That creates a greater risk for damage to healthy nerves and muscles surrounding the prostate. "It becomes a tradeoff between killing off all the cancer cells and avoiding such side effects as impotence and incontinence," said Dr. Israel Barken, chairman and medical director of the Prostate Cancer Research and Education Foundation, an organization founded by cancer survivors that helped fund the research.

"The beauty of the study is the synergistic effect of pairing cryosurgery together with chemotherapy," said Barken. "By using bleomycin, there's no need to be as aggressive with the cryosurgery. By freezing the cells, you can use very low doses of bleomycin. This should drastically reduce the harmful side effects of using either treatment alone."

The study was funded by grants from the Centre National de la Recherche Scientifique and the Institut Gustave-Roussy in France, and the Prostate Cancer Research and Education Foundation in San Diego.