Plasma protein-bound sialic acid in patients with colorectal polyps of known histology.

Protein-bound sialic acid (PBSA) was measured in serial plasma specimens from 62 healthy subjects, 48 patients with colorectal polyps, and 30 patients with colorectal adenocarcinomas. The mean plasma PBSA concentration in healthy smokers was significantly greater than that in healthy nonsmokers and healthy ex-smokers (P less than 0.0001). Villoglandular polyps were associated with higher plasma PBSA values than were the most benign hyperplastic polyps (P less than 0.025). Patients with the most neoplastic villoglandular and villous polyps had significantly greater (P less than 0.010-0.050) plasma PBSA values than healthy subjects. Polypectomy decreased the mean PBSA value significantly to the mean value for healthy subjects only for patients with villoglandular (P less than 0.010) or villous (P less than 0.050) polyps. Colorectal cancer patients had mean plasma PBSA concentrations significantly greater than those for the healthy subjects (P much less than 0.001) and the polyp patients (P much less than 0.001). Surgery significantly reduced (P less than 0.025) the mean PBSA value for the cancer patients to the mean PBSA value observed for the healthy subjects.