Preliminary observation on human saliva alpha-fetoprotein in patients with hepatocellular carcinoma

The saliva samples from 13 patients with hepatocellular carcinoma and a control group of 21 random healthy adults were measured for alpha-fetoprotein (AFP), using a highly sensitive sandwich enzyme immunoassay specific for human AFP. In patients with hepatocellular carcinoma, significantly higher levels of saliva AFP were observed (mean +/- Sx: 3 552.6 +/- 2 829.9 ng/L) when compared with the value of the normal controls (mean +/- Sx18.1 +/- 3.8 ng/L, P < 0.001). There was significant correlation between saliva and serum AFP in both normal controls (rs = 0.526, n = 21, P < 0.005) and patients with hepatocellular carcinoma (rs = 0.931, n = 13, P < 0.001). In patients with hepatocellular carcinoma, those with positive serum AFP had positive saliva AFP, while those whose serum AFP was negative showed saliva AFP negative as well. It is likely that saliva AFP is derived from plasma by passive seepage. It is promising that the saliva AFP surveillance may be helpful in detection of AFP positive hepatocellular carcinoma, because of its noninvasiveness, acceptableness by almost every person, simplicity in technique, and the strong correlation between saliva and serum AFP.