Table 1.
Clinical, pathological, and molecular characteristics according to let-7a expression in 795 colorectal cancer tissues
|
let-7a expression
|
||||||
|---|---|---|---|---|---|---|
| Characteristica | Total (795) | Q1 (198) | Q2 (199) | Q3 (199) | Q4 (199) | Pb |
| Age | ||||||
| Mean ± SD (year) | 68.6 ± 8.7 | 69.3 ± 8.5 | 69.1 ± 8.9 | 67.7 ± 8.6 | 68.4 ± 8.7 | 0.26 |
| Sex | 0.49 | |||||
| Men | 348 (44%) | 86 (43%) | 94 (47%) | 89 (45%) | 79 (40%) | |
| Women | 447 (56%) | 112 (57%) | 105 (53%) | 110 (55%) | 120 (60%) | |
| BMI (kg/m2) | 0.30 | |||||
| <25 | 317 (40%) | 78 (40%) | 87 (44%) | 83 (42%) | 69 (35%) | |
| 25–30 | 315 (40%) | 75 (38%) | 81 (41%) | 78 (39%) | 81 (41%) | |
| >30 | 161 (20%) | 44 (22%) | 31 (16%) | 37 (19%) | 49 (25%) | |
| Year of diagnosis | 0.01 | |||||
| Prior to 1998 | 374 (47%) | 85 (43%) | 113 (57%) | 91 (46%) | 85 (43%) | |
| 1998 to 2008 | 421 (53%) | 113 (57%) | 86 (43%) | 108 (54%) | 114 (57%) | |
| Family history of colorectal cancer | 0.82 | |||||
| Absent | 631 (80%) | 155 (79%) | 156 (78%) | 157 (80%) | 163 (82%) | |
| Present | 161 (20%) | 42 (21%) | 43 (22%) | 40 (20%) | 36 (18%) | |
| Tumor location | 0.38 | |||||
| Cecum | 139 (17%) | 35 (18%) | 40 (20%) | 33 (17%) | 31 (16%) | |
| Ascending to transverse colon | 251 (32%) | 62 (31%) | 51 (26%) | 72 (36%) | 66 (33%) | |
| Splenic flexure to sigmoid | 223 (28%) | 53 (27%) | 58 (29%) | 48 (24%) | 64 (32%) | |
| Rectosigmoid and rectum | 179 (23%) | 47 (24%) | 50 (25%) | 45 (23%) | 37 (19%) | |
| No. of negative lymph nodes | 0.42 | |||||
| Median (interquartile range) | 7 (0–12) | 7.5 (0–14) | 7 (2–11) | 6 (0–12) | 7 (0–12) | |
| Disease stage | 0.10 | |||||
| I | 183 (24%) | 52 (28%) | 52 (28%) | 41 (22%) | 38 (20%) | |
| II | 242 (32%) | 70 (37%) | 58 (31%) | 60 (32%) | 54 (29%) | |
| III | 221 (30%) | 48 (26%) | 54 (29%) | 61 (33%) | 58 (31%) | |
| IV | 104 (14%) | 18 (10%) | 24 (13%) | 25 (13%) | 37 (20%) | |
| Tumor differentiation | 0.65 | |||||
| Well to moderate | 721 (91%) | 183 (93%) | 179 (90%) | 181 (91%) | 178 (89%) | |
| Poor | 73 (9%) | 14 (7%) | 20 (10%) | 18 (9%) | 21 (11%) | |
| MSI status | 0.37 | |||||
| MSI-low/MSS | 648 (85%) | 162 (86%) | 164 (84%) | 155 (82%) | 167 (88%) | |
| MSI-high | 116 (15%) | 27 (14%) | 31 (16%) | 35 (18%) | 23 (12%) | |
| CIMP status | 0.34 | |||||
| Low/negative | 595 (82%) | 144 (84%) | 154 (81%) | 148 (80%) | 149 (82%) | |
| High | 132 (18%) | 28(16%) | 35 (19%) | 36 (20%) | 33 (18%) | |
| BRAF mutation | 0.04 | |||||
| (−) | 650 (84%) | 166 (88%) | 173 (88%) | 155 (80%) | 156 (81%) | |
| (+) | 122 (16%) | 23 (12%) | 23 (12%) | 38 (20%) | 38 (19%) | |
| KRAS mutation | 0.56 | |||||
| (−) | 459 (60%) | 114 (60%) | 109 (56%) | 121 (63%) | 115 (60%) | |
| (+) | 308 (40%) | 76 (40%) | 85 (44%) | 70 (37%) | 77 (40%) | |
| PIK3CA mutation | 0.52 | |||||
| (−) | 595 (83%) | 155 (86%) | 143 (80%) | 152 (83%) | 145 (82%) | |
| (+) | 123 (17%) | 25 (14%) | 35 (20%) | 31 (17%) | 32 (18%) | |
| LINE-1 methylation level | 0.63 | |||||
| Mean ± SD (%) | 62.2 ± 9.3 | 62.0 ± 8.0 | 61.7 ± 9.6 | 62.1 ± 9.5 | 62.9 ± 10.0 | |
Percentage indicates the proportion of cases with a specific clinical, pathological, or tumor molecular feature in patients with each expression level of let-7a. There were cases that had missing values for any of the characteristics except for age, sex and year of diagnosis.
To assess associations between the ordinal categories (first to fourth quartile) of let-7a expression and categorical data, the chi-square test was performed. To compare mean age and mean LINE-1 methylation levels, the analysis of variance was performed. We adjusted two-sided α level to 0.003 (= 0.05/15) by simple Bonferroni correction.
BMI, body mass index; Q1 to Q4, quartile 1 (lowest) to quartile 4 (highest); SD, standard deviation.