THE "NEW" PROSTATE CANCER INFOLINK

Here is the last of our data-based reports from the annual meeting of the American Society for Clinical Oncology (ASCO), which ended last Tuesday. It deals with two presentations that are at least intellectually interesting but do not as yet “translate” into any type of clinical certainty.

In the first presentation, entitled “A double-blind, placebo RCT evaluating the effect of a polyphenol-rich whole food supplement on PSA progression in men with prostate cancer: The U.K. National Cancer Research Network (NCRN) Pomi-T study“, Thomas et al. discuss the effects of a polyphenol-rich blend of pomegranate seed, green tea, broccoli, and turmeric (Pomi-T) or an identical placebo for 6 months in the management of men initially diagnosed with localized prostate cancer. Information about this trial was published earlier (in the UK) in The Daily Telegraph under the heading “‘Superfoods’ shown to fight prostate cancer” — a typically newspaper-like headline!

This study involved > 200 men in a randomized, double-blind, controlled, Phase II clinical trial. All patients received either an oral capsule containing the food supplement twice a day or they received an identical placebo. Here are the early trial results:

• 203 men diagnosed with localized prostate cancer were enrolled into the trial.
  • The average age of the patients was 74 years.
  • 59 percent were being managed with active surveillance.
  • 41 percent were being managed with watchful waiting (progressive PSA relapse following previous radical interventions).
• The patients were randomized into two groups (to receive either the food supplement or the placebo).
  • The groups were statistically balanced in terms of Gleason grade, body mass index (BMI), treatment category, and fasting cholesterol.
  • Men in the food supplement group were younger (average age 71.8 years) than men in the placebo group (average age 76.4 years).
  • Four men withdrew from the study after randomization.
• The average (median) change in PSA levels of men in the two groups at 6 months was:
  • +14.7 percent for the men receiving the food supplement
  • +78.5 percent for the men receiving the placebo
  • This difference is statistically significant.
• At 6 months, stable or lower PSA levels were observed in
  • 46 percent of men receiving the food supplement
  • 14 percent of the men receiving the placebo.
  • This difference is statistically significant.
• There were no significant differences in change of PSA level within the predetermined subgroups (age, Gleason grade, treatment category, BMI).
• There were no significant differences in cholesterol, blood pressure, blood sugar or c-reactive protein.
• Data on reports of side effects were as follows:
  • 24 percent of men receiving the food supplement reported such events.
  • 34 percent of men receiving the placebo reported such events.
  • This difference was not statistically significant.
  • Mild gastrointestinal effects were reported by 17 percent of men receiving the food supplement in the FSG but 8 percent of these men reported an improvement in stool quality.

The authors conclude that, “This study found a statistically significant, short-term, favorable effect on the percentage rise in PSA in these men managed with observation following intake of this specific food supplement.”

This particular food supplement is commercially available at this time … at least in the UK and the USA, but the authors of the paper all state that they had “No relationships to disclose” and so we assume that the manufacturer was not in any way involved with this trial. The authors also state that “future trials should look at the longer-term clinical benefits particularly in terms of preventing medical intervention.”

This study does certainly add further support to the existing evidence that older men with (potentially) lower risk forms of prostate cancer or men who are on watchful waiting after first-line therapy may be able to allay PSA-related stress while on active surveillance or other forms of expectant management through dietary interventions. We do not yet know whether such dietary interventions have any impact on overall survival in such men.

Certainly some men may feel that they may want to add this particular food supplement to their diets based on the above information. The “New” Prostate Cancer InfoLink would only note that, if you want to do that, you might want to show the results of this study to your doctor and discuss them with him/her before you proceed. (An additional article about this study appeared on the Medscape web site on Monday July 10.)

In the second of these two presentations, Mahammedi et al. have suggested — based on data from a small Phase II clinical trial — that adding products known as curcumoinoids (derived from the herb known as turmeric) to docetaxel-based chemotherapy can significantly lower PSA levels and extend progression-free survival among men with castrate-resistant prostate cancer (CRPC).

A complete discussion of this paper is available on the CancerNetwork.com web site where Dr. Mahammedi is quoted as stating,

I think that the combination of curcuminoids and docetaxel has the potential in the future to enhance the efficacy of chemotherapy with no additional toxicity. If the studies are positive we can expect to take purified curcuminoid for a long time to neutralize the spread of cancer.

However, note the caution in the statement from Dr. Derek Rhaghavan, who says that that the information provided in the abstract is insufficient “to assess the utility of this novel compound.” He goes on to observe that, “The patient population is poorly characterized, the definition of progression is unclear, and there appears to be an absence of strong preclinical modeling data.”

The “New” Prostate Cancer InfoLink would point out simply that turmeric was a component of the food supplement used in the Pomi-T trial discussed above. One has to wonder whether a simple dietary intervention in combination with docetaxel-based chemotherapy might have similar effects to docetaxel + curcuminoids.

Filed under: Living with Prostate Cancer, Management, Treatment | Tagged: curcuminoid, diet, food, outcome, Pomi-T, poolyphenol-rich, supplement, trial |