Men with rising PSA following initial therapy for localized prostate cancer experienced an increase in PSA doubling time (PSADT) after being treated with pomegranate extract, according to a new study.
In a phase 2 trial, researchers randomly assigned patients to receive either 1 or 3 grams of pomegranate extract daily for up to 18 months. For the 101 patients included in the analyses, the median PSADT increased from 11.9 months at baseline to 18.5 months after treatment. PSADT increased from 11.9 to 18.8 months in the low-dose group and from 12.2 to 17.5 months in the high-dose group, with no significant difference between the treatment arms, researchers reported online in Prostate Cancer and Prostatic Diseases.
The investigators, led by Michael A. Carducci, MD, of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University in Baltimore, observed declining PSA levels in 13 patients (13%).
Forty-two percent of patients left the study prematurely over the 18 months, mainly because of rising PSA levels. The researchers observed no significant changes in testosterone levels and no drug-related serious adverse events or deaths.
Dr. Carducci’s group acknowledged that the lack of a placebo arm was a major study limitation. “A placebo arm was considered, but given the perceived positivity of pomegranate juice, a placebo control was felt to pose difficulties for patient accrual,” they noted.