Introduction
The C-reactive protein (CRP) belongs to the so-called acute phase proteins and is produced by the liver and released into the blood as a non-specific response to inflammatory processes in the body. It serves to attract cells of the immune system and to point them to the focus of inflammation. In addition to infections, this reaction can also occur, for example, in certain types of cancer. However, it should be noted that the CRP value always only indicates a general activation of the immune system and is neither organ nor disease specific. Therefore, the CRP value alone can never be used to determine the exact cause and must always be assessed by the physician in the overall context.
Can a high CRP level indicate cancer?
An elevated CRP value is always conspicuous and requires clarification of the cause in each case. This is often quickly apparent, for example when the patient has an acute cold. The CRP is therefore one of the unspecific blood values and as such can give an indication of malignant disease, but it can also have many other causes and must always be assessed in the overall context.
How can cancer increase CRP levels?
Certain cancers also sometimes cause an increase in the CRP value. The exact reason for this non-infectious increase is the subject of current research and has not yet been conclusively clarified. In various studies it has been shown that especially already metastasized as well as very large tumors with a large tumor mass can increase the CRP.
A possible cause is that cancers can also lead to inflammation. Particularly in the case of very aggressive tumours, i.e. those whose cells double extremely often and which therefore grow rapidly, the tumour can no longer be supplied with sufficient blood and oxygen above a critical size, which leads to necrosis (tissue destruction). The body wants to get rid of this dead tissue quickly and sends so-called scavenger cells to the site of the event, which in turn trigger an inflammatory reaction, which among other things increases the CRP.
An example of such fast-growing tumours is high-malignant lymphomas such as lymphoblastic lymphomas. Furthermore, it has been observed that some tumor cells are themselves capable of forming CRP, thus increasing its value. The reason for this behaviour is probably that this improves the metabolism of the cancer cells and the tumour is better supplied with blood by newly ingrowing vessels.
In addition, especially in cancers of the immune system such as leukaemias and lymphomas, there can be a pronounced impairment of the immune system by the tumor cells disrupting the formation of healthy immune cells in the bone marrow. The reduced immune competence in this way often leads to infection with otherwise harmless pathogens such as certain bacteria or fungi, which in turn leads to an increase in CRP and fever. This is known as neutropic fever and is acutely life-threatening if it is not detected quickly and treated with strong antibiotics.
In addition to the increase in CRP, the mechanisms described above can lead to further symptoms of infection in the context of cancer, without the patient actually having an infection. These include, for example, fever, feeling ill or heavy night sweats. An overview of different types of cancer can be found under Tumour diseases
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