Testosterone and Prostate Cancer

The evidence as it now stands

For over sixty-five years, there has been a fear that T therapy will cause new prostate cancers to arise or hidden ones to grow.  Although no large-scale studies have have provided a verdict on the safety of T therapy, fears about testosterone and prostate cancer have little scientific support.  The old concepts do not stand up to critical examination.  To summarize the risk of prostate cancer from T therapy:

No relationship was found between prostate cancer and testosterone and minor androgens, according to a 2008 article published in the Journal of National Cancer Institute.  For men undergoing testosterone therapy, this is the most reassuring study published.  The authors of 18 separate, international clinical trials pooled their data regarding the likelihood of developing prostate cancer based on concentrations of various hormones, including testosterone.  This enormous study included more than 3,000 men with prostate cancer and more than 6,000 men without prostate cancer.  In an accompanying editorial, Dr. Carpenter and colleagues from the University of North Carolina School of Public Health suggest scientists finally move beyond the long-believed but unsupported view that high testosterone levels signal a risk for prostate cancer.

FAQ

I’m fifty-three years old and I’ve been on testosterone therapy for two years, with good results.  However, my father was diagnosed with prostate cancer at age seventy-five.  Does this mean I need to stop testosterone?

There is a familial form of prostate cancer, but only in families in which prostate cancer occurs at age sixty-five years or younger.  Even in those families where a family member develops cancer at a young age, this does not necessarily mean that every other male in the family will develop cancer.  Men with a family history of prostate cancer should be sure to have a yearly PSA and prostate exam.  There is no need to discontinue testosterone treatment.

My physician started me on testosterone, but I never had a prostate biopsy.  I am sixty-four years old.  Was this a mistake?

No, this isn't a mistake, because there is no evidence that testosterone treatment increases the risk of prostate cancer.  The Stocks Institute recommends prostate biopsy in men with low T because published data indicate there is an increased risk of cancer in men with low T, but this is by no means a standard recommendation yet among physicians.

Why do you perform prostate biopsies on men with low T if you don’t feel that testosterone treatment will make a hidden cancer grow?

Low T represents a slightly increased risk of prostate cancer in men over age 50, making a biopsy worthwhile.  However, because prostate cancer is not always terminal, even without treatment, it's debatable how aggressive to be in making the diagnosis.

A man in my bowling league began testosterone treatment, then developed prostate cancer one year later.  Doesn’t that show that testosterone is risky for prostate cancer?

If the wife of this man had switched to a new type of laundry detergent before the cancer was diagnosed, would we assume the cancer was caused by the detergent?  Of course not.  But we are predisposed to believe negative anecdotes regarding T therapy.  Prostate cancer and T thereapy are both common in the United States, and both tend to occur in the same age range, so there will always be overlapping instances.  If testosterone makes prostate cancers grow, then we would see high rates of cancer among men who start testosterone therapy.  But we don’t.  It’s false logic.

Isn’t it true that all men would eventually get prostate cancer if they lived long enough?  If so, why does it even matter if testosterone were to increase the risk of something that is inevitable anyway?

Men do get prostate cancer at an increasingly high rate as they age.  And it is true that most men diagnosed with prostate cancer would never have a moment’s trouble from it, even if it were left untreated, because most of these cancers grow so slowly that other medical conditions eventually become more troublesome.  Yet for those with more aggressive forms of prostate cancer, the danger is very real.  The challenge is to identify men at risk, because even high-grade prostate cancer is curable when caught early.

It took more than thirty years for scientists to learn that hormones were dangerous for women and caused breast cancer.  Isn’t it possible we’ll eventually find out the same is true for testosterone and prostate cancer?

The fear that hormone therapy is dangerous in women is currently being reevaluated, and it appears to be safer than originally proclaimed.  It is critical to understand that men are not women and that testosterone is not estrogen.  After so much research over so many decades, there is little reason to believe that T therapy poses a major risk for prostate cancer.  As a medical student once said to me, “If testosterone is really so dangerous for prostate cancer, why is it so hard to show it?”