People who take cholesterol-lowering statin drugs for more than six months — even smokers — cut their lung cancer risk by 55 percent, a Veterans Administration study suggests.

Taking the drugs for four or more years cuts lung cancer risk by 77 percent.

"The data obtained after six months of statin use clearly shows a decreasing risk for lung cancer with increasing duration of statin use," reports Vikas Khurana, MD, of the Overton Brooks VA Medical Center in Shreveport, La., and colleagues.

The findings, first reported in 2005, come from an analysis of nearly half a million patient records collected from 1998 to 2004 in eight southern states. The updated report appears in the May issue of the journal Chest.

Examples of statins include Zocor, Lipitor, Pravachol, Crestor, Lescol, and Mevacor. This isn't the first study to suggest that these drugs help prevent cancer. Studies have suggested that statins may cut a person's risk of many cancers, including breast cancer, colon cancer, prostate cancer, brain cancer, kidney cancer, and leukemia, the researchers note.

Though this research strongly suggests that the statin drugs help prevent cancer, they do not prove that taking one of these drugs will reduce a person's cancer risk. Even so, the lung cancer data is compelling.

"The protective effect of statin [use] was seen across different age and racial groups and was irrespective of the presence of diabetes, smoking, or alcohol use," Khurana and colleagues note.

While statin drugs reduced lung cancer risk, they did not eliminate it. Of the 7,280 patients who got lung cancer, 1,994 — 27.4 percent — were taking statins.

"Due to the high prevalence of statin use and the grave prognosis of lung cancer, even a modest risk reduction means a considerable effect on public health," Khurana and colleagues suggest.