PURPOSE: A 11-gene set by methylation-specific PCR in urine sediments for 
sensitive/specific detection of bladder cancer has been identified previously. 
In this study, we have evaluated 10 DNA methylation biomarkers that have been 
reported informative in western countries for bladder cancer diagnosis for a 
better set.
MATERIALS AND METHODS: The promoter CpG Islands of the following 10 genes: CDH1, 
FANCF, LOXL1, LOXL4, p16INK4, SFRP1, SOX9, TIG1, TIMP3, and XAF1 have been 
subjected to methylation-specific PCR analysis in the DNA of 2 bladder cancer 
cell lines, 2 normal bladder tissues and urine sediments of 82 bladder cancer 
patients, 15 non-cancerous urogenital patients and 5 healthy volunteers.
RESULTS: Both XAF1 and LOXL1 genes were heterozygously methylated in the normal 
bladder tissues, showing no cancer state specificity. While the hypermethylated 
states were detected in urine sediments of bladder cancer at a frequency not 
less than 2.4% (2/82 cases), nine genes were also methylated in the patients of 
the non-cancerous urogenital diseases. The methylated SFRP1 was detected in 
36.6% (30/82 cases) of bladder cancer and 6.7% (1/15 cases) of non-cancerous 
urogenital diseases, showing the bladder cancer specificity.
CONCLUSIONS: Inclusion of the SFRP1 gene into a set of 11 genes has improved the 
bladder cancer detection. The insufficiency of predicting disease onset in this 
study with the previously recommended targets in western countries suggests a 
possible disease disparity between these two populations. Alternatively, the 
tissue-specific methylation might be mistaken as the cancer specific in the 
studies where no non-cancerous lesion controls were involved.