BACKGROUND: Temsirolimus is a mTOR inhibitor approved for the first-line 
treatment of advanced or metastatic renal cell carcinoma (a/mRCC) with poor 
prognosis. In treatment of a/mRCC several prognostic scoring systems are used. 
We assessed the prognostic value of these scores in a large temsirolimus treated 
cohort and compared the results with the physician's prognosis.
METHODS: A German multicenter registry (STAR-TOR) for a/mRCC patients 
(NCT00700258) was established to evaluate the efficacy and safety of 
temsirolimus 25 mg weekly in a routine clinical setting. These prospective data 
were systematically analyzed and followed-up by an independent clinical research 
organization to compare established prognostic scores (MSKCC, IMDC and Hudes) 
with the risk assessment by treating physicians based on their medical expertise 
and match them with survival outcomes.
RESULTS: This interim analysis included 547 patients between 02/2008 and 05/2015 
in 87 centers. Either prognostic tool resulted in significant and clinically 
meaningful differentiation between good, intermediate and poor prognosis. 
However, physician's prognosis identified more patients with good prognosis 
(9.1% vs. 1.3%). In patients with good physician's prognosis and intermediate 
prognosis by MSKCC, overall survival was nearly doubled compared to consensual 
intermediate prognosis (26.6 vs. 13.6 months), albeit without reaching 
statistical significance (P=0.09). For poor prognosis assessed by the physician, 
MSKCC performed statistically better for differentiation between poor and 
intermediate prognosis with a median overall survival of 10.3 vs. 5.5 months 
(P<0.01).
CONCLUSIONS: Physician's prognosis may be able to identify a subset of patients 
treated with temsirolimus with good prognosis when MSKCC-determines intermediate 
prognosis while the MSKCC score could identify patients which were falsely 
placed in the poor risk group by physicians.