By uncovering a broader range of inherited genetic mutations, more widespread use of genetic testing could lead to more individualized cancer therapies, better detection and management of cancer within families and improved survival rates, scientists at the Mayo Clinic have found.
During a two-year study, Mayo Clinic provided free genetic testing and counseling to more than 3,000 patients at three of its locations as part of their standard cancer care. The testing included a broad mix of cancer stages and types – including breast, colorectal, lung, ovarian, pancreatic, bladder, prostate and endometrial cancers.
Currently, physicians use a set of standard guidelines to determine which patients with cancer should undergo genetic testing. However, the researchers were surprised to find that these guidelines could only identify 48% of the patients with an inherited genetic mutation, when compared with universal testing of the entire group.
“More than half of the patients who developed cancer due to inherited mutations were being missed, and that has major implications for family members,” said Dr. Niloy Jewel Samadder, a Mayo Clinic gastroenterologist and hepatologist who led the study.
In all, the scientists found that one in eight patients who participated in the study had an inherited cancer-related gene mutation, half of which would not have been detected using a standard guideline-based approach. Discovering these mutations led to changes in the management of their cancer for one-third of the patients with the highest-risk genes, including the type of surgery or chemotherapy they received.
“This targeted treatment would have been lost if the patients had not received genetic testing,” Samadder said. The study, called Interrogating Cancer Etiology Using Proactive Genetic Testing (INTERCEPT), was published in JAMA Oncology.