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 al22).
†Excluding basal cell cancer of the skin.