Statins reduce relapse rates after prostate radiotherapy
MedWire News: Statins may reduce the likelihood of relapse after radiotherapy for prostate cancer, indicate US study results.
The findings show that high-risk prostate radiotherapy patients had a significant improvement in prostate-specific antigen (PSA) relapse-free survival (PRFS) time after treatment if they were taking concurrent statins at the time of prostate therapy.
"Statins have been shown to induce cell-cycle arrest in the late G1 phase in prostate cancer cell lines, theoretically providing a mechanism of radiosensitization," explain Michael Zelefsky (Memorial Sloan-Kettering Cancer Center, New York) and colleagues.
However, they add that the exact mechanism for this action is unclear.
The team reviewed the records of 1681 prostate cancer patients treated with high-dose external-beam radiotherapy at their institution from 1995 through 2007. Among these men, 382 were taking a statin for conditions unrelated to prostate cancer.
During a median follow-up of 5.9 years, 301 patients had a PSA relapse (a 2-ng/ml increase from nadir) and overall 5- and 8-year PRFS rates for the entire cohort were 85% and 75%, respectively.
The corresponding 5- and 8-year PRFS rates for patients taking statin medications were 89% and 80%, compared with 83% and 74% in those who were not.
Multivariate analysis, adjusted for potentially confounding factors, showed that statin use was a significant predictor of improved PRFS, with a hazard ratio of 0.52, but only in high-risk patients (n=489), as stratified by National Comprehensive Cancer Network criteria.
For low- (n=495) and intermediate-risk patients (n=697), there was no difference in PRFS among statin users and nonusers.
A low Gleason score, a pretreatment PSA level below 10 mg/ml, and use of androgen deprivation therapy were also significantly associated with improved PRFS.
Speaking to MedWire News, first author Marisa Kollmeier, also from the Memorial Sloan-Kettering Cancer Centre, said that the idea of physicians prescribing statins alongside radiotherapy for high-risk prostate cancer was not too extreme a suggestion.
She emphasized, however, that studies into the effects of statins on prostate cancer treatment have been retrospective to date.
Writing in the International Journal of Radiation Oncology Biology Physics, Zelefsky and team conclude : "Ultimately a prospective randomized trial will be necessary to firmly establish a role of statin therapy and its effect on therapeutic outcomes."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Sarah Guy