Background
Materials and methods
Data source
Eligibility criteria
Study variables
Comorbidities
Statistical analysis
Results
Overall comparison of the BO and non-BO groups
Patient characteristics | Overall (N%) | No BO (N%) | BO (N%) |
---|---|---|---|
Gender | |||
Male | 5293 (44.8%) | 3831 (44.0%) | 1462 (47.1%) |
Female | 6521 (55.2%) | 4879 (56.0%) | 1642 (52.9%) |
Age at diagnosis, years | |||
66–70 | 1525 (12.9%) | 966 (11.1%) | 559 (18.0%) |
71–75 | 1975 (16.7%) | 1296 (14.9%) | 679 (21.9%) |
76–80 | 2342 (19.8%) | 1617 (18.6%) | 725 (23.4%) |
> 80 | 5972 (50.6%) | 4831 (55.5%) | 1141 (36.8%) |
Race | |||
White | 9421 (79.7%) | 6945 (79.7%) | 2476 (79.8%) |
Black | 1566 (13.3%) | 1185 (13.6%) | 381 (12.3%) |
Asian | 372 (3.1%) | 244 (2.8%) | 128 (4.1%) |
Other | 455 (3.9%) | 336 (3.9%) | 119 (3.8%) |
Marital status | |||
Single + separated | 1358 (11.5%) | 1023 (11.7%) | 335 (10.8%) |
Married | 4441 (37.6%) | 3015 (34.6%) | 1426 (45.9%) |
Divorced + widowed | 5296 (44.8%) | 4073 (46.8%) | 1223 (39.4%) |
Other | 719 (6.1%) | 599 (6.9%) | 120 (3.9%) |
Residence location* | |||
Big metro | 6750 (57.2%) | 4869 (55.9%) | 1881 (60.6%) |
Metro or urban | 3814 (32.3%) | 2886 (33.1%) | 928 (29.9%) |
Less urban or rural | 1247 (10.6%) | 952 (10.9%) | 295 (9.5%) |
Median household income | |||
1st quartile | 2781 (23.5%) | 2094 (24.0%) | 687 (22.1%) |
2nd quartile | 2791 (23.6%) | 2058 (23.6%) | 733 (23.6%) |
3rd quartile | 2786 (23.6%) | 2037 (23.4%) | 749 (24.1%) |
4th quartile | 2791 (23.6%) | 2015 (23.1%) | 776 (25.0%) |
Unknown | 665 (5.6%) | 506 (5.8%) | 159 (5.1%) |
Level of education | |||
1st quartile | 2770 (23.4%) | 2032 (23.3%) | 738 (23.8%) |
2nd quartile | 2817 (23.8%) | 2068 (23.7%) | 749 (24.1%) |
3rd quartile | 2798 (23.7%) | 2061 (23.7%) | 737 (23.7%) |
4th quartile | 2762 (23.4%) | 2043 (23.5%) | 719 (23.2%) |
Unknown | 667 (5.6%) | 506 (5.8%) | 161 (5.2%) |
Year of diagnosis | |||
1992–1996 | 1228 (10.4%) | 758 (8.7%) | 470 (15.1%) |
1997–2001 | 1999 (16.9%) | 1478 (17.0%) | 521 (16.8%) |
2002–2005 | 3752 (31.8%) | 2796 (32.1%) | 956 (30.8%) |
2006–2009 | 4835 (40.9%) | 3678 (42.2%) | 1157 (37.3%) |
Tumor characteristics | |||
T category | |||
Tis | 595 (5.0%) | 491 (5.6%) | 104 (3.4%) |
T1 | 2054 (17.4%) | 1662 (19.1%) | 392 (12.6%) |
T2 | 307 (2.6%) | 126 (1.4%) | 181 (5.8%) |
T3 | 1647 (13.9%) | 596 (6.8%) | 1051 (33.9%) |
T4a | 161 (1.4%) | 35 (0.4%) | 126 (4.1%) |
T4b | 717 (6.1%) | 457 (5.2%) | 260 (8.4%) |
Unknown | 6333 (53.6%) | 5343 (61.3%) | 990 (31.9%) |
M category | |||
M0 | 2475 (20.9%) | 1686 (19.4%) | 789 (25.4%) |
M1 | 3311 (28.0%) | 2684 (30.8%) | 627 (20.2%) |
Unknown | 6028 (51.0%) | 4340 (49.8%) | 1688 (54.4%) |
Primary tumor site | |||
Rectum | 4674 (39.6%) | 3666 (42.1%) | 1008 (32.5%) |
Left-sided colon | 2624 (22.2%) | 1648 (18.9%) | 976 (31.4%) |
Right-sided colon | 4516 (38.2%) | 3396 (39.0%) | 1120 (36.1%) |
Histologic type | |||
Adenocarcinoma | 11,200 (94.8%) | 8375 (96.2%) | 2825 (91.0%) |
Mucinous carcinoma | 523 (4.4%) | 281 (3.2%) | 242 (7.8%) |
Signet-ring cell carcinoma | 91 (0.8%) | 54 (0.6%) | 37 (1.2%) |
Histologic grade | |||
Well | 724 (6.1%) | 509 (5.8%) | 215 (6.9%) |
Moderate | 5011 (42.4%) | 3327 (38.2%) | 1684 (54.3%) |
Poor | 1488 (12.6%) | 973 (11.2%) | 515 (16.6%) |
Undifferentiated | 96 (0.8%) | 69 (0.8%) | 27 (0.9%) |
Unknown | 4495 (38.0%) | 3832 (44.0%) | 663 (21.4%) |
Tumor size | |||
< 35 mm | 1134 (9.6%) | 693 (8.0%) | 441 (14.2%) |
35–50 mm | 1039 (8.8%) | 522 (6.0%) | 517 (16.7%) |
50–65 mm | 1241 (10.5%) | 760 (8.7%) | 481 (15.5%) |
≥ 65 mm | 1103 (9.3%) | 639 (7.3%) | 464 (14.9%) |
Unknown | 7297 (61.8%) | 6096 (70.0%) | 1201 (38.7%) |
Presenting features | |||
HCC risk score | |||
1st quartile | 2955 (25.0%) | 2232 (25.6%) | 723 (23.3%) |
2nd quartile | 2980 (25.2%) | 2079 (23.9%) | 901 (29.0%) |
3rd quartile | 2917 (24.7%) | 2089 (24.0%) | 828 (26.7%) |
4th quartile | 2962 (25.1%) | 2310 (26.5%) | 652 (21.0%) |
History of alcoholism | |||
No | 11,390 (96.4%) | 8369 (96.1%) | 3021 (97.3%) |
Yes | 424 (3.6%) | 341 (3.9%) | 83 (2.7%) |
Tobacco | |||
No | 10,457 (88.5%) | 7690 (88.3%) | 2767 (89.1%) |
Yes | 1357 (11.5%) | 1020 (11.7%) | 337 (10.9%) |
History of colorectal polyps | |||
No | 10,459 (88.5%) | 7710 (88.5%) | 2749 (88.6%) |
Yes | 1355 (11.5%) | 1000 (11.5%) | 355 (11.4%) |
Obesity | |||
No | 10,916 (92.4%) | 8045 (92.4%) | 2871 (92.5%) |
Yes | 898 (7.6%) | 665 (7.6%) | 233 (7.5%) |
Treatment | |||
Chemotherapy | |||
Nonchemotherapy | 9105 (77.1%) | 6651 (76.4%) | 2454 (79.1%) |
5-FU/capecitabine | 1398 (11.8%) | 1047 (12.0%) | 351 (11.3%) |
FOLFOX/CapeOX | 277 (2.3%) | 213 (2.4%) | 64 (2.1%) |
FOLFIRI/XELIRI | 242 (2.0%) | 186 (2.1%) | 56 (1.8%) |
FOLFOX/CapeOX + bevacizumab | 273 (2.3%) | 227 (2.6%) | 46 (1.5%) |
FOLFIRI/XELIRI + bevacizumab | 42 (0.4%) | 29 (0.3%) | 13 (0.4%) |
Other | 477 (4.0%) | 357 (4.1%) | 120 (3.9%) |
Radiotherapy | |||
No | 9912 (83.9%) | 7252 (83.3%) | 2660 (85.7%) |
Yes | 1902 (16.1%) | 1458 (16.7%) | 444 (14.3%) |
Presenting symptoms | |||
Abdominal pain | |||
No | 9091 (77.0%) | 6773 (77.8%) | 2318 (74.7%) |
Yes | 2723 (23.0%) | 1937 (22.2%) | 786 (25.3%) |
Abdominal mass | |||
No | 11,414 (96.6%) | 8431 (96.8%) | 2983 (96.1%) |
Yes | 400 (3.4%) | 279 (3.2%) | 121 (3.9%) |
Abdominal distension | |||
No | 11,624 (98.4%) | 8574 (98.4%) | 3050 (98.3%) |
Yes | 190 (1.6%) | 136 (1.6%) | 54 (1.7%) |
Ascites | |||
No | 11,712 (99.1%) | 8630 (99.1%) | 3082 (99.3%) |
Yes | 102 (0.9%) | 80 (0.9%) | 22 (0.7%) |
Anemia | |||
No | 10,688 (90.5%) | 7803 (89.6%) | 2885 (92.9%) |
Yes | 1126 (9.5%) | 907 (10.4%) | 219 (7.1%) |
Nutritional deficiency | |||
No | 11,152 (94.4%) | 8153 (93.6%) | 2999 (96.6%) |
Yes | 662 (5.6%) | 557 (6.4%) | 105 (3.4%) |
Cachexia | |||
No | 11,742 (99.4%) | 8649 (99.3%) | 3093 (99.6%) |
Yes | 72 (0.6%) | 61 (0.7%) | 11 (0.4%) |
Change of bowel habits | |||
No | 11,394 (96.4%) | 8395 (96.4%) | 2999 (96.6%) |
Yes | 420 (3.6%) | 315 (3.6%) | 105 (3.4%) |
Change of character of stool | |||
No | 9536 (80.7%) | 7064 (81.1%) | 2472 (79.6%) |
Yes | 2278 (19.3%) | 1646 (18.9%) | 632 (20.4%) |
Hemorrhage | |||
No | 9366 (79.3%) | 6859 (78.7%) | 2507 (80.8%) |
Yes | 2448 (20.7%) | 1851 (21.3%) | 597 (19.2%) |
Diarrhea | |||
No | 10,899 (92.3%) | 8022 (92.1%) | 2877 (92.7%) |
Yes | 915 (7.7%) | 688 (7.9%) | 227 (7.3%) |
Gatism | |||
No | 11,728 (99.3%) | 8640 (99.2%) | 3088 (99.5%) |
Yes | 86 (0.7%) | 70 (0.8%) | 16 (0.5%) |
Loss of appetite | |||
No | 11,569 (97.9%) | 8501 (97.6%) | 3068 (98.8%) |
Yes | 245 (2.1%) | 209 (2.4%) | 36 (1.2%) |
Vomiting | |||
No | 11,066 (93.7%) | 8142 (93.5%) | 2924 (94.2%) |
Yes | 748 (6.3%) | 568 (6.5%) | 180 (5.8%) |
Weight loss | |||
No | 10,672 (90.3%) | 7838 (90.0%) | 2834 (91.3%) |
Yes | 1142 (9.7%) | 872 (10.0%) | 270 (8.7%) |
Patient characteristics | Univariate analysis | Multivariate analysis | ||||
---|---|---|---|---|---|---|
HR | 95% CI | p value | HR | 95% CI | p value | |
Gender | ||||||
Men | 1.087 | 1.013–1.167 | 0.020 | |||
Women | 1.000 | |||||
Age at diagnosis, years | ||||||
66–70 | 1.818 | 1.642–2.013 | < 0.001 | 1.737 | 1.558–1.935 | < 0.001 |
71–75 | 1.765 | 1.605–1.942 | 1.765 | 1.596–1.953 | ||
76–80 | 1.636 | 1.490–1.796 | 1.523 | 1.384–1.677 | ||
≥ 81 | 1.000 | 1.000 | ||||
Race | ||||||
White | 1.000 | 0.001 | 1.000 | 0.004 | ||
Black | 0.873 | 0.783–0.972 | 0.825 | 0.738–0.922 | ||
Asian | 1.291 | 1.081–1.542 | 1.062 | 0.887–1.271 | ||
Other | 0.962 | 0.800–1.156 | 0.887 | 0.737–1.067 | ||
Marital status | ||||||
Single + separated | 1.067 | 0.945–1.204 | < 0.001 | 1.058 | 0.936–1.197 | < 0.001 |
Married | 1.369 | 1.269–1.478 | 1.115 | 1.028–1.208 | ||
Divorced + widowed | 1.000 | 1.000 | ||||
Other | 0.565 | 0.468–0.682 | 0.622 | 0.514–0.752 | ||
Residence location* | ||||||
Big metro | 1.000 | < 0.001 | 1.000 | 0.050 | ||
Metro or urban | 0.863 | 0.797–0.933 | 0.906 | 0.837–0.981 | ||
Less urban or rural | 0.844 | 0.747–0.955 | 0.946 | 0.835–1.072 | ||
Median household income | ||||||
1st quartile | 1.000 | 0.107 | ||||
2nd quartile | 1.066 | 0.961–1.183 | ||||
3rd quartile | 1.081 | 0.975–1.199 | ||||
4th quartile | 1.118 | 1.009–1.239 | ||||
Unknown | 0.929 | 0.782–1.104 | ||||
Level of education | ||||||
1st quartile | 1.000 | 0.571 | ||||
2nd quartile | 0.996 | 0.899–1.102 | ||||
3rd quartile | 0.993 | 0.897–1.100 | ||||
4th quartile | 0.968 | 0.873–1.072 | ||||
Unknown | 0.872 | 0.735–1.034 | ||||
Tumor characteristics | ||||||
T category | ||||||
Tis | 1.000 | < 0.001 | 1.000 | < 0.001 | ||
T1 | 1.532 | 1.233–1.904 | 1.434 | 1.144–1.796 | ||
T2 | 6.878 | 5.396–8.768 | 6.175 | 4.768–7.997 | ||
T3 | 8.408 | 6.855–10.313 | 7.187 | 5.738–9.003 | ||
T4a | 15.416 | 11.848–20.059 | 9.064 | 6.824–12.039 | ||
T4b | 4.566 | 3.626–5.750 | 4.466 | 3.489–5.717 | ||
Unknown | 1.559 | 1.270–1.913 | 1.562 | 1.257–1.941 | ||
M category | ||||||
M0 | 1.000 | < 0.001 | 1.000 | < 0.001 | ||
M1 | 0.665 | 0.598–0.738 | 0.793 | 0.707–0.889 | ||
Unknown | 0.925 | 0.850–1.007 | 1.213 | 1.108–1.328 | ||
Primary tumor site | ||||||
Rectum | 1.000 | < 0.001 | 1.000 | < 0.001 | ||
Left-sided colon | 2.055 | 1.881–2.244 | 2.093 | 1.892–2.315 | ||
Right-sided colon | 1.445 | 1.326–1.574 | 1.583 | 1.432–1.750 | ||
Histologic type | ||||||
Adenocarcinoma | 1.000 | < 0.001 | 1.000 | < 0.001 | ||
Mucinous carcinoma | 2.368 | 2.076–2.701 | 1.593 | 1.392–1.823 | ||
Signet-ring cell carcinoma | 2.096 | 1.515–2.899 | 1.220 | 0.875–1.701 | ||
Histologic grade | ||||||
Well | 0.771 | 0.669–0.889 | < 0.001 | 0.842 | 0.729–0.972 | < 0.001 |
Moderate | 1.000 | 1.000 | ||||
Poor | 1.203 | 1.090–1.328 | 1.131 | 1.022–1.251 | ||
Undifferentiated | 0.954 | 0.652–1.395 | 0.992 | 0.676–1.456 | ||
Unknown | 0.383 | 0.350–0.419 | 0.548 | 0.498–0.604 | ||
Tumor size, mm | ||||||
< 35 | 1.000 | < 0.001 | 1.000 | < 0.001 | ||
35–50 | 1.734 | 1.526–1.970 | 1.266 | 1.110–1.444 | ||
50–65 | 1.269 | 1.114–1.446 | 1.133 | 0.991–1.295 | ||
≥ 65 | 1.543 | 1.353–1.759 | 1.253 | 1.093–1.436 | ||
Unknown | 0.419 | 0.376–0.467 | 0.616 | 0.549–0.690 | ||
Presenting features | ||||||
HCC risk score | ||||||
1st quartile | 1.000 | < 0.001 | ||||
2nd quartile | 1.187 | 1.076–1.309 | ||||
3rd quartile | 1.126 | 1.019–1.245 | ||||
4th quartile | 0.913 | 0.821–1.015 | ||||
History of alcoholism | ||||||
No | 1.000 | 0.011 | 1.000 | 0.027 | ||
Yes | 0.753 | 0.606–0.937 | 0.781 | 0.627–0.973 | ||
Tobacco | ||||||
No | 1.000 | 0.385 | ||||
Yes | 0.951 | 0.849–1.065 | ||||
History of colorectal polyps | ||||||
No | 1.000 | 0.004 | ||||
Yes | 0.850 | 0.760–0.949 | ||||
Obesity | ||||||
No | 1.000 | 0.845 | ||||
Yes | 0.987 | 0.863–1.128 | ||||
Treatment | ||||||
Chemotherapy | ||||||
Nonchemotherapy | 1.000 | < 0.001 | 1.000 | < 0.001 | ||
5-FU/capecitabine | 0.758 | 0.677–0.847 | 0.752 | 0.655–0.864 | ||
FOLFOX/CapeOX | 0.719 | 0.561–0.922 | 0.595 | 0.459–0.770 | ||
FOLFIRI/XELIRI | 0.729 | 0.559–0.950 | 0.629 | 0.480–0.825 | ||
FOLFOX/CapeOX + bevacizumab | 0.482 | 0.360–0.645 | 0.395 | 0.292–0.535 | ||
FOLFIRI/XELIRI + bevacizumab | 0.921 | 0.534–1.589 | 0.980 | 0.564–1.705 | ||
Other | 0.798 | 0.664–0.958 | 0.715 | 0.590–0.867 | ||
Radiotherapy | ||||||
No | 1.000 | < 0.001 | 1.000 | < 0.001 | ||
Yes | 0.705 | 0.637–0.780 | 0.591 | 0.514–0.679 | ||
Presenting symptoms | ||||||
Abdominal pain | ||||||
No | 1.000 | < 0.001 | < 0.001 | |||
Yes | 1.179 | 1.087–1.278 | 1.202 | 1.105–1.307 | ||
Abdominal mass | ||||||
No | 1.000 | 0.025 | 1.000 | 0.056 | ||
Yes | 1.230 | 1.026–1.476 | 1.199 | 0.996–1.445 | ||
Abdominal distension | ||||||
No | 1.000 | 0.381 | ||||
Yes | 1.128 | 0.862–1.476 | ||||
Ascites | ||||||
No | 1.000 | 0.497 | ||||
Yes | 0.865 | 0.569–1.315 | ||||
Anemia | ||||||
No | 1.000 | < 0.001 | 1.000 | 0.002 | ||
Yes | 0.736 | 0.642–0.845 | 0.802 | 0.696–0.923 | ||
Nutritional deficiency | ||||||
No | 1.000 | < 0.001 | 1.000 | 0.067 | ||
Yes | 0.624 | 0.513–0.758 | 0.830 | 0.680–1.013 | ||
Cachexia | ||||||
No | 1.000 | 0.166 | ||||
Yes | 0.658 | 0.364–1.189 | ||||
Change of bowel habit | ||||||
No | 1.000 | 0.023 | ||||
Yes | 0.798 | 0.657–0.969 | ||||
Change of character of stool | ||||||
No | 1.000 | 0.348 | ||||
Yes | 1.043 | 0.955–1.138 | ||||
Hemorrhage | ||||||
No | 1.000 | < 0.001 | ||||
Yes | 0.841 | 0.769–0.920 | ||||
Diarrhea | ||||||
No | 1.000 | 0.458 | ||||
Yes | 0.950 | 0.830–1.088 | ||||
Gatism | ||||||
No | 1.000 | 0.183 | ||||
Yes | 0.716 | 0.438–1.170 | ||||
Loss of appetite | ||||||
No | 1.000 | 0.002 | 1.000 | 0.077 | ||
Yes | 0.598 | 0.431–0.831 | 0.742 | 0.533–1.033 | ||
Vomiting | ||||||
No | 1.000 | 0.537 | ||||
Yes | 0.954 | 0.820–1.109 | ||||
Weight loss | ||||||
No | 1.000 | 0.579 | ||||
Yes | 0.965 | 0.852–1.094 |