Table 1.
Characteristics of Patients With Stage IV Colon Cancer Stratified by Occurrence of BOa
| No. (%) of Patients | P Valueb | |||
|---|---|---|---|---|
| Overall (N = 12 553) | No BO (n = 11 549) | BO (n = 1004) | ||
| Patient Characteristics | ||||
| Age at diagnosis, y | ||||
| 65–69 | 1928 (15.4) | 1734 (15.0) | 194 (19.3) | .01 |
| 70–74 | 2933 (23.4) | 2617 (22.7) | 316 (31.5) | |
| 75–79 | 3064 (24.4) | 2810 (24.3) | 254 (25.3) | |
| ≥80 | 4628 (36.9) | 4388 (38.0) | 240 (23.9) | |
| Sex | ||||
| Male | 5645 (45.0) | 5192 (45.0) | 453 (45.1) | .19 |
| Female | 6908 (55.0) | 6357 (55.0) | 551 (54.9) | |
| Race | ||||
| White | 10 505 (83.7) | 9662 (83.7) | 843 (84.0) | .87 |
| Black | 1266 (10.1) | 1170 (10.1) | 96 (9.6) | |
| Other/unknown | 782 (6.2) | 717 (6.2) | 65 (6.5) | |
| Marital status | ||||
| Married | 6162 (49.1) | 5599 (48.5) | 563 (56.1) | .75 |
| Unmarried | 6032 (48.1) | 5616 (48.6) | 416 (41.4) | |
| Unknown | 359 (2.9) | 334 (2.9) | 25 (2.5) | |
| Charlson Comorbidity Index | ||||
| 0c | 8254 (65.8) | 7553 (65.4) | 701 (69.8) | .45 |
| 1 | 2489 (19.8) | 2298 (19.9) | 191 (19.0) | |
| ≥2 | 1810 (14.4) | 1698 (14.7) | 112 (11.2) | |
| Presenting Features and Treatment | ||||
| Year of diagnosis | ||||
| 1991–1995 | 3512 (28.0) | 3195 (27.7) | 317 (31.6) | .051 |
| 1996–2000 | 3549 (28.3) | 3250 (28.1) | 299 (29.8) | |
| 2001–2005 | 5492 (43.8) | 5104 (44.2) | 388 (38.6) | |
| Obstruction at presentation | ||||
| No | 10 879 (86.7) | 10 049 (87.0) | 830 (82.7) | <.001 |
| Yes | 1674 (13.3) | 1500 (13.0) | 174 (17.3) | |
| Primary tumor resection | ||||
| No | 3627 (28.9) | 3435 (29.7) | 192 (19.1) | <.001 |
| Yes, without perforation | 8628 (68.7) | 7841 (67.9) | 787 (78.4) | |
| Yes, with perforation | 298 (2.4) | 273 (2.4) | 25 (2.5) | |
| Chemotherapyd | ||||
| No | 7375 (58.8) | 7021 (60.8) | 354 (35.3) | .16 |
| Yes | 5178 (41.2) | 4528 (39.2) | 650 (64.7) | |
| Tumor Characteristics | ||||
| Cancer site | ||||
| Left | 4541 (36.2) | 4167 (36.1) | 374 (37.3) | <.001 |
| Right | 6999 (55.8) | 6425 (55.6) | 574 (57.2) | |
| NOS | 1013 (8.1) | 957 (8.3) | 56 (5.6) | |
| Tumor histological type | ||||
| Nonmucinous | 10 811 (86.1) | 9989 (86.5) | 822 (81.9) | <.001 |
| Mucinous | 1742 (13.9) | 1560 (13.5) | 182 (18.1) | |
| Tumor grade | ||||
| Low | 7052 (56.2) | 6473 (56.0) | 579 (57.7) | <.001 |
| High | 3486 (27.8) | 3204 (27.7) | 282 (28.1) | |
| Unknown | 2015 (16.1) | 1872 (16.2) | 143 (14.2) | |
| Lymph node stage | ||||
| N0 | 1827 (14.6) | 1658 (14.4) | 169 (16.8) | <.001 |
| N1 | 2783 (22.2) | 2544 (22.0) | 239 (23.8) | |
| N2 | 3885 (30.9) | 3533 (30.6) | 352 (35.1) | |
| Missing | 4058 (32.3) | 3814 (33.0) | 244 (24.3) | |
Abbreviations: BO, bowel obstruction; 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. Percentages have been rounded and may not total 100.
b
Calculated from univariable Cox proportional hazards models of obstruction.
c
Includes 0.5% of the population with missing comorbidity information.
d
Defined as a claim for chemotherapy before BO or death.