Objectives: Quantitative cytology (Quanticyt) provides an objective reproducible alternative for routine cytology. To increase the sensitivity of cytology, we studied the application of consecutive cytology in patients in follow-up for superficial bladder cancer.
Methods: Between 1991 and 1998, a set of five or more bladder wash samples was obtained from 614 patients. These patients were retrospectively studied for follow-up data. Each sample was scored according to the Quanticyt risk score.
Results: In 614 patients (508 men, 106 women), 5832 bladder wash samples were taken. The mean interval between the first and fifth sample per patient was 21.5 months (SD 13.8 months). The mean number of tumor recurrences per patient was 2.17 (SD 1.82). The risk score of the first sample was not predictive of recurrence. Invasive disease was found in 0%, 0%, and 0.8% of patients with one low, intermediate, and high-risk sample, respectively. After five samples, the corresponding rate was 0%, 0%, and 10%. A comparison of visual cytology and quantitative cytology revealed that the false-negative rate was significantly different (17% versus 3.8%). The positive predictive value was highest for visual cytology (17% versus 9.2%).
Conclusions: Adding consecutive quantitative cytology to urine cytopathologic evaluation improves the detection rate of high-grade lesions. Combining quantitative cytology and visual cytology provided a more accurate prediction of tumor stage.