Screening for cancers of internal organs is notoriously difficult, and by the time the disease has progressed to symptoms in the patient that indicate cancer, the outlook is often poor. In the October 30th issue of The Lancet, Kai Stoeber and colleagues from Cambridge, UK, with the Cancer Research Campaign, describe the result of a new screening test for cancer of the urinary tract that does not involve invasive procedures. The test detects the minichromosome maintenance (Mcm5) protein involved in the replication of DNA that occurs when cells divide. The protein is expressed at a high concentration in many cancers, probably because the cancer cells divide rapidly. The investigators used an immunofluorometric assay to show that the protein was detected in cells shed in the urine of all eight patients with a cancer of the urinary tract, and in only one of 28 control individuals. This particular test could be automated, and because the Mcm5 protein is over-expressed in other cancers, the same test could potentially be used to screen for these.
