Detection of Methylated RAR in the Urine of Bladder Cancer Patients

Bladder cancer is an important public health problem in Egypt which constitutes 30% of all cancers. Cytology could serve as an excellent test for screening but it is of lower sensitivity. Early diagnosis is critical for maximizing the cure rate of bladder cancer patients, so many urine-based tumor markers have been developed for use in detecting and monitoring bladder cancers. Hypermethylation of CpG islands in the promoter regions of RARβ2 tumor suppressor gene is a major event in the origin of many cancers. In the present study detection of methylated RARβ2 gene was done in the urine of 183 subjects including normal, benign and malignant cases using MS-PCR technique. Results revealed marked urinary RARβ2 promoter hypermethylation in malignant group as compared to benign and normal groups. The sensitivity of detection of RARβ2 promoter hypermethylation was (83.6%) and the specificity was (89.7%), while the sensitivity of urine cytology was (52.2%). Combined use of detection of urinary RARβ2 promoter hypermethylation with urine cytology increased the sensitivity of cytology from 52.2% to 89.5%.