Carcinoembryonic antigen in serum of patients with colorectal polyps: correlation with histology and smoking status.

To measure the concentration of carcinoembryonic antigen (CEA) in serial serum specimens of 47 healthy subjects and in serial sera of 59 patients with colorectal polyps of confirmed histology, obtained before or after (sometimes both) polypectomy, we used the Roche EIA and the Hybritech Tandem-E double monoclonal immunoenzymometric assays. Both methods gave comparable results for the healthy subjects but discordant values for some polyp patients. The Tandem-E test gave increased CEA results more frequently for two groups of polyp patients, the group of ex-smokers with neoplastic polyps (n = 14) and the group of smokers (n = 20). Smokers had significantly greater (P less than 0.025) mean concentrations of serum CEA than did nonsmokers, irrespective of whether they were healthy or had colorectal polyps. Smokers with recurrent polyps demonstrated significantly greater (P less than 0.050) mean concentrations of serum CEA than did smokers with a first occurrence of polyps. Polypectomy was followed by statistically significant decreases (P less than 0.050) of mean concentrations of serum CEA, primarily in polyp patients who were smokers. However, although CEA increases occurred frequently in polyp patients who smoked, these abnormalities did not fully correlate with polyp histology.