June 11, 2024
Researchers within the cancer precision genomics program at Mayo Clinic Comprehensive Cancer Center are refining germline testing using a hair follicle DNA extraction method, an innovation especially important for hematologic malignancies. Effective in identifying hereditary cancer predispositions, this technique was validated in a study of 144 patients with germline predisposition syndromes. Mayo Clinic Laboratory Medicine and Pathology has secured the College of American Pathologists (CAP) accreditation and Clinical Laboratory Improvement Amendments (CLIA) certification for this method, underscoring its potential to revolutionize oncological germline testing.
"In addition to improving patient care and reducing costs, the faster approach increases the efficiency of testing processes, allowing for quicker decision-making in treatment plans."
In hematologic malignancies, blood samples are unreliable for testing hereditary predispositions because blood is affected by the cancer and no longer represents germline DNA. Traditional germline testing for blood cancers involves extracting DNA from skin biopsies — a process fraught with complications such as infection and bleeding risks, especially problematic in patients with low blood counts typical of hematologic disorders. Additionally, this method is costly and time-consuming, with results taking up to seven weeks.
DNA extraction from hair follicles offers a better alternative to DNA extraction from skin biopsy. The less invasive nature of hair follicle DNA extraction, requiring only about 20 follicles, improves patient care standards by reducing discomfort, risk and procedural complexity. Using hair follicles also expedites the extraction process and reduces cost, providing results in a shorter time with significant cost savings.
"In addition to improving patient care and reducing costs, the faster approach increases the efficiency of testing processes, allowing for quicker decision-making in treatment plans," says Mrinal S. Patnaik, M.B.B.S., a hematologist-oncologist at Mayo Clinic Comprehensive Cancer Center in Rochester, Minnesota, and a key researcher in this development. For example, rapid germline testing can identify whether related donors for allogeneic stem cell transplant carry the same risk for hematologic malignancies, minimizing the risk for donor-derived leukemias.
Dr. Patnaik highlights the importance of this advancement: "There are increasing data to suggest that maybe even 1 in 5 patients who have cancer have a hereditary predisposition. This underlines the critical need for germline testing as part of our cancer precision genomics program."
Clinical validation of hair follicle DNA extraction for germline testing
Mayo Clinic's DNA extraction technique using hair follicles has demonstrated efficacy against the traditional skin biopsy method. Researchers have been working to enhance quality and extraction techniques, and Mayo Clinic Laboratory Medicine and Pathology has been clinically validated with CAP/CLIA certification for this hair follicle DNA extraction technique.
Details on validating the efficacy of hair follicle DNA extraction against skin biopsy DNA extraction were published in the November 2021 issue of American Journal of Hematology.
Expanding access and improving outcomes in precision medicine
The vision for the future involves distributing kits to patients for at-home hair follicle collection before their visits to the clinic, simplifying the process further and enhancing patient compliance and convenience. "This method has the potential to revolutionize germline testing for hematologic disorders," says Dr. Patnaik. "If we can have patients collect and send their samples in advance, we can enhance their level of care."
Looking ahead, Mayo Clinic aims to expand this testing to all patients at the Cancer Center, particularly those diagnosed with advanced cancers. The integration of this hair follicle-based DNA extraction method represents a leap forward in the field of precision medicine, making germline testing more accessible and efficient. Mayo Clinic is dedicated to enhancing diagnostic processes and improving patient care.
For more information
St. Martin E, et al. Spectrum of hematological malignancies, clonal evolution and outcomes in 144 Mayo Clinic patients with germline predisposition syndromes. American Journal of Hematology. 2021;96:1450.
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