Diagnostic evaluation of apoptosis inhibitory gene and tissue inhibitor matrix metalloproteinase-2 in patients with bladder cancer

Bladder carcinoma is an important worldwide health problem. Both cystoscopy and urine cytology used in detecting bladder cancer suffer from drawbacks where cystoscopy is an invasive method and urine cytology shows low sensitivity in low-grade tumors. This study validates easier and less time-consuming techniques for the estimation of survivin and TIMP-2 in urine of bladder cancer patients to evaluate them in comparison with cytology. This study includes malignant (bladder cancer patients, n = 42), benign (patients with bilharzial cystitis, n = 22) and healthy (n = 21) groups. The studied groups were subjected to cystoscopic examination, detection of bilharzial antibodies, urine cytology, and estimation of urinary survivin by qualitative RT-nested PCR and TIMP-2 by ELISA. Significantly higher positivity rates of urinary survivin and TIMP-2 were observed in the malignant group compared with benign and healthy groups. On associating the two urinary markers with different clinicopathological factors, only TIMP-2 exerted significantly higher positivity rate in invasive stage (100%) than superficial stage (82.3%). Survivin showed 78.6% sensitivity, 95.3% specificity, 94.3% PPV, 82% NPV, and 87% accuracy. When combined with urine cytology, the sensitivity increased to 83.3%. While on applying the cutoff value of urinary TIMP-2 (< or =639.5 pg/mg protein), it showed 93% sensitivity, 83.7% specificity, 85% PPV, 92.3% NPV, and 88.2% accuracy. When combined with urine cytology, the TIMP-2 sensitivity remained 93%. On combining cytology with both urinary survivin and TIMP-2, the highest sensitivity was reached (98%). Survivin and TIMP-2 can be considered as potentially useful urine markers in early detection of bladder cancer.