Creatinine is a substance that comes from muscle metabolism and is filtered by the kidneys at a rate that is usually constant in healthy individuals. In some cases, both the underlying disease and medications can alter this rate.
Since creatinine can be easily measured through blood or urine tests, the measurement of this substance is a good indicator of kidney function.
It should be noted that changes in creatinine levels in the blood and urine, as well as changes in its filtration rate, can be found in various situations, many of which have no relation to cancer.
