Annual Meeting Proceedings Part 1 - American Society of Clinical ...

4564 Poster Discussion Session (Board #18), Mon, 8:00 AM-12:00 PM and
11:30 AM-12:30 PM
Pretreatment (pre-tx) neutrophil to lymphocyte ratio (NLR) in metastatic
castration-resistant prostate cancer (mCRPC) patients (pts) treated with
ketoconazole (keto): Association with outcome and predictive model.
Presenting Author: Avishay Sella, Assaf Harofeh Medical Center, Zerifin,
Israel
Background: The CYP17 inhibitor keto is active in mCRPC. The NLR, an
index of systemic inflammation, is associated with prognosis in several
types of cancer. We assessed the association between pre-tx NLR and
outcome of mCRPC pts treated with keto. Methods: We performed an
international multicenter retrospective study of pts with mCRPC, who were
treated with keto. We analyzed the pre-tx NLR and previously described
factors associated with keto tx outcome as prior response to hormonal tx,
pre-tx PSADT, and extent of metastatic disease (limited vs extensive).
Progression free survival (PFS) was determined by the Kaplan-Meier
method. Multivariate analyses using Cox regression model were performed
to determine their independent effect, and to form a predictive model. A
survival tree analysis was used to find the best NLR cut-off value. Results:
From 1999-2011, 156 mCRPR pts (median age 69) were treated with
keto. 78/156 (50%) had � 50% PSA decline. Overall median PFS was 8
months (mos) (range 1-144). Excluded from the analysis were 23 pts
without available data on pre-tx NLR, and those with recent (�1 mos)
health event or tx (surgery, steroids, radiation) associated with a change of
blood counts. 133 pts were included in the analysis. 62 (47%) had an
elevated pre-tx NLR �3. Risk factors associated with PFS (table) were
pre-tx NLR �3, prior response to GnRH-a �24 mos and to antiandrogen
(AA) �6 mos, and pre-tx PSADT �3 mos. The number of risk factors was
used to categorize patients into three risk groups (table): favorable (0-1
factors), intermediate (2 factors), and poor (3-4 factors). Conclusions: In
mCRPC pts treated with keto, pre-tx NLR, prior response to hormonal tx,
and pre-tx PSADT are associated with PFS, and may be used to categorize
pts into risk groups.
Factor PFS (mos) (HR, p value)
NLR < 3vs>3 14 vs 3, (0.353, �0.0001)
Response to prior GnRH-a
12 vs 5, (0.513, 0.035)
> 24 vs < 24 mos
Response to prior AA
18 vs 3, (0.445, 0.003)
>6vs3vs