Method, device, and kit for population screening for cancer, cancer recurrence and precancerous conditions in symptom free individuals

A screening method for rapidly testing a subject for a cancerous or precancerous condition, wherein the subject displays no obvious signs or symptoms of a cancerous or precancerous condition, the method comprising the steps of (a) obtaining a biological sample from an individual;

• (b) assaying a portion of the sample for the presence therein of glycoprotein containing at least one carbohydrate selected from the group consisting of beta-D-Gal-(1->3)-D-GalNAc, Fuc-alpha-1->2 Gal-Beta(1->4)-Fuc-alpha-1->3-G1cNAc, Fuc-Alpha-1->2 Gal-beta-(1->4)-Fuc-alpha-1->3-G1cNAc-beta-(1->3)-Gal-beta-(1>4)-G1cNAc and Fuc-alpha-1->2-Gal-beta-(1->4)-Fuc-alpha-1->3-G1cNAc-beta-(1->3)-Gal-beta-(1->4)-Fuc-alpha-1->3-G1cNAc, by briefly subjecting the sample to oxidizing conditions which are capable of selectively oxidizing only the cyclic sugar moieties of any said marker carbohydrate present in the glycoprotein in the sample at a hydroxy group-bearing ring carbon atom thereof to form an aldehydic sugar moiety and then visualizing any aldehydic saccharide groups thus formed with a Schiff's base dye;
• (c) also assaying a portion of the biological sample for the presence therein of any glycoprotein by subjecting the sample to the oxidizing action of an oxidizing agent which oxidizes the saccharide moieties of any glycoprotein therein to aldehydic sugar moieties and then visualizing any thus-produced aldehydic sugar moieties, the presence of thereby formed aldehydic sugar moieties confirming the adequacy of the sampling and the absence therein of thereby formed aldehyde sugar moieties establishing that the negative test results were due to sampling error;
• (d) retesting the individual in the same manner with a fresh biological sample, if the first sample assays negative in steps (b) and (c);
• and (e) diagnosing the asymptomatic patient as having cancer or a precancerous condition based on visualizing a color change in the Schiff's base dye.