Bipolar Androgen Therapy yields promising results in prostate cancer
High doses of testosterone kill prostate cancer cells
Researchers at Johns Hopkins University in the US have shown that high doses of the male sexual hormone testosterone can kill prostate cancer cells when administered intermittently with the well-established ADT (Androgen Deprivation Therapy).
47 men with metastatic prostate cancer received injections with high doses of testosterone every 28 days whilst conventional androgen deprivation therapy was continued with so-called LHRH agonists (Lupron®, Zoladex®, etc.).
40% of the men receiving this therapy showed a drop in their PSA levels. In several patients disease progression was halted and in some patients the tumor mass decreased.
In addition, the disease progression was halted in several patients for more than a year. In some patients, the size of the tumor decreased. In one patient, PSA levels dropped to zero and have remained at that level for 22 cycles of treatment, almost 2 years.
In another group of patients, which did not respond to the treatment with Zytiga® and/or Xtandi®, the testosterone injection resulted in a renewed response to treatment.
The "side effects" of the bipolar androgen treatment are welcomed by most men: the testosterone injections results in a return of the sexual functions, such as libido and erection, in most men, but also in an increase in vitality and muscle mass.
The testosterone treatment was well tolerated by all men, but has to be monitored closely by a physician. In men who had suffered from bone pain before their ADT, these can recur.
So far it is not entirely clear why high doses of testosterone kill prostate cancer cells. The effect is probably linked to the increase of testosterone receptors on the tumor cells which occurs under androgen deprivation—the same mechanism which is responsible for resistance to ADT. Under these conditions the sudden application of testosterone results in an unnaturally high concentration of testosterone bound to the cells receptors which in turn "poison" the tumor cell.