Urine cytology is a diagnostic method for transitional cell carcinoma. Since it has less sensitivity, especially in low grade tumors, it cannot be a substitute for cystoscopy. Flow cytometry is also a technic for measuring the deoxyribonucleic acid (DNA) in urine for diagnosis of bladder tumors, but flow cytometry requires a minimum of 5,000 cells, so it can be obtained only by bladder lavage, an invasive procedure
14. Some novel biomarkers of bladder tumors have been identified. The BTA test detects antigens in voided urine specimens but BTA test has a negative result in 60% of patients who had tumors
15. Another test, NMP22 measures the concentration of nuclear matrix proteins in voided urine. Had a sensitivity of 70% and a specificity of 79% in bladder cancer
16. Berlac and Holm used ultrasound and urine cytology as an alternative to cystoscopy for bladder tumors
17. In our study we used ultrasound for the detection of primary bladder tumors and for surveillance after transurethral resection of bladder tumors. All of the tumors missed by ultrasound were small papillary tumors or carcinoma in situ. The specificity of ultrasound was 97.2% in our study but ultrasound cannot be substitute for cystoscopy.
Some antibodies are expressed in high grade or invasive tumors. The expression of T43 and T138 antigens occurs in 15% of superficial tumors but more than 60% of invasive bladder cancers 18. Also M344 and 19A211 are expressed on 70% of superficial bladder tumors 19. Sagerman used combinations of antibodies against Lewis X antigen, M344 and 19A211 for the detection of bladder tumor 20. Friedrich found false positive results in 9.5 % for Lewis X detection 21. The combination of cytopathology and immunocytology had a sensitivity of 83.7% and specificity of 83.3%. In Cordon-Cardo’s study they had shown that the Lewis X antigen may be expressed on normal uroepithelial umbrella cells 9. So we tried to determine the precentage of transitional cells in the urine of optimal threshold for the diagnosis of a bladder tumor. In our study we found that for the diagnosis of a transitional cell tumor , 5% or more of the cells must have to express the Lewis X antigen. These result are same as Sheinfeld’s study 10.
As a result immunostaining of cells from voided urine for the Lewis X antigen detection is more sensitive than cytopathology, but this method may miss small, superficial or low grade tumors. And cystoscopy is still the gold standard for evaluation and following of bladder cancers until the new methods have to need more studies to improve these technics.