Gastrointestinal cancer-associated antigen (GICA) in oral carcinoma.

Gastrointestinal cancer-associated antigen (GICA) is detected by means of a monoclonal antibody in the serum and pathologic tissues of patients with gastrointestinal tumors. This article compares serum and salivary GICA and carcinoembryonic antigen (CEA) levels in 19 healthy control subjects, 17 patients with benign oral cavity lesions, and 11 patients with squamous cell carcinoma of the oral cavity. Serum CEA levels were similar in all three groups, whereas salivary CEA levels were higher in patients with squamous cell carcinoma than in the control subjects (p less than 0.001) and the patients with benign lesions (p less than 0.025). Serum GICA levels gave the opposite result and were significantly lower in squamous cell cancer when compared with control subjects (p less than 0.0001) and patients with benign lesions (p less than 0.02). Values of GICA in saliva of patients with oral cancer were also lower than in the control subjects (p less than 0.02). The possible significance of this difference between the two antigens is discussed.