Your genetic makeup ― half from your mother and half from your father ― is responsible for your hair and eye color. Yet it’s more than curious exploration of your family tree. Today, up to 15 percent of cancers are tied to a hereditary link. Knowing about them may help you prevent or reduce your risk of cancer.
February is National Cancer Prevention Month. To save lives, the experts at Baptist Health’s Lynn Cancer Institute and Miami Cancer Institute would like to raise awareness of the value of genetic assessment and testing.
Scientists have identified many mutations that increase the risk for breast and gynecologic cancers, colon cancer, some gastro-intestinal cancers, kidney cancer and more. And because the field of genetics moves at a rapid pace, discoveries may impact everything from guidelines for cancer screenings to treatment options for those who have cancer.
Information is Key
“The more accurate our information, the better our guidance on prevention,” says Louise Morrell, M.D., a cancer genetics specialist and medical director of Lynn Cancer Institute. “In genetics, unlike other areas, the benefit extends to family members and perhaps for generations to come.”
Researchers have worked for decades on uncovering the link between genetic mutations and cancer, but public knowledge grew when actress Angelina Jolie had her breasts removed in 2013, and then her ovaries in 2015, because she carried the BRCA1 gene mutation that is linked to a higher risk of breast and ovarian cancer. The same BRCA1 and BRCA2 mutations that raise the risk of breast cancer in women, also raise the odds of breast cancer in men by eight times, according to the American Cancer Society, and increase the chances of prostate cancer.
Ms. Jolie’s mother, grandmother and aunt had died from cancer, and her decision to prophylactically remove her breasts, ovaries and fallopian tubes to lower her cancer risk came after multiple tests and conversations with experts. In addition to Ms. Jolie’s public sharing of her story, technological advances have made it possible to test for more genes, sped up testing and made it less expensive. The answers from genetic testing can also help drive treatment and surgery decisions in someone already diagnosed with cancer.
Where Your Genes Come From
It’s not only your mother’s history you must be aware of, however, says Arelis Mártir-Negrόn, M.D., medical geneticist and head of the Clinical Genetics program at Miami Cancer Institute. “As many men pass down mutations as women. That means you should be as aware of your father’s family’s cancer history as your mother’s. Know your family history. Ask questions.”
All people inherit two copies of each gene: one from their mother and one from their father. Variations in genes are normal and are what give us our diversity. Thinking of genetics as a recipe, may help some people better understand, genetic counselors say. A slight change in the recipe may not make much of a difference, but the wrong ingredient or too much or too little of something, may change the recipe drastically.
Two articles published recently in the New England Journal of Medicine highlight the risk of cancer associated with specific genes tested in large populations. The research is important, says Dr. Morrell, because not every gene mutation carries the same risk. “A BRCA mutation might lead to an 80 percent risk of breast cancer but an ATM mutation might have a 20 percent lifetime risk,” she says. “These are very different, which is why having this information is so valuable.”
The genetic teams at Lynn Cancer Institute and Miami Cancer Institute offer multidisciplinary care to patients ― and often their family members who may also be affected ― to better understand their risks, help them determine if genetic testing would be beneficial, and assist them with understanding the results, whether they are positive, negative or inconclusive.
The team also develops personalized cancer prevention plans for “previvors,” the term used for those with a predisposition to cancer. The plans could include lifestyle changes, such as specific diet, exercise and stress reduction recommendations, or lead a discussion about medication options or even preventive surgery.
Who should consider cancer genetic assessment?
In addition to seeing more men ― who don’t often come for genetic assessment and sometimes don’t understand the implications for their family members ― the doctors would especially like people to consider assessment if they:
- Have had cancer themselves
- Have an early age of onset for cancer in their family
- Have a family member with multiple types of cancer
- Have a family tree with multiple cancers, especially on one side or the other
- Are a member of certain ancestry groups with higher rates of some genetic mutations, including those of Eastern European Jewish descent.
Couples who have a family history of cancer and are considering pregnancy also frequently take advantage of genetic assessment. “If you really want to be able to tell your children they are not at risk to have a particular mutation, you need to test both parents,” Dr. Morrell says. “The offspring can only inherit a mutation that the parents have. Mutations do not skip a generation and move from grandparent to grandchild without the parent inheriting it.”
For more information on genetic assessment, testing and counseling at the Morgan Pressel Center for Cancer Genetics at Lynn Cancer Institute, click here; for information on Miami Cancer Institute’s Clinical Genetics program, click here.