Saw Palmetto for Symptom Management During Radiation Therapy for Prostate Cancer

Lower urinary tract symptoms (LUTSs) affect 75%-80% of men undergoing radiation therapy (RT) for prostate cancer.

To determine the safety, maximum tolerated dose (MTD), and preliminary efficacy of Serenoa repens commonly known as saw palmetto (SP) for management of LUTS during RT for prostate cancer.

The dose finding phase used the time-to-event continual reassessment method to evaluate safety of three doses (320, 640, and 960 mg) of SP. Dose-limiting toxicities were assessed for 22 weeks using the Common Terminology Criteria for Adverse Events for nausea, gastritis, and anorexia. The exploratory randomized controlled trial phase assessed preliminary efficacy of the MTD against placebo. The primary outcome of LUTS was measured over 22 weeks using the International Prostate Symptom Score. Additional longitudinal assessments included quality of life measured with the Functional Assessment of Cancer Therapy-Prostate.

The dose finding phase was completed by 27 men who reported no dose-limiting toxicities and with 20 participants at the MTD of 960 mg daily. The exploratory randomized controlled trial phase included 21 men, and no statistically significant differences in the International Prostate Symptom Score were observed. The prostate-specific concerns score of the Functional Assessment of Cancer Therapy-Prostate improved in the SP group (P = 0.03). Of 11 men in the placebo group, two received physician-prescribed medications to manage LUTS compared with none of the 10 men in the SP group.

SP at 960 mg may be a safe herbal supplement, but its efficacy in managing LUTS during RT needs further investigation.