Table 2. . Multivariable Cox regression analysis for overall survival.
| Characteristics | Overall survival | |
|---|---|---|
| HR (95% CI) | p-value | |
| KRAS status | ||
| KRAS mutated | Ref | |
| KRAS wildtype | 0.92 (0.89–0.95) | <0.001 |
| Gender | ||
| Male | Ref | |
| Female | 0.96 (0.94–0.99) | 0.011 |
| Age at diagnosis | ||
| <50 years | Ref | |
| 50–69 years | 1.07 (1.03–1.12) | 0.001 |
| ≥70 years | 1.30 (1.23–1.38) | <0.001 |
| Race and ethnicity | ||
| Non-Hispanic white | Ref | |
| Non-Hispanic black | 0.97 (0.93–1.02) | 0.20 |
| Hispanics | 0.74 (0.69–0.78) | <0.001 |
| Other/unknown | 0.94 (0.89–0.99) | 0.038 |
| Comorbidity score | ||
| 0 | Ref | |
| 1 | 1.06 (1.02–1.10) | 0.004 |
| 2+ | 1.17 (1.10–1.25) | <0.001 |
| Facility type | ||
| Academic | Ref | |
| Nonacademic | 1.19 (1.15–1.22) | <0.001 |
| Unknown | 1.12 (1.04–1.20) | 0.002 |
| Travel distance | ||
| <12.5 miles | Ref | |
| 12.5–49.9 miles | 0.94 (0.90–0.97) | <0.001 |
| ≥50 miles | 0.84 (0.80–0.89) | <0.001 |
| Unknown | 0.95 (0.68–1.31) | 0.74 |
| Income | ||
| <$40,227 | Ref | |
| $40,227–50,353 | 0.95 (0.91–0.99) | 0.037 |
| $50,354–63,332 | 0.96 (0.92–1.00) | 0.075 |
| ≥$63,333 | 0.91 (0.87–0.95) | <0.001 |
| Unknown | 1.07 (0.94–1.23) | 0.29 |
| Insurance status | ||
| Private | Ref | |
| Uninsured | 1.22 (1.14–1.29) | <0.001 |
| Medicaid | 1.14 (1.09–1.20) | <0.001 |
| Medicare | 1.18 (1.13–1.23) | <0.001 |
| Other government/unknown | 1.09 (0.99–1.20) | 0.08 |
| Rurality | ||
| Metropolitan | Ref | |
| Non-metropolitan | 1.09 (1.04–1.14) | <0.001 |
| Unknown | 1.05 (0.95–1.15) | 0.36 |
| Tumor side | ||
| Right | Ref | |
| Left | 0.68 (0.66–0.71) | <0.001 |
| Unspecified | 0.94 (0.88–1.00) | 0.05 |
| Chemotherapy | ||
| Yes | Ref | |
| No | 2.47 (2.36–2.58) | <0.001 |
| Unknown | 1.21 (1.09–1.34) | <0.001 |
| Radiotherapy | ||
| Yes | Ref | |
| No | 1.08 (1.03–1.14) | 0.001 |
| Unknown | 0.85 (0.69–1.05) | 0.14 |
| Surgery | ||
| Yes | Ref | |
| No | 2.10 (2.04–2.17) | <0.001 |
| Unknown | 1.12 (0.94–1.33) | 0.22 |
| Interaction term of age and KRAS status | <0.001 | |
| Age (<50 vs 50–69)* KRAS status (KRAS mutated vs KRAS wildtype) | 1.14 (1.06–1.23) | 0.001 |
| Age (<50 vs ≥70)* KRAS status (KRAS mutated vs KRAS wildtype) | 1.20 (1.10–1.30) | <0.001 |
HR: Hazard ratio.