[Tumor marker--present and future].

It is known that the serum in cancer patients has the characteristics of the heat-stability. The factor produce the heat-stability is known to be due to tumor marker(TM) such as CEA, CA125(glycoprotein), CA19-9, CA15-3, SLX, CA50, CA72-4, DU-PAN-2, ST-439, SPAN-1(mucin) and alpha 1-acid glycoprotein, IAP(acute reactants). CEA belongs to IgG supergene family protein and is not oncofetal protein. CA19-9 is synthesis in subjects with Le(a) or Le(b) type, but negative in Le(a- b-) type. Thus, CA19-9 is not available as TM in Le(a- b-) type. Many TMs can be classified in 3 types because cancer cell has the character of immature cells which composed of immature proteins or glycoproteins. (1) Oncofetal protein: AFP(fetal albumin), PTHrP(fetal PTH) (2) The immature isozyme type: increase of amylase(salivary type), CPK(brain type) and aldolase (muscle and brain type) (3) The immature protein in biosynthesis process: increase of precursor protein(prepro type or pro type) such as PIVKA-II(preprothrombin), ProGRP, TPA or CYFRA 21-1(pro-keratin?) and hormone precursor in hormone producing tumor.