Objective: The Bard BTA test is an immunochromatographic reaction to detect the bladder tumor antigen in patients with bladder cancer. The sensitivity, specificity and predictive values of this test are analyzed and compared with the standard methods of bladder cancer diagnosis (cystoscopy and cytology).
Methods: In 120 patients with symptoms suggestive of bladder cancer or who came for follow-up control evaluation for bladder cancer, we performed the BTA test and cytology in a voided urine sample prior to cystoscopy. TUR and randomized biopsies were performed in patients with a suspicion of bladder cancer.
Results: 76 patients had bladder cancer and 44 were free of cancer. The sensitivity was 76.36% for the BTA test, 61.84% for cytology and 98.5% for cystoscopy. The specificity was 77.7% for the BTA test, 86.36% for cytology and 86.36% for cystoscopy. The positive and negative predictive values were 85.29% and 65.38%, 88.68% and 56.72%, and 91.5% and 97.4%, respectively, for each of the foregoing tests. The sensitivity by grade was 43.75% for G1, 78.38% for G2, 95.65% for G3 for the BTA test; 18.75%, 59.46% and 95.65% for G1, G2 and G3, respectively, for cytology. The sensitivity by stage was 53.8% for Ta, 76% for T1, and 100% for T2-4 and Tis for the BTA test, whereas the sensitivity for cytology was 23.08%, 62% and 100%, respectively, for the foregoing tumor stages.
Conclusions: The BTA test is simple, fast and useful in bladder cancer diagnosis. Our results show that the BTA test is superior to cytology.