Advances in Colorectal Cancer
New drugs show promise, but more research needs to be done.
Focusing on Inflammation
Increasingly, researchers believe that inflammation -- the
villain that contributes to heart disease, stroke, and diabetes -- may play a
role in colorectal cancer.
In one recent study published in TheJournal of the
American Medical Association, researchers found that higher levels of a
marker for inflammation -- C-reactive protein, or CRP -- in the blood were
associated with an increased risk of colon cancer. After studying the records
of 22,000 people, researchers found that people with high levels of CRP were
2.5 times more likely to eventually develop colon cancer than those with low
"We've seen that inflammation is an underlying component of
a lot of diseases, including cancer," says Mooney. "The next step is to
see whether we can manipulate that mechanism and alter the course of the
Many researchers have looked at using drugs that reduce
inflammation, in the hopes that they might cut the risk of colorectal cancer.
And there is evidence that using a class of such drugs, nonsteroidal
anti-inflammatory drugs, or NSAIDs, does just that. This class of drugs
includes that humble and trusted resident of everyone's medicine tablet,
"We know that people who use NSAIDs reduce their risk of
developing colon cancer," says Polly Newcomb, PhD, Head of the Cancer
Prevention Program at the Fred Hutchinson Cancer Research Center. "It's
However, she points out that researchers don't yet know what
dosage should be used. Also, some doctors are concerned that the risks of using
NSAIDs, such as increased danger of bleeding and ulcers, may outweigh the
Newcomb and Mooney say that the next step is to try using
NSAIDs in people who already have colorectal cancer to see if they help
lengthen life or shrink tumors. Several studies are being conducted now.
Screening and Prevention
The connection between colorectal cancer and inflammation has
potential implications in how the disease can be prevented as well. If further
studies establish the relationship between high levels of CRP and colorectal
cancer, it's possible that researchers could develop a blood test that would
identify people at high risk of the disease. Other new screening tests are also
While researchers are devising new ways of identifying people
at risk of colorectal cancer, Newcomb points out that the screening tests we
have now work pretty well.
"About 60%-80% of all cases of colorectal cancer can be
prevented by endoscopies," she tells WebMD.
The endoscopy -- a procedure in which a doctor examines the
colon with a device inserted into the rectum -- does not have a good
reputation, Newcomb admits. "People worry it's unpleasant, and it's not as
easy as a blood test," she says, "but it works pretty well."
The reason endoscopies -- either sigmoidoscopy or colonoscopy
-- are so successful at preventing colorectal cancer is that they can detect
abnormalities, such as polyps, that may be precursors to developing cancer.
While other cancer screening tests, such as a mammography for breast cancer,
only find cancer that's already in the body, endoscopies can catch
abnormalities before they turn cancerous.
While people may avoid getting an endoscopy, Newcomb points out
that the benefits are long lasting - five to 10 years or more -- because the
test is so accurate.
Newcomb also says that researchers continue to look at the
effects of diet and exercise on colorectal cancer risk. A number of studies
have found that regular exercise does cut the risk; other studies have
suggested that a diet low in meats and high in vegetables may do the same.