CALCA and liver neuroendocrine carcinoma: Thus, elevated PCT levels have been indicated to be a tumor biomarker for medullary thyroid cancers and have been found in some neuroendocrine carcinomas.[5,8] Due to the clinical unfamiliarity and low incidence of elevated PCT levels in other types of tumors, there is no previous evidence of an extremely high PCT level in liver neuroendocrine carcinoma.