Table 2.
Multivariable Cox Proportional Hazards Regression Analysis of Association Between BO and Clinical and Tumor Characteristics in 12 553 Patients With Stage IV Colon Cancera
| Adjusted HR (95% CI) | P Value | |
|---|---|---|
| Presenting Features and Treatment | ||
| Age at diagnosis, y | ||
| 65–69 | 1 [Reference] | .01 |
| 70–74 | 1.17 (0.98–1.39) | |
| 75–79 | 1.05 (0.87–1.26) | |
| ≥80 | 0.88 (0.73–1.06) | |
| Year of diagnosis | ||
| 1991–1995 | 1 [Reference] | .047 |
| 1996–2000 | 0.97 (0.83–1.14) | |
| 2001–2005 | 0.84 (0.72–0.98) | |
| Obstruction at diagnosis | ||
| No | 1 [Reference] | <.001 |
| Yes | 1.75 (1.47–2.04) | |
| Tumor Characteristics | ||
| Cancer site | ||
| Left | 1 [Reference] | .01 |
| Right | 1.22 (1.07–1.40) | |
| NOS | 1.08 (0.80–1.46) | |
| Histological type | ||
| Nonmucinous | 1 [Reference] | .004 |
| Mucinous | 1.27 (1.08–1.50) | |
| Tumor grade | ||
| Low | 1 [Reference] | <.001 |
| High | 1.34 (1.16–1.55) | |
| Unknown | 1.48 (1.19–1.83) | |
| Lymph node stage | ||
| N0 | 1 [Reference] | <.001 |
| N1 | 1.10 (0.90–1.34) | |
| N2 | 1.52 (1.26–1.84) | |
| Unknown | 1.89 (1.52–2.35) | |
Abbreviations: BO, bowel obstruction; HR, hazard ratio; NOS, not otherwise specified.
a
Data are calculated from the Surveillance, Epidemiology, and End Results and Medicare claims linked databases from January 1, 1991, through December 31, 2005.