Table 5.

CGA-IGC recommendations for individuals who should be considered for multigene panel testing for evaluation of hereditary colorectal cancer and/or polyposis

Individuals who should undergo multigene panel testinga
Colorectal cancer diagnosed age < 50 yearsb
Multiple Lynch syndrome primary tumorsb,c
Colorectal cancerb and at least one first degree relative with colorectal or endometrial cancer
PREMM5 score ≥ 2.5% or MMRpro or MMRpredict score ≥ 5%
Mismatch repair-deficient colorectal cancer, not attributed to MLH1 promoter methylation
Patients meeting any other genetic testing criteria [4, 6]
≥ 10 cumulative colorectal adenomas
≥ 3 cumulative gastrointestinal hamartomatous polypsd

^aIn some instances, the individual affected with colorectal cancer/polyposis is unavailable for testing. In this case, genetic testing should be offered to any first-degree relative (FDR) with a family history meeting these criteria. Consideration can be given to testing second-degree relatives with a family history meeting these criteria when the affected family member and FDRs are unavailable to be tested

^bIrrespecitve of microsatellite instability (MSI)/immunohistochemistry (IHC) status

^cColorectal cancer, endometrial cancer, ovarian cancer, urothelial cancer, small bowel cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, sebaceous carcinoma, glioblastoma

^dIncluding hamartomas, ganglioneuromas, Peutz-Jeghers polyps, and/or juvenile polyps