Genetic research is leading to a brave new world of personalized healthcare. It is giving us the tools to predict the likelihood of developing a particular disease and to determine in advance whether a medication will be more or less effective. This is well illustrated in my area of specialization, breast cancer care.
While the majority of breast cancer cases occur by chance, often influenced by lifestyle and environment, we now know that up to 10 percent of all breast cancers can be attributed to specific genetic mutations that change how our cells work. For example, the most common causes of hereditary breast cancer are linked to mutations in the BRCA 1 and BRCA 2 genes, which can be inherited from either parent.
The BRCA genes are tumor suppressors and work to prevent cancer from developing. In the presence of a BRCA mutation, there is less protection. Women who inherit a mutation in either of these genes have an increased risk of developing breast and ovarian cancer, while men have an increased risk of breast cancer and possibly prostate cancer.
More recently, researchers have identified another genetic abnormality linked to an increased risk of developing breast cancer. A study published this past August in the New England Journal of Medicine found that mutations in the PALB2 gene can make breast cancer five to nine times more likely to develop depending on an individual’s age. According to researchers, women with a PALB2 mutation appear to have a 14 percent chance of developing breast cancer by age 50 and a 35 percent chance by age 70.
Many other genes are thought to play a role in developing breast cancer. Through research, our goal is to develop better testing tools that can diagnose breast cancer earlier when it is easier to treat.
Similarly, advances in pharmacogenetics are also allowing us to provide more tailored care by predicting how patients will respond to certain drug treatments. Today we can individualize treatment for breast cancer on the basis of certain molecular signatures within a tumor, such as the overexpression of the HER2 receptor.
As a medical oncologist and the son of a breast cancer survivor, I’m heartened by the ongoing research that promises to bring us new drugs and therapies to target the specific genetic abnormalities that cause certain cancers. This research could lead to treatments with better success rates and fewer side effects.
The first step to personalized breast cancer care is for the patient to discuss her family history with her doctor. If a hereditary cancer risk is suspected, the doctor can make the determination if a referral to a genetic counselor for consultation and testing is appropriate. The patient can then decide whether or not she wants to learn if an abnormal gene linked to higher breast cancer risk is present. Genetic testing might also be used to determine if a woman previously diagnosed with breast cancer is at an increased risk for a breast cancer recurrence or the development of ovarian cancer.
At Cleveland Clinic Florida, high-risk women can be tested to screen for mutations in the BRCA genes as well as PALB2. Recognized for our state-of-the-art treatment capabilities, Cleveland Clinic Florida’s Breast Center has earned a three-year/full accreditation designation from the National Accreditation Program for Breast Centers (NAPBC) by the American College of Surgeons. Our team of breast care specialists also provides a range of treatment options for patients who have been diagnosed with breast cancer: surgery, radiation, hormone therapy, chemotherapy, and clinical trials, among others.
