Drug Could Pull Plug On Prostate Cancer
New Class Of Drug Also Hopeful For Colon Cancer
Doctors at Columbia Presbyterian Medical Center in New York City are studying a new drug called Exisulind that, in a small study, caused cancer cells in the prostate to self-destruct.
The doctors are planning new, larger studies to determine if the drug has long-term side effects, according to the chief researcher, Dr. Erik Goluboff.
Gubuloff said that Exisulind increases the rate at which cancer cells die off -- a process doctors call "programmed cell death" -- while leaving normal cells untouched.
"This means that the cancerous cells die and can no longer keep dividing and multiplying, which stops the cancer from growing," Gubuloff said.
Guboloff and his colleagues reported their research findings at this year's annual meeting of the American Urological Association.
Almost 185,000 new cases of prostate cancer will be diagnosed in the United States this year. More than 39,000 men will die of the disease in the U.S., making it the second leading cause of cancer death in men.
The prognosis is good when prostate cancer is detected early, but in an advanced stage the disease has no cure. Available therapies, such as drugs, hormones, radiation, or chemotherapy, try to limit spread of the disease and increase survival time by shrinking or stabilizing tumors.
Hope For Colon Cancer, Too
Previous studies in mice had showed that Exisulind inhibits the growth of prostate cancer by 80 percent to 90 percent, Gubuloff said. In a related study of patients, researchers found that the drug also caused regression in the growth of precancerous colon polyps, a condition that often leads to colon cancer, he said.
Gubuloff and his co-workers followed 96 prostate cancer patients, who had already had their prostate glands removed, for 12 months. All had rising prostate-specific antigen or PSA levels indicating that cancer cells were active.
In the study, half of the participants were given doses of Exisulind, while the other half received a dummy or placebo pill. The researchers measured the drug's ability to slow or halt the progression of the disease by monitoring patients' PSA levels. The higher the PSA count, the more aggressive the prostate tumor.
Gubuloff and his colleagues also took X-rays and did other imaging tests before and after the study. At the end of the study, all the patients who got Exisulind showed a significant decrease in the rate of rise in their PSA levels. The patients who got the dummy pill showed no similar decline, Gubuloff said.
"Research indicates that Exisulind reduced the growth of prostate cancer in men with progressive, recurrent disease, thereby possibly providing long-term disease control with low incidence of side effects otherwise unattainable for this patient group," Gubuloff said.
While saying that the study is encouraging, Gubuloff cautioned that additional larger studies are needed to confirm the effectiveness of the drug and to determine its long-term side effects.
For a more complete look at prostate cancer treatment options and risks, visit the National Cancer Institute's CancerNet site.
