Urothelial carcinoma is the most common cancer of the urinary tract and while urine cytology is used to screen for the cancer, it has a low sensitivity, promoting the need for a more specific marker.
Urothelial carcinoma (UC) or transitional cell carcinoma, is the most common form of bladder cancer and is the tenth most common cancer in the world. The urothelial cells that line the bladder and urinary tract are constantly exposed to environmental agents that are filtered through the kidneys and not surprisingly, 90% of bladder cancers arise in these cells. Detection of UC is based on subjective microscopic features that are not always able to distinguish between benign and low-grade UC. Now a team from Yale Cancer Centre, US have developed a urine screening test based on immunocytochemistry and detects keratin 17, a molecule that has been found to be over-expressed in a range of cancers such as those affecting the breast, ovaries and pancreas. The researchers wanted to examine whether identification of keratin 17 could be used to screen for UC and detect recurrent UC in urine samples.
The study involved two patient cohorts: one with haematuria and one with recurrent UC. In screening samples with haematuria, the test was found to have a sensitivity of 100% and specificity of 83%. In patients with recurrent UC, the corresponding specificity and sensitivities were 92% and 100%.
The test itself, URO17 is developed by KDx diagnostics and commenting on the results of the study, co-author, Dr Nam Kim, said “there is now a growing body of evidence that the non-invasive K17 urine test will make a significant positive impact on detection and management of UC”. The study authors concluded that the study provides evidence to support the development of prospective trials to further define the clinical and diagnostic impact of K17.
Babu S et al. Keratin 17 Is a Novel Cytologic Biomarker for Urothelial Carcinoma Diagnosis. Am J Clin Pathol 2021