Table 2.
Comparison of p53 mutations in somatic mutation with proximal and distal colon and rectal tumors
| Proximal | Distal | Rectal | |||||
|---|---|---|---|---|---|---|---|
| N | (percent) | N | (percent) | N | (percent) | p-valuea | |
| Cases with p53 statusb | 725 | (100.0) | 698 | (100.0) | 954 | (100.0) | |
| p53 negative | 437 | (60.3) | 342 | (49.0) | 509 | (53.4) | |
| p53 positive | 288 | (39.7) | 356 | (51.0) | 445 | (46.7) | 0.01 |
| Total p53 mutationsc | 303 | (100.0) | 378 | (100.0) | 472 | (100.0) | |
| Missense | 232 | (76.6) | 283 | (74.9) | 368 | (78.0) | |
| Stop codon | 24 | (7.9) | 41 | (10.9) | 51 | (10.8) | |
| Frameshift | 32 | (10.6) | 29 | (7.7) | 33 | (7.0) | |
| In frame ins./del. | 8 | (2.6) | 12 | (3.2) | 10 | (2.1) | |
| Splice site | 7 | (2.3) | 13 | (3.4) | 10 | (2.1) | 0.48 |
| Transitions | 214 | (70.6) | 279 | (73.8) | 339 | (71.8) | |
| Transversions | 48 | (15.8) | 57 | (15.1) | 88 | (18.7) | |
| Inactivating | 41 | (13.5) | 42 | (11.1) | 45 | (9.5) | 0.07 |
| Non-CpG Island | 158 | (52.2) | 192 | (50.8) | 247 | (52.3) | |
| CpG Island | 145 | (47.9) | 186 | (49.2) | 225 | (47.7) | 0.91 |
| Non-hot spot | 192 | (63.4) | 224 | (59.3) | 314 | (66.5) | |
| R175 | 19 | (6.3) | 28 | (7.4) | 43 | (9.1) | |
| G245 | 8 | (2.6) | 16 | (4.2) | 21 | (4.5) | |
| R248 | 30 | (9.9) | 44 | (11.6) | 45 | (9.5) | |
| R273 | 36 | (11.9) | 51 | (13.5) | 35 | (7.4) | |
| R282 | 18 | (5.9) | 15 | (4.0) | 14 | (3.0) | 0.10 |
| p53 Location | |||||||
| Helix | 72 | (23.8) | 91 | (24.1) | 73 | (15.5) | |
| L3 loop | 60 | (19.8) | 84 | (22.2) | 113 | (23.9) | |
| L2 loop | 42 | (13.9) | 63 | (16.7) | 102 | (21.6) | |
| β sandwich | 47 | (15.5) | 39 | (10.3) | 65 | (13.8) | |
| Loop-sheet | 20 | (6.6) | 27 | (7.1) | 27 | (5.7) | |
| Other | 62 | (20.5) | 74 | (19.6) | 92 | (19.5) | 0.24 |
a
Mantel-Haenszel chi-squared test, compares differences for proximal and distal colon and rectal.
b
Negative (no mutations) or positive for one or more p53 mutations in exons 5-8.