Table 3.
Molecular features in The Cancer Genome Atlas colorectal and endometrial cancer cases by MSI subgroup.
| Somatic gene mutationa | All cases | Double somatic | Lynch syndrome | MLH1 Methyl | Microsatellite stable | p-valueb | |
|---|---|---|---|---|---|---|---|
| All cases (n=291) | n=291 | n=8 | n=8 | n=73 | n=202 | ||
| PIK3CA | 135 (46%) | 8 (100%) | 4 (50%) | 37 (51%) | 86 (43%) | 0.007 | |
| BRAF | 15 (5%) | 0 | 0 | 13 (18%) | 2 (1%) | <0.0001 | |
| KRAS | 79 (27%) | 2 (25%) | 4 (50%) | 24 (33%) | 79 (39%) | 0.22 | |
| NRAS | 10 (3%) | 0 | 0 | 3 (4%) | 7 (3%) | 0.85 | |
| PTEN | 147 (51%) | 8 (100%) | 4 (50%) | 56 (77%) | 79 (39%) | <0.0001 | |
| Colorectal cancer (n=113) | n=113 | n=2 | n=4 | n=17 | n=90 | ||
| PIK3CA | 34 (30%) | 2 (100%) | 1 (25%) | 7 (41%) | 24 (27%) | 0.09 | |
| BRAF | 14 (12%) | 0 | 0 | 12 (71%) | 2 (2%) | <0.0001 | |
| KRAS | 43 (38%) | 1 (50%) | 3 (75%) | 3 (18%) | 36 (40%) | 0.08 | |
| NRAS | 6 (5%) | 0 | 0 | 0 | 6 (7%) | 0.70 | |
| PTEN | 12 (11%) | 2 (100%) | 1 (25%) | 3 (18%) | 6 (7%) | 0.004 | |
| Endometrial cancer (n=178) | n=178 | n=6 | n=4 | n=56 | n=112 | ||
| PIK3CA | 101 (57%) | 6 (100%) | 3 (75%) | 30 (54%) | 62 (55%) | 0.13 | |
| BRAF | 1 (1%) | 0 | 0 | 1 (2%) | 0 | 0.37 | |
| KRAS | 36 (20%) | 1 (17%) | 1 (25%) | 21 (38%) | 13 (12%) | 0.0009 | |
| NRAS | 4 (2%) | 0 | 0 | 3 (5%) | 1 (1%) | 0.29 | |
| PTEN | 135 (76%) | 6 (100%) | 3 (75%) | 53 (95%) | 73 (65%) | <0.0001 |
MLH1 methyl = MLH1 hypermethylation
a
Only activating mutations in BRAF, KRAS, and NRAS are included in these analyses.
b
p-value from Fisher’s exact test