Types of tumors that may be indicated by PCT:
(1) hepatoma (often associated with cirrhosis, which may occur as a result of underlying liver disease or of the hepatotoxic effect of the porphyrins)
(2) metastatic cancer to the liver which are porphyrinogenic (produce porphyrins)
When to suspect a cancer in a patient with PCT:
(1) new onset of PCT OR worsening of symptoms OR poor response to previously successful therapy
(2) exclusion of other precipitating causes (medications, toxins, malnutrition, stress, iron overload, increased alcohol use)
(3) history or presence of cirrhosis
(4) systemic features of malignancy (unexplained weight loss, anorexia, night sweats, fevers, etc)