Table 1.
Characteristic | No. (%) |
---|---|
Sex | |
Male | 204 (45) |
Female | 253 (55) |
Race | |
White | 382 (84) |
Black/African American | 11 (2) |
Hispanic | 7 (2) |
Asian | 16 (4) |
Native American | 1 (<1) |
Middle Eastern | 4 (1) |
Other | 3 (1) |
Missing/unknown | 33 (7) |
Cancer history | |
1 CRC only | 389 (85) |
1 CRC + other cancer(s) | 34 (7) |
Synchronous/metachronous CRCs only | 26 (6) |
Synchronous/metachronous CRCs + other cancer(s) | 8 (2) |
Site of colorectal cancer | |
Right colon | 121 (26) |
Left colon | 105 (23) |
Rectum | 149 (33) |
Appendix | 7 (2) |
Missing/unknown | 75 (16) |
MSI and MMR IHC statusa | |
MSI-H and/or abnormal MMR IHC | 47 (10) |
MSS/MSI-L and/or normal MMR IHC | 279 (61) |
Missing tumor testing data | 131 (29) |
Prior genetic testing results (Lynch genes and/or MUTYH)b | |
Prior genetic testing of ≥1 Lynch genes | 162 (35) |
Negative result for MLH1 testing | 142 (31) |
MLH1 VUS detected | 12 (3) |
Negative result for MSH2 testing | 129 (28) |
MSH2 VUS detected | 2 (<1) |
Negative result for MSH6 testing | 40 (9) |
MSH6 VUS detected | 2 (<1) |
Negative result for PMS2 testing | 22 (5) |
PMS2 VUS detected | 1 (<1) |
Negative result for MUTYH testing | 387 (85) |
Monoallelic MUTYH mutation detected | 10 (2) |
MUTYH VUS detected | 0 |
Recruitment method | |
Population-based | 314 (69) |
Clinic-based | 143 (31) |
Abbreviations: CRC, colorectal cancer; MSI, microsatellite instability; MMR IHC, mismatch repair immunohistochemistry testing; MSI-H, high-level microsatellite instability; MSI-L, low-level microsatellite instability; MSS, microsatellite stable; VUS, variant of uncertain significance.
No participants had discordant MSI and MMR IHC results.
Rows are not mutually exclusive; numerous participants had prior genetic testing for more than 1 gene.