Changing the Standard of Care for Men with Recurrent and Advanced Prostate Cancer,

Men receiving androgen deprivation therapy (ADT) for the treatment of advanced or metastatic prostate cancer know all to well the terrible side effects this treatment modality can cause. These side effects can include fatigue, hot flashes, mood swings, inability to concentrate as well as memory loss. More serious and potentially life threatening effects also can include coronary problems and diabetes. Basically, ADT is no picnic.

Results from a large phase III randomized controlled study conducted by the National Cancer Institute of Canada show that shorter, eight month cycles of intermittent androgen deprivation (IAD) therapy can deliver comparable clinical outcomes for some men whose PSA levels rise following radical prostatectomy or radiation therapy.

Results of this study were released at the recent American Society of Clinical Oncologists (ASCO) meeting in Chicago. The overall consensus at the meeting was that these results are a “practice changing” milestone. ASCO is now endorsing that the concept that IAD be presented to men at the time of biochemical PSA recurrence in the absence of metastatic disease on scans (detectable lesions in bone or soft tissue).

“We have known since the mid-1990’s that androgen suppressive therapy could be used in an interrupted fashion, but we didn’t know until now that men were not sacrificing length of life in the hopes of having a better quality of life,” says Juanita M. Crook, MD, principal investigator and radiation oncologist with the British Columbia Cancer Agency. “The results of this trial will change the standard of care.”

The Canadian study, supported by a team of cross-border North American scientists, administered IAD in men for eight months then stopped and restarted only when their PSA levels reached >3 ng/ml when off the treatment, compared to men treated with continuous androgen deprivation (CAD).

The data showed that intermittent antiandrogen treatment was equivalent to continuous antiandrogen treatment with similar overall survival and quality-of-life measures. Bio-statiscally, intermittent therapy was called “a non-inferior” (comparable) arm of the trial—disease specific death was 18% in the intermittent arm compared with 15% in the continuous arm.

Dr. Crook believes the IAD method will be widely accepted. “There is no detriment to survival, some men see quality-of-life benefit, and it also happens to be cheaper,” says Crook.

Summary

IAD provides similar outcomes to continuous therapy with the potential for fewer side effects and less disruption to quality of life. IAD patients complained of fewer hot flashes and 35% of them had full recovery of serum testosterone after completing IAD. Cardiac events and osteoporotic fracture events were equal in both arms. Further, intermittent androgen deprivation offers cost-savings to health systems as both patients and the systems pay only 27% of the cost of continuous treatment.

Before starting and if you have already started CAD ask your oncologist about doing IAD instead of CAD.

Joel T Nowak, M.A., M.S.W.