New Weapon in Metastatic Cancer: Testosterone
Shutting down the supply of testosterone, through medication or surgical removal of the testicles, has been a standard form of treatment for metastatic prostate cancer ever since 1941, when urologist Charles Huggins discovered that it can dramatically slow the progress of the disease – work that earned him the Nobel Prize. But the beneficial effect of this hormonal therapy on cancer doesn’t last forever.
"Over time, all men become resistant to it," says oncologist Samuel Denmeade, M.D. "Further blockade of testosterone by new agents such as abiraterone acetate (Zytiga) or enzalutamide (Xtandi) produces a modest effect in some patients, but resistance to these drugs also develops."
But in a recent clinical study, Denmeade and his team have found that when they give prostate cancer a big shock – high doses of testosterone, after cancer has percolated along for months or years in a very low-testosterone environment – it makes a big difference.
"Surprisingly, many of the men
had a drop in PSA levels and
a decrease in the size of their
"We gave high doses of testosterone to men with prostate cancer who were progressing on long-term hormonal therapy," he says. "Surprisingly, many of the men in the trial had a drop in PSA levels and a decrease in the size of their tumor sites." The testosterone did not cause any harmful side effects. Instead, "most men experienced an improvement in their quality of life. In some men, sexual function returned." The results of these studies are expected to be published soon. Denmeade is now testing this concept in men with earlier-stage prostate cancer, with alternating three-month cycles of testosterone followed by three months of low testosterone.