Genetic testing can identify gene variants (that is, specific mutations) linked to inheritable forms of cancer. However, faulty genes inherited from parents only contribute to 5% of all cancers, and this occurs only in certain types of cancer. Even if someone has the faulty gene, it doesn’t guarantee that they will develop cancer, but the risks are significantly greater.
Lifestyle, environmental factors, and random genetic mutations always contribute to an individual’s likelihood of developing cancer, even in cases of inherited cancer types.
Genetic testing, however, provides valuable information that can help individuals make informed decisions about their health, such as pursuing additional screenings or preventive measures.
Three different approaches to test for cancer risk.
If a highly heritable cancer runs in your family, it’s crucial to get tested. There are three different assessments available, each evaluating risk in their own way. All three are useful in determining your likelihood of developing cancer.
- Predisposition testing uses genetic tests to find specific mutations associated with cancer risk. Breast and ovarian cancers are prime examples of heritable cancers that can be detected through this type of testing.
- Risk stratification assessment places patients into low, medium, or high-risk categories. This is based on various information and observations, such as lifestyle, family history, access to resources, or a history of chronic illnesses. Stratification may or may not involve genetic testing.
- Early detection strategies aim to identify symptoms to make an early diagnosis. These strategies may involve blood tests, physical exams, scans, and biopsies. Education is also an essential component of early detection.
Certain cancers are highly inheritable:
- Breast and ovarian cancers (mutations in BRCA1 or BRCA2 genes)
- Melanoma (mutations in CDKN2A, MITF or CDK4 genes)
- Colorectal cancer, adenomatous polyposis (mutations in APC or MUTYH genes)
- Colorectal cancer, nonpolyposis (mutations in MLH1, MSH2, MSH6, PMS2 or EPCAM genes)
- Neurofibromatosis type II (mutations in the NF2 gene)
- Retinoblastoma (mutations in the RB1 gene)
- Multiple endocrine neoplasia type 1 (mutations in the MEN1 gene)
Genetic testing reveals cancer risk, but isn’t diagnostic.
Imagine genetic predisposition testing for cancer risk as a smoke detector. It does not tell you if a fire is already burning (cancer diagnosis), but it can alert you to a situation (genetic predisposition) that increases your risk of a fire (cancer development). Risk stratification assessments and early detection strategies are like having a fire extinguisher readily available to address the potential fire.
