Statin use is associated with freedom from rising levels of PSA after radiation therapy

The authors aimed to determine whether statin use can prevent prostate cancer recurrence after brachytherapy. 

Brachytherapy is a form of radiation, where a radiation source is internally placed at the tumor site. It is sometimes given in combination with external beam radiation therapy (EBRT – radiation therapy that directs high energy x-rays at the the tumor from outside the body).

Statins are drugs used to lower cholesterol. They do this by stopping a protein from producing cholesterol in the liver. Cholesterol produces products that are important in cell growth and the formation of new cells. However, it can also enable tumor cell growth. By disrupting the production of cholesterol, statins may reduce tumor cell formation following treatment.

The aim of this study was to determine whether statins could improve prostate cancer patient outcomes following brachytherapy.

247 men with prostate cancer were used in this study. Each patient received treatment with Iodine-125 (a radioactive particle that omits radiation at the tumor site) brachytherapy. The average age of the patient group was 62 years and average follow-up time was 51 months after implantation.

Each patient wasidentified  as having low risk (80.6%), intermediate risk  (16.6%) or high risk (2.8%) prostate cancer based on standard guidelines. 9.7% of intermediate/high risk patients received additional EBRT treatment. 25.9% of patients received androgen deprivation therapy (treatment that targets the male sex hormones involved in prostate cancer) before brachytherapy to shrink the prostate.

Overall the biochemical failure rate (an increase of PSA at least 2ng/mL from the lowest PSA reading) was 7.3%.

Of the 247 patients, 70% used statins. Pre-treatment PSA and Gleason scores were significantly lower in these patients than in non-statin users. The biochemical failure rate was 3.4% in statin users. The biochemical failure rate in non-users was 16.4%. Five-year freedom from biochemical failure in statin users was 97.2% compared to  89.6% in non-users. 

Statins were associated with a significant improvement in freedom from biochemical failure following brachytherapy treatment. 

Limitations included the short follow-up time, and the fact that the majority of patients had low-risk prostate cancer. 

Discuss the benefits and drawbacks of statin use following brachytherapy wth your doctor.