An experimental procedure, dubbed "Trojan horse therapy", has completely eliminated prostate cancer in mice. While the technique is still in its infancy and it will be a while before the procedure is performed on human patients, it has shown a tremendous amount of promise.

The technique builds on a growing arena of medicine that uses viruses to target cancer. Previously, we reported on a technique that used the disabled reprogrammed HIV virus to attack cancer. There, as in here, part of the delicacy of the treatment lies in getting enough of the virus inside the tumor to kill it from within.

In this trial, the team hid tens of thousands of the virus inside the body's immune system itself, using white blood cells to transport the warriors. White blood cells are singled out because, among other functions, the cells swamp the area to treat tissue damaged by chemotherapy and radiation. The team took blood samples and extracted macrophages, a portion of the immune system that attacks foreign invaders. The macrophages were mixed with a virus which, like HIV, resists attack from the immune system. The product was then reinserted into the body two days after the end of chemotherapy. While the team only inserted a limited quantity of the virus, the virus replicated once inside the body. About 12 hours later, the white blood cells burst, uncovering 12,000 viruses that killed the cancerous cells.

The treatment, which was monitored over the course of 40 days, would have ordinarily been considered a success simply because more mice who were subjected to the therapy lived longer than those who received other treatments. However, the treatment was considered to be an astounding success because all of the mice who were given the therapy were alive at the end of the trial. In addition, all of the mice's tumors had disappeared.

Researchers hope to start human trials as early as next year. The study was published in the journal Cancer Research.