For over sixty-five years, there has been a fear that Testosterone 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 Testosterone therapy:
- Low blood levels of testosterone do not protect against prostate cancer.
- Low testosterone levels may increase the risk of prostate cancer.
- High blood levels of testosterone do not increase the risk of prostate cancer.
- Treatment with testosterone does not increase the risk of prostate cancer, even among men who are already at high risk for it.
- In patients treated for metastatic prostate cancer with drugs that drop testosterone blood levels to near zero, starting treatment with testosterone might increase the risk that residual cancer will again start to grow.
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.