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SOURCE: National Kidney and Urologic Disease Information Clearinghouse.

Bladder cancer is diagnosed in more than 60,000 Americans per year.

Researchers report protein suppresses growth of cancer in bladder cells

by Sandy McAfee
Jan 16, 2013

University of Colorado Cancer Center researchers are reporting that a naturally occurring protein acts like an anti-inflammatory drug to counteract inflamed tissue surrounding bladder cancer cells. The Denver researchers believe the discovery could lead to new therapies for the cancer,

The study, published Wednesday in the Journal of Clinical Investigation, shows how the secreted protein acidic and rich in cysteine, or SPARC, suppresses cancer growth. The protein, which was thought by many to promote cancer growth, actually attempts to heal tissues inflamed by tumors where cancer cells can metastasize and grow, researchers said.

“We hope to eventually infuse a modified version of SPARC in patients and see if you can repress the tumor,” said Dr. Dan Theodorescu, director of the University of Colorado Cancer Center and senior author of the study. “We envision treating patients with SPARC at the same time as giving chemotherapy.”

Researchers studied SPARC levels in human bladder cancers cells and found that healthy tissue increases SPARC production to battle the tumor. In less aggressive cancers, they found that both the tumor and surrounding tissue made SPARC. In more aggressive cancers, only the surrounding tissue made SPARC and the tumor itself suppressed its production.

Characteristics of SPARC were confirmed when researchers tested animal models that did not have the ability to produce SPARC. In these models, bladder cancer developed at a higher rate and was more likely to spread to the lungs. They found that cancer growthslowed when SPARC was added.

“We hope this provides the rational basis for further exploring manipulation of SPARC as a therapeutic intervention,” Theodorescu said.

The study represents a new era of cancer research, where doctors and researchers are beginning to identify and understand the complexities of cancer, said Dr. Gary Steinberg, director of urologic oncology at the University of Chicago Medical Center, who himself a bladder cancer researcher. 

 “Cancer is not caused by one mutation but hundreds of mutations. We may not necessarily need to know what type of cancer, what’s more important is the genetic signature,” he said. “Understanding that, we can understand metabolic activity, protein activity and then we can understand what to target.”

According to Steinberg, around 40 percent of those diagnosed with bladder cancer have invasive, high-grade tumors that require additional therapy. Ninety percent of diagnosed patients require surgery that involves the removal of the bladder and then diversion of the urinary tract. Sometimes, depending on the cancer, it may be necessary to remove the prostate in men and reproductive organs in women.

Though it is one of top 10 most common cancers in the U.S. with more 60,000 people diagnosed every year, both Steinberg and Theodorescu said that the disease is highly understudied. Data from the University of Chicago shows that men are three to four times more likely to develop bladder cancer than women. Caucasian males are twice more likely their African-American counterparts. The average age of those diagnosed is 68, and the cancer often causes changes in body image, sexuality and social abilities in patients.

Pat Shevlin, 67, a former Roman Catholic nun from La Grange, lived a healthy life before she was diagnosed two years ago with a high-grade, aggressive form of bladder cancer. She underwent six weeks of biotherapy and was clear of symptoms until the tumor recurred nine months later and doctors told her she needed surgery to remove the bladder.

“In terms of bladder removal, the big decision was what kind of diversion to choose,” Shevlin said.

Shevlin selected bladder reconstruction with a neobladder, a new bladder constructed from the intestine and attached to the urethra. After the surgery with a few months of rest, life resumed normally for Shevlin.

“It knocked me out for about two months,” Shevlin said. “I was never the type to just sit and not do something, but I did that. After about three months, I felt like I was where I should be.”

Not everyone is a candidate for a neobladder. Wheaton resident Anthony Giordano, 79, who leads a support group for bladder cancer patients, was diagnosed in 1993. He said that there were still perceived problems with the procedure at the time. Giordano underwent surgery for a continent cutaneous urinary diversion procedure, also known as the Indiana pouch, another form of reconstruction that involves the use of catheters.

“It’s a little awkward sometimes, but it’s still doable,” Giordano said, who says he’s been able do normal activities including tennis, skiing and camping.

Surgery to remove the bladder is common for patients with bladder cancer. Theodorescu’s study shows that the future of cancer treatment involves various forms of medication at one time.

“I think we’re in a very exciting era,” Steinberg said of the progress of bladder cancer research, “With all these things, we’re really, truly beginning to drill down and understand the complexities of cancer.”