Two new studies show that
statins, the popular drugs used to lower cholesterol and
prevent heart attacks, offer no protection against cancer,
contrary to what some earlier studies suggested.
In one study, in today's Journal
of the American Medical Association, scientists pooled
results of 27 previous articles involving 87,000 patients
and examined overall cancer risk and individual tumor
types. In the second article, in today's Journal of
the National Cancer Institute, researchers studied
more than 132,000 people enrolled in an American Cancer
Society prevention study and focused just on colon cancer.
In both studies, patients who took statins were just as
likely as others to develop cancer.
The authors of both papers note that
statins remain valuable therapies for people at risk of
a heart attack. But C. Michael White, a professor at the
University of Connecticut and an author of the JAMA
article, says patients should not take statins in hopes
of preventing cancer. The drugs cost $2 to $3 a day and
pose a small risk of damaging muscles and the liver.
Recent studies have suggested that
statins might fight a variety of cancers. In May, researchers
reported in the New England Journal of Medicine that
patients taking statins for five years or more cut their
risk of colorectal cancer in half.
White notes that many of these studies
had limitations. In the May article, for example, doctors
compared patients who developed colorectal cancer with
those who did not, then noted whether they had taken statins.
But something other than statins could have caused the
difference in cancer rates, White says. In contrast, White
examined mostly randomized trials — considered the
gold standard of evidence — in which patients took
statins or a placebo.
Some say statins may still ward off
cancer. Peter Higgins, an assistant professor at the University
of Michigan who co-wrote the May paper, notes that the
two new papers looked mostly at short-term studies. Tumors
may take a decade or more to cause symptoms, Higgins says,
so patients may need to take statins for many years to
see any measurable benefit.
Scientists may want to study whether
statins can protect against tumors that are harder to
prevent, such as pancreatic cancers, Higgins says. Yet
he agrees patients who want to avoid colon cancer should
not bank on experimental therapies such as statins. Instead,
Higgins says, patients should opt for colon cancer screenings.
Colonoscopies allow doctors to remove polyps before they
turn malignant and may reduce the risk of cancer by 80%
to 90%.
Eric Jacobs, a senior epidemiologist
with the cancer society and lead author of the colon cancer
paper, agrees that patients should follow proven steps
to prevent cancer, such as avoiding tobacco, exercising
and controlling their weight.
