With Testosterone, It's Love and Hate

Prostate cancer treatment with continuous androgen deprivation

(RxWiki News) Cancer patients have to filter through a lot of very unfamiliar terms that only vaguely seem to make any sense. It's a lot to process, during a very emotional time.

While it sounds quite menacing, castration resistant prostate cancer is another way of saying that the normal relationship between prostate growth and male hormones, like testosterone, is gone.

"Ask your oncologist about Intermittent Androgen Deprivation."

Research presented by Maha Hussain, MD, a professor at the University of Michigan Comprehensive Cancer Center in Ann Arbor during the annual meeting of the American Society of Clinical Oncology showed that there was a notable difference in results when treating advanced cases of prostate cancer with a continuous dose of hormone-blocking drugs.

The study compared the treatment results of continuously blocking testosterone and similar hormones in men with advanced prostate cancer against a stop and go treatment, called intermittent therapy, in a study that followed 3,040 prostate cancer patients.

The researchers concluded that continuously blocking testosterone and similar molecules was necessary in the most advanced cases of prostate cancer.  

There is a strong case to be made for using the stop and go treatment in less serious cases, since the severe side effects could be avoided.

"In the past when it came to using hormone therapy in this disease, doctors viewed the disease as one entity and adopted a 'one size fits all' approach," Dr. Hussain stated during her presentation. "Based on this study's findings, it seems that one size does not necessarily fit all."

Apart from surgery, part of the treatment for prostate cancer also depends on blocking testosterone to stop further growth. The most common drug used for this effect is Proscar, also marketed as Propecia.

The regular, non-cancerous version of prostate gland growth is benign prostatic hyperplasia (BPH). While not the same as prostate cancer, it is responsible for giving every man in his seventies an intimate relationship with the bathroom at two in the morning, and treatment for BPH also uses much lower doses of the same drugs.

As the researchers explained, the main conflict in the medical literature is whether to use hormone-blocking therapy continuously, or to break it up with gaps so that the significant effects of blocking testosterone are less severe.

The researchers argued that given the difference in quality of life, since there was no difference in survival, the best therapy for early cases of prostate cancer is to break up the hormone blocking in gaps.

The quality of life argument has its roots in the countless essential functions of testosterone in both men and women, with effects on everything from muscle strength and energy to immune system function to libido.

When considering that the range of symptoms found in men given long term testosterone blocking treatments can include serious depression, it's important for doctors to consider the big picture when choosing treatments.

Blocking testosterone and other male hormones only works for about two and a half years, after that point the prostate cancer is less likely to require hormones for growth. At the point of losing the normal response to testosterone, prostate cancer is referred to as castration resistant.

It's important for oncologists to test prostate cancers for hormone response, and not to give patients the hormone blocking therapy if it will not help slow the cancer's growth.

Research findings presented during conferences should be considered preliminary until publication in a peer-reviewed journal.

Funding for the trial was provided by the National Cancer Institute and AstraZeneca Pharmaceuticals.

Researchers involved on the project disclosed financial ties with several dozen corporations involved in the research and development of pharmaceuticals and/or different cancer biotechnologies

Review Date: 
June 23, 2012