What is the connection between CRP and cancer?

The connection between C-reactive protein, or CRP, and cancer is not fully understood. What is currently known is that high levels of this protein may be associated with an increased risk of cancer. People with certain types of cancer appear to have elevated CRP before development and during cancerous disease. On the other hand, this level of protein can also indicate numerous other diseases that cause inflammation. It is possible that the association between inflamed tissues in the body and cancer is much more direct.

C-reactive protein tends to increase when there is inflammation in the body. It can predict or confirm many different diseases, and can be used to determine how serious a known condition is. For example, people with lupus can have a simple CRP blood test to determine the importance of the inflammatory response. Alternatively, higher levels of the protein may suggest an elevated risk of heart disease, arthritis, or certain gastrointestinal conditions.

Scientists have also found that elevated CRP and cancer are sometimes associated. Larger amounts of the protein can occasionally predict cancer or indicate its severity. This is complicated by the fact that this protein can also be increased in perfectly healthy people who are, for example, pregnant or have an intrauterine device (IUD). Patients with mild infections may also have abnormal CRP test readings.

Several studies have looked at large groups of individuals to determine if CRP and cancer are directly related. This has not been proven, although further research in the future may provide more definitive answers. Until now, many clinical findings show that C-reactive protein tends to increase when people have cancer, mainly because the cancerous disease causes inflammation in the body. Possibly the opposite is also true. Some clinical breast cancer research has even established that higher CRP rates correlate with higher mortality.

It is not yet clear that the relationship between CRP and cancer is causal, especially since many conditions can increase C-reactive protein without increasing cancer risk. Instead, many medical researchers believe that it is the inflammatory response indicated by CRP, rather than the elevated protein, that is most closely associated with cancer risk. Very high CRP indicates significant inflammation, which, in turn, may indicate the presence of cancer, a higher chance of developing the disease, or a more aggressive course of the disease. In other words, the inflammatory response and cancer are strongly correlated, and CRP may be more of an incidental player.

Even if CRP and cancer are not directly related, measurement of C-reactive protein can be useful for diagnosis. Also, establishing a connection between inflammation and cancer could be important. It may indicate that part of the treatment of the cancerous disease should involve the use of anti-inflammatory drugs. Since high CRP levels have been associated with cancer that is more severe, doctors may also use more aggressive measures to treat cancer in patients with higher C-reactive protein counts to improve survival rates.

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