Dietary Supplement May Derive Benefit in Prostate Cancer, Larger Studies are Warranted

A modified citrus pectin, naturally found in the peel of citrus fruits, showed continued benefit among men with prostate cancer.

Use of a dietary supplement, PectaSol (modified citrus pectin) has shown continued benefit among men with prostate cancer, according to results from 18 months of follow-up.

"This study confirmed results seen in two previous, smaller studies," Dr. Daniel Keizman, the principal investigator of the multicenter phase 2b clinical trial being conducted in Israel, said in a press release. "The interim results of the 18 months long-term follow up, are demonstrating the potential of this specific modified citrus pectin) to benefit prostate cancer patients with biochemical relapse for long periods of time."

Six-month interim results of PectaSol showed that 31 of 45 patients (68%) experienced a reduction in disease progression. Pectasol appeared to slow PSA doubling time (an indicator if biochemical and clinical progression of prostate cancer following surgery and/or radiation).

Updated results at 12 months, following the 31 patients who completed the first six months of the trial and were treated with 5g of PectaSol three times daily for eight weeks, showed that 65% of men had no disease progression. Moreover, during this analysis, there was no treatment interruption due to side effects.

In this analysis, 50% of patients had a lower PSA, or PSA doubling time lengthening at 18 months, compared to their baseline 18 months prior.

Currently, the 60 patients planned for the study have completed the initial six months and all patients who showed benefit previously are continuing treatment for an additional 12 months.

Pectin is a naturally occurring substance found in the peel of citrus fruits, such as lemons, oranges, and grapefruits, as well as apples. Modified citrus pectin, like PectaSol, has been changed so that it is absorbed in the gut.

While these studies show promise, Cancer Research UK warned that larger studies are warranted and patients should still proceed with caution. “It is understandable that you might want to try anything if you think it may help treat your cancer. It is important to talk with your doctor first before taking an alternative or complementary therapy,” the group stated on its website. “You could harm your health if you stop your cancer treatment for an unproven treatment. Larger studies need to be done to test (modified citrus pectin) to see whether it is useful in cancer care. Until further studies are carried out and published, Cancer Research UK will not be able to offer any other view on this substance.”

Co-investigator Isaac Eliaz mirrored these warnings: "These results, coupled with the safety of modified citrus pectin), warrant larger control double-blind clinical trials to optimize its use in prostate cancer patients, and possibly in other cancers.”