Vitamin D as a treatment for low-risk prostate cancer? Not based on these data!


A presentation at a meeting of the American Chemical Society in Denver earlier this week suggested the possibility that men who took 4,000 IU of vitamin D every day for 60 days prior to a radical prostatectomy did better than similar men taking a placebo.

While this was a randomized trial, it has to be said that it was extremely small (just 37 patients in total) and there is very little available information about the comparability of the patients. Did they, for example, all meet strict criteria for low-risk prostate cancer, and if they did, did they even need a radical prostatectomy at all? The available data come from a report on the HeathDay web site.

The senior author of the study, Bruce Hollis, PhD, a professor of pediatrics, biochemistry, and molecular biology at the Medical University of South Carolina in Charleston, claimed that

In greater than 60 percent of those taking it, vitamin D actually made the cancer better.

He also said that when the patients’ prostate glands were examined after their surgery, many of the men treated with vitamin D had improvements in their prostate tumors, while the tumors in the placebo group remained the same or got worse.

However, Dr. Anthony D’Amico, chief of radiation oncology at Brigham and Women’s Hospital in Boston, appears to be utterly unimpressed by these data, saying that this study was too small to reach any definitive conclusion about the value of vitamin D in fighting prostate cancer. He went on to emphasize that men should not start taking vitamin D supplements in hopes of slowing or curing prostate cancer based on this trial. We tend to agree with him, rather strongly. The data just don’t support such a decision.

It’s all too easy to see this sort of result in a trial of this size — especially if there wasn’t any strict comparability of the men in the vitamin D arm and the placebo arm of the study. (Information on the comparability of the patients in the two study arms was not provided by HeathDay.) And exactly what does Dr. Hollis mean when he says that vitamin D “made the cancer better”? Did the patients’ tumors vanish? Did their Gleason scores go down when the biopsy Gleason scores and the pathologic Gleason scores were compared?

As Dr. D’Amico notes in his comments, we’d be wise to want to see a good deal more data that confirmed these very preliminary results before anyone would be well advised to start taking 4,000 IU of vitamin D per day instead of having a radical prostatectomy that they may well actually need!

6 Responses

  1. Why not take vitamin D? it’s got a lot of benefits, other than cancer, and a lot of evidence for cancer, as well.

    Zero risk, and possible gain.

  2. Doug:

    It’s only got additional benefits if your vitamin D levels are depleted for some reason.

  3. The overwhelming number of people in the USA have sub-optimal levels (50-80) of vitamin D.

  4. Have to agree with Doug on this one. Almost everyone’s D3 is low this time of year, in most of the country. Can’t eat enough food to get it up in the right range. Have to supplement in the winter.

    Low D3 does a tremendous amount of harm.

  5. Others have noted an association between elevated serum levels of vitamin D and increased risk and more aggressive prostate cancer. For example, see Ahn et al.. Vitamin D is more a steroidal hormone than a vitamin and has a complex biochemistry in humans. There is negative feedback, vitamin D binding protein, and vitamin D receptor sites (some with mutations) that all play a role in how it is utilized. Supplementing, especially at supraphysiological levels like 4,000 IU, will not necessarily be beneficial, and may be harmful. I’m not sure how the authors were able to compare random biopsy findings to full gland pathology findings to announce an improvement, but I look forward to reading the full article when published. So far, the only proven preventive for prostate cancer is a 5-ARi (Proscar or Avodart).

  6. LARGER TRIAL NOW UNDERWAY

    Thanks for posting about this. So many of us are taking vitamin D3 and are interested in developments. Dr. Donald “Skip” Trump, MD, formerly of Roswell Park Cancer Institute (birth place of the PSA test) and now the CEO of Northern Virginia’s Inova Comprehensive Cancer and Research Institute, just launching, spoke to our support group about vitamin D just this month. I suspect he would have the same reservations about the small study as Dr. D’Amico at this point, but I also suspect he is following this research with interest.

    The linked article mentioned a larger study, and that study has got to be Vitamin D3 Supplementation for Low-Risk Prostate Cancer: A Randomized Trial (VD3 PC) (NCT01759771), which is a randomized, double-blind, placebo-controlled Phase II trial run by the Medical University of South Carolina in conjunction with the sponsor, the Department of Veterans Affairs. It looks very much like the study described by Sitemaster as a proof-of-concept version of the larger study. The larger study will involve 136 patients (68 per arm) and is mid-way to completion, having started in January 2013 and targeting December 2017 for completion of all data collection for the primary endpoint. Patients must be low-risk (classic D’Amico criteria) and on active surveillance. The study will use the 1-year follow-up biopsy and other data, some longer term such as decisions to have treatment, to assess results of the intervention with 4,000 IU daily vitamin D3.

    Aims 3 and 4 of the larger study describe the data they are collecting, but it is not certain that the earlier study covered the same points:

    “3. To analyze changes in the serum levels of cholecalciferol, 25(OH)D, 1,25(OH)2D, and prostate-specific antigen (PSA) at baseline and at the end of the study, and to estimate the associations between changes in these measures and pathology outcomes (Gleason score and number of positive cores).
    “4. To compare the expression of molecular biomarkers, which are prognostically relevant to prostate cancer progression, in pre- and post- treatment biopsy tissue specimens. Paraffin-embedded sections will be processed to assess by immunohistochemical techniques the expression of the following biomarkers: Vitamin D Receptor (VDR), P21, Tumor Growth Factor (TGF ), Cyclooxygenase 2 (COX-2), and NF B. All of these protein products impact growth control and chronic inflammation in prostate cancer progression and are specifically affected by Vitamin D status.”

    More information is available at http://www.clinicaltrials.gov. It strikes me that this is a worthy Phase II study.

    Even the larger study will still be fairly small, but if successful we could be on our way to a large Phase III trial in about 2 years.

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