Table 1.
Descriptive Characteristics of Overall Study Sample.
| All stage III Colon Cancer Patients | Received 5-Fu | Received Oxaliplatin | Received other, unknown chemo | Received No Chemo | Oxaliplatin vs. 5-FU3 | Any vs. no Chemo4 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| ||||||||||||
| n | (%) | n | (%) | n | (%) | n | (%) | n | (%) | |||
| Patient Characteristics | 4054 | 1432 | (35.3%) | 821 | (20.3%) | 264 | (6.5%) | 1537 | (37.9%) | |||
|
| ||||||||||||
| Gender | ||||||||||||
| Male | 1728 | (42.6%) | 626 | (43.7%) | 405 | (49.3%) | 120 | (45.5%) | 577 | (37.5%) | *** | *** |
| Female | 2326 | (57.4%) | 806 | (56.3%) | 416 | (50.7%) | 144 | (54.5%) | 960 | (62.5%) | ||
| Race | ||||||||||||
| Caucasian American | 3519 | (86.8%) | 1257 | (87.8%) | 709 | (86.4%) | 217 | (82.2%) | 1336 | (86.9%) | ||
| African American | 316 | (7.8%) | 95 | (6.6%) | 58 | (7.1%) | 30 | (11.4%) | 133 | (8.7%) | ||
| Other/Unknown | 219 | (5.4%) | 80 | (5.6%) | 54 | (6.6%) | 17 | (6.4%) | 68 | (4.4%) | ||
| Age (in years) | ||||||||||||
| Mean (SD); (Range) | 77.6 (6.95) | (66–105) | 75.9 (5.72) | (66–94) | 72.9 (4.87) | (66–88) | 77.9 (6.89) | (66–95) | 81.5 (6.82) | (66–105) | ||
| 65–69 | 597 | (14.7%) | 224 | (15.6%) | 260 | (31.7%) | 38 | (14.4%) | 75 | (4.9%) | ||
| 70–74 | 862 | (21.3%) | 372 | (26.0%) | 254 | (30.9%) | 53 | (20.1%) | 183 | (11.9%) | ||
| 75–79 | 1022 | (25.2%) | 448 | (31.3%) | 216 | (26.3%) | 61 | (23.1%) | 297 | (19.3%) | ||
| 80+ | 1573 | (38.8%) | 388 | (27.1%) | 91 | (11.1%) | 112 | (42.4%) | 982 | (63.9%) | ||
| Income1 | ||||||||||||
| Quartile 1: lowest income | 1056 | (26.0%) | 389 | (27.2%) | 174 | (21.2%) | 74 | (28.0%) | 420 | (27.3%) | *** | ** |
| Quartile 2: low-med income | 1039 | (25.6%) | 344 | (24.0%) | 204 | (24.8%) | 69 | (26.1%) | 423 | (27.5%) | ||
| Quartile 3: med-high income | 1021 | (25.2%) | 378 | (26.4%) | 214 | (26.1%) | 71 | (26.9%) | 356 | (23.2%) | ||
| Quartile 4: highest income | 938 | (23.1%) | 321 | (22.4%) | 229 | (27.9%) | 50 | (18.9%) | 338 | (22.0%) | ||
| Education2 | ||||||||||||
| Quartile 1: lowest education | 1017 | (25.1%) | 362 | (25.3%) | 189 | (23.0%) | 70 | (26.5%) | 396 | (25.8%) | *** | |
| Quartile 2: low-med education | 1047 | (25.8%) | 371 | (25.9%) | 207 | (25.2%) | 79 | (29.9%) | 390 | (25.4%) | ||
| Quartile 3: med-high education | 1050 | (25.9%) | 389 | (27.2%) | 194 | (23.6%) | 64 | (24.2%) | 406 | (26.4%) | ||
| Quartile 4: highest education | 940 | (23.2%) | 310 | (21.6%) | 231 | (28.1%) | 51 | (19.3%) | 345 | (22.4%) | ||
| NCI combined comorbidity index | ||||||||||||
| Mean (SD); (Range) | 0.27 (0.46) | (0 – 3.66) | 0.22 (0.42) | (0 – 3.66) | 0.16 (0.34) | (0 – 2.05) | 0.33 (0.49) | (0 – 2.22) | 0.36 (0.52) | (0 – 2.70) | *** | *** |
| Primary site of tumor | ||||||||||||
| Cecum, Ascending | 2042 | (50.4%) | 715 | (49.9%) | 408 | (49.7%) | 123 | (46.6%) | 796 | (51.8%) | ** | |
| Flexures, Transverse/Descending | 939 | (23.2%) | 318 | (22.2%) | 177 | (21.6%) | 72 | (27.3%) | 372 | (24.2%) | ||
| Signmoid; Large intestine/NOS | 1073 | (26.5%) | 399 | (27.9%) | 236 | (28.7%) | 69 | (26.1%) | 369 | (24.0%) | ||
| Tumor grade | ||||||||||||
| Well-differentiated | 186 | (4.6%) | 76 | (5.3%) | 37 | (4.5%) | 15 | (5.7%) | 58 | (3.8%) | * | |
| Moderately differentiated | 2537 | (62.6%) | 920 | (64.2%) | 498 | (60.7%) | 169 | (64.0%) | 950 | (61.8%) | ||
| Poorly differentiated | 1152 | (28.4%) | 384 | (26.8%) | 252 | (30.7%) | 65 | (24.6%) | 451 | (29.3%) | ||
| Unknown | 179 | (4.4%) | 52 | (3.6%) | 34 | (4.1%) | 15 | (5.7%) | 78 | (5.1%) | ||
| Year of Chemo | ||||||||||||
| no chemo | 1537 | (37.9%) | - | - | - | - | - | - | 1537 | (100.0%) | *** | |
| 2003 | 775 | (19.1%) | 591 | (41.3%) | 126 | (15.3%) | 58 | (22.0%) | 0 | (0%) | *** | |
| 2004 | 813 | (20.1%) | 465 | (32.5%) | 264 | (32.2%) | 84 | (31.8%) | 0 | (0%) | ||
| 2005 | 800 | (19.7%) | 323 | (22.6%) | 364 | (44.3%) | 110–120 | (42–43%) | 0 | (0%) | ||
| 2006 (partial year examined) | 129 | (3.2%) | 53 | (3.7%) | 67 | (8.2%) | <11 | (<4%) | 0 | (0%) | ||
| Dual eligibility | ||||||||||||
| Yes | 707 | (17.4%) | 196 | (13.7%) | 95 | (11.6%) | 62 | (23.5%) | 354 | (23.0%) | *** | |
|
| ||||||||||||
| Organization characteristics (treating hospital) | ||||||||||||
|
| ||||||||||||
| Cooperative Group Affiliation | ||||||||||||
| Mean (SD); (Range) | 1.47 (1.62) | (0–9) | 1.41 (1.57) | (0–9) | 1.58 (1.75) | (0–8) | 1.33 (1.61) | (0–8) | 1.49 (1.60) | (0–8) | * | |
| No affiliation | 1649 | (40.7%) | 591 | (41.3%) | 318 | (38.7%) | 119 | (45.1%) | 621 | (40.4%) | ||
| Affiliated with 1+ C.G. | 2405 | (59.3%) | 841 | (58.7%) | 503 | (61.3%) | 145 | (54.9%) | 916 | (59.6%) | ||
| Medical School Affiliation | ||||||||||||
| Unaffiliated | 3237 | (79.8%) | 1146 | (80.0%) | 658 | (80.1%) | 205 | (77.7%) | 1228 | (79.9%) | ||
| Limited | 817 | (20.2%) | 286 | (20.0%) | 163 | (19.9%) | 59 | (22.3%) | 309 | (20.1%) | ||
| NCI-center affiliated | ||||||||||||
| Yes | <11 | (<1%) | <11 | (<1%) | <11 | (<1%) | <11 | (<1%) | <11 | (<1%) | ||
|
| ||||||||||||
| Primary Exposure | ||||||||||||
|
| ||||||||||||
| Any CCOP MD/hospital affiliated claims | ||||||||||||
| Yes | 1029 | (25.4%) | 361 | (25.2%) | 255 | (31.1%) | 76 | (28.8%) | 337 | (21.9%) | *** | *** |
| Proportion of claims from CCOP-affiliated MD or Hospital | ||||||||||||
| Mean (SD); (Range) | 0.11 (0.25) | (0–1) | 0.13 (0.27) | (0–1) | 0.18 (0.33) | (0–1) | 0.10 (0.22) | (0–0.96) | 0.05 (0.14) | (0–0.92) | *** | *** |
|
| ||||||||||||
| Outcome | ||||||||||||
|
| ||||||||||||
| 5-Fu | 1432 | (35.3%) | ||||||||||
| Folfox/Oxaliplatin | 821 | (20.3%) | ||||||||||
| Other/Unknown Chemotherapy | 264 | (6.5%) | ||||||||||
| No chemo | 1537 | (37.9%) | ||||||||||
Median household income in patient’s census tract.
Proportion of patient’s census tract population with high school education or greater.
Chi-square test (categorial) or t-test (continuous):
p<0.01: ***,
p<0.05: **,
p<0.10: *
-SEER regions were examined but are not reported. They were found to be statistically different (p <0.10) by chemotherapy use.
-Specific comorbidities were examined but not reported. Oxaliplatin patients were less likely to have renal disease (p <0.05) or history of cardio/cerebrovascular disease (p <0.01). Patients receiving chemotherapy were less likely to have dementia or paralysis (p <0.01), history of cardio/cerebrovascular disease (p <0.01), neruropathy (p <0.05), or diabetes (p <0.10).
-Per SEER-Medicare data use requirements, methods were used to suppress cell sizes smaller than 11, and included collapsing some categories of measures, using “<11” to reflect small numbers, and partially masking values to prevent mathematical derivation of small numbers.