Objectives: To determine whether DD23 increases the sensitivity of urinary-based detection of transitional cell carcinoma (TCC) recurrence. The murine monoclonal antibody DD23 recognizes a 185-kDa tumor-associated antigen that is expressed in human bladder cancer cells in vitro and in vivo but is not detected in normal urothelium.
Methods: Using alcohol-fixed urinary cytology, matched voided urine and bladder wash specimens were evaluated for the contribution of DD23 antigen expression in the detection of recurrent TCC. The selected patient population had a history of bladder cancer, and urine cytology analysis was performed in a single commercial reference laboratory. DD23 antigen expression in a cohort of 81 patients was compared with urine cytology findings, and the sensitivity and specificity for each urine-based test was determined. The presence of recurrent disease was determined by positive pathologic biopsy.
Results: The 81-patient cohort produced 151 urine specimens for which both biopsy and cytology information were obtained. Of these specimens, 64 were confirmed by a tissue diagnosis for TCC recurrence. These biopsy-proven recurrences were used as the dependent variable to assess the accuracy of cytology testing. For the detection of TCC, the DD23 antigen had a sensitivity of 70.3% and a specificity of 59.8%. Combined with cytopathologic findings, DD23 enhanced the sensitivity for the detection of TCC from 43.8% (cytology alone) to 78.1%. For low-grade TCC (n = 20) DD23 enhanced the sensitivity from 20.0% (cytology alone) to 55.0%. For high-grade TCC (n = 25), DD23 enhanced the sensitivity from 64.0% (cytology alone) to 76.0%. In patients with a prior history of intravesical treatment, DD23 had a sensitivity of 94.7% and a specificity of 33.3% compared with a sensitivity of 52.6% and a specificity of 83.3% for cytology.
Conclusions: DD23 antigen expression can be used as an adjunct to cytopathologic evaluation to enhance the sensitivity of urinary cytology detection of TCC. In addition, DD23 does not appear to lose sensitivity in patients with a prior history of bladder cancer treated with intravesical agents.