A study presented at the 2004 annual Clinical Congress of the American College of Surgeons wass the first to show that a Celebrex slowed the progression of recurrent prostate cancer. The study was terminated early after information about the cardiovascular safety of celecoxib prompted review of ongoing clinical studies. Before discontinuation of the study, 78 men were assigned randomly to either celecoxib or placebo. Eight (20%) of 40 men in the placebo group and 15 (40%) of 38 men in the celecoxib group had post-treatment PSADT of more than 200% of baseline PSADT with no new metastases (P = .08). Mean PSA velocity increased by 3.0% for the placebo group and decreased by 3.4% for the celecoxib group (P = .02). Although the primary efficacy objective was not met, this study provides some evidence for biologic activity of celecoxib in prostate cancer. Compared with placebo, celecoxib significantly decreased mean PSA velocity and tended to increase the proportion of men who doubled their PSADT.
A recent review concludes: “The results of the clinical trial by Smith et al confirm that celecoxib does seem to inhibit rising PSA levels in men who have undergone treatment for prostate cancer. Questions still remain as to whether or not these effects will correlate with an actual decrease in clinical recurrence of prostate cancer. Many concerns exist over the safety of using NSAIDs or selective COX-2 inhibitors in an older population. NSAIDs are known to cause life-threatening gastrointestinal side effects and the use of selective COX-2 inhibitors daily (> 12 months) is associated with increased cardiovascular side effects. Clearly, the risk versus the benefit of any intervention needs to be carefully considered before initiation of therapy. In those individuals in whom we can predict an almost certain recurrence of disease, the benefit of a chemopreventive agent might justify its use even if it is associated with other adverse effects. In men who have very little or no risk for disease recurrence, then the potential for adverse effects of COX-2 inhibitors is probably too high to recommend their use.”
There are many remaining questions about the safety and efficacy of Celebrex for cancers. Ongoing studies in breast, lung and prostate cancer might asnwer these questions but at this time, Celebrex should not be used outside of clinical trials.
J. Zhang, E. L. Ding, and Y. Song
Adverse Effects of Cyclooxygenase 2 Inhibitors on Renal and Arrhythmia Events: Meta-analysis of Randomized Trials
JAMA, October 4, 2006; 296(13): 1619 – 1632.
R. N. DuBois
Cyclooxygenase-2 Selective Inhibitors and Prostate Cancer: What Is the Clinical Benefit?
J. Clin. Oncol., June 20, 2006; 24(18): 2691 – 2693.