|Researchers from the University of Washington and Johns Hopkin University have found evidence which suggests hormone replacement therapy can reduce cancer cell growth for patients with prostate cancer.
Dr. Michael Schweizer of the University of Washington School of Medicine led a team of medical researchers in a trial which focused on hormone therapy for prostate cancer patients. Traditionally, prostate cancer has been treated by “chemical castration therapy,” which is the process of deliberately reducing testosterone levels in the body. Also known as “androgen deprivation therapy,” chemical castration involves injecting antiandrogens into the body, in order to both halt testosterone production and block hormonal receptors. Because prostate cancer cells rely on hormones for growth, reducing testosterone can inhibit the growth of tumors.
However, chemical castration is not always effective against prostate cancer and often comes with debilitating side effects such as nausea, loss of libido, and hair loss. Prostate cancer cells can develop a resistance to antiandrogens and adapt to low testosterone levels. When this happens, the condition becomes known as castration-resistant prostate cancer (CRPC), and is usually fatal, even with treatment.
The medical team, fully aware of this issue, decided to use an approach known as “bipolar androgen therapy.” Rather than giving the patients exclusively antiandrogens and other hormone blockers, the researches would also administer high levels of testosterone about every month. The treatment would create severe but temporary testosterone imbalances.
The results were promising. Of the 16 patients that participated in the trial, seven showed signs of reduced cancer growth and 10 responded positively to androgen deprivation therapy after the testosterone injections ended. Furthermore, four men saw their tumors shrink by half and one patient’s cancer disappeared altogether. It should be noted, however, that three of the patients have died since the study commenced in 2010.
The results impressed the researchers. Some have expressed optimism that this experimental treatment can effectively fight prostate cancer.
“The results were unexpectedly promising,” said Dr. Samuel Denmeade of Johns Hopkins University, “and we’ll need a lot more study. But this cycling on and off of testosterone could become a part of the treatment.”
In addition to injecting patients with synthetic hormones, it is also possible to increase testosterone growth by naturally increasing “free testosterone.” Free testosterone is the testosterone in the blood that is available to bind to receptors in the brain, muscle, and other organs of the body. Some testosterone in the body is naturally blocked. By injecting medication that can unblock these testosterone molecules, the body can naturally increase its testosterone levels.