Table 2. Univariate and multivariate analyses of patient, tumor and DESCT characteristics with KRAS mutations.
| Variables | KRAS | Multivariate analysis+ | ||||
|---|---|---|---|---|---|---|
| Mutation | Wild type | P value | OR (95% CI) | P value | ||
| No. of patients | 13 | 83 | ||||
| Age (y) | 60.2±8.9 | 54.9±11.9 | 0.130 | |||
| Sex | 0.136 | |||||
| Female | 4 (30.8) | 44 (53.0) | ||||
| Male | 9 (69.2) | 39 (47.0) | ||||
| Smoking | 0.024 | |||||
| Never smoked | 4 (30.8) | 53 (63.9) | ||||
| Smoker | 9 (69.2) | 30 (36.1) | ||||
| Location | 0.363 | |||||
| Central | 0 (0.0) | 5 (6.0) | ||||
| Peripheral | 13 (100.0) | 78 (94.0) | ||||
| Maximum diameter* | 3.2±1.3 | 3.3±1.7 | 0.923 | |||
| DESCT quantitative parameter | ||||||
| CT value at 70 keV | 32.1±21.4 | 47.8±19.3 | 0.008 | |||
| IC | 9.7±6.3 | 14.7±6.8 | 0.014 | 2.075 (0.939–4.588) | 0.071 | |
| WC* | 1,008.6±18.8 | 1,012.6±16.9 | 0.645 | |||
| λHU slope | 1.1±0.8 | 1.7±0.8 | 0.014 | |||
| Effective-Z | 8.1±0.4 | 8.5±0.4 | 0.005 | 0.047 (0.005–0.440) | 0.032 | |
Numbers in parentheses are percentages. *, non-parametric two-sample K-S test for non-normally distributed continuous data. +, obtained by a logistic regression model with forward stepwise selection. P<0.05 indicates significant difference; significant P values are in italic. OR, odds ratio; 95% CI, 95% confidence interval; IC, iodine concentration; WC, water concentration; λHU slope, spectral Hounsfield unit curve slope; Effective-Z, effective atomic number.