WEST PALM BEACH, Fla. - A genetic test can be found for any one of about 1,300 conditions, and three to five new tests emerge every month.
Millions of people, from cancer patients to would-be parents, have tapped into these tests to reveal what is making them sick or could sicken their children.
Two-thirds of doctors report that the technology has helped them identify diseases they couldn't have identified otherwise, according to a survey commissioned by health care giant UnitedHealth Group. The survey is part of a study that concludes that a $5 billion-a-year market in genetic testing is poised to mushroom to $15 billion to $25 billion within a decade.
"Genetic science offers unprecedented potential to prevent disease and improve diagnosis and treatment, ushering in an era of truly personalized care," Simon Stevens, UnitedHealth's executive vice president, said in a prepared statement.
Doctors and other health care professionals echo that sentiment, saying they have seen the benefits of genetic testing firsthand and are eager to see more breakthroughs.
But they also note the concerns, mapped out in the study, that come with this explosion of knowledge and possibilities:
• Gathering enough genetic information to create personalized treatments that work, and making sure doctors know about them.
• Ensuring patient privacy and preventing genetic discrimination.
• Addressing the potential for skyrocketing health care costs.
• Testing related to cancer
Genetic testing is commonly used two ways: to determine a person's predisposition to disease from the womb to adulthood, and to fine-tune treatment of an existing ailment based on the disease's genetics.
In the survey, more than two-thirds of doctors reported recommending genetic testing related to cancer.
Until recently, what we knew about a person's cancer came from what could be seen under a microscope and inferred from family history. Chemotherapy was typically the blanket attack, but it can cost up to $100,000 a year and is not necessarily effective.
"For solid tumors, the likelihood of actually shrinking the tumor with standard chemotherapy is less than 50 percent," said Dr. Robert Green, an oncologist with the Palm Beach Cancer Institute.
But in recent years, genetic testing has delivered information about various cancer mutations. Scientists have used that information to find treatments to target them.
"If someone comes to me with a new diagnosis of lung cancer, I will now always send them for testing for certain mutations because there's a drug out there," Green said. "For melanoma, you never checked before and now you do it on everyone."
There's still a long way to go, Green and others caution.
Even if a genetic test can spot a disease, a treatment may not be available. According to the UnitedHealth Group study, scientists have come up with more than 1,000 tests for about 2,500 conditions, but only 400 of those tests have proven treatments.
Prenatal & Newborn Tests
Not everyone is looking to treat an existing illness. Nearly half the doctors surveyed reported recommending tests for expectant parents and newborns.
"The technology has just changed so much," said Dr. Danielle Esters, a clinical geneticist at the Maternal Fetal Center in Wellington, Fla.
Doctors can test for more diseases and do it earlier. Detection rates for diseases such as spina bifida, Down syndrome and cystic fibrosis have increased sharply. Testing for other disorders such as Fragile X, a leading genetic cause for mental retardation and one cause of autism, are now available, Esters said.
Some adults are tipped off early about the need to test a fetus. In some cases, they choose not to become parents.
"People have the impression we're doing prenatal screening and if things aren't right, we're going to have an abortion, but that's not always true," said Esters, who estimated that about half of her patients go that route. "A lot of patients continue with the pregnancy, but it's important they know. They can start putting their ducks in order with their family, their doctors, support groups."
The genetic test that most women have heard about is one that can identify a hereditary form of breast cancer -- the test for mutations in the so-called BRCA genes. Mutations in those genes also can lead to increased risk of ovarian cancer.
"I have practiced oncology for 25 years as a nurse and this has made a difference," said Robin Stevens, who counsels patients at the Palm Beach Cancer Institute. "It is providing answers. It also offers an opportunity for prevention."
But the discovery highlights both the upside and downside of genetic testing.
With this information, millions of women with a family history of breast and ovarian cancer now can point to its cause. They can be tested and make medical decisions accordingly, such as whether to have their ovaries removed after bearing children, whether to avoid hormone therapy or remove breast tissue before cancer develops.
Amy Shainman of Jupiter, Fla., knew her grandmother had died of breast cancer at 33, but it wasn't until her older sister developed cancer and subsequently tested positive for a BRCA mutation that she realized her own health could be in danger. A genetic test confirmed it.
Shainman, at the time a 40-year-old mother of two, chose to have a hysterectomy and surgical removal of her breast tissue.
"I still am constantly checking and feeling, but I'm relieved," she said, adding that her chances of getting breast cancer "went from potentially 87 percent down to 3 percent. And I won't get, or die from, ovarian cancer."
Each year, about 200,000 women in the U.S. are diagnosed with breast cancer. The National Cancer Institute reports that the hereditary form, which ran in Shainman's family, accounts for 5 percent to 10 percent of cases.
Also, the cost to test the BRCA genes can be steep -- $3,400 or more. Only one company does the testing.
Health Care Spending
The UnitedHealth study indicates that nearly two-thirds of doctors surveyed believe the surge in testing would increase spending on health care. The company's analysis of its own claims indicates that its genetic testing costs increased by 14 percent from 2008 to 2010.
The study also concludes that more Americans need to be tested. The more data collected, the easier it will be for researchers to create effective treatments.
"In order to understand what's going to work for which patients, you need to study patients," said Dr. William Dalton, chief executive of Moffitt Cancer Center and Research Institute in Tampa, Fla. "I'm talking hundreds of thousands of patients."
Six years ago, Moffitt began collecting genetic data on six of the most common cancers and following patients and their cancers through their lifetime. The center collects data at 18 sites in 10 states and now has information from 86,000 patients, Dalton said.
"This is something that must continue to grow," he said. "Now we are getting information and beginning to be able to predict who is responding to what."
Finally, people must keep in mind that having a genetic predisposition to a disease is not the same as having the disease. There's an entire branch of science that studies what turns on a gene.
Ensuring that patients who get tested are properly counseled promises to be another challenge.
By the study's count, only 3,000 clinicians and 1,400 physicians in the U.S. are board-certified to conduct genetic counseling.
"While genetics are incredible, and that's what I do, I think anybody who thinks this is the end-all, be-all and the answer to all men's ills is wrong," Dalton said.
"A major cause of cancer is still cigarettes. It causes not only lung cancer, but bladder cancer and others as well. And then there's obesity. All those things can be controlled in other ways."