Background and aims: Cystoscopy and urine cytology are the standard tools for monitoring superficial bladder cancer. The sensitivity of cystoscopy is, however, limited to the tumours that can be visualised, and the sensitivity of cytology is relatively low in low-stage/low-grade tumours. Therefore, new tumour markers have been developed. BTA stat has been reported to have high sensitivity in detecting both primary and recurrent bladder tumours, and may have the potential to detect tumours that cannot be visualised by routine cystoscopy including recurrences in upper tract. The objective of the study was to analyse the reliability of routine follow-up cystoscopy by further investigating patients with positive marker status, BTA stat Test and urine cytology, but negative cystoscopy.
Material and methods: 446 consecutive patients being followed for bladder cancer were analysed in a prospective multicenter study. A voided urine sample was obtained prior to cystoscopy and split for culture, cytology and BTA stat testing. In the case of positive marker status, BTA stat Test or urine cytology, but negative cystoscopy patients were further investigated by i.v. urography or renal ultrasound and random biopsies. The sensitivity of routine follow-up cystoscopy is reported.
Results: Of 446 patients 131 (29.4%) had a bladder cancer recurrence at routine cystoscopy. Of the remaining 315 patients not having recurrent tumour at cystoscopy, 56 patients (17.8%) had positive BTA stat Test result, 6 (1.9%) had positive cytology and 5 were positive by both tests. Nine recurrences that were missed at routine follow-up cystoscopy were detected by further investigations making the total number of bladder confined recurrent tumours 140 (140/446, 31.4%). Five of these 9 recurrences were high grade lesions (1 T1G3, 4 CIS), of which 4 were detected by positive cytology. The overall sensitivity of cystoscopy was 93.6%.
Conclusions: We found that routine follow-up cystoscopy may miss over five percent of the recurrent tumours. Although cystoscopy remains the gold standard for bladder cancer follow-up, it is suggested that even with negative cystoscopy patients with positive marker status, BTA stat Test and especially urine cytology, should be considered at risk for coexisting, and in some case even high grade recurrence.