Yes, biology can be confounding. Who would have thought that testosterone, which normally fosters cancer growth, can actually be applied in such a way that it kills prostate cancer? It defies logic and reasoning, but if it works, then I don't see a problem with using it as a tool to fight cancer.
Often-times science and medical research surprises us. While our intuition tells us one thing, the results of a research study or scientific experiment give us results that counter this. Often, it takes multiple studies and experiments to verify a result and "make sure" that it is true. Once this is done, we should certainly follow the results. This, however, is not the case with the testosterone shocking prostate tumours. We are speaking of an isolated case of a man who had success with this type of medical intervention. We cannot say yet whether it would be a good idea to apply this type of intervention on a widespread basis yet. We should absolutely not, however, avoid looking into it. Sam Denmeade, a professor from the School of Medicine of John Hopkins University in Baltimore, MD is studying this type of intervention. They have had some success so far. We should forget about intuition, and continuously study this intervention with great rigor, multiple times, and see what the results are. If the results are successful and can be replicated over and over, then this would certainly be an ethical treatment. Multiple, successful studies must be completed first, but if it works, it works.
Yes it is ethical to try to kill cancer with something that normally fosters its growth. Cancer is a horrible disease and should be fought in any way possible. Vaccinations work by introducing into the body a small amount of the very disease you're trying to prevent. It is not a lot different.
Testosterone has been known to have its own complications. Even if a testosterone overdose can kill cancer, one has to question the side effects of such a treatment. It is apparent that sometimes the cure can be worse than the disease. If this were the case concerning the use of testosterone, one would also have to also question the ethics of such a treatment.