Selenium is a supplement taken daily by millions in hopes of protection against cancer and a host of other diseases. However, it has proven to be of no benefit in reducing a patient’s risk of developing lung cancer, either a recurrence or second primary malignancy, according to results of a decade-long, international Phase III clinical trial.
“Several epidemiological and animal studies have long suggested a link between deficiency of selenium and cancer development,” says Daniel Karp, M.D., professor in the Department of Thoracic/Head and Neck Medical Oncology.
From 2000 to 2009, the international NCI-sponsored Phase III study enrolled 1,522 stage I non-small cell lung cancer patients, all of whom had their tumors surgically removed and were cancer-free for at least six months post-surgery.
The study was halted early after an interim analysis revealed that the progression-free survival was superior in the placebo arm. The researchers did find that in a small group of lung cancer patients who had never smoked, selenium provided a small benefit. However, the size of the group of patients, 94, was too small to be statistically significant.
“Our results demonstrate that selenium is not an effective chemoprevention agent in an unselected group of lung cancer patients, and it’s not something we can recommend to our patients to prevent a second cancer from developing or recurring,” Karp says. “These findings also remind us that people who never smoked may represent a unique disease and should be an area for special consideration for research focus.”
Reported in June at the 2010 annual meeting of the American Society of Clinical Oncology.