Current scientific research suggests that about 10% of cancers are caused by genetic mutations. Your individual risk for some hereditary cancers can be determined by genetic testing. Although not all genetic causes for all types of cancer have been identified, we are certain several gene changes, or mutations such as BRCA2 mutations, passed down from parent to child can increase a person’s risk of developing cancer. These changes are known as hereditary cancer syndromes.
You may wish to learn more about your risk for hereditary cancers if you have a strong family history of cancer or if you come from a line of ancestry in a high-risk ethnic group, such as the Ashkenazi Jewish population. For them, genetic testing for the type of cancer can make a lot of sense.
Understanding your genetic cancer risk not only helps you plan for your future health but also the health of your children or future children. As mutations in your DNA have been passed down to you, you will pass the same cancer genetics, and your risk for hereditary cancers, to the next generation if you choose to have children. A person with a strong family history of certain types of cancers may want to learn if they carry a gene mutation that increases their risk of cancer.
If you are considering genetic testing for cancer screening, we strongly recommended you consider speaking with a professional trained in genetics before deciding. The professionals can include doctors, genetic counselors, and other health care providers. Genetic counseling can help you consider the healthcare risks, benefits, and limitations of genetic testing in their particular situation. Sometimes the genetic professional finds that testing is not needed.
How Does Genetic Testing for Cancer Work?
Genetic testing is simple and relatively affordable. Your doctor will collect a small blood sample and send it to a laboratory. In less than 2 weeks, you should receive your test results. You can discuss your genetic test results with a genetic counselor, who can provide more information about your risk of cancer and risk assessment for your children, and talk with you about your next healthcare steps.
Most health insurance companies cover 90% of costs for genetic testing, and payment plans may be available for some patients.
What Can Genetic Testing for Cancer Tell Me?
If you have a family medical history of breast, ovarian, uterine, or endometrial cancer, your gynecologist might recommend genetic testing for cancer to assess your risk.
Genetic information can tell you if you carry one or more of the genetic mutations that have been strongly linked to cancer. A positive result does NOT tell you that you have cancer, or that you definitely will develop cancer. It can also help other family members decide if they want to be tested for the gene mutation. However, it does mean that you are at an increased risk.
Genetic Testing for Breast and Ovarian Cancer
Studies have indicated that about 7% of breast cancers and 10-15% of ovarian cancers are caused by mutations in the BRCA mutation, BRCA1 or BRCA2 genes. If you are a carrier of one or both of these genetic mutations, then your doctor may diagnose you with a condition known as Hereditary Breast and Ovarian Cancer (HBOC) Syndrome, and possibly related cancers, such as pancreatic cancer.
Men with these gene mutations have an increased risk of male breast cancer as well, especially if the BRCA2 gene is affected, and possibly of prostate cancer. Many inherited cases of breast cancer have been associated with mutations in these genes.
Patients with HBOC syndrome have an 87% risk of breast cancer and a 63% chance of developing ovarian cancer by age 70. By undergoing genetic testing, you and your doctor can better understand your risk for breast and ovarian cancer and take early steps to delay or prevent cancer.
Genetic Testing for Lynch Syndrome
Lynch syndrome, also known as Hereditary Non-polyposis Colorectal Cancer (HNPCC), is a genetic condition that is strongly linked to uterine, endometrial, and colorectal cancers. Lynch syndrome is caused by mutations in the EPCAM, MLH1, MSH2, MSH6, and PMS2 genes.
Lynch syndrome is also associated with a higher risk for developing ovarian, stomach, pancreatic, renal, urinary tract, biliary tract, small bowel, and brain cancers. Additionally, many patients with Lynch syndrome develop benign tumors in the skin’s oil glands, called sebaceous adenomas.
What Happens if I Test Positive for a Cancerous Genetic Mutation?
If you receive a positive test result, it means that you are at an increased risk of developing cancer. Your gynecologist will discuss with you some ways in which you can decrease your risk, delay, or prevent the development of cancer. Your doctor may refer you to an oncologist for specialized cancer care treatment.
Generally, doctors rely on the tested family member to share the genetic information with their relatives so that family members will know that a genetic condition has been identified. Then, each family member should make their own decision regarding whether or not to be tested to learn if they are also at risk of developing cancer.
Some treatment options your oncologist may recommend include:
- Early and frequent screenings for breast, ovarian, uterine, and other cancers associated with your mutation.
- Cancer risk-reducing medication, known as chemoprevention
- Surgical removal of the affected tissue, such as a mastectomy or hysterectomy, before the onset of cancer.