Can testosterone cause cancer? When men start hormone therapy, this is one of the most pressing questions they ask because of concern about prostate cancer. Up until recently, this question would likely have been answered by most doctors with a resounding “yes.”
However, much research has been done to determine whether the “yes” response to the question “can testosterone cause cancer?” and specifically prostate cancer is accurate. Based on accumulating evidence, it appears the answer to “can testosterone cause cancer?” is “no.” One compelling reason for the “no” response can be attributed to the investigative work done by Abraham Morganthaler, MD, FACS, author of Testosterone for Life. He evaluated the original study by urologist Charles Higgins in the 1940s, research that led to the misconception that taking testosterone can cause prostate cancer.
Morganthaler discovered that this idea arose out of one case study involving one patient. Thus, the fear that testosterone can cause cancer was based on nothing.
In fact, many studies have dispelled the myth that testosterone replacement therapy causes prostate cancer or has a significant negative impact on the prostate. For example:
- A Beth Israel Deaconess Medical Center review of 72 studies found “no compelling evidence that testosterone replacement therapy increases the incidence of prostate cancer.”
- A report by The Prostate Cancer Center Hamburg-Eppendorf in Germany (Isbarn 2009) stated “the available research strongly suggested that testosterone therapy neither increases the risk of prostate cancer in normal men nor causes a recurrence of the cancer in men who have been treated successfully for prostate cancer.”
- In a study of 57 men who received testosterone for an average of 36 months after prostatectomy, mean testosterone levels rose in all the men before testosterone therapy. However, there was no increase in PSA values after testosterone therapy started. (Khera 2009)
- A study conducted within the ongoing Osteoporotic Fractures in Men cohort looked at the association between testosterone, estradiol, estrone, and sex hormone-binding globulin and prostate cancer. Only estrone was strongly related to an increased risk of prostate cancer. (Daniels 2010)
- In a landmark study, men with low testosterone levels were given testosterone injections or placebo every two weeks for six months. Before and during the study, investigators measured testosterone and DHT from blood and the prostate. Although blood concentrations of testosterone and DHT rose substantially in men who received hormone replacement, these concentrations did not change in the prostate gland. Testosterone therapy also had no effect on biochemical markers of prostate cell growth. Morganthaler noted “it is as if once the prostate has been exposed to enough testosterone, any additional testosterone is treated as excess and does not accumulate in the prostate.” Again, the answer to “can testosterone cause cancer?” is no. (Marks 2006; Morganthaler 2008)
According to a Johns Hopkins Prostate Disorders Special Report, “Testosterone-Replacement Therapy: Does It Increase Prostate Cancer Risk?” the jury is still out on whether “can testosterone cause cancer?” when men take it for a prolonged time. Morganthaler might add, as he has noted that “The relationship of testosterone to prostate cancer has undergone a significant reevaluation, and all recent evidence has reinforced the position that testosterone therapy is safe for the prostate.”
For men with prostate cancer, the concern has been that taking testosterone could make the cancer progress faster or promote tumor growth. These worries are why some doctors will not prescribe testosterone therapy for men who have a history of prostate cancer.
Morganthaler explains why this is not a concern by referring to the study by Marks and noting that “once the prostate has been exposed to enough testosterone, any additional testosterone is treated as excess and does not accumulate in the prostate.”
Basically, when men have very low testosterone levels, prostate growth is hypersensitive to any change in testosterone concentration. Therefore, while severely reducing testosterone levels with hormone therapy will cause prostate cancer to shrink, giving testosterone can cause prostate cancer to regrow. “However,” Morganthaler notes, “once we get above the point where the prostate is saturated with testosterone, adding more testosterone will have little, if any, further impact on prostate cancer growth. Experimental studies suggest the concentration at which this saturation occurs is quite low.”
If you are considering testosterone replacement therapy
- You should be monitored closely for any rise in PSA levels and/or return of prostate cancer
- Avoid synthetic testosterone. Instead, ask your healthcare provider about bio-identical testosterone therapy. This form of the hormone mimics the activity of the testosterone naturally produced by the body.
- Have your physician balance testosterone with estradiol. The proper testosterone:estradiol ratio is necessary for prostate (and overall) health.
Another fear associated with taking testosterone is that the prostate begins to grow. This increase in size usually stops after the first few months of treatment. Thus the prostate typically ends up being no larger than it was before the hormone level began to drop. Bottom line: the increase in prostate size resulting from testosterone therapy is not usually sufficient to cause urinary symptoms associated with BPH or to worry about “can testosterone cause cancer?”
Daniels NA et al. Sex hormones and the risk of incident prostate cancer. Urology 2010 Nov; 76(5): 1034-40
Isbarn H et al. Testosterone and prostate cancer: revisiting old paradigms. European Urology 2009 Jul; 56(1): 48-56
Khera M et al. Testosterone replacement therapy following radical prostatectomy. Journal of Sexual Medicine 2009 Apr; 6(4): 1165-70
Marks LS et al. Effect of testosterone replacement therapy on prostate tissue in men with late-onset hypogonadism. JAMA 2006 Nov 15; 296(19): 2351-61
Morganthaler A. Destroying the myth about testosterone replacement therapy and prostate cancer. Life Extension 2008 December