Conflicting studies on statins and colon cancer
Statin use may not protect high-risk persons against colon cancer and may even increase the risk of precancerous lesions, according to a subset analysis of a large prevention trial presented at the 2010 meeting of the American Association for Cancer Research (AACR).
According to the researchers, "preclinical studies had suggested that statins inhibit cancer development, but observational studies in humans and meta-analyses produced conflicting results that included a suggestion of increased cancer risk in statin users." Results of the study reported at AACR revealed that not only did statin users have a nonsignificant 24% increased risk of ademonas during 5 years of follow-up but this also increased to 40% with long-term use (more than 3 years).
In commenting on the study, John Baron, MD, of Dartmouth University noted that although most studies to date have shown no evidence of a chemopreventive effect with statins, researchers at New York-Presbyterian Hospital/Weill Cornell Medical Center have discovered genetic variance in cancer protection from statin drugs. Their study, which was published in Cancer Prevention Research (2010;3(5):597-603), involved a genetic test used to help determine in which patients statin drugs might have the most benefit in reducing the risk of colorectal cancer. They found that genetic variation prevented the chemoprotective benefits of statin drugs; specifically, about 44% of whites taking statins were likely not protected against cancers because of an inherited gene variant.
"Carriers of the A allele express more of the full-length protein that binds statins, and are therefore more sensitive to statins and are more likely to experience the colorectal cancer risk reduction associated with long-term use," said the study's co-lead author, Steven Lipkin, MD. "We anticipate that genotyping for these alleles in patients may help identify those who are most likely to benefit from statins." ONA