Does the current evidence support the use of intermittent over continuous androgen deprivation therapy (ADT) in men with advanced prostate cancer who require ADT?

Dr. Penson: I really feel as though the jury is still out on this one. The results of the SWOG study of men with metastatic disease couldn’t rule out the inferiority of intermittent ADT when compared with continuous ADT.1 In other words, it is possible that intermittent ADT may not work as well.


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Conversely, in the Canadian trial of men with biochemical failure M0 disease only, the results documented that intermittent therapy was statistically non-inferior to continuous treatment.2

To translate the results out of statistical-ese and into somewhat plain English, it is probably still best to treat men with documented metastatic disease with continuous ADT.

In the case of M0 disease (biochemical failures), however, intermittent therapy is certainly a reasonable choice and may even be superior in terms of cardiovascular-event rates and quality of life outcomes.

Would you consider using active surveillance for selected men with intermediate-risk prostate cancer, and if so, what would be the selection criteria?

Dr. Penson: I remain reluctant to endorse active surveillance in intermediate-risk disease. Simply put, many and perhaps the majority of these cancers are clinically significant, and patients might realize a benefit from aggressive intervention as early as possible.

The advent of genomic testing may change this over the next few years. But right now, I don’t recommend active surveillance to my patients with intermediate-risk disease.

In your view, what is the most critical study in prostate cancer management that has yet to be conducted?

Dr. Penson: There are so many studies that need to be done. A big part of the problem is that they take so long to complete that researchers are not willing to undertake them. Rather than focus on a particular study, I will state that the greatest need for research is in the patient who has biochemical recurrence after primary therapy.

RELATED: Active Surveillance Should Be Considered for Favorable-risk Prostate Cancer

We have no idea when to treat these patients, or do we know how best to treat these patients. This is a big segment of the prostate cancer population, and it’s clear that many biochemical recurrences are clinically indolent, so any information to guide treatment here would be highly impactful.

Is there a place for surgery as a salvage therapy for patients with prostate cancer who experience biochemical recurrence after primary radiotherapy?

Dr. Penson: Yes, there is but it’s the great minority of patients in my opinion. In my practice, I reserve salvage prostatectomy for younger patients with biopsy-proven higher-grade localized disease recurrence.

What do you predict will be the most important game changer in prostate cancer management in the next 10 years?

Dr. Penson: Additional novel medical therapies to treat prostate cancer and earlier use of the existing medical therapies. I think we have gone as far as we are going to go in the treatment of localized disease with surgery or radiation, but we are just scratching the surface with regard to medical treatment of this common malignancy. There is surely more to come in the next decade that will really help our patients.

References

  1. Hussain M, Tangen CM, Berry DL, et al. Intermittent versus continuous androgen deprivation in prostate cancer. N Engl J Med. 2013;368(14):1314-1325.
  2. Crook JM, O’Callaghan CJ, Duncan G, et al. Intermittent androgen suppression for rising PSA level after radiotherapy. N Engl J Med. 2012;367(10):895-903.