A Comparison Between ThinPrep Monolayer and Cytospin Cytology for the Detection of Bladder Cancer

The sensitivity of urine cytology is higher for carcinoma in situ and poorly differentiated tumors in bladder cancer, while being fairly low for low-grade or well-differentiated tumors. Development of a sensitive diagnostic test to detect bladder carcinoma would significantly facilitate patient management and allow earlier treatment of this disease. This study compared ThinPrep urine cytology (Cytyc Co.) and conventional Cytospin urine cytology (Shandon Scientific Ltd.) in the diagnosis of bladder cancer.

From January 2002 to December 2010, ThinPrep cytology and conventional urine Cytospin cytologic examination of bladder washings were performed in 3,085 subjects suspected of having bladder cancer and in 379 patients with follow-up after transurethral resection of bladder tumor (TUR-BT). The sensitivity and specificity of the urine ThinPrep test was compared with that of conventional Cytospin cytology according to tumor number, size, pathological stage, grade, and recurrence.

Of 3,085 subjects, bladder cancer was confirmed by TUR-BT in 379 subjects. The overall sensitivity of ThinPrep and Cytospin cytology was 60.9% and 59.9% in patients suspected of having bladder cancer, respectively. The overall specificity of ThinPrep and Cytospin cytology was 94.8% and 95.3% in patients suspected of having bladder cancer, respectively. The sensitivity of ThinPrep and Cytospin cytology was increased with increasing number, size, pathological stage, and grade, but there was no significant difference between the two tests.

These results suggest that ThinPrep cytology has no advantage in the diagnosis of bladder cancer of a low grade or low stage.