When we replace testosterone, we bring the serum testosterone levels in hormone-deficient men to that of their eugonadal peers.
These symptoms also are commonly seen in aging men whose testosterone levels are normal. If testosterone is replaced, sex drive and erections often improve, men feel more energetic and less depressed, and they have a better outlook on life.
The question arises: "Is it safe to replace this hormone?" Certainly, the intramuscular form of testosterone therapy has been used for decades, and now transdermal testosterone preparations are widely used successfully to elevate testosterone levels to the normal range and to improve the symptoms mentioned above in many men. No negative cardiovascular sequelae have been definitively associated with this therapy.
Physicians have been hesitant to give testosterone to hormone-deficient men for fear of causing or contributing to the growth of prostate cancer. In reality, when we replace testosterone, we bring the serum testosterone levels in hormone-deficient men to that of their eugonadal peers. This realization will be helpful in counseling patients about hormone replacement therapy.
The recent study by Marks et al (see article, page 22) showed no change in levels of testosterone and dihydrotestosterone in the prostate tissue of men undergoing treatment with biweekly intramuscular testosterone shots, although serum levels of these two hormones increased.
Recently, intermittent hormone ablation has been used successfully. Men with advanced prostate cancer whose testosterone levels have been reduced by LHRH-agonist therapy and whose symptoms of testosterone removal are very bothersome are given a reprieve or holiday by stopping the LHRH agonist and allowing the testosterone level to rise. Signs of prostate cancer progression, such as rising serum PSA levels, are monitored closely. If tumor progression is seen, LHRH-agonist therapy is reinstituted, serum testosterone declines, and cancer growth is once again arrested.
There have been reports of physicians replacing testosterone in patients with prostate cancer who are symptomatic from low male hormone levels and who are likely cured of the cancer. A developing trend is to use hormone replacement therapy to treat symptomatic patients with low testosterone levels who are at risk of developing prostate cancer and in those who already are known to have or have had this tumor. In these cases, careful monitoring for the development, recurrence, or progression of this tumor is advisable by obtaining periodic serum PSA levels.
We expect to see many more studies assessing the results of male hormone replacement in the face of potential prostate cancer to more accurately define the role of this therapy.
John J. Mulcahy, MD, PhD, is in private practice in Phoenix.