Serum amyloid A protein (SAA) in colorectal carcinoma

The changes in serum levels of serum amyloid A protein were studied in 67 p atients suffering from colorectal carcinoma and compared to three other maj or acute phase proteins: C-reactive protein, alpha (1)-antichymotrypsin and alpha (1)-acid glycoprotein. Although the presence of colorectal carcinoma caused an increase in serum levels of all the acute phase reactants studie d, serum amyloid A protein showed the most powerful reaction in pre-operati ve disease stage, with the mean value of 330 mg/l (range 7-2506 mg/l) as co mpared to the normal values of <1.2 mg/l obtained in 30 healthy adults. The mean serum amyloid A protein concentration increased to 487 mg/l after sur gery, declining during the post-operative clinical course until the sixth c hemotherapy cycle (from 167 mg/l to 64 mg/l), but never returned to the nor mal range. In the later chemotherapy cycles, mean serum amyloid A protein i ncreased to 163 mg/l, probably as a result of the disease relapse. Accordin g to the statistical relations among exact confidence intervals for proport ions, serum amyloid A protein showed the best specificity for colorectal ca rcinoma of all the acute phase proteins studied (83-100%) and also a sensit ivity of 100%. We concluded that serum amyloid A protein seems to be a reli able parameter, which could be recommended for clinical routine as a non-sp ecific tumour marker for colorectal carcinoma.