Use of pain at baseline and pain progression to predict overall survival (OS) in patients (pts) with docetaxel pretreated metastatic castration-refractory prostate cancer (CRPC): Results from the SPARC trial.

5148 Background: First-line chemotherapy trials have reported that pain predicts OS in CRPC. We report relationships between OS and baseline pain -a major component of CRPC patient reported outcomes (PRO) -and pain at progression, for docetaxel pre-treated patients in a second-line chemotherapy trial in CRPC. METHODS: Docetaxel pre-treated pts (N = 488) were analyzed from the multi-national, randomized, double-blind SPARC trial, comparing second-line satraplatin + prednisone vs placebo + prednisone in 950 metastatic CRPC pts. Daily pain intensity and narcotic analgesic use were recorded as a PRO from one week prior to randomization until end-of-study. Pain was measured by the 6-point Present Pain Intensity (PPI) component of the McGill-Melzack Pain Questionnaire. After randomization, weekly PPI scores were calculated as the mean of the daily PPI scores (using ≥3 daily measurements/week). Baseline pain was the mean of ≥5 daily PPI scores recorded during 7 days preceding randomization. An independent blinded review committee (IRC) determined pain progression (defined as an increase in weekly PPI score ≥1 point from baseline or ≥2 points from nadir, or a >25% increase from baseline in weekly average analgesic score for ≥2 consecutive weeks). To examine the effects of pain on OS, pts were categorized as "no pain" (PPI ≤1) or pain (PPI ≥2) by baseline assessment; and, as either pain progressors or pain non-progressors. RESULTS: Shortened OS was observed in pts with baseline pain; median survival of 178 pts with pain was 44 weeks vs 72 weeks for 287 pts without pain (Strat. Log-rank p < 0.0001, Strat. HR 0.59; 95% CI: 0.48-0.74). IRC found disease progression in 414 (84.4%) of the docetaxel pre-treated pts with 196 of these pts showing pain progression. Pain progression was strongly linked to OS with 196 pain progressors having median OS of 47 weeks compared to 71 weeks for 292 pain non-progressors (Strat. Log-Rank p = 0.0022; Strat. HR 0.71; 95% CI: 0.57-0.87). CONCLUSIONS: Both pain at baseline and pain at progression are important prognostic indicators of OS in metastatic CRPC pts failing first-line docetaxel. [Table: see text].

Duke Scholars

Author Susan Halabi Biostatistics & Bioinformatics, Division of Biostatistics