factors in metastatic renal cell carcinoma with bone metastases treated with sunitinib.

Abstract

388 Background: With a median progression-free survival(PFS) of 8.2 months (mo) (vs. 19.1 mo; p<0.0001) and overall survival (OS) of 19.5 mo (vs. 38.5 mo; p<0.0001), metastatic renal cell carcinoma (m-RCC) patients (pts) with bone metastases (BM) have a poorer outcome under sunitinib (SUN) than pts without BM (Beuselinck et al, Annals of Oncology 2010). The aim of this retrospective study was to determine additional prognostic factors in this poor risk subgroup of pts. Methods: We collected data on classical prognostic factors for m-RCC, Fuhrman grade, number of BM, and bone-oriented therapy in the charts of 80 m-RCC pts with BM who started first-line SUN between 01/2005 and 12/2009 in 4 academic centers in Belgium and France. Univariate analysis was conducted using Maentel Hetzel test. Validation of these findings on a second series of m-RCC patients is ongoing. Multivariate analysis will be performed on the total series. Results: In the total population, median PFS and OS were 9.8 and 20.6 mo. Pts with Fuhrman grade 4 tumors (MSKCC prognosis: intermediate 50%; poor 50%) had a PFS of 4.5 mo vs. 12.3 mo for Fuhrman grade 1-2-3 tumors (MSKCC prognosis: good 20%; intermediate 60%; poor 20%) (p=0.005). OS was 13.5 mo vs. 26.5 mo respectively (p=0.003). There was no difference in PFS and OS between pts with Fuhrman grade 1-2 and Fuhrman grade 3 tumors. The number of BM had no significant influence on PFS and OS. Whether or not radiation therapy and/or surgery had been applied to all BM before starting SUN was a factor without influence on PFS or OS. Concomitant bisphosphonates (BF) and SUN administration was analyzed on all the evaluable pts (24) treated at the University Hospitals Leuven. 14 pts (MSKCC prognosis: poor: 8; intermediate: 6) received concomitant BF. 10 pts (MSKCC prognosis: poor: 5; intermediate: 5) did not. Median PFS was 16.3 and 3.4 mo (p=0.03) and OS 18.1 and 13.9 mo respectively (not significant). Results of the validation series and multivariate analysis will be presented. Conclusions: m-RCC pts combining BM and Fuhrman grade 4 tumors have a very poor outcome on SUN. Concomitant use of BF may be a strategy to improve PFS in pts with bone metastatic RCC. No significant financial relationships to disclose.