Which blood value constellations can indicate colorectal cancer? | Can colon cancer be detected in the blood?

Which blood value constellations can indicate colorectal cancer?

An elevated CEA level in the blood can be an indication of the presence of colorectal cancer. However, the value alone does not provide sufficient information, as it can also be elevated in numerous other diseases. In addition to the tumor marker, colorectal cancer may also be anemic.

This is the case if the tumor tissue has infiltrated the intestinal wall and small vessels are attacked by the tumor cells. This can lead to small oozing bleedings but also larger bleedings. Clinically, a greater loss of blood can be shown, for example, by a black coloration of the stool (tarry stool).

There are also tests that can detect small amounts of blood (occult blood) in the stool. Such a bleeding can be seen in the blood by means of the red blood cells or the haemoglobin value. If this value is lowered, this is called anemia. Such an anemia can therefore be a sign of intestinal cancer. However, it is completely unspecific as it can occur in a wide variety of diseases.

Can one have colorectal cancer despite good blood values?

Unfortunately, many cancers do not show up in the blood. This makes the diagnosis difficult in some cases and leads to the fact that some cancers are detected late. Only very few cancers show up on the basis of certain blood values.

Thus, there are also many patients with colorectal cancer who have completely normal blood values. An increase in the CEA value is common, but not a reliable criterion.