AFP and hepatocellular carcinoma: In addition, the high costs and potential harm related to contrast-related injury and radiation exposure associated with these tests make them poor candidates for surveillance tests in most clinical settings.[33] In our regular surveillance series, nearly 83.2% of the cancers positive for AFP screening alone were detected at early, potentially curable, stages, as were the HCC nodules primarily identified on US that did not produce AFP and had more indolent phenotypes.