Laurel & Hardy and prostate cancer chemoprevention

In the sometimes Laurel-and-Hardy-like (“Here’s another fine mess you’ve gotten us into!”) interactions between industry, government, and clinicians, there’s a debate brewing about whether drugs used to treat benign prostate problems (BPH) should also be used to try to prevent cancer of the prostate.

(Photo credit: http://www.flickr.com/photos/karlosofsyston/)

The drugs are of the class called 5-alpha reductase inhibitors (5-ARIs) – drugs like finasteride (Proscar) or dutasteride (Avodart).

For more than two years the American Urological Association and the American Society of Clinical Oncology have recommended that “healthy men who are screened regularly for prostate cancer and show no symptoms of the disease should talk to their doctors about using a 5-alpha reductase inhibitor (5-ARI) to prevent the disease.”

Earlier this year, two drug companies making these drugs asked the FDA to label their drugs as effective for cancer chemoprevention. Both requests were resoundingly defeated at the advisory committee level.

Oncology Times reported:

“During the wide-ranging discussion, several committee members expressed concern about the possibility of widespread chemoprevention prescriptions being written by varied practitioners for these drugs, and about patients possibly influenced by direct-to-consumer advertising. “It’s a little frightening, to be honest,” aid temporary voting member Inger Rosner, MD, LTC, US Army Medical Corps, Urologic Oncologist at Walter Reed Army Medical Center’s Urology Service.”

The FDA accepted the advisory committee’s recommendation, and, in June, informed doctors that that the labels for these drugs had been revised “to include new safety information about the increased risk of being diagnosed with a more serious form of prostate cancer (high-grade prostate cancer).” In other words, there was some evidence that these drugs that had been proposed to prevent prostate cancers had actually been linked to more aggressive prostate cancers in men who took them.

A physician friend wrote to me: “Questionable science led to a questionable guideline that led to an aggressive marketing strategy that backfired.”

Interestingly, rather than refute that label change or the evidence behind it, the American Urological Association wrote to the FDA (pdf file) with concern about one line in the FDA statement:

“Prior to initiating therapy with 5-ARIs, perform appropriate evaluation to rule out other urological conditions, including prostate cancer, that might mimic benign prostatic hyperplasia (BPH).”

The AUA countered:

“Because a biopsy is the most effective means by which we can distinguish malignant from benign disease, the current wording implies that all men obtain a routine prostate biopsy prior to commencing treatment – something that is, at present, not supported by the literature.”

Or, another view would be that all men should think really carefully before even considering treatment with this drug – which was the point of the FDA labeling action.

An article in the Journal of General Internal Medicine* in January concluded that:

“If reducing prostate caner incidence without regard to mortality is the desired outcome, forgoing PSA screening in the first place would be a much more effective strategy.”

Of course, the entire issue may be a moot point depending on what goes on behind urologists’ office doors when they meet with men, since, as a New England Journal of Medicine perspective piece by FDA authors stated last month:

“There is clearly ongoing off-label use of 5 alpha reductase inhibitors for this indication.”

It will be interesting to see how the FDA responds.

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* Dr. Michael Barry, one of the authors of the JGIM piece, is president of the Foundation for Informed Medical Decision Making, which supports the HealthNewsReview.org project. Dr. Richard Hoffman, another of the authors, is one of the project’s medical editors.