Urinary biomarkers miss a substantial proportion of patients with bladder cancer and are falsely positive in others, according to an article in Annals of Internal Medicine.
Bladder cancer is the fourth most commonly diagnosed cancer in U.S. men and the tenth most commonly diagnosed cancer in U.S. women. Urine-based biomarkers have been developed as potential alternatives or adjuncts to cystoscopy for the diagnosis of bladder cancer. Five such biomarkers have been approved by the U.S. Food and Drug Administration: quantitative or qualitative nuclear matrix protein 22 (NMP22); qualitative or quantitative bladder tumor antigen (BTA); florescent in situ hybridization (FISH); fluorescent immunohistochemistry (ImmunoCyt [Scimedx]); and Cxbladder (Pacific Edge Diagnostics USA).
Researchers reviewed 57 published studies to ascertain the accuracy of the five FDA-approved urinary biomarkers for diagnosis of bladder cancer in adults who have signs or symptoms of bladder cancer or are undergoing surveillance for recurrent disease. They found that urinary biomarkers had sensitivities for bladder cancer that ranged from 0.57 to 0.82 and specificities that ranged from 0.74 to 0.88. Their sensitivity seemed to be particularly poor for low-stage and low-grade tumors. Diagnostic accuracy may be slightly higher for initial diagnosis of bladder cancer in patients with signs and symptoms than for surveillance. The author of an accompanying editorial cautions that these biomarkers should not replace current methods for diagnosing bladder cancer.
The article can be viewed here.
The editorial can be viewed here.