Identifying clinical applications of genetic and genomic profiling for individuals with breast, colorectal, and thyroid cancer has the potential to transform the surgical management of these oncologic diseases, according to panelists presenting during the Genetics and Genomics in Cancer Surgery for the General Surgeon session Tuesday morning.
Approximately 10% to 15% of cancer is hereditary, with possibly higher rates for rare cancers. “Testing of affected family members is the most revealing,” said panelist Judy E. Garber, MD, MPH, chief of the Division for Cancer Genetics and Prevention at the Dana-Farber Cancer Institute in Boston, Massachusetts, referring to an individual’s predisposition or susceptibility to cancer.
Within the context of oncologic patient care, genetics provides an understanding of the DNA, RNA, and microRNA that are altered for specific diseases. “Genetic profiling can be used to understand an individual’s likelihood of developing specific kinds of cancer, and it can be used to better diagnose tumors and determining treatment for those patients,” said Jennifer E. Rosen, MD, FACS, regional chief of endocrine surgery at MedStar Washington Hospital Center in Washington, DC.
Genomic testing, on the other hand, focuses on mutations that occur within the cancer cells due to external factors (e.g., smoking) or internal factors, including molecular alterations within the cells. Tumors have their own genomic makeup, and in certain cases, identifying genomic variability may help determine targeted therapies.
Panelists outlined specific queries that genetic and genomic profiling can address depending on the type of cancer. For breast and thyroid cancers, profiling can help determine who should be treated and how aggressively; for colorectal cancer, profiling is fundamentally used to understand what caused the cancer.
However, the key to integrating genetics into the practice of modern medical oncology begins with improved patient education and access to genetic testing. Dr. Garber cited a study published in the Journal of the American Medical Association (JAMA) in June 2023 that revealed only 6.8% of more than 1 million patients with cancer underwent germline genetic testing—an analysis of inherited genes—within 2 years of diagnoses.
According to the JAMA study, even patients with cancer types with higher testing rates, including male breast, ovarian, and female breast, were not tested as often as guidelines recommend.
Dr. Garber encouraged physicians to seek out the advice of genetic counselors to help communicate the testing process and potential results to patients.
