Can You Take Testosterone If You Have Prostate Cancer?

A certain question frequently arises in my daily medical practice. Patients ask, “I have a history of prostate cancer but my testosterone levels are low. Can I take testosterone?” The pat answer offered by many doctors is "definitely not"—the testosterone will act like fuel on the fire and accelerate the growth of cancer.

But is this true? The answer is a qualified “yes,” but there are at least four situations with exceptions that will be addressed below. However, before we describe the situations in which men with prostate cancer can consider taking testosterone, we need to discuss how blood tests that measure testosterone are interpreted. What is the exact threshold that defines when the level of testosterone in the blood is excessively low?

There are a number of issues related to testing testosterone in the blood. First, testosterone blood levels are higher in the morning and lower in the evening. A test drawn at 4 pm that was “low” may simply be outside the normal range due to the time of day the blood was taken.

Second, there are actually two types of testosterone tests: total testosterone and free testosterone. Most routine tests only measure total testosterone. However, free testosterone is a much more accurate measure of the physiologic activity of testosterone. That said, experts clearly realize that the connection between accurately measured levels of free testosterone and the subjective feelings that men report about their energy and libido are often at odds. Some men with relatively low free testosterone feel just fine.

Determining an individual’s testosterone status and making a decision about the need for testosterone therapy should never be based solely on the level of testosterone in the blood. It is equally important to base the decision to use testosterone on the individual’s symptoms. What is the point of giving testosterone to someone simply to correct the low results observed on a blood test if the patient already feels good?

Now let’s discuss the situations where giving testosterone therapy might be acceptable in a man with known prostate cancer.

The first situation is giving testosterone to men with low grade or benign tumors. Certain types of prostate cancer are so low grade they are essentially harmless. These types of prostate cancer never spread and should actually be called benign tumors. Unfortunately, the “cancer” terminology was wrongly assigned to these benign forms of prostate cancer decades ago and this policy of calling them cancer survives to this day.

The second situation where giving testosterone might be reasonably safe is when men have previously undergone therapy with surgery or radiation and appear to be cured. After an appropriate waiting period of somewhere between two and five years, the risk of cancer recurrence is generally quite low. Fear of using testosterone in this situation seems unfounded.

The third situation occurs in men with prostate cancer who have relapsed after surgery or radiation. This phenomenon is signaled by the development of a rising level of PSA in the blood. Traditionally, these men are managed with intermittent testosterone-lowering drugs such as Lupron or Firmagon. Studies show that long term cancer control is equal by using either intermittent Lupron or continuous Lupron.

Yes, this sounds outlandish, but it is actually safe to stop the anticancer treatment and take a holiday. Once treatment is stopped, the natural production of testosterone from the testicles restores normal testosterone levels in the blood. However, sometimes testosterone remains low, especially in elderly men. Previous Lupron has permanently put these men’s testicles to sleep. When normal production of testosterone fails to resume, it is reasonable to consider administering testosterone. After all, since it has been proven that allowing the intermittent return of testosterone from the testicles is safe, how would it not be safe to administer bioidentical testosterone in doses designed to attain exactly the same blood levels of testosterone normally achieved by the testicles?

The fourth situation to be considered is when there are low testosterone levels in a man with known prostate cancer who has a severe physical infirmity or very advanced muscle loss that is associated with notable weakness and debility. This scenario can occur in men with very advanced age or due to some other serious illness. When men have become so weakened (due to some non-prostate cancer-related process) it may be more dangerous to withhold testosterone than to give it, even though the prostate cancer could conceivably grow more quickly due to the exposure to testosterone. It's worth remembering that even the “bad” types of prostate cancer are notably languid in their growth rate. If a decision is made to initiate testosterone, the rate of disease progression can be closely monitored with PSA blood tests and body scans. If these tests indicate that the cancer is progressing unduly quickly, the testosterone therapy can be stopped with the expectation that cancer will stop progressing or even regress after the testosterone is stopped.

The confusion about using testosterone therapy in men with known prostate cancer arises because prostate cancer is not a single illness. There are low, intermediate, and high-grade forms; localized disease and metastatic cancer; hormonally sensitive types and types that are insensitive to hormone treatment. A single protocol would not be universally appropriate for every type of prostate cancer.

The decision to start testosterone, therefore, comes down to two issues. I have briefly outlined the first consideration by the above description of four potential scenarios in men with known prostate cancer who have low testosterone and may benefit by using supplemental testosterone. The second issue is related to the risks of using testosterone in an otherwise normal healthy male who does not have prostate cancer. Studies have shown that giving testosterone is not totally safe—even in men that don’t have any prostate cancer whatsoever.

Testosterone levels in the blood tend to decrease with age. Most men adapt to these modest reductions in testosterone without experiencing undue difficulty. However, there are certain, potentially negative consequences to having low testosterone, especially when testosterone is notably suppressed. These effects of low testosterone include low energy levels, low sex drive, moodiness, memory issues, weight gain, breast enlargement, and sometimes, acceleration of calcium loss from the bones—i.e., osteoporosis. All these negative effects of low testosterone can be counteracted by restoring a normal level of testosterone in the blood.

Giving testosterone therapy can be conveniently achieved in a variety of different fashions, including the use of short or long-acting injections, creams, gels, and transdermal patches. The application of the treatment is relatively simple. However, as noted above, testosterone therapy is not without risks (aside from the risks of using it in men with prostate cancer). The biggest concern from testosterone replacement therapy is the development of red blood cell counts that are higher than normal—the technical term is a high hematocrit. The hematocrit, often abbreviated as Hct, is a component of a blood panel, the CBC or complete blood count. Another technical word you may come across that conveys the same meaning as a high hematocrit is “polycythemia.”

High red counts mean that the blood becomes more viscous (thickening of the blood), which can predispose to serious problems such as heart attacks and strokes. Careful monitoring of the hematocrit is necessary, therefore, in everyone planning to undergo testosterone replacement. Should a high hematocrit develop while on testosterone therapy, that is, should the hematocrit rise above 50 percent, some sort of countermeasure needs to be implemented. Such measures may include the periodic removal of a unit of blood at a hematologist practice or perhaps reduction in the administered dosage of testosterone.

Management of testosterone replacement therapy has become fairly standardized, and in men without prostate cancer, its use has become very popular. As noted above, not everyone who goes on testosterone treatment experiences the type of benefits that might be anticipated—benefits such as an increase in libido or increased energy levels.

After many years of experience giving testosterone therapy to many men, I have learned that there is tremendous variability in the way that men will respond. Sometimes the impact of the testosterone is prompt and dramatic. In other men, even after an adequate trial period of six months, a noticeable benefit may be lacking.

The only way to determine whether a specific individual will benefit from testosterone is to initiate a trial and observe what transpires over a period of six months or more. An adequate trial period is needed to determine if a beneficial effect will occur. Testosterone does not cause instantaneous results like some other hormones, like adrenaline, for example.

To this point, much of what we have discussed is fairly standard and many endocrinologists and general physicians are familiar with the delivery of testosterone treatment to men without prostate cancer. The trickier situation, as noted above, is in men with active or previously treated prostate cancer. After all, testosterone reduction therapy is one of the most popular ways to counteract prostate cancer. How, therefore, can the administration of additional testosterone in men with prostate cancer not be harmful? The answer is that the type of prostate cancer needs to be clearly defined.

Active prostate cancer basically can be divided into two broad categories—the harmless types (in particular, those that are determined to be of a grade of six or less as determined through a needle biopsy or by surgery), and the more consequential types, which are graded from seven through ten. Additional factors such as PSA and the results of various scans may also affect decision making. In most cases, evaluation by a prostate cancer expert will probably be necessary to make a final determination about the safety of giving testosterone treatment to someone who has a history of prostate cancer.