By Michelle Oswald
Genetic Counseling Services Coordinator, Armes Family Cancer Care Center

Genetic counseling and testing play a critical role in the diagnosis, treatment, and prevention of cancer. As our understanding of the genetic basis of cancer has advanced over the years, it is clear that inherited genetic mutations contribute to an increased risk of developing certain types of cancer. Genetic counseling and testing can help identify individuals with these mutations, guiding both patients and healthcare providers in making informed medical decisions.

Approximately 10% of cancers are hereditary, meaning they are caused by inherited gene mutations. Some of the most well-known inherited cancer syndromes include the breast cancer gene (BRCA1 and Some of the most well-known inherited cancer syndromes include mutations in the breast cancer genes (BRCA1 and BRCA2), which are linked to breast and ovarian cancers. Another common inherited syndrome is Lynch syndrome, which is associated with colorectal and endometrial cancers. Identifying these genetic mutations early can help predict cancer risk not only for the individual but also for their family members, who may share the same genetic predisposition.

Genetic testing can impact treatment decisions for cancer patients. Certain therapies are more effective in patients with specific genetic mutations. For instance, poly ADP-ribose polymerase (PARP) inhibitors are particularly beneficial in patients with BRCA mutations. In colorectal cancer, mismatch repair deficiency, often found in Lynch syndrome mutations, can predict response to immunotherapy. Thus, genetic information can personalize treatment, improving outcomes and avoiding unnecessary treatments.

Additionally, genetic testing can help prevent secondary cancers. If a patient is found to have a hereditary cancer syndrome, they can be monitored more closely for the development of additional cancers. Preventative measures such as prophylactic surgery, lifestyle changes, or regular screening can then be initiated.

The process of genetic testing begins with a consultation with a genetic counselor, a healthcare professional with specialized training in providing support to individuals and families facing who are considering genetic testing. The genetic counselor will perform a detailed assessment of the patient's personal and family medical history. This evaluation helps determine the likelihood of a hereditary cancer syndrome. They then explain the risks, benefits, and limitations of genetic testing, ensuring that the patients can make informed decisions about undergoing testing.

If testing is pursued, a simple blood or saliva sample is taken and analyzed in a laboratory for specific gene mutations associated with cancer. The results are interpreted in the context of the patient's medical and family history. Genetic counselors then explain the results, whether positive, negative, or uncertain, and help the patient understand their implications.

When a mutation is identified, a care plan is developed in collaboration with oncologists and other providers. This plan may include targeted therapies, additional screenings, risk-reducing surgeries, or family member testing. Even if no mutation is found, the information provided in the genetic test can still guide future surveillance based on overall risk factors.

Genetic counseling and testing are vital tools in the management of cancer. They can provide critical information about the underlying causes of the disease, influence treatment decisions, and give patients and families the knowledge about their health risks. As cancer care continues to move toward more personalized approaches, early identification of genetic risk can not only improve outcomes for individuals already diagnosed with cancer but also prevent cancer in at-risk family members, which can save lives.