Enzyme that destroys vitamin D predicts lung cancer survival
An enzyme, called CYP24A1 is commonly found in patients with aggressive types of lung cancer and is identified by researchers as a predictor of cancer survival rates at 5 years. Based on the study, scientists say vitamin D may extend lifespan for patients with lung cancer,
Researchers at the University of Michigan Comprehensive Cancer Center say CYP24A1 enzyme levels can determine which patients will survive lung cancer. Those with highest levels of CYP24A1 were found by the scientists to have half the survival rate at five years as patients with lower levels of the enzyme.
For the study, researchers looked at CYP24A1 interacts with vitamin D in 86 patients, comparing normal tissue to adenocarcinoma of the lung. Normally, the CYP24A1 enzyme breaks down calcitrol, the active form of vitamin D, but when it is overexpressed the enzyme destroys the vitamin's anti-tumor effect.
“Half of lung cancers will recur after surgery, so it’s important to find a way to prevent or delay this recurrence. A natural compound like vitamin D is attractive because it has few side effects, but it’s even better if we can determine exactly who would benefit from receiving vitamin D,” says study author Nithya Ramnath, M.D., associate professor of internal medicine at the U-M Medical School.
The researchers found CYP24A1 was elevated 8 to 50 times in cancerous lung tissue, compared to normal, cancer-free tissue specimens. The authors concluded that overexpression of the enzyme interferes with the anti-cancer effect of vitamin D and leads to poorer survival.
The study that appears in the journal Clinical Cancer Research suggests patients with lung cancer would benefit from vitamin D. Measuring levels of CYP24A1 could personalize cancer treatment by identifying patients at highest risk from elevated levels of the enzyme.
Clinical Cancer Research: doi: 10.1158/1078-0432.CCR-10-178
"CYP24A1 Is an Independent Prognostic Marker of Survival in Patients with Lung Adenocarcinoma"