[Alpha-fetoprotein in non-hepatocellular malignant tumors]

Alpha-fetoprotein (AFP), a very useful tumor marker for hepatocellular carcinoma and yolk sac tumor, is rarely elevated in other malignant tumors. However, since 1978, 9 cases of non-hepatocellular malignant tumor with elevated AFP (greater than 400 ng/ml), 3/206 gastric carcinoma, 1/112 esophageal carcinoma, 1/87 colorectal carcinoma, 2/83 pancreatic carcinoma and 2/192 lung cancer had been collected. Seven of the 9 cases had liver involvement. AFP might be originated from the tumor cells of the primary cancer and, in cases with liver metastases, from the regenerative hepatocytes surrounding the metastatic foci. It is of the opinion that elevated AFP is not specific for hepatocellular carcinoma, as it may also be seen in the other malignant tumors.