New genetic tests offer more precise diagnosis

June 14, 2013 9:50:48 PM PDT
The promise of human genome research can now be seen in a new generation of precision diagnostics. And one of the most recent, a test for prostate cancer, could change the way many men choose to be treated.

Nearly four years ago, John Shoemaker was slugging his way past a diagnosis of prostate cancer. But instead of surgery or radiation, the Silicon Valley executive opted for a strategy called "active surveillance," monitoring his slow growing form of the cancer.

"I've truly realized now what a good decision it was," he says. "Having had almost seven years now and having all my regular tests and check-ups, and I've basically, as far as they can tell, I have had no progression."

But Shoemaker's decision puts him in the minority. Of the 240,000 men diagnosed with prostate cancer in the U.S. every year, nearly nine out of 10 opt for immediate treatment even though only a small fraction face a risk of the disease advancing to a dangerous stage in their lifetime.

Dr. Matthew Cooperberg and his team at UCSF have just finished studies on a new test developed by a company called Genomic Health Incorporated based in Redwood City. The technology analyzes tumor tissue taken during a biopsy and identifies a series of genomic markers. It then uses those biomarkers to determine the tumors' likelihood of becoming aggressive.

"So the goal with genomics is to improve on what we can already do clinically, add new independent prognostic information above and beyond. And specifically to find a larger portion of men who can confidently make decisions they don't need to go into surgery," says Cooperberg.

Last month UCSF launched a campaign to expand the availability of genetic information for use in patient care. It's a model the university refers to as precision medicine. Dr. Bruce Miller directs the UCSF Memory and Aging Center.

"I think increasingly genetic information will be part of our record," he says. "We will be telling you about risk factors, drugs that you shouldn't take because you'll get bad reactions. We are increasingly excited by the idea that we will be able to think with you about preventing diseases decades before they ever arrive."

Dr. Steven Shak is chief medical officer at Genomic Health. He believes new genetic tests under development will soon revolutionize diagnostics for a variety of diseases.

"I have no doubt in 10 years there will be a test that helps to inform every patient at the time of their cancer diagnosis," says Shak.

For patients like Shoemaker, advanced testing offers a chance to make decisions about their care with far more confidence. He plans to undergo the new prostate cancer test, known commercially as Oncotype DX, which became available to patients outside the clinical trial in April.

"And perhaps I'll be able to stretch out, instead of having a biopsy every 18 months, I could have a biopsy every three years or something like that, so it will be a huge difference for me," says Shoemaker.

Written and produced by Tim Didion


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