LONDON - A gene variation of prostate stem cell antigen (PSCA) gene, called rs2294008, can increase the risk of urinary bladder cancer, according to researchers at The University of Texas M. D. Anderson Cancer Center.

The researchers determined that people with the variant had a 30 to 40 percent higher risk for bladder cancer.

They hope that the results of this large, multi-site international study may help determine who is at high risk to contract this deadly cancer, which in turn may lead to better survival rates and the development of chemopreventive interventions.

“With this research, we were able to find a novel specific gene and a functional variation that are independent of the previous suspects. We found a ‘why’ to many of the questions about genetic causes of bladder cancer. The neighbouring genomic region has been identified previously as a possible problem for breast, prostate, colorectal and bladder cancer, but we didn’t know why,” Nature magazine quoted Dr. Xifeng Wu, the lead and corresponding author of the study, as saying.

Cigarette smoking and occupational exposure to certain chemicals are known risk factors for bladder cancer, but almost one-third of people who get the disease have an inherited genetic susceptibility.

Prostate stem cell antigen (PSCA) is over-expressed in prostate cancer, and the level of PSCA increases with tumour grade and stage.

However, the cellular function of PSCA in prostate cancer is not clear.

While PSCA’s involvement in bladder cancer had been suggested previously, this is the first time it has been linked definitively.

The first step of this study was a genomewide evaluation of 969 people with bladder cancer and 954 healthy people.

Thus, the researchers evaluated patients from three additional U.S. and nine European groups, for a total of 6,667 people with bladder cancer and 39,590 healthy people.

A variant in the PSCA gene (rs2294008) was associated consistently with bladder cancer.

The researchers then re-examined the PSCA gene region, and found rs2294008 was the only common missense genetic variation in the PSCA region.

A missense mutation occurs at a single point in the genome, and swaps one amino acid for another in a protein.

Low levels of PSCA were found in the bladders of healthy people, but it was over-produced in the majority of patients with bladder cancer.

Previous reports have suggested that measurement of PSCA in urine may be a simple and accurate marker to help diagnose bladder cancer.

Wu hopes that the new findings will help targeted bladder cancer prevention efforts.

The findings have been reported in the online edition of Nature Genetics. (ANI)