Table 2.
MRI features and clinical characteristics of patients with rectal cancer(n=158)
| Factors | Total (No./values) | KRAS Status | P-value | |
|---|---|---|---|---|
| Wild-type (n=98) |
Mutant (n=60) |
|||
| Age | 60.66±13.38 | 60.42±12.89 | 61.07±14.26 | 0.388 |
| Gender | 0.769 | |||
| Male | 106 | 66(67.35%) | 40(66.67%) | |
| Female | 52 | 32(32.65%) | 20(33.33%) | |
| ADC (×10-3mm2/ms ) | 1.22±0.39 | 1.37±0.37 | 1.15±0.38 | 0.008* |
| Texture features | ||||
| Mean | 66.47±14.55 | 62.66±10.53 | 73.34±18.38 | <0.0001 |
| Variance | 289.19±118.96 | 267.65±122.51 | 334.39±94.27 | <0.0001 |
| Skewness | 0.54±0.67 | 0.43±0.53 | 0.73±0.42 | <0.0001 |
| Entropy | 1.89±0.23 | 1.80±0.19 | 1.97±0.14 | <0.0001 |
| RLUN | 178.38±65.19 | 159.87±53.38 | 208.12±69.14 | <0.0001 |
| GLUN | 7.53±3.44 | 6.55±2.83 | 9.26±3.33 | <0.0001 |
| Tumor location | ||||
| Upper Rectum | 48 | 33(33.67%) | 15(25.00%) | 0.095 |
| Middle Rectum | 72 | 47(47.96%) | 25(41.67%) | |
| Lower Rectum | 38 | 18(18.37%) | 20(33.33%) | |
| Tumor shape | 0.022 | |||
| Intraluminal polypoid mass | 40 | 31(31.63%) | 9(15.00%) | |
| Ulcerofungating/Ulceroinfiltrative mass | 95 | 57(58.16%) | 38(63.33%) | |
| Bulky | 23 | 10(10.20%) | 13(21.67%) | |
| Tumor length(cm) | 4.12±1.68 | 4.04±1.62 | 4.25±1.78 | 0.446* |
| Tumor type | 0.556 | |||
| Mucinous adenocarcinoma | 23 | 13(13.27%) | 10(16.67%) | |
| Non-mucinous adenocarcinoma | 135 | 85(86.73%) | 50(83.33%) | |
| Cirumferential extent | 0.872** | |||
| C1 | 6 | 4(4.08%) | 2(3.33%) | |
| C2 | 56 | 36(36.73%) | 20(33.33%) | |
| C3 | 56 | 34(34.69%) | 22(36.67%) | |
| C4 | 40 | 24(24.49%) | 16(26.67%) | |
| Radiologic T stage | 0.029 | |||
| T1-2 | 49 | 35(35.71%) | 14(23.33%) | |
| T3 | 94 | 58(59.18%) | 36(60.00%) | |
| T4 | 15 | 5(5.10%) | 10(16.67%) | |
| T3 substage | 0.041 | |||
| T3a | 23 | 19(32.76%) | 4(11.11%) | |
| T3b | 36 | 23(39.66%) | 13(36.11%) | |
| T3c | 23 | 11(18.97%) | 12(33.33%) | |
| T3d | 12 | 5(8.62%) | 7(19.44%) | |
| MEMD(cm) | 0.30±0.60 | 0.30±0.60 | 0.50±0.60 | 0.028* |
| N stage | 0.754 | |||
| N0 | 74 | 48(48.98%) | 26(43.33%) | |
| N1 | 51 | 31(31.63%) | 20(33.33%) | |
| N2 | 23 | 19(19.39%) | 14(23.33%) | |
| EMVI | 0.664 | |||
| Positive | 34 | 20(20.41%) | 14(23.33%) | |
| Negative | 124 | 78(79.59%) | 46(76.67%) | |
| CRM | 0.337 | |||
| Positive | 38 | 28(28.57%) | 13(21.67%) | |
| Negative | 120 | 70(71.43%) | 47(78.33%) | |
Abbreviations: ADC apparent diffusion coefficient, MEMD the maximal extramural depth of tumour; EMVI extramural vascular invasion, CRM circumferential resection margin, RLNU run-length nonuniformity, GLNU grey-level nonuniformity
*independent samples t test, data is mean ± standard deviation;Δ Mann-Whitney U test, data is data is median ± interquartile range. **Considering limited patients’ numbers in subgroups of circumferential extent, reclassification was adopted as follows: C1-2, C3, and C4, and P value was the result of new categorization