I am a Certified Genetic Counselor by training and Director of the Texas Oncology Genetic Risk Evaluation and Testing (GREAT) Program. Genetic counselors are healthcare professionals with specialized training in medical genetics and counseling. Genetic counselors work as members of a healthcare team, providing information and support to families who have members with genetic disorders and to families who may be at risk for a variety of inherited conditions.
I think of myself as an educator, a translator and a support person for families with a hereditary disease. I help families take closer looks at their family trees, determine if genetic testing is right for them and interpret the often-complex results so that they can take proactive steps in their healthcare plans. In my role at Texas Oncology, I also help to educate other healthcare providers on the importance of genetic counseling and testing.
Cancer is a group of diseases that can occur in any place in the body. Cancer starts when cells grow out of control and crowd out normal cells. All cancers are genetic, but only some cancers are hereditary or inherited.
Cancer is caused by changes or mutations in certain types of genes, especially in those that control how cells grow and divide. As we live our lives, we can acquire mutations in our DNA, most of which occur by chance or due to environmental exposures. If a gene that is responsible for cell growth acquires a mutation, then that gene no longer works and cells will grow uncontrollably. This is cancer.
The majority of cancers happen by chance; but about 5-10 percent of all people are actually born with a mutation in an important gene that can lead to an increased risk for certain cancers.
Individuals who have a hereditary cancer syndrome are born with a mutation in a gene that is critical to cancer development. Because the gene doesn’t work correctly, these individuals and their family members tend to be diagnosed at younger ages and have more cancers.
It’s very important to know if a person has a hereditary predisposition to cancer because they can take steps to help prevent cancers or find them earlier. For example, individuals with a mutation in a BRCA1 or BRCA2 gene have increased risks for breast cancer, ovarian cancer, prostate cancer, pancreatic cancer and melanoma. If we know a woman has these increased risks, we can consider starting surveillance at younger ages and performing multiple types, such as breast MRIs in addition to mammograms.
In addition, we can consider medications or preventative surgeries that reduce risk. For example, if a woman has a high risk for ovarian cancer, she may consider an oophorectomy or a removal of her ovaries after childbearing is complete.
Recommendations for surveillance, medications and surgeries depend on the underlying gene mutation and its associated cancer risks. While BRCA1 and BRCA2 are the most well recognized cancer genes, there are many others now that we can test for and design surveillance and prevention plans to stay ahead of!
Most of the time cancer is NOT hereditary. In fact, only about 5-10 percent of all cancers are hereditary. While it is very important to know if a family has a hereditary predisposition to certain cancer types, most cancer occurrences are sporadic. The World Health Organization estimates that 30-50 percent of all cancer cases are preventable.
Both genes and the environment are important to determining a person’s risk for cancer. If you have a significant personal or family history of cancer, then you should talk to your healthcare provider about a referral for genetic evaluation. Genetic evaluations include reviews of both genetic and environmental risk factors as well as discussions about genetic testing options. After your genetic testing is complete, a surveillance plan would be made based on your results and family history. The goal of genetic testing is cancer prevention.
If you do NOT have a family history of cancer, you still should talk to your healthcare provider about ways to reduce your risk for cancer and screening options. Given that most cancer is sporadic, all people should be offered routine surveillance for certain cancers.
For examples of those with average risk, colonoscopy screening for colon cancer should begin around age 45 and continue every 10 years while mammography screenings for breast cancer should begin annually around age 40. Your healthcare provider can help you determine when to start screening and what the best route is for you based on individual risk factors such as age, family history and environment.
Changes in lifestyle can be used to modify risk for cancer. For example, smoking cessation can reduce the risk for many types of cancers including lung, head and neck, and bladder cancers. Other lifestyle factors that are believed to reduce the risk for cancers are a healthy weight, being physically active, a diet rich in whole grains, fruits, vegetables and beans, limiting processed foods and red meat, limiting alcohol, protecting your skin from the sun and considering preventative vaccines against the HPV virus. Scheduling screenings in accordance with recommendations is also the most effective tool available for identifying cancers in their earliest stages — often before symptoms are experienced — when they are the most treatable.
*Gayle Patel, MS, CGC, is a certified genetic counselor and director of the Genetic Risk Evaluation and Testing (GREAT) Program at Texas Oncology in Austin.