Serum and salivary CEA and GICA levels in oral cavity tumours.

The gastrointestinal cancer-associated antigen (GICA) is recognised by a monoclonal antibody in both serum and tissues of patients with neoplasm of the GI tract. This study compared the serum and saliva values of carcinoembryonic antigen (CEA) and GICA in 19 healthy subjects, 43 patients with benign oral cavity lesions and 26 with histologically confirmed squamous-cell carcinomas. Serum CEA levels were much the same in all three groups, whereas salivary values were significantly higher (p less than 0.001) in both patient groups than in the controls. Serum GICA gave the opposite result: lower in carcinoma than in controls (p less than 0.001) and benign lesions (N.S.), while salivary GICA was significantly lower in carcinoma than in both the other two groups (p less than 0.001). The meaning of this difference between the values for the two antigens is discussed.