Is AFP (alpha-fetoprotein) 21 ug/L indicative of liver cancer?

Alpha-fetoprotein (AFP) at 21 μg/L is generally not indicative of liver cancer. The detailed analysis is as follows:

Alpha-fetoprotein is primarily synthesized by fetal liver cells and the yolk sac. It is normally present at high concentrations in fetal circulation but gradually replaced by albumin after birth. Therefore, serum AFP levels in healthy individuals are relatively low, with a normal reference value typically less than 25 μg/L. An AFP level of 21 μg/L falls within the normal range and usually does not indicate liver cancer.

In clinical practice, AFP serves as a serum marker for primary liver cancer and can be used for both diagnosis and monitoring treatment response. If liver cancer is suspected, AFP testing may be performed, but diagnosis should also include other evaluations such as additional tumor marker tests and biopsy pathology.