P0332 - Assessing Multidisciplinary Provider Perspectives and Practice Patterns in Germline Genetic Testing in Patients With Newly Diagnosed Colorectal Cancer in the Universal Testing Era

Nghiem B. Ha, MD, MAS¹, Zoe Memel, MD¹, Amy Yu, MD¹, Chelsea Xu, MD¹, Nathan Alhalel, MD¹, Margaret Osha, BS², Laurel Hochsteler, LCGC, MS², Amie M. Blanco, MS, CGC², Najwa El-Nachef, MD¹, Aparajita Singh, MD, MPH^1
1University of California, San Francisco, San Francisco, CA; ²Cancer Genetics and Prevention Program, University of California, San Francisco, CA

Introduction: Lynch syndrome, accounting for 3% of diagnosed colorectal cancer (CRC), often goes undiagnosed in 90-95% of affected individuals. To address this, the National Comprehensive Cancer Network (NCCN) recently recommended universal germline genetic testing for all newly diagnosed CRC patients. We aim to explore providers' perspectives and practice preferences regarding germline genetic testing in this population.

Methods: We surveyed faculty from various specialties, including gastroenterology (GI), GI oncology, colorectal surgery, and genetic counselor, at a tertiary academic medical center. The survey consisted of 16 questions to assess providers' perspectives and practice preferences using Likert scale and free-response format.

Results: Survey response rates: 60% GI (9/15), 100% GI oncology (7/7), 100% colorectal surgery (6/6), and 100% genetic counselors (10/10) with years since training as 1-3 (41%), 4-6 (22%), 7-9 (9%), and >10 (28%). While most providers (66%) were familiar with NCCN germline genetic testing criteria, the majority of colorectal surgery (67%) and GI oncology (100%) providers reported that < 10% of CRC patients meeting genetic testing criteria had available pre-consultation germline testing (Figure). Half of colorectal surgeons (50%) would consider alternative surgery based on specific genetic mutations (e.g., extended colectomy for MLH1/MSH2 mutation or simultaneous total hysterectomy and/or bilateral salpingo-oophorectomy to non-childbearing/post-menopausal women for Lynch syndrome). All GI oncologists deemed microsatellite instability/DNA mismatched repair results important for treatment decisions. Genetic counselors preferred GI providers (60%) as the primary ordering source for germline genetic testing at CRC diagnosis, followed by GI oncology (30%) and colorectal surgery (10%). All providers recognized the importance of standardized evaluations, including staging imaging, tumor markers, and germline genetic testing, to ensure consistency in care.

Discussion: Prior to universal genetic testing for CRC susceptibility syndrome, most colorectal surgeons and GI oncologists reported limited access to germline testing results at the initial consultation, which would have influenced their surgical/non-surgical plan of care. The shift towards universal testing emphasizes the need for standardized evaluations and integrating genetic screening into CRC management, particularly with GI providers initiating genetic testing at CRC diagnosis to facilitate guideline implementation.



Disclosures:


Nghiem B. Ha, MD, MAS¹, Zoe Memel, MD¹, Amy Yu, MD¹, Chelsea Xu, MD¹, Nathan Alhalel, MD¹, Margaret Osha, BS², Laurel Hochsteler, LCGC, MS², Amie M. Blanco, MS, CGC², Najwa El-Nachef, MD¹, Aparajita Singh, MD, MPH¹. P0332 - Assessing Multidisciplinary Provider Perspectives and Practice Patterns in Germline Genetic Testing in Patients With Newly Diagnosed Colorectal Cancer in the Universal Testing Era, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.