Clinical and molecular characteristics of GI malignancies exhibiting MTAP loss as compared with MTAP unaltered GI tumours from the TCGA PanCancer Atlas Studies
| MTAP loss | MTAP unaltered | P value | |
| No of patients | 128 | 1224 | |
| Median age (IQR) | 63 (56–72) | 66 (57–74) | 0.151 |
| Sex (%) | 0.039 | ||
| Male | 89 (69.5) | 730 (59.6) | |
| Female | 39 (30.5) | 462 (40.2) | |
| NA | 0 (0.0) | 2 (0.2) | |
| Cancer type (%) | <0.001 | ||
| Gastro-oesophageal | 78 (60.9) | 534 (43.6) | |
| Pancreatic | 40 (31.3) | 138 (11.3) | |
| Colorectal | 6 (4.7) | 520 (42.5) | |
| Biliary | 4 (3.1) | 32 (2.6) | |
| Tumour histology (%) | <0.001 | ||
| Adenocarcinoma | 95 (74.2) | 1002 (81.9) | |
| Mucinous adenocarcinoma | 2 (1.6) | 75 (6.1) | |
| Signet ring carcinoma | 4 (3.1) | 80 (6.5) | |
| Squamous carcinoma | 27 (21.1) | 67 (5.5) | |
| Stage at diagnosis (%) | 0.495 | ||
| Non metastatic | 82 (64.1) | 931 (76.1) | |
| Metastatic | 12 (9.4) | 103 (8.4) | |
| NA | 34 (36.2) | 190 (15.5) | |
| Tumour mutational burden* (median (IQR)) | 2.5 (1.6–4.1) | 3.3 (2.07–5.3) | <0.001 |
| Microsatellite instability† (%) | 1 (0.8) | 164 (13.4) | <0.001 |
| CDKN2A/B loss (%) | 125 (97.7) | 57 (8.1) | <0.001 |
| TP53 mutant (%) | 84 (65.6) | 703 (57.4) | 0.044 |
| KRAS mutant (%) | 41 (32.0) | 332 (27.1) | 0.253 |
| BRAF V600E mutant (%) | 1 (0.8) | 48 (3.9) | 0.080 |
| APC mutant (%) | 6 (7.1) | 435 (35.5) | <0.001 |
| ERBB2 amplification | 21 (16.4) | 92 (7.5) | 0.001 |
*Nonsynonymous TMB.
†According to the MANTIS score with a threshold of 0.4.
GI, gastrointestinal; MANTIS, Microsatellite Analysis for Normal-Tumor InStability; NA, not available; TCGA, The Cancer Genome Atlas; TMB, Tumour mutational burden.