Study halted early because of supplement's poor performance
SATURDAY, June 5 (HealthDay News) -- Taking the popular mineral supplement selenium doesn't reduce the likelihood of lung cancer recurrence, a new study reveals.
Lead author Dr. Daniel D. Karp, a professor in the department of thoracic/head and neck medical oncology at the University of Texas M.D. Anderson Cancer Center, is scheduled to present the finding Saturday at the American Society of Clinical Oncology annual meeting, in Chicago.
"Several epidemiological and animal studies have long-suggested a link between deficiency of selenium and cancer development," said Karp in a news release. "Interest and research escalated in the late 1990s after a skin cancer and selenium study, published in 1996, found no benefit against the skin cancer, but did suggest an approximate 30 percent reduction of prostate and lung cancers. Our lung cancer research and another major study for the prevention of prostate cancer evolved from that finding."
But the new study found that among more than 1,500 stage 1 (early) non-small cell lung cancer patients who had survived their initial bout with the disease, selenium offered no protection against recurrence or the onset of a new cancer or second primary cancer.
The patients were tracked from 2000 to 2009, after all had undergone surgery to remove their initial tumors and remained cancer-free for a minimum of six months post-treatment.
Half the patients were placed on a regimen of 200 micrograms of selenium, while the other half took a placebo.
Those in the placebo group had better survival rates five years later than those taking the supplement -- an observation that led the research team to halt the study earlier than planned.
While 78 percent taking the placebo stayed alive over that time frame, the rate was just 72 percent among the selenium group. And while 1.4 percent of the placebo group developed a second primary tumor within a year, that figure rose to 1.9 percent among the selenium group, the researchers said.
Some benefit of selenium was observed in a small group of patients who had never smoked, but the study authors said the group was too small to render the finding meaningful.
For more on lung cancer prevention, visit the U.S. National Cancer Institute.
SOURCE: June 5, 2010, news release, University of Texas M. D. Anderson Cancer Center
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