January 16, 2019 by Laura Pincus and Patty Shillington
Cancer Prevention and Genetic Testing: Deciphering the Facts
Do you have a history of breast cancer in your family? That’s a question that many women cannot answer concisely, if at all.
At Miami Cancer Institute, certified genetic counselors and a physician clinical geneticist help individuals understand the complexities and potential benefits of genetic testing. They also clarify how the results can be used in a treatment plan or to prevent cancer from developing. The Miami Cancer Institute operates the Division of Clinical Genetics, which is part of its Center for Genomic Medicine.
Developments in the genetics realm of cancer research is breaking at a rapid pace. Just this month, researchers from 300 institutions around the world announced the discovery of 72 previously unknown gene mutations that can lead to the development of breast cancer. The two studies that comprised the research were published Oct. 23 in Nature and Nature Genetics. Researchers found that 65 of the newly identified genetic variants are common in women with breast cancer.
In response such publicized advances in this field of cancer research, there definitely has been a significant increase in people interested in clinical genetics, according to Arelis Martir-Negron, M.D., clinical geneticist with Miami Cancer Institute, and Jessica Ordonez, a certified genetic counselor with the Institute. Most of the individual referrals come from breast surgeons, oncologists, gynecologists (GYN) and GYN-oncologists, primary care physicians and cancer survivors who are interested in determining if their genetics could increase their risk of developing other types of cancers.
By the time Dr. Martir-Negron and the genetic counseling team speak to a patient about genetic testing, that individual likely already qualifies for the labwork necessary to determine if cancer was part of his or her family history.
The Jolie Effect
In 2013, actress Angelina Jolie brought genetic testing into the global spotlight after sharing her personal story. Jolie’s mother died of ovarian cancer at age 56. Jolie also had multiple people with breast cancer in her family. After testing positive for a BRCA1 mutation, putting her at high risk of developing breast and ovarian cancer, Jolie opted to have a preventive double mastectomy and — two years later — a preventive operation to remove her ovaries. Specific inherited mutations in BRCA1 and BRCA2 (human genes that produce tumor-suppressor proteins when working properly) increase the risk of female breast and ovarian cancers, and they have been associated with increased risks of several additional types of cancer.
Even those who underwent genetic testing in 2012 or earlier can now benefit from advances in technology and a broader range of genetic testing options that can advance cancer prevention options or treatment, say Dr. Martir-Negron and Ms. Ordonez.
“Genetics is a difficult subject to address,” explains Dr. Martir-Negron. “When someone gets to us, we already know if they qualify for genetic testing. We go over pros and cons. Some clearly understand. Some want to know more. People see in the news about genetic testing. They’ve read about Angelina Jolie. As long as they understand the implications, we feel comfortable in moving forward.”
What exactly are the implications if, for example, a women carries a mutation in the BRCA1 or BRCA2 genes? According to the National Cancer Institute, part of the National Institutes of Health, about 12 percent of women in the general population, or 1 in 8, will develop breast cancer sometime during their lives. By contrast, according to the most recent and strongest scientific data, 72 percent of women who inherit a BRCA1 mutation and about 69 percent of women who inherit a BRCA2 mutation will develop breast cancer, with a cumulative risk to age 80. Overall, research shows that about 10 percent of cancers are hereditary.
Cancer Prevention Strategies
“Germline tests assess the cause of a person’s cancer diagnosis, as well as predict the risk of developing a specific type of cancer in the future,” says Ms. Ordonez. “Germline testing is the bread and butter of the Division of Clinical Genetics and results have a large impact on cancer prevention strategies.”
However, both Dr. Martir-Negron and Ms. Ordonez caution patients that having tested positive for a gene mutation is NOT a guarantee that a person will develop cancer. “Your risk of developing breast cancer with a BRCA mutation is higher, but many won’t develop cancer,” says Dr. Martir-Negron.
One of the key takeaways from a genetic counseling session is that cancer carries many risk factors, of which genetics is just one. Beyond a family history, other risk factors for breast cancer include lifestyle factors, such as obesity or being overweight, lack of exercise, smoking and drinking alcohol.
Non-lifestyle factors include race and ethnicity, pregnancy history, menstrual history, and using hormone replacement therapy.
“Even if you carry a mutation, that doesn’t mean you have to have a bilateral mastectomy (as in the case of Ms. Jolie),” says Dr. Martir-Negron. “That’s a very important decision between patient and doctor. We don’t want people coming here and thinking that a genetic history will result in cancer. This is about prevention. There is something you can do about risk factors and there are other screening recommendations for many cancers.”
Embrace Tomorrow by Getting Your Mammogram Today
When breast cancer is detected early, at a localized stage, the survival rate is 98 percent. Baptist Health South Florida is committed to changing the future of cancer care with Miami Cancer Institute, a world-class cancer center offering the most advanced technology with renowned cancer experts dedicated to the physical and emotional well-being of patients. In conjunction with National Breast Cancer Awareness Month, Baptist Health is offering special mammogram pricing in October to patients without insurance. Through October 31, 2017, a screening mammogram is $50, and a diagnostic mammogram is $100. The radiologist’s fee for 3D mammogram is included in the special prices. To schedule an appointment, call 786-573-6000 in Miami-Dade or Broward, 305-434-1588 in Monroe, or visit BaptistHealth.net/BreastHealth.