What is genetic testing for cancer?
Current scientific research suggests that about 10% of cancers are caused by genetic mutations. Your risk for some hereditary cancers can be determined by genetic testing.
Although doctors haven’t identified all the genetic causes for all types of cancer, we do know some of them. Several gene changes — 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. If you have a strong family history of cancer or if you come from a high-risk ethnic group, you may wish to learn more about your risk for hereditary cancers. In these cases, genetic testing for your potential hereditary type of cancer can make a lot of sense.
Understanding your genetic cancer risk
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 inherited 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 recommend you consider speaking with a professional trained in genetics — such as a genetic counselor — before deciding.
Genetic counseling can help you consider the healthcare risks, benefits, and limitations of genetic testing in your particular situation. Sometimes, genetic testing is not needed.
How does genetic testing for cancer work?
Genetic testing is simple (usually a blood test) and relatively affordable. The doctor will collect a small blood sample and send it to a laboratory. In less than two 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 steps. Most health insurance companies cover 90% of the 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, or uterine cancer, our gynecologist might give you a referral for cancer genetic testing to assess your risk factors.
Genetic information can tell you if you carry one or more of the genetic mutations that have been strongly linked to these gynecological cancers. A positive result does NOT tell you that you have cancer or that you definitely will develop cancer. It just means you are at an increased risk.
Testing negative for a gene mutation does not mean that you will never get cancer. Your testing results can also help other family members decide if they want to be tested for the gene mutation.
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 BRCA1, or BRCA2 “cancer genes.” If you are a carrier of one or both BRCA genetic mutations, then your doctor may diagnose you with a condition known as Hereditary Breast and Ovarian Cancer (HBOC) Syndrome.
Men with these gene mutations have an increased risk of male breast cancer as well — especially if the BRCA2 gene is affected — and possibly an increased risk of prostate cancer. 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 can better understand your risk 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 colon cancers. Lynch syndrome is caused by mutations in the EPCAM, MLH1, MSH2, MSH6, or PMS2 genes.
Lynch syndrome is also associated with a higher risk of developing ovarian, stomach, renal, urinary tract, biliary tract, small bowel, brain, and pancreatic 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 have an increased cancer risk. For breast and gynecological cancers, Dr. Aliabadi will discuss ways in which you can decrease your risk, delay, or prevent the development of cancer.
Generally, doctors rely on the tested family member to share the genetic information with their relatives, so that family members will know 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.
What does a negative result mean?
If a genetic test result is negative, it means no mutations were found in the genes tested. For families with a known gene mutation, a negative result can be reassuring, but it doesn’t eliminate cancer risk entirely — it simply means your risk is similar to the general population.
Family members with negative test results might feel guilty if others test positive. Genetic counselors can help you interpret these results and manage any emotional responses. In families without a known mutation, a negative result indicates that the specific mutation tested for isn’t present.
However, it doesn’t rule out other undetected mutations or those not yet discovered. Despite a negative result, your family history might still suggest a higher cancer risk, so detailed discussions with your healthcare provider are essential to understand your risk and next steps.
What are the benefits of genetic testing for cancer?
Genetic testing for cancer can alleviate anxiety by providing clarity about potential risks. For individuals with inherited cancer, it can lead to tailored cancer treatments based on identified genetic changes and mutations.
Furthermore, those with the same hereditary mutation, including healthy family members, can collaborate with healthcare providers on preventive measures. Additionally, individuals with inherited cancer types can take steps to avoid passing the mutation to their biological children.
Want to know more about your cancer risk? Talk to Dr. Aliabadi
As a breast cancer survivor herself, Dr. Aliabadi understands the importance of knowing your cancer risk and having the necessary information to advocate for your own health.
When you’re treated by Dr. Aliabadi and her warm, caring team, you’re guaranteed to feel safe, heard, and well cared for.
We invite you to establish care with Dr. Aliabadi. Please make an appointment online or call us at (844) 863-6700.
The practice of Dr. Thais Aliabadi and the Outpatient Hysterectomy Center is conveniently located for patients throughout Southern California and the Los Angeles area. We are near Beverly Hills, West Hollywood, Santa Monica, West Los Angeles, Culver City, Hollywood, Venice, Marina del Rey, Malibu, Manhattan Beach, and Downtown Los Angeles.
Sources
National Cancer Institute. Cancer Genetics Overview (PDQ®)–Health Professional Version. 2022. Accessed at https://www.cancer.gov/publications/pdq/information-summaries/genetics/overview-hp-pdq
U.S. Food & Drug Administration. Direct-to-Consumer Tests. 2019. Accessed at https://www.fda.gov/medical-devices/in-vitro-diagnostics/direct-consumer-tests
Kurian AW, Abrahamse P, Furgal A, et al. Germline genetic testing after cancer diagnosis. JAMA 2023; 330(1):43–51. [PubMed Abstract]
Retrospective Cohort Study on the Limitations of Direct-to-Consumer Genetic Screening in Hereditary Breast and Ovarian Cancer. JCO Precision Oncology 2023; 7:e2200695. [PubMed Abstract]
Supported by her warm professional team, Dr. Aliabadi treats women through all phases of life and cherishes the special one-on-one relationship between patient and doctor.