Provenge, an experimental treatment vaccine for advanced prostate cancer, met researchers’ goal in a key trial needed for FDA approval.
That news comes from Dendreon, the company that makes Provenge.
“We believe this is truly a breakthrough for the prostate cancer community and a testament to the promise of the field of cancer immunotherapies,” Dendreon’s president and chief executive officer Mitchell Gold, MD, said in a conference call today.
According to the results of two large randomized studies, selenium and vitamin E supplements do not reduce the risk of prostate cancer. These results were published in early online publications in the Journal of the American Medical Association on December 9, 2008.
Other than skin cancer, prostate cancer is the most commonly diagnosed cancer in U.S. men. In 2008 there were expected to be more than 186,000 new diagnoses of prostate cancer and more than 28,000 deaths from the disease. Previous studies suggested the risk of developing prostate cancer was reduced among men receiving selenium supplements or vitamin E supplements.
Men with locally advanced prostate cancer — cancer that has spread beyond the wall of the prostate gland — who undergo radiation plus long-term hormone treatment cut their risk of dying in half, a new study has found.
The addition of radiotherapy kept patients healthy much longer, the Swedish research team concluded. In fact, by adding radiotherapy, men’s overall survival was increased by 10 percent with only a modest increase in the risk of radiation-related side effects.
Selenium, vitamin E and vitamin C won’t prevent men from getting prostate cancer.
In findings that were released early because of the public health implications, the results of two large randomized, controlled clinical trials showed the supplements failed to provide a cancer-prevention benefit, despite past findings that seemed to indicate great promise — particularly for selenium. Both studies were expected to be published in the Jan. 7 print issue of the Journal of the American Medical Association.
“Our results showed no evidence of benefit from selenium and vitamin E on prostate cancer and other cancers,” said the lead author of one of the studies, Dr. Scott Lippman, a professor of medicine in the division of cancer medicine at M.D. Anderson Cancer Center, in Houston.
Lippman’s study, known as the SELECT trial, included more than 35,000 men. Black men included in the study were all over 50, and men from other races were all over 55. (Blacks have a higher risk of developing prostate cancer than do men of other races, according to the American Cancer Society.)
The men were randomly assigned to one of four groups: selenium; vitamin E; selenium and vitamin E; or a placebo. The average follow-up time was more than five years.
The researchers found no statistically significant difference between the groups, and the trial was ended early, because there was no convincing evidence of efficacy.
The second study, done by Harvard researchers, included almost 15,000 male physicians over 50 who were randomly assigned to receive vitamin E, vitamin C, or a placebo. The average follow-up time for this trial was eight years.
Again, no statistically significant benefits were found from either vitamin C or E when it came to preventing prostate and other cancers.
These studies are just the latest in a long list of recent research that’s been discounting the use of individual vitamins and supplements for chemoprevention. Other recent studies have suggested that vitamins, B, C, D, E, folic acid and calcium taken alone, or in various combinations, aren’t effective for cancer prevention.
“Single-agent interventions, even in combinations, may be an ineffective approach to primary prevention in average-risk populations,” wrote Dr. Peter Gann, the author of an accompanying editorial in the same issue of the journal.
Andrew Shao, vice president of scientific and regulatory affairs for the Center for Responsible Nutrition in Washington, D.C., said he thought researchers need to “redefine our expectations for nutrients. They’re not magic bullets, though they do have tangible effects.”
Shao said studies that look at vitamins and cancer prevention tend to treat vitamins the same way they would a targeted pharmaceutical agent. But, he said, “the whole body is affected by nutrients, while pharmaceuticals are highly specialized and targeted to specific cells.”
“It would be a mistake to look at one trial that answers a very specific question and say these nutrients don’t work at all,” said Shao.
Lippman, however, said he doesn’t recommend the use of supplements for cancer prevention. “There’s no evidence to support taking these,” he said.
WASHINGTON – Men with elevated levels of calcium in their blood may have a much higher risk of getting fatal prostate cancer, U.S. researchers said on Wednesday.
The findings indicate that a simple blood test may identify men at high risk for the most dangerous prostate tumors, and there already are drugs available that cut calcium levels in the bloodstream, the researchers said.
They tracked 2,814 men in a government health survey in which they gave blood samples that revealed calcium levels.
The men in the top third of blood calcium levels had 2.68 times the risk of developing fatal prostate cancer later in life compared to those in the bottom third, the study found.
NEW YORK (Reuters Health) – Data from the Geneva Cancer Registry show an increased long-term risk of colon cancer in men who have undergone external radiation therapy for prostate cancer.
"The risk of second cancer after irradiation, although probably small, needs nevertheless to be carefully monitored," the study team advises.
Dr. Christine Bouchardy from the University of Geneva, Switzerland and colleagues analyzed data on 1,134 men diagnosed with prostate cancer between 1980 and 1998 who survived for at least 5 years after diagnosis. Of these, 264 were treated with external radiation.
New research indicates that giving patients a continuous low dose of an immune system booster, a method known as metronomic dosing, as part of a therapeutic prostate cancer vaccine strategy is safe and produces similar immune responses and fewer side effects than the more common dosing method, which is not well tolerated by many patients.
This study, led by researchers at that National Cancer Institute (NCI), part of the National Institutes of Health, was published in the August 15, 2008, issue of Clinical Cancer Research.
