Why some bladder cancer is more invasive than others discovered

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Researchers learn how bladder cancer becomes invasive 

Researchers have a new understanding of why some bladder cancer is more invasive than others. According to findings from University of Stanford scientists, the discovery could mean new ways to diagnose and treat bladder cancer. 

One stem cell responsible for invasive bladder cancer

The study that was conducted in mice is the first to show bladder cancer as well as lesions considered precancerous arise from one single cell. The scientists says it also explains why cancer of the bladder can recur. 

We've learned that, at an intermediate stage during cancer progression, a single cancer stem cell and its progeny can quickly and completely replace the entire bladder lining," said Philip Beachy, PhD, professor of biochemistry and of developmental biology. in a press release."All of these cells have already taken several steps along the path to becoming an aggressive tumor. Thus, even when invasive carcinomas are successfully removed through surgery, this corrupted lining remains in place and has a high probability of progression."

The Stanford group was able to identify a cellular "switch" that domes from a signaling protein called sonic hedgehog. The protein is expressed in precancerous and cancerous cells in the bladder, but not in cells that spread and become aggressive. 

Michael Hsieh, MD, PhD, assistant professor of urology and a co-author of the study, published in the journal Nature Cell Biologysaid:
'Until now, it's not been clear whether bladder cancers arise as the result of cancerous mutations in many cells in the bladder lining as the result of ongoing exposure to toxins excreted in the urine, or if it's due instead to a defect in one cell or cell type.'
Risk factors for bladder cancer include:
  • Smoking
  • Repeated bladder infections
  • Age
  • Male gender
  • Occupational  toxin exposure
  • Heredity
  • Arsenic in drinking water
Not all bladder cancers are invasive, nor do they have the same risks factors. One type is invasive and spread to other organs while another of the main two types only affects the bladder. 

The invasive form is difficult to treat and incurable, which means frequent monitoring is needed to check for recurrence. 

Hsieh added  understanding how cancer develops and becomes invasive could provide a new target for earlier diagnosis and monitoring of the disease.