G.R. Pond and A. Armstrong contributed equally to this article.
Ability of C-reactive protein to complement multiple prognostic classifiers in men with metastatic castration resistant prostate cancer receiving docetaxel-based chemotherapy
Version of Record online: 23 APR 2012
© 2012 BJU INTERNATIONAL
Volume 110, Issue 11b, pages E461–E468, December 2012
How to Cite
Pond, G. R., Armstrong, A. J., Wood, B. A., Leopold, L., Galsky, M. D. and Sonpavde, G. (2012), Ability of C-reactive protein to complement multiple prognostic classifiers in men with metastatic castration resistant prostate cancer receiving docetaxel-based chemotherapy. BJU International, 110: E461–E468. doi: 10.1111/j.1464-410X.2012.11148.x
- Issue online: 22 JAN 2013
- Version of Record online: 23 APR 2012
- Accepted for publication 18 January 2012
- C-reactive protein;
- metastatic castration resistant prostate cancer;
- PCWG-2 clinical subtypes;
- risk groups
Study Type – Retrospective analysis of clinical trial
Level of Evidence 3
What's known on the subject? and What does the study add?
Serum C-reactive protein (C-reactive protein) is emerging as a potential novel prognostic factor in metastatic castration-resistant prostate cancer (mCRPC).
In the present study, a prospective trial was investigated retrospectively and a significant prognostic impact for C-reactive protein that was independent of multiple published prognostic models was identified in men receiving docetaxel-based chemotherapy for mCRPC. Prospective validation is warranted.
- • Given the recent emergence of C-reactive protein levels as a novel prognostic factor in men with metastatic castration-resistant prostate cancer (mCRPC), we sought to evaluate the independent prognostic ability of C-reactive protein in the context of published prognostic nomograms, risk grouping and disease state models in men receiving docetaxel-based chemotherapy for mCRPC.
PATIENTS AND METHODS
- • A large randomized phase II trial (CS-205) of mCRPC patients who received docetaxel-prednisone + AT-101 (Bcl-2 inhibitor) or docetaxel-prednisone + placebo was analyzed retrospectively (n= 220).
- • Overall survival (OS), progression-free survival (PFS) and measures of discriminatory ability were assessed in a hypothesis-generating analysis using Cox regression and concordance probabilities.
- • Patients from both treatment groups were combined for this analysis because no significant differences in outcomes were observed.
- • Because some factors used in nomograms were not collected or defined differently, risk was estimated based on slightly modified versions of nomograms.
- • C-reactive protein was independently prognostic for OS and PFS (P≤ 0.002) after adjusting for all modeled risk estimates and classifiers.
- • C-reactive protein showed a concordance probability of 0.65 for both OS and PFS.
- • A 10-factor modified prognostic model based on the TAX327 trial had the greatest observed discrimination ability for OS and PFS (concordance probability = 0.623 and 0.603, respectively) among the modified nomograms or classifiers.
- • Adding the TAX327 model risk estimates to C-reactive protein did not substantially increase discrimination ability over C-reactive protein alone.
- • Current prognostic classifications provide modest discrimination of outcomes in mCRPC receiving docetaxel-based chemotherapy, highlighting the need for improved risk-based models.
- • Baseline C-reactive protein appears to be an useful, independent prognostic factor and prospective external validation is warranted.