LOS ANGELES—Men who have undergone high-dose radiation therapy for prostate cancer have a reduced risk of relapse if they were taking statins during their radiation therapy, finds a retrospective study reported at the 2007 ASTRO annual meeting (abstract 203). The benefit was greatest among those men with high-risk disease.

"There are some studies that have shown or suggested that statins may interfere with antiapoptotic pathways and may, in fact, act as radiation sensitizers in experimental tumor models," said senior author Michael J. Zelefsky, MD, of Memorial Sloan-Kettering Cancer Center.

The researchers assessed associations between use of statins during high-dose 3D conformal/intensity-modulated radiation therapy (75.6 to 86.4 Gy) and various outcomes among 871 men with clinical stage T1c to T3 prostate cancer treated between 1994 and 2000 at the center.

Nineteen percent of the patients were taking a statin at the time of diagnosis and continued to do so during radiation therapy, Dr. Zelefsky said. Some 29% had favorable-risk disease, 46% had intermediate-risk disease, and 25% had high-risk disease. About half (54%) were treated with neoadjuvant hormonal therapy.

Improved relapse-free survival

With a median follow-up of 7 years, the 10-year estimated probability of survival free of a PSA relapse was significantly higher among the statin users than among the nonusers overall (76% vs 66%), Dr. Zelefsky said.

By risk category, the difference was marginal among the intermediate-risk group (P = .07) and significant among the high-risk group (P = .005).