ENTREVISTA REALIZADA AL ESCRITOR ABDÓN UBIDIA

NMP22 test evaluates urine levels of a nuclear mitotic apparatus protein found in nuclear matrix of all cells. The test can be quantitative as enzyme-linked immunosorbent assay (ELISA) test or qualitative as immunochromatographic assay. The immunochromatographic assay in form of

NMP22 BladderChek® (Matritech Inc.Newton, Massachusetts) is available as point of care (POC) test with overall sensitivity and specificity of 56% and 86% respectively ⁷⁹.

ii Fibrinogen degradation products (FDPs).

Bladder tumour cells have increased vessel wall permeability due to the effect of vascular growth factors produced by the tumour cells. This allows the leakage of various cellular proteins, including plasminogen and fibrinogen into the urine. Urokinase converts plasminogen to plasmin which catalyses the conversion of fibrinogen to fibrin and FDPs. The level of plasmin is proportional to the tumour grade and stage.Fibrinogen degradation products can be detected in the urine by a monoclonal anti-FDP antibody latex-agglutination assay in 7 minutes with higher overall sensitivity but lower specificity than cytology ¹⁴.

iii Cytokeratins - (CK 8, 18, 19, and 20)

Cytokeratins are cytoskeletal proteins that form a major component of intermediate filaments of all epithelial cells, released in urine after cell death and lysis. Soluble cytokeratins 8, 18, 19 and 20 have been identified as potential urinary tumour markers. Cytokeratin 8 and 18 are detected by urinary bladder cancer test (UBC). Unlike other CKs that are ubiquitous, CK 20 is expressed only in malignant bladder cells. Cytokeratin 20 detects mRNA by RT-PCR or immunohistochemistry with sensitivity and specificity of 78% to 87% and 55% to 63%

respectively. Soluble fragment of CK 19 can be measured by CYFRA 21 test with sensitivity and specificity of 75- 96 % and 67- 74 % respectively for detecting bladder carcinoma ⁹.

iv Urinary BC tests (IDL Biotech AB, Bromma, Sweden)

These tests can be done as a POC qualitative assay in 2 hours, or as a UBC ELISA, a quantitative assay that measures cytokeratins 8 and 18 in urine.A study measuring UBC Rapid in the urine of 180 patients found an overall sensitivity of 66% and a specificity of 90%. In comparison, BTA STAT and BTA TRAK have better sensitivity than the UBC Rapid test in the same study. Urine cytology had better sensitivity and specificity than either UBC or UBC II ELISA ⁸⁰.

v Urine hyaluronic acid (HA) and hyaluronidase

Hyaluronic acid is a nonsulfated glycosaminoglycan and has been shown to yield 92% sensitivity and 93% specificity for bladder carcinoma detection ⁸¹. Hyaluronidase (HAase), an endoglycosidase, degrades HA into small fragments that promote angiogenesis.There is a positive correlation between the secretion of HAase by bladder carcinoma cells and their invasive potential. A five- to eightfold elevation of HAase in the urine of patients with grade 2 or 3 bladder carcinoma could be detected ⁸².

vi Aurora kinase A gene

Aurora kinase A gene encodes a serine/threonine kinase associated with aneuploidy and chromosome instability. Fluorescent in-situ hybridisation is used for detection of this gene.

Park et al ⁸³ study 100 patients with bladder carcinoma, 92 healthy individuals, and 56 patients with benign urologic disease, the test had sensitivity and specificity of 87% and 97%

respectively.

vii Bladder cancer (BLCA)-1,4

Bladder cancer 1 and 4 are nuclear transcription factors present in bladder carcinoma. Bladder cancer 1 is not expressed in nonmalignant urothelium, whereas BLCA-4 is expressed in the area

of bladder tumour and adjacent benign areas of the bladder.Bladder cancer-4 is measured in urine by ELISA ⁸⁴. It has a sensitivity of 89% to 96% and specificity of 100%.Bladder cancer-1 has sensitivity and specificity of 80% and 87% respectively ⁸⁵.

viii Human carcinoembryonic antigen-related cell adhesion molecule (CEACAM1)

Human CECAM1 is a cell adhesion molecule with proangiogenic activity. It is expressed on normal bladder urothelium but down regulated in bladder carcinoma cells. It is up regulated in endothelial cells of adjacent blood vessels in urothelial cell carcinoma. Urinary levels of the marker are measured by ELISA. High urinary levels of CEACAM1 is associated with invasive tumour or advanced stage ⁸⁶.

vix Hypermethylation of E-cadherin, and p16

Hypermethylation of E-cadherin and p16 in urine has been shown to have a good sensitivity and specificity for bladder carcinoma detection. Methylation of rat sarcoma virus gene (RAS) association domain family protein 1, Isoform A (RASSF1A) has been reported in up to 97% of primary bladder tumours ⁶.

x Mutations in FGFR3

Low-grade/ stage primary bladder cancer is associated with mutation in FGFR3, with pTa tumours harbouring 85% of the mutations ²⁶. van Oers and co-workers ⁸⁷ described a simple assay for detection of nine different FGFR3 mutations in bladder carcinoma in voided urine from patients with bladder tumour with sensitivity of 62% .

Further studies are required to verify and establish the role of urinary molecular markers in bladder carcinoma diagnosis. Cystoscopy and cytology remains the gold standard for early bladder cancer detection until discovery of reliable combination of markers. This is possible only after improved standardisation of the methods for urine marker studies through large prospective randomised control studies ³⁵.

CHAPTER FOUR 4.0 MATERIALS AND METHOD