The Palpable Prostate

Prostate cancer topics, links and more. Now at 100+ posts!

News: Health Day, Medical News Today, ScienceDaily, Urol Times, Urotoday, Zero Cancer Papers: Pubmed (all), Pubmed (Free only), Amedeo
Journals: Eur Urol, J Urol, JCO, The Prostate Others Pubmed Central Journals (Free): Adv Urol, BMC Urol, J Endourol, Kor J Urol, Rev Urol, Ther Adv Urol, Urol Ann
Reviews: Cochrane Summaries, PC Infolink Newsletters: PCRI, US Too General Medical Reviews: f1000, Health News Review
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Friday, August 14, 2015

Nutritional Supplements and Prostate Cancer

[Updated August 17, 2015]

Literature Review

A 2015 survey of nutritional approaches to prostate cancer published in BMC Medicine contains a table of approaches for which the authors found research. See table 1 in [Full Free Text of paper].

UK NCRN POMI-T Study

A 2014 six month randomized placebo-controlled double blind UK study published in Prostate Cancer and Prostatic Diseases of a mixture of polyphenols (pomegranate, green tea, turmeric and brocolli) with 199 prostate cancer patients on Active Surveillance or Watchful Waiting found that the treatment arm had an increase in PSA of 14% vs. 79% for the control arm (lesser increase is more favorable). The paper notes that the study received no funding from the manufacturer of the supplement. [Full Free Text of Paper] [Cancernet UK Charity info] [video interview with researcher Robert Thomas] [Manufacturer's FAQ].

PSA Doubling Time. Note that a 14% increase in PSA over a 6 month period (as found in the treatment arm) represents a doubling time of 6 / log2(1.14) = 31.74 months whereas an increase of 79% over 6 months (as found in the control arm) represents a doubling time of 6 / log2(1.79) = 7.14 months. Thus the doubling time was 31.74 / 7.14 = 4.4x times longer in the treatment arm (higher is more favorable).

Disease Progression. MRI scans were not part of the protocol but many of the patients had them anyways as part of their routine medical visits and these scans were consistent with lesser disease progression in the treatment arm (as opposed to just a matter of just modifying the PSA kinetics).

Group Composition. The treatment and control groups were assigned randomly subject to assigning 2 patients in the treatment group for every patient in the control group. By chance the average age in the treatment group was 5 years less than the average age in the control group so statistical methods were used to adjust the results to correct for this difference. On other measured variables the two groups were statistically similar.

A 12 month US study on effects of pomegranate extract on rising PSA levels

A randomized double blind trial of pomegranate extract on 183 men with rising PSA after primary therapy published in Prostate Cancer and Prostatic Disease 2015 found no effect on PSA doubling time. It did find some indications that patients with the MnSOD AA genotype might benefit but this would require a further study to confirm. Some of the study authors received funding from the manufacturer of the extract. See [PMID: 26169045] [Full Free Text].

Key differences between this study and the UK NCRN POMI-T study are that:
  • this study was performed after primary therapy whereas the UK study was performed on patients undergoing Active Surveillance and Watchful waiting.
  • this study examined only pomegranate extract whereas the prior study examined pomegranate extract in combination with 3 other polyphenols.
  • this study followed men for one year and the UK study for 6 months

Saturday, August 1, 2015

Blog updates for July 2015

August 1, 2015.  In PSADT Part 1 we add: PSA Doubling Time (PSADT) was found to be the most consistent of the top prognostic factors for a variety of endpoints (prostate cancer-specific survival, metastases-free survival, overall or all cause survival) in a 2015 literature review of relevant studies so we focus this 5 part series of posts specifically on it. [PMID: 26180662] [Full Free Text]. (The other consistent key factors were Gleason Score and Time to Biochemical Failure.)

Wednesday, July 1, 2015

Demographic Factors Affecting Prostate Cancer Mortality

In a June 25, 2015 PLoS One paper [full text] Yao et al perform a regression of prostate cancer mortality (one point per county) using the following explanatory variables:

Significant at 0.1% level:

- more urologists per 100,000 people decreases prostate cancer mortality
- being in a metropolitan country decreases prostate cancer mortality
- greater percentage of population being non-white increases prostate cancer mortality
- greater percentage of population with high school diploma decreases prostate cancer mortality

Significant at 1% level:
- greater prostate cancer incidence per 100,000 men increases prostate cancer mortality

Significant at 5% level:
- if county is a designated Health Professional Shortage Area it increases prostate cancer mortality
- if per capita income is higher then it reduces prostate cancer mortality

Factors that were not significant were:
- radiation oncologists per 100,000 people
- beds per 100,000 people
- percent of population over 65

Monday, June 1, 2015

Less lethal prostate cancer among those diagnosed with asthma

In a review of the Health Professionals Follow Up study (47,000 men) researchers found the proportion of subjects with lethal prostate cancer was 29% less among those who had been diagnosed with asthma vs. those who had not.   For those had been disagosed with hayfever the risk was 10% higher.  

The finding for asthma is odd because both prostate cancer and asthma are thought to be related to inflammation so that if there were a correlation the risk of lethal prostate cancer would be expected to be higher, not lower.
See [PMID: http://www.ncbi.nlm.nih.gov/pubmed/25648070] and [Science Daily]

Thursday, April 30, 2015

4-MU

A study of prostate cancer in a mouse model published this month [PMID: 25868577] concludes that "4-MU is an effective nontoxic, oral chemopreventive, and therapeutic agent that targets PCa development, growth, and metastasis by abrogating HA signaling." 4-MU (short for 4-Methylumbelliferone). It is also known as Hymecromone. It works by inhibiting hyaluronic acid.

Regarding the animal studies the researchers said:
"We found that when treatment started early, at eight or 12 weeks it completely inhibited prostate cancer development and growth ...  At 22 weeks, we found small cancers that had stopped growing and even regressed in some cases. Also to our amazement, while 60 percent of the animals in the control group experienced metastasis to distant organs, none in the treatment group developed metastasis. 4-MU did all of this without causing any toxicity to the host." Quoted in this News article

Although success in mice models is far from success in humans if 4-MU were effective for prostate cancer in humans as well, it would have the advantages that:
  1. it is already an approved for use in Europe and Asia (in Italy it goes by the name Cantabilin® for biliary applications and is called Cantabiline® in France and Belgium and in other countries by other names).
  2. Numerous human trials of 4-MU have been carried out.  See Table; however, these trials were for use in non-cancer applications and safety in cancer applications does not necessarily follow.  For example, if higher doses were required for cancer application at those higher doses there could be additional safety concerns; nevertheless, this is better from the viewpoint of unknown risks than a completely new drug.
A March, 2015 review of 4-MU appears here: [PMID: 25852691]

Tuesday, March 31, 2015

Blog updates for March 2015

March 15, In USPSTF Draft Report we added: Partly due to the controversy that this decision has generated, a new bipartisan bill HR1151 designed to reform the USPSTF process is under consideration.  The bill is supported by the American Urological Association (AUA).  A summary of some of the key points is available in this [June 3, 2013 Urology Times article] and this [March 11, 2015 Medscape article].

March 15. In Fasting we added: A recent experiment on fruit flies supports this idea [of only eating during certain hours of a day] finding that fruit flies who were restricted to eat within a 12 hour window each day had superior cardiac health than fruit flies allowed to eat any time they wished. See [PMID: 25766238] and [San Diego University news release].

March 25. In USPSTF Draft Report we added: A 36 minute presentation by Peter C. Albertsen largely in support of the USPSTF recommendations is found at [January 14, 2015 UBC Urology Rounds]

Saturday, February 28, 2015

Extrapolating the increase in prostate cancer diagnoses

"prostate cancer cases increased by 54% between 1975 and 2010, but mortality declined by 30% over the same period." [link]

Focusing on the increasing number of men diagnosed, "Our earliest data point comes from 1973. Back then, 1 man in 16 could expect to be diagnosed with the disease. Between 1973 and 2013, 38 available data points document the increase in the reported incidence of prostate cancer over 40 years." [link] The current proportion is 1 in 6 or 1 in 5. This proportion seems to be increasing linearly with time and based on linear extrapolation half of all men will be diagnosed with prostate cancer by 2124 (110 years from now). See this [figure] illustrating the extrapolated regression cursve.