Clinical significance of carcinoembryonic antigen in colorectal malignancy

Carcinoembryonic antigen (CEA) assay was performed in 40 patients of histologically proven colorectal carcinoma. The overall incidence of positivity was 72.5%. The incidence increased from 40% in Duke's A stage to 84.6% in Duke's C stage. Similarly the mean CEa levels also increased as the disease advanced i.e. 4.96 ng/ml, 8.07 ng/ml and 12.7 ng/ml in Duke's A, B and C respectively. Cancer with poor prognosis i.e. poorly differentiated and colloid carcinoma, had significantly less rise in CEA values (P < 0.05) as compared to well differentiated carcinoma. There was no relation of CEA values with the gross appearance of the tumour and lymph node involvement. CEA level came down in all the patients after surgery. Based on the postoperative CEA estimation, complete tumour clearance had been achieved in 86.2% of patients.