Statins may not reduce colon cancer risk. (Bob Chamberlin / Los Angeles…)
Colorectal cancer is the third-leading cause of cancer and death in the United States. So previous research hinting that statins, which an estimated 20 million Americans take to improve their cholesterol levels, might cut the risk of colorectal cancer has generated high interest. However, a study released Monday yielded disappointing news.
Researchers studying a large group of postmenopausal women found that those who took statins did not have a reduced risk of colorectal cancer. The study included almost 160,000 women from the Women's Health Initiative. Two-thousand cases of colorectal cancer cases were identified among the women over a 10-year follow-up study. The type, class or potency of statins did not make a difference in reducing risk. Nor were there any links between statin use and the type and location of the tumor.
Other studies on statins and colorectal cancer are mixed, however. It's possible that people with particular gene variants may benefit from statins while others don't, said Dr. Michael S. Simon, a professor on oncology at Wayne State University and Barbara Ann Karmanos Cancer Institute in Detroit.
"The recent meta-analysis overall suggests an 8% reduction in risk," Simons said. "Future studies perhaps should be focused more on individuals at high risk for colorectal cancer.
The study was presented at the annual meeting of the American Public Health Assn. in Philadelphia.
Related: Effectiveness of statins is called into question
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In other research on chemoprevention -- medications that can reduce cancer risk -- presented at the meeting, scientists found that the drug gefitinib, or Iressa, may help prevent or abort pancreatic cancer at a very early stage of development. Pancreatic cancer is usually diagnosed at a late stage and has an extremely poor survival rate. Researchers fed mice at high risk for pancreatic cancer various doses of gefitinib for 35 weeks or no medication. The mice that received the drug had 77% fewer pancreatic cancers compared with the mice that received no medication. The mice taking the highest dose of gefitinib had 100% fewer tumors. "If you intervene early you can block the carcinoma formation," said the lead author of the study, Chinthalapally V. Rao, of the University of Oklahoma Cancer Institute. When given to people who have advanced cases of pancreatic cancer, gefitinib prolongs survival by only a few weeks. Some people have precursor pancreatic lesions that raise the risk of pancreatic cancer or have a significant family history of the disease.