New gene test guides prostate therapy
The first genetic test to help men with low-risk prostate cancer and their doctors determine whether they can simply monitor the disease rather than treat it with more aggressive radiation or chemotherapy treatments became available Wednesday.
Genomic Health of Redwood City decided to put the test on the market after a UCSF study released Wednesday showed it accurately predicted whether prostate cancer was likely to spread.
“What this test does is give them more accurate information about the likelihood that their tumor is low grade and confined to the prostate,” said Dr. Peter Carroll, co-director of urologic cancer at the UCSF Helen Diller Family Comprehensive Cancer Center and an author of the study.
Carroll said the additional information should help allay fears about decisions to not treat the disease aggressively — a careful monitoring ap-
proach for low-risk prostate cancer known as active surveillance.
The test “can increase substantially the number of the men who can confidentially choose active surveillance,” he said.
Prostate cancer, the most common non-skin cancer in the United States, has long posed the problem of overtreatment. Costs to treat the disease add up to about $12 billion a year, and some health experts argue much of that may not even be necessary.
About the PSA test
The prostate-specific antigen test, or PSA, has made it possible to catch the disease early and saved many lives since it was introduced in the 1980s. But the screening test also finds tumors that may never need to be treated and has led to unnecessary surgeries and radiation treatment, which can have life-altering complications such as incontinence and sexual dysfunction.
Of the 240,000 men diagnosed in this country each year with prostate cancer, about half are classified as low risk using such measures as a physical exam, the PSA test and a Gleason score, which relies on the cancer’s appearance under a microscope from a needle biopsy.
Genomic Health’s test — called the Oncotype DX prostate cancer test — takes tissue from the biopsy and then uses it to measure the level of expression of the 17 genes important to prostate cancer growth. The sample is then scored from zero to 100 with higher scores considered more aggressive.
“This is really going to help patients,” said Dr. Jonathan Simons, president and chief executive officer of the Prostate Cancer Foundation, a research and advocacy group in Santa Monica. “I don’t know how many yet, but this is what all the investing in and understanding genetics and prostate cancer is about.”
The Oncotype test may be the first on the market designed to help men make a decision about treatment, but other companies are working on similar genetic prostate cancer tests. The one most likely to become available next is being developed by Myriad Genetics, a Salt Lake City company that already has a genetic prostate cancer test available to assess risk after surgery.
On that slim chance
More than 90 percent of patients with prostate cancer identified as low risk still opt to undergo some sort of radiation or chemotherapy treatment despite a less than 3 percent chance of the disease spreading. The diagnosis and the uncertainty of the disease spreading is often enough to push men to seek treatment when monitoring might be more appropriate.
“Even when the biopsy looks favorable, there is a concern that maybe we left a focus that’s more aggressive,” said Dr. Steven Shak, chief medical officer for Genomic Health.
The UCSF study, which was announced Wednesday during this week’s annual American Urological Association’s meeting in San Diego, validated earlier studies of the test.
The study found the test increased the number of patients appropriate for active surveillance — rather than treatment — from less than 10 percent to 26 percent of the 400 Northern California prostate cancer patients involved in the study. It also determined that about 10 percent of patients originally thought to have very low or low-risk cancer actually harbored more aggressive genetic traits of the disease.
Insurance coverage
The test, which will cost $3,820, is likely to be covered by insurance, according to Genomic Health officials. That’s because the company’s two other available Oncotype cancers tests — for breast and colon cancer — are generally covered by private insurers and Medicare, and the hope is that the new test will reduce the amount of expensive and unnecessary treatments.
For patients, the test could be used when they are initially diagnosed, but it could also be used later to provide reassurance.
Fred Walsh, a retired San Francisco firefighter who lives in Santa Rosa, was diagnosed with seemingly low-risk prostate cancer in 2010 and opted to monitor the disease. After hearing the results of the study, he said he would discuss taking the test with his doctor at his next biopsy.
“I have always been playing a waiting game that maybe there would be a new development I could take advantage of,” he said. “There’s always the unknown.”
But Walsh, 61, said he’s comfortable with his choice of active surveillance. “After all,” he said, “I’ve gone into burning buildings.”