Bladder cancer (BC) in Europe accounts for 6,2 % of all cancers in men and 1,6 % in women. In three-quarters of cases, it is detected in the initial, superficial stage, which can eventually progress to muscle-invasive cancer, which in turn causes severe health problems and can even lead to the death of the patient. The main principle of treatment of superficial BC is immediate transurethral resection of the tumor and frequent monitoring with cystoscopic examinations, which are invasive, painful and have a risk of severe complications.
Over the last decade, several tumor markers have been discovered that are present in urine and could theoretically replace cystoscopic monitoring or at least allow longer intervals between cystoscopic examinations. One of the tests based on these markers is the Cepheid Xpert Bladder Cancer test, which has not been used clinically in Slovenia until our research.
The purpose of the master's thesis was to evaluate the clinical significance of the Cepheid Xpert Bladder Cancer test for the detection and monitoring of bladder cancer.
We included 54 patients in the study, of which 42 were men and 12 were women. All already had a confirmed diagnosis of BC. Among them were patients with newly discovered BC and were hospitalized at the Clinical Department of Urology at the University Medical Center Ljubljana before the first transurethral resection of the BC and patients who came for regular control cystoscopy in the cystoscopy room of the Clinical Department of Urology at the University Medical Center Ljubljana after previous transurethral resection.
The results of our study showed that the sensitivity of the Xpert BC Monitor test to predict a positive and suspicious cystoscopy result is significantly higher than in the cytological examination of urine (75,0 % compared to 41,2 %), the negative prognostic value is also better (93,0 % compared to 85,4 %).
The high discriminant power of the Xpert BC Monitor test between malignant and benign histological groups is due to an incredibly significant difference between the median total LDA values in both groups (0,2486 for the benign and 0,9869 for the malignant group). The overall sensitivity and negative predictive value of the Xpert BC Monitor test for predicting malignant histological outcome are 76,9 % and 93,0 %, respectively, and greatly exceed the values of urine cytological examination (46,2 % and 85,4 %).
Based on the obtained results, we can make the following conclusions: Xpert BC Monitor test showed significantly higher sensitivity and negative prognostic value compared to cytological examination of urine. Its ability to detect tumor recurrence could alter further cystoscopy follow-up schedules. In patients with a negative Xpert BC Monitor test result, the recommended intervals between individual cystoscopies could be increased. The combination of both tests, the Xpert BC Monitor test and the cytological examination of the urine, does not improve the performance of the Xpert BC Monitor test itself.