COMPARISON OF SCREENING METHODS IN THE DETECTION OF BLADDER CANCER

Abstract

We prospectively evaluate and compare the sensitivity and specificity of urine cytology, BTA stat, NMP22, fibrin/fibrinogen degradation products (FDP), telomerase, chemiluminescent hemoglobin and hemoglobin dipstick to detect bladder cancer. Single voided specimens were obtained from 57 patients with bladder cancer, and 139 without evidence of bladder malignancy on cystoscopy or a negative biopsy of indeterminate lesions. A cytology report was available for 125 patients and interpreted independently. BTA stat, NMP22 and FDP were analyzed according to manufacturer specifications. The telomerase assay was performed on cells collected from urine by centrifugation in preparation for polymerase chain reaction based amplification using the telomeric repeat amplification protocol assay. The chemiluminescent screening assay for hemoglobin in urine uses the pseudoperoxidase activity of hemoglobin on hydrogen peroxide and subsequent oxidation of 7-dimethylaminonaphthalene-1,2-dicarbonic acid hydrazide to generate chemiluminescence emission. Hemoglobin dipstick was interpreted as positive if the hemoglobin content in the urine was trace or greater. Overall sensitivity with urine cytology, BTA stat, NMP22, FDP, telomerase, chemiluminescent hemoglobin and the hemoglobin dipstick was 44, 74, 53, 52, 70, 67 and 47%, respectively. Specificity with cytology, telomerase and FDP was high (95, 99 and 91%, respectively) but BTA stat, NMP22 (optimized), chemiluminescent hemoglobin (optimized) and the hemoglobin dipstick demonstrated lower specificity of 73, 60, 63 and 84%, respectively. Stepwise logistic regression analysis revealed that for all tumors, and within each tumor grade and stage telomerase had the strongest association with bladder cancer among all tests (69% overall concordance). Telomerase was also positive in 91% of the patients (10 of 11) with carcinoma in situ. Urinary telomerase had the highest combination of sensitivity and specificity (70 and 99%, respectively) for bladder cancer screening in these patients. It was the strongest predictor with superior accuracy in patients with grade 1 and noninvasive tumors (pTa), and extremely useful in patients with carcinoma in situ. Telomerase appears to be promising and outperformed cytology, BTA stat, NMP22, FDP, chemiluminescent hemoglobin and hemoglobin dipstick in the prediction of bladder cancer.