Prostate Cancer Drug Zytiga May Extend Life
Study Shows Zytiga Adds 4 Months of Life to Patients With Advanced Prostate Cancer
Drug May Have Wider Role in Treatment continued...
"It absolutely will work in untreated patients as well and clearly there are studies ongoing now that are looking at this drug in combination with standard hormone therapies prior to [prostate-removal] surgery," he says.
One mainstay treatment for spreading prostate cancer is to deplete or block the action of male hormones known as androgens. This typically works initially, but the cancer eventually progresses even though levels of male hormones are low. Until recently, researchers assumed that tumors became resistant to hormonal therapies.
The opposite may be true. "These tumors may actually be hyper-sensitive to hormone therapies," Scher says. "Androgen levels are higher in the tumors than in the normal prostate."
American Cancer Society Chief Medical Officer Otis Brawley, MD, explains it this way: "Hormonally unresponsive prostate cancer is really just incredibly sensitive to hormones. We have even taken away hormones from these guys through medical or surgical castration or androgen blockers and the tumor responds, but then starts growing again."
"It may be the tumor changes, so it is very sensitive to the small amount of androgen in the man's body," Brawley says. The drug interferes with the tumor's handling of that small level of androgen that was left behind.
New Treatment Option
"There has been a lot of buzz and excitement about this drug for a while," Brawley says.
Having another option to treat these men is "incredibly important," he says. "There are clear, definite gains in survival. Yes they are small, but they are clear, definite gains. And because of the rigorous design of this trial, there is no doubt that this drug works."
Study researcher Christopher J. Logothetis, MD, chair of the department of genitourinary medical oncology at the University of Texas M.D. Anderson Cancer Center in Houston, says this study is important on several levels.
"There is a new effective drug for patients with [spreading] prostate cancer, and it's nontoxic, relieves symptoms, and prolongs survival. That is exciting," he says.
"This indicates that even among patients who have run out of all alternatives, abiraterone prolongs survival by a third," he says.