BOSTON -- A pioneering genome scientist believes all women older than 30 should consider an at-home cancer risk test, despite some national experts who say the tests aren't for everyone.
Dr. Mary-Claire King is an American Cancer Society professor and genome scientist at the University of Washington School of Medicine. In 1990, she first discovered and named the BRCA 1 gene, showing that inherited mutations in the genes lead to increased breast cancer risk. It revolutionized how doctors detect cancer by changing their screening procedures for thousands of women who are genetically predisposed for higher cancer risk.
While everyone’s DNA includes BRCA 1 and BRCA 2 genes, having a mutation can increase a woman’s breast cancer risk from about 10 percent to as much as 80 percent.
“It was a game changer,” King said. “It gave us a tool so that women could learn, woman by woman, their actual risk.”
Color Genomics has released two separate at-home tests that simply require a person to send back a tube of their saliva to test their risk for certain hereditary cancers.
The kits can be ordered online on the Color website and even on Amazon.com. Depending on the test, Color can test the DNA not only for BRCA mutations that can lead to higher breast cancer and ovarian cancer risk, but also for mutations to other genes that lead to higher risks in breast cancer and other cancers.
Jenn Nudelman, a breast cancer survivor, said she wants to take it herself. She does not have the BRCA gene, but she is the eighth woman in her family to be diagnosed with breast cancer.
“[In 2011, my surgeon] said, ‘It’s likely that your family has a mutation we just haven’t discovered yet,” Nudelman said.
To test the effectiveness of the Color test, Dr. King’s lab sent the company 400 of their trickiest DNA samples, challenging them to find the mutations.
“They got every single one correct,” she said. “They even got one mutation that we had missed because it was a gene that back when we first evaluated that patient, that gene hadn’t been known to be a breast cancer gene. So they got 101 percent of the samples correct! They did a perfect job, and I said, ‘OK, you’re serious.’”
She said what’s key is if a test finds any mutations where a person needs to take action, one of Color’s trained genetic counselors will call the patient to deliver the results and walk them through exactly what they mean.
Genetic counselor Nancy Hanson says, while many people expect the results to be clear and easily understandable, they may not be, especially when looking at a larger gene panel.
That's why she says it's important to go over the results with a genetic counselor.
Hanson said finding out you have a mutation does not mean you have or will definitely get cancer. And the job of a genetic counselor, by phone or in person, is to help patients understand their options.
“People who have an inherited susceptibility to cancer might never get cancer,” Hanson said. “They just have a dramatically higher risk, and we can make screening recommendations or preventative strategies to help them prevent cancer or catch it early.”
Hanson also looks at other factors, including family medical history, when a woman has had children, and, for example, whether she’s had any hormone replacement therapy. These factors can also modify a person’s risk of cancer over their lifetime.
Preventing and catching cancer early is why King is taking a strong stance when it comes to who should take the Color test.
“I believe that every woman over 30 should consider it,” she said, “and I think we have a choice. We can choose not to do it this year and we can change our minds and do it next year. I don’t think that anyone should be required to have a test, but I think it’s a very good idea. And I think every woman should have the information that enables her to understand what she can learn from such a test."
The Color test analyzes DNA for hereditary cancer risk due to genetic mutations passed down through families, which scientists estimate account for 10 percent to 15 percent of certain cancers.
Most cancers are called “sporadic,” and are not due to any one cause; environmental impacts, exposure to chemicals and pollutants and lifestyle all play a part. So if a person takes the Color test and does not have a mutation in any of the genes tested, it’s not a guarantee they will be free of cancer in their lifetime.
King recommends the test even though current guidelines from a national panel of experts called the U.S. Preventative Services Task Force say that “testing for BRCA mutations should be done only when an individual has a personal or family history that suggests an inherited cancer susceptibility.”
These recommendations are echoed on the websites of the Susan G. Komen Foundation and the National Cancer Institute.
But King’s own recent work shows people could have mutations without anyone else in their families ever having cancer. And that’s why, she said, more people should get tested.
“The most common misconception about testing for inherited risk of breast cancer is that only women with a severe family history of breast cancer need worry about it,” she said, “because men have genes, too. And a mutation that increases one's chances of breast or ovarian cancer can be passed from a father who will remain unaffected as frequently as from a mother.”
King believes the guidelines will evolve. She also thinks clinical experts may be concerned about other at-home tests such as '23andMe' and 'Ancestry DNA' that are often confused with the Color test, but which are actually based on very different genetic science.
“[That] recreational testing has nothing to do with risk of breast and ovarian cancer,” King said. “I think that organizations that cast such a very broad inclusive net, like Komen, are very concerned that no one be misled. I think there’s a concern about confusing results of those tests [like 23andMe] with results of test that actually measure whether one has a mutation in BRCA 1 or BRCA 2 or one of the sister genes.”
As for Jenn Nudelman, she ordered the Color test and says she is ready for whatever the test might reveal.
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