Immunocyt Test Improves the Diagnostic Accuracy of Urinary Cytology: Results of a French Multicenter Study

Abstract

The limitations of urinary cytology and the invasiveness of cystoscopy generate an increasing interest in noninvasive diagnostic tools for the management of transitional cell carcinoma. We assess the clinical performance of ImmunoCyt (DiagnoCure, Inc., Saint-Foy, Canada) in the detection of bladder cancer in a 10-center French trial. From October 2000 to April 2001, 694 patients undergoing cystoscopy were prospectively included in the study. Of the patients 458 (66%) had been previously treated for superficial transitional cell carcinoma and 236 (34%) were referred for symptoms suggestive of bladder cancer. All patients underwent ImmunoCyt test and standard urinary cytology from voided urine as well as a complete evaluation including cystoscopy and transurethral resection or biopsy of suspicious lesions. Sensitivity and specificity values of urinary cytology and ImmunoCyt whether or not combined were calculated using cystoscopy as the gold standard and histopathology when available. A total of 85 recurrent and 58 newly diagnosed bladder tumors were diagnosed by cystoscopy and histologicaly confirmed. Overall sensitivity of urinary cytology was 17.9%, 46.3% and 63.8% respectively, for G1, G2 and G3 transitional cell carcinoma, whereas that of ImmunoCyt was 60.7%, 75.6% and 76.8%. Sensitivity of the combined tests was 66.7%, 78% and 87%, respectively. Moreover, 10 of 55 (18.2%) new pT1 and pT2 or greater tumors were diagnosed by ImmunoCyt alone. Specificity of urinary cytology was 94.5%, whereas that of ImmunoCyt was 84.2%. Specificity of the combined tests was 80.7%. Marked variations in urinary cytology sensitivity were observed among the different centers (27.3% to 66.7%), whereas combined assays (urinary cytology and ImmunoCyt) enhanced the overall sensitivity in the 80% range at most centers. This prospective multicenter series confirmed a marked increase in sensitivity without significant loss in specificity when including ImmunoCyt in standard urinary cytology protocol. This increased sensitivity was observed in high grade lesions (with 100% sensitivity for carcinoma in situ) as well in low grade, low stage tumors.