Cohort characteristics for Lynch syndrome versus mismatch repair (MMR) proficient versus MMR-deficient cases
| MMR-proficient N=243 | Sporadic MMR-deficient carcinomas N=44 | Lynch syndrome N=20 | P value | ||
| Gender—male | 126 (51.9%) | 23 (52.3%) | 13 (65.0%) | 0.525 | |
| Mean age at diagnosis in years (range) | 66.6 (27–91) | 68.8 (43–90) | 54.6 (35–77) | <0.000 | |
| Location (%) | Duodenum | 126 (51.9%) | 26 (59.1%) | 12 (60.0%) | 0.893 |
| Jejunum | 51 (21.0%) | 7 (15.9%) | 3 (15.0%) | ||
| Ileum | 33 (13.6%) | 4 (9.1%) | 3 (15.0%) | ||
| Small bowel not otherwise specified | 33 (13.6%) | 7 (15.9%) | 2 (10.0%) | ||
| Previous history of Lynch syndrome-associated cancer* | 28 (11.5%) | 8 (18.2%) | 13 (65.0%) | <0.000 | |
| Previous history of other cancer type(s) (non-Lynch)† | 27 (11.1%) | 6 (13.6%) | 6 (30.0%) | 0.050 | |
| Crohn’s disease—yes | 8 (3.3%) | 0 (0%) | 0 (0%) | 0.339 | |
| Coeliac disease—yes | |||||
*Lynch syndrome-associated cancers: colorectal cancer, endometrial cancer, ovarian cancer, gastric cancer, cancer of the bile duct or gallbladder, pancreatic cancer or urothelial cancer (Møller et al 22).
†Excluding basal cell cancer of the skin.