Vitamin B12 binding protein as a tumour marker for hepatocellular carcinoma.

Grossly raised levels of tumour related vitamin B12 binding protein, reflected by rises in serum vitamin B12 and unsaturated vitamin B12 binding capacity (UBBC), were found in three of 44 patients with hepatocellular carcinoma. All three were HBsAg negative and had normal serum alpha fetoprotein levels. The patients did not have underlying cirrhosis and the tumours contained characteristic intracellular inclusions. In the first patient the UBBC level fell during a partial remission induced by adriamycin therapy and in the second patient UBBC levels rose with progression of her disease. In the third patient serum B12 binding protein levels fell after tumour resection. Assay and subsequent monitoring of serum vitamin B12 and UBCC may prove valuable in the assessment and follow-up of some patients with hepatocellular carcinoma whose alpha fetoprotein levels are normal.