Background: Colorectal cancer (CRC) affects approximately 104,000 patients (pts) annually in the United States, up to 45% of which are estimated to be genetic and/or familial. Aligned with clinical guidelines, in 2020, a large U.S. insurer established Medical Policy allowing for and reimbursing germline genetic testing (GGT) for all CRC pts. This study reports overall uptake of GGT in CRC pts under this inclusive policy, actionable findings and treatment implications for pts tested, stratified by self-reported ancestry/ethnicity. Methods: Two independent de-identified datasets were reviewed, including administrative claims data of commercially insured and Medicare Advantage enrollees, aged 18+ with CRC (≥1 claim with ICD10 C18, C19 or C20 in the first position) who were continuously enrolled (CE) in the health plan from 1/2019-10/2020. Evidence of genetic testing based on CPT codes, was examined during 2020. A second de-identified dataset of CRC pts whose GGT was billed to the insurer under the Medical Policy, was also reviewed. Patient demographics, clinical information and GGT results were descriptively analyzed. Results: Of the >18,000,000 CE enrollees, 55,595 were identified as CRC pts, of whom 1,675 (3%) received GGT. From the GGT dataset, 788 pts had test results available for review. 143 (18%) pts had pathogenic/likely pathogenic (P/LP) variants in genes including MSH2,MLH1, PMS2, MSH6, CHEK2, APC, BRCA2, ATM, MUTYH (biallelic). Of pts with P/LP variants, 96 (67%) were potentially eligible for precision therapy and/or clinical treatment trials. Overall, 133 (93%) had P/LP variants in genes with precision therapy, clinical trial and/or published management implications. In a subset of pts (n=674) with ethnicity data; Asian, Black/African-American and Hispanic pts showed lower relative uptake of germline testing than Caucasians (Table). Conclusions: Despite Medical Policy allowing for GGT for all pts with CRC, only 3% of eligible pts received testing. If all CRC pts had been tested, these data suggest up to 6,705 pts with P/LP variants conferring potential eligibility for precision therapy (PD-1/PD-L1 inhibitors) or clinical treatment trials (PARP inhibitors), and an additional 2,602 pts with mutations in genes with published management recommendations, could have been identified, but were missed. Additional research is needed to identify obstacles to systematic implementation of this Medical Policy, the best timing of GGT to prevent CRC and improve access to underrepresented populations. CRC patients with germline genetic testing.

VUS - variant of uncertain significance.