Clinical Studies on Carcinoembryonic Antigen (CEA) of Patients with Squamous Cell Carcinoma in the Oral Cavity

The tumor markers are divided roughly into tumor-specific substances and tumor associated substances. Since no materials biosynthesized specifically by tumor cells have yet been discovered, tumor-associated substances have been applied widely and clinically as tumor markers for determination of clinical diagnosis and effect of treatment and monitoring progress and prognosis. Carcinoembryonic antigen (CEA), among various tumor markers, has been known to appear with high positive rates not only in patients with gastrointestinal cancer but also in those with malignant tumor in another organ. Clinical utility of this fact has been attracting attention. Sixty-five patients with squamous cell carcinoma in the oral cavity were therefore examined for serum CEA level and localization of tissue CEA (indirect peroxidase-antiperoxidase method) and clinical evaluation was made. The results were as follows : 1. The average serum CEA of 65 patients with oral cancer (squamous cell carcinoma) was 3.06±3.89 ng/ml and the positive rate was 38.5% (25/65 cases). In contrast, the average for control patients with benign oral disease was 1.60±0.51 ng/ml and the positive rate was 5.8% (3/52 cases). Statistical significance difference was found. 2. With progress of clinical stage, namely, as the tumor grew and the lesion developed, serum CEA level gradually increased its average and positive rate. Also, in comparison with primary cancer, advanced cancer showed higher values in many cases. 3. The posotive rate of tissue CEA was 59.5% (25/42 cases) on the whole. With the progress of clinical stage of oral cancer, the positive rate tended to increase gradually. 4. The average serum CEA of the cases of cancerous tissue CEA-positive was 4.44±1.82 ng/ml. That of cancerous tissue CEA-negative was 1.90±0.56 ng/ml and statistical significance was found between the two (p<0.01). In the cancerous tissue CEA-positive, there were many cases of serum CEA-positive. In the tissue CEA-negative cases, many tended to be serum CEA-negative. 5. By prognosis, the average of serum CEA level and positive rate for good prognosis cases were 2.21±0.49 ng/ml and 18.4% (7/38 cases), respectively. For poor prognosis cases, they were 4.09±2.71ng/ml and 59.3% (16/27 cases), and statistical significance difference was found (p<0.01). 6. As to change in serum CEA level before and after treatment, serum CEA level tended to decrease and become negative after treatment for the cases of good prognosis. For the cases of poor prognosis, serum CEA level was unchanged or increased in many and tended to become negative. With imminent death especially, serum CEA level was markedly high. 7. On the basis of the foregoing findings, serum CEA level well reflects the extent of the tumor and severity of conditions. Serum CEA level is though to be a useful indicator for estimating progress, effect of treatment, and prognosis. Its clinical untility is considerable.