Colon Cancer and CRP Connection
C-reactive protein (CRP) is known to be a marker for cardiovascular disease.
This protein is measurable in the blood and is linked to numerous acute causes
of inflammation including aging, high blood pressure, alcohol use, birth control
pill or estrogen use, smoking, low levels of physical activity, rheumatoid arthritis,
rheumatic fever, chronic fatigue, coffee consumption, having elevated triglycerides,
heart attacks, insulin resistance and diabetes, eating a high protein diet,
tuberculosis, pneumonia, lupus, sleep disturbances, and depression. A new study
in the Journal of the American Medical Association (JAMA, 2/4/04)
now adds colon cancer to that list.
CRP is a protein produced primarily in the liver and is a marker of inflammation.
It has been hypothesized that inflammation could play a role in the development
of colorectal cancer, the second most common cause of cancer death in adult
Americans. This study of more than 22,000 adults showed a link between those
with the highest CRP levels and those who developed colon cancer over 11 years.
The trend was clear in this study that those with the highest CRP levels were
twice as likely to develop colon cancer than those with the lowest levels.
This is important news, since aspirin and other anti-inflammatory drugs are
known to be able to reduce CRP. These findings beg the question of whether
aspirin therapy may now have a role in reducing colon cancer risk, similar to
its already established role in reducing heart attack risk. These findings
also raise the question of whether CRP should become a standard screening test,
especially for individuals at risk of colon cancer.
Unfortunately, this study is not able to answer those questions; that will
undoubtedly be the subject of future research, however. CRP is not yet ready
for prime time as a reliable screening test. It is not specific enough for any
one disease entity. Furthermore, it is unclear whether the elevated CRP is a
marker indicating a risk factor for future colon cancer or if it is actually
produced by very early colon cancers. In addition, the CRP results were not
uniformly indicative of colon cancer even in this study: 20 of the patients
diagnosed with colon cancer had the lowest initial CRP levels.
Created: 3/22/2004  - Donnica Moore, M.D.