ORLANDO—A pomegranate extract slowed progression of prostate cancer (PCa) in a study of men who had rising PSA levels after primary treatment for the malignancy.
The phase 2 double-blind study, led by Michael A. Carducci, MD, of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University in Baltimore, found that treatment with the pomegranate extract (POMx) was associated with a greater than six-month median increase in PSA doubling time (PSADT).
Previous research has shown that pomegranate extract has antitumor effects.
The study focused on 92 men who were randomized to receive a low dose or a high dose of POMx. The low-dose group took one POMx capsule (1 gram of extract) plus two placebo capsules; the high-dose group took three POMx capsules (3 grams of extract). Men were treated until they had disease progression or for 18 months. Investigators measured PSA levels every three months. Overall, 92%, 70%, and 36% of patients were treated for up to six, 12, and 18 months, respectively.
The median PSADT increased from 11.9 months prior to treatment to 18.5 months after treatment, Dr. Carducci reported at the fourth annual Genitourinary Cancers Symposium. PSADT did not differ significantly between the treatment arms. In the low-dose arm, it increased from 11.9 to 18.8 months, and in the high-dose arm, it rose from 12.2 to 17.5 months. Dr. Carducci’s group observed PSA declines in 13 patients during the study. They observed no significant changes in testosterone in either group and no clinically significant toxicities, although eight patients (7.7%) experienced mild to moderate diarrhea.
Dr. Carducci noted that one of the study limitations is the absence of a control arm with patients taking only placebo.