Prostate cancer is diagnosed in about 240,000 American men and leads to about 34,000 deaths each year, according to the National Cancer Institute.
The treatment of this cancer in its more advanced stages brings about chemical castration by targeting one of several mechanisms involved in the production of testosterone. In most patients, cancer cells develop castration resistance over time on average, between 1 and two years after the start of treatment. However, the overall range of resistance development spans from a few months to more than 10 years.
Jain said that some scientists have proposed that this treatment leads directly to castrate-resistant disease because once testosterone is removed from the body, mutant cancer cells that can survive in a no- or low-testosterone environment are able to take over the tumor.
Currently, continuous treatment to eliminate testosterone is the standard of care. But because clinicians know castration resistance is inevitable, a new approach is under study. A national clinical trial is assessing the benefits and risks of intermittent androgen ablation keeping patients on the drugs until symptoms improve, and then giving men time off from the medication until the disease begins to progress again.
The math model developed by Ohio State scientists suggests that based on average clinical data currently available, such intermittent therapy could actually accelerate the development of castration resistance.
"In the same way that intermittent use of antibiotics gives a chance for bacteria that are resistant to the drug to take over, you might actually end up with intermittent anti-androgen therapy even more positively selecting for mutating cancer cells," Jain said.
However, the averages don't always apply, which is why the scientists are pursuing a system of dif
|Contact: Harsh Jain|
Ohio State University