MUC1 mucin as a tumour marker in bladder cancer

Objective To evaluate serum MUC1 levels (a high molecular weight glycoprote in which is upregulated and abnormally glycosylated in bladder cancer and o ther carcinomas) in patients with a variety of stages and grades of transit ional cell carcinoma (TCC) of the bladder, to assess its potential as a tum our marker. Patients and methods Blood samples were taken before treatment in 87 patien ts with TCC of the bladder and in 31 controls undergoing cystoscopy for ben ign conditions. Serum MUC1 levels were estimated with an enzyme-linked immu nosorbent assay using the C595 monoclonal antibody. Results Of patients with T4 tumours, 47% had MUC1 levels above the normal r ange (P<0.001); patients with T3 tumours also had significantly higher MUC1 levels than controls. The overall sensitivity was only 34% for all tumours when the upper limit of normal was defined as 4.8 U/mL; the specificity wa s 97%. Conclusion Serum MUC1 is not as useful tumour marker for screening, as if: has a low sensitivity. However, MUC1 levels are high in advanced disease an d serum MUC1 levels may be useful for disease monitoring.