Author Credentials

Alex R. Jones MD

Submission Type

Original Research


Introduction: Defined germline mutations contribute to 5% to 10% of cases of colorectal carcinoma (CRC). While protocols for universal tumor screening have been adopted to detect mismatch repair (MMR) protein deficiency, widespread multigene panel testing has not been achieved. Barriers to implementing testing protocols may occur in community settings.

Methods: A total of 160 patients presenting for surgical management of CRC between 2011 and 2020 were considered for retrospective analysis in a single-surgeon, single-institution, community-based cohort. The rate of multigene panel testing and prevalence of germline mutations were calculated, and patient characteristics were assessed.

Results: A total of 32/160 (20%) patients underwent multigene panel testing, with 14/160 (9%) patients having germline mutations. While 88% of patients underwent panel testing after CRC diagnosis, 43% of these patients would have met testing criteria before diagnosis. Among the patients meeting criteria before diagnosis, 50% were found to carry a germline mutation.

Discussion: The prevalence of germline mutations was similar to previously reported values, while the rate of multigene panel testing was higher than previously reported. These results may be unique to the study setting or result from multidisciplinary conference discussion. A significant number of patients with abnormal panel testing were not tested before CRC diagnosis, despite meeting the criteria. This finding represents a missed opportunity for risk stratification and underscores the importance of addressing testing barriers in the primary care setting.

Conclusions: Primary care providers and oncologists in community hospitals must remain cognizant of changing guidelines as multigene panel testing becomes increasingly available.



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