Breast cancer kills 40,000 people a year in the U.S. This is about the population of Atlantic City, New Jersey. Imagine, each year an entire city wiped out by breast cancer.
To help fight breast cancer, a new test assessing individual risk has just become available. For women without a clear family history of the disease, the deCODE BreastCancerTM test assesses their personal risk of developing the most common forms of breast cancer. The DNA test, launched by the biopharmaceutical company deCODE, makes it possible to identify those women at significantly higher than average risk, helping doctors use new screening technologies and treatments in a more targeted, personalized and effective manner.
The key to fighting breast cancer, like all cancers, is early detection, which is why the medical field is buzzing over deCODE’s new breast cancer test.
“This test helps define individual prevention which is what so many of my patients want,” says Owen Winsett, MD, founder and director of the Breast Center of Austin.
Dr. Winsett, who has already ordered the test for 25 of his patients, can’t hide his enthusiasm over how the decode breast cancer test is changing the way he screens for the disease.
“I’m excited to be able to extend my screening and prevention practice. I plan to make this test a standard tool for helping me decide which of my patients may benefit from screening at an earlier age, or benefit from more intensive screening, including breast MRI’s. And then if my patients don’t have breast cancer, to motivate them to begin healthy preventive strategies.”
The test is not offered directly to individual women, but rather ordered by doctors on the request of their patients. deCODE advises that the test-which scans a woman’s genome for seven widely replicated single-letter variations (SNPs) in the human genome that are linked to increased risk of breast cancer-is a way to better connect doctor and patient.
Dr. Winsett agrees. He recommends that before taking this test women should consult their general practitioner, and if their doctor is uncertain about how to use the results of the test, to seek out a breast cancer specialist.
Like all new technologies – particularly those that may change accepted clinical practice – this type of risk screening has raised concerns in some quarters. Some critics have argued that the test is not accurate enough because it’s not based on a large enough sample of women to predict risk of breast cancer. However, the evidence tells a different story. According to Dr. Winsett, epidemiological studies on breast cancer present a fairly straightforward argument that deCODE’s genetic test does indeed give a picture of a patient’s baseline risk. The evidence shows that the seven SNPs in the human genome that the decode test scans for are linked to an estimated 60 percent of all breast cancer cases. These findings are derived from integrated data from discovery and replication studies published in major peer-reviewed journals and involving nearly 100,000 breast cancer patients.
“I remind patients this test is one peice of the puzzle,” says Dr. Winsett. “The test won’t tell patients if they will get breast cancer or if they won’t. It shows the average risk, and then says where a woman stands in relation to that average and then what her absolute risk is. As a doctor, deCODE’s breast cancer test helps me evaluate a patient and make a future plan for prevention and testing.”
Still, some non-clinicians feel genetic testing only benefits women who have a strong family history of breast cancer. One bioethicist recently wrote on an MSNBC blog that “the tests Decode and other companies are offering are more likely to empty family pocketbooks and leave women with a false sense of security than they are to prevent breast cancer.”
Dr. Winsett finds this argument muddled. There are already tests to pick up genetic risk factors for highly familial forms of the disease, and neither those tests nor deCODE’s for measuring risk will cure or prevent breast cancer. Dr. Winsett notes that mammograms, ultrasounds and breast MRIs don’t prevent women from getting breast cancer either, but doctors still use them because they are tools to help detect breast cancer.
“Sometimes a patient will say, ‘I’ve had a mammogram regularly, so how can I get breast cancer?’ It’s easy to think that. But neither mammograms nor the deCODE test can on their own prevent breast cancer. It’s how you use the information from the genetic test to shape a patient’s care that leads to prevention or early detection.”
Genetic risk screening for breast cancer might sound like cutting-edge medicine, but doctors have been using genetics to assess risk of developing breast cancer for years. There are genetic tests that look for mutations of the BRCA 1 and BRCA 2 genes. Variations in these genes are linked to the rare and essentially purely genetic forms of breast cancer.
While detecting the BRCA variants is considered very valuable information to women with a family history of the disease, doctors and researchers knew genetics would one day play a bigger role in the remaining 95 percent of breast cancers. The deCODE BreastCancerTM test is aimed squarely at filling this gap, and to broadening the use of genetics in fight against breast cancer.
When a woman’s genome is scanned with deCODE BreastCancer, deCODE’s CLIA-registered laboratory checks for certain versions of seven single-letter variations in the genome, called SNPs. According to which versions are detected, that woman’s risk is then tallied, adding together the risk of each of the seven SNPs, to yield a score in relation to average risk, which is about 12% for American women of European origin. By multiplying the relative risk by the average, the results also provide a score of a woman’s absolute risk of developing breast cancer in her lifetime.
Depending upon a woman’s assessed risk, her doctor may suggest that she receive regular mammograms earlier than age 40, the standard starting age in the United States. If the test reveals a high risk, clinicians like Dr. Winsett might order a more advanced breast MRI or an ultrasound test for his patient. In some cases, high-risk patients with other contributing risk factors might start on a course of treatment to reduce the risk of tumors.
Decode’s breast cancer test is not a silver bullet. It won’t cure cancer. It measures risk and will be used in conjunction with other diagnostic tools and treatments to reduce the impact of the disease. But by using deCODE’s genetic test to find out which patients have a higher risk for the disease, says Dr. Winsett, earlier detection of breast cancer is possible.
“With the advent of deCODE’s breast cancer test we can intervene before the cancer happens. My hope is that we’ll see fewer breast cancers. I’m in business of dealing with breast lumps. I’m hoping this test can help reduce the breast lumps that I see.”