Cytokeratin-20 immunocytology in voided urine exhibits greater sensitivity and reliability than standard cytology in the diagnosis of transitional cell carcinoma of the bladder.
OBJECTIVE
To investigate whether immunocytochemical detection of cytokeratin (CK)-20 could serve as a reliable diagnostic marker for transitional cell carcinoma (TCC) of the bladder.


METHODS
A total of 232 patients were enrolled in the study. Group 1 consisted of 144 patients with histologically confirmed TCC (62 at diagnosis and 82 in follow-up), and group 2 consisted of 88 subjects, including healthy volunteers and individuals with "non-TCC" conditions. Spontaneously voided urine specimens were obtained from each patient and submitted to immunocytologic and standard cytologic examination.


RESULTS
CK-20 immunocytology yielded an overall sensitivity of 65.3%, significantly greater than the sensitivity of urine cytology (54.2%, P = 0.013). A more detailed analysis revealed a sensitivity advantage for the former technique in the detection of primary (61.3% versus 51.6%, P = 0.046), recurrent (68.3% versus 56.1%, P = 0.027), Stage pT1 (81.8% versus 59.1%, P = 0.006), grade 2 (76.2% versus 61.9%, P = 0.031), and grade 3 (82.1% versus 67.9%, P = 0.039) tumors. Moreover, CK-20 immunocytochemistry demonstrated greater overall specificity than cytology (90.9% versus 86.4%, respectively), a difference stemming from the subgroup of lithiasis patients (100% versus 66.7%, P = 0.024). In terms of reliability, the positive and negative predictive values of the immunoassay were greater than those calculated for cytology (92.2% versus 86.7% and 61.5% versus 53.5%, respectively).


CONCLUSIONS
CK-20 immunocytology is more sensitive than standard cytology in the detection of TCC, particularly of Stage pT1, grade 2, and grade 3 tumors. In view of its high overall specificity and predictive accuracy, it is conceivable that the proposed immunoassay may progressively replace conventional cytologic screening in the diagnosis of bladder cancer.
Melissourgos
Nikolaos D
ND
Department of Urology, Medical Diagnosis Primary Health Care Unit, Athens, Greece. psari@otenet.gr
Kastrinakis
Nikolaos G
NG
Skolarikos
Andreas
A
Pappa
Maria
M
Vassilakis
Georgios
G
Gorgoulis
Vassilis G
VG
Salla
Charitini
C
D014408:Biomarkers, Tumor; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D007381:Intermediate Filament Proteins; D053554:Keratin-20; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
D014408:Biomarkers, Tumor; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; D053554:Keratin-20