Usefulness of liquid-based preparation in urine cytology

ThinPrep (TP), a liquid-based cytological and non-invasive technique to confirm the diagnosis of bladder cancer, is reported to be a better screening test than the conventional cytospin method. This study compared the new MonoPrep2 (MP), a liquid-based cytological technique, with TP for diagnosing bladder cancer.

Between January 2003 and June 2004, urine samples from 284 patients were processed using the TP and MP methods. The cytological diagnosis and the determination of specimen quality were performed separately. The cytological diagnoses were classified into four categories: unsatisfactory, benign, borderline, and malignant. A subsequent biopsy was performed in 73 patients. The cytological diagnoses were compared with the biopsy results to evaluate the sensitivity and specificity of the two methods.

Considering all the features examined, the overall specimen quality was comparable between the MP and TP techniques in the majority of cases. The rate of satisfactory specimens was 100% for TP and 98.6% for MP. The diagnostic capacity was similar between MP and TP. The overall sensitivities with MP and TP were 58.6 and 62.0%, respectively, and the specificities were 100 and 97.7%; the differences were not significant (P > 0.05).

MP and TP produced comparable results in diagnosing bladder cancer. As MP is less expensive than TP, we recommend MP as an alternative liquid-based cytology method for use in bladder cancer screening.