TABLE 1.
Characteristics of CRC cases and controls1
| Cases |
Controls |
||||
| Characteristics | n | Value | n | Value | P value |
| Age | 988 | 67 ± 7 | 988 | 67 ± 7 | 0.50 |
| 50–54 y | 58 | 5.9 | 55 | 5.6 | 0.96 |
| 55–59 y | 105 | 10.6 | 104 | 10.5 | |
| 60–64 y | 190 | 19.2 | 192 | 19.4 | |
| 65–69 y | 260 | 26.3 | 245 | 24.8 | |
| 70–74 y | 230 | 23.3 | 246 | 24.9 | |
| 75–79 y | 145 | 14.7 | 146 | 14.8 | |
| BMI2 | 976 | 28.1 ± 6.0 | 978 | 27.1 ± 5.9 | 0.0001 |
| <25.0 kg/m2 | 342 | 35.1 | 394 | 40.3 | 0.002 |
| 25.0–29.9 kg/m2 | 331 | 33.9 | 355 | 36.3 | |
| 30–34.9 kg/m2 | 187 | 19.2 | 143 | 14.6 | |
| ≥35.0 kg/m2 | 116 | 11.8 | 86 | 8.8 | |
| Ethnicity (several categories) | 988 | 100 | 988 | 100 | 1.0 |
| White | 842 | 85.2 | 842 | 85.2 | |
| Black or African American | 88 | 8.9 | 88 | 8.9 | |
| Other3 | 58 | 5.9 | 58 | 5.9 | |
| Family income | 950 | 100 | 940 | 100 | 0.08 |
| <$34,999 | 457 | 48.1 | 421 | 44.8 | |
| $35,000–$74,999 | 343 | 36.1 | 329 | 35.0 | |
| ≥$75,000 | 125 | 13.1 | 162 | 17.2 | |
| Don't know | 25 | 2.6 | 28 | 3.0 | |
| Education (high school or less) | 195 | 19.9 | 223 | 22.8 | 0.12 |
| Residence location (US region) | 988 | 100 | 988 | 100 | 0.42 |
| Northeast | 255 | 25.8 | 227 | 22.3 | |
| South | 223 | 22.6 | 240 | 24.3 | |
| Midwest | 228 | 23.1 | 222 | 22.5 | |
| West | 282 | 28.5 | 299 | 30.3 | |
| Smoking (pack-years) | 951 | 13.0 ± 21.7 | 951 | 8.9 ± 17.0 | <0.0001 |
| Moderate or strenuous activity (min/wk) | 975 | 95.9 ± 135.9 | 979 | 109.1 ± 143.4 | 0.04 |
| Family history of CRC (yes) | 192 | 21 | 163 | 18 | 0.10 |
| History of colonoscopy or sigmoidoscopy (yes) | 508 | 52 | 589 | 60 | 0.0003 |
| History of colon polyp removal (yes) | 123 | 25 | 105 | 18 | 0.008 |
| Tumor location4 | 990 | 100 | — | — | |
| Proximal | 577 | 58.3 | — | — | |
| Distal | 211 | 21.3 | — | — | |
| Rectal | 184 | 18.6 | — | — | |
| Overlapping/unknown | 18 | 1.8 | — | — | |
| Tumor grade4 | 990 | 100 | — | — | |
| Well differentiated | 75 | 7.6 | — | — | |
| Moderately differentiated | 616 | 62.2 | — | — | |
| Poorly differentiated | 202 | 20.4 | — | — | |
| Anaplastic | 12 | 1.2 | — | — | |
| Unknown/not determined | 85 | 8.6 | — | — | |
| Tumor stage (SEER staging)4 | 989 | 100 | — | — | |
| Localized | 431 | 43.6 | — | — | |
| Regional | 409 | 41.3 | — | — | |
| Distant | 127 | 12.8 | — | — | |
| Unknown/not determined | 22 | 2.2 | — | — | |
| Homocysteine | 966 | 9.42 ± 1.315 | 966 | 9.12 ± 1.285 | 0.04 |
| ≤6.74 μmol/L | 227 | 23.5 | 257 | 26.6 | |
| >6.74–7.85 μmol/L | 235 | 24.3 | 253 | 26.2 | |
| >7.85–9.85 μmol/L | 238 | 24.6 | 243 | 25.1 | |
| >9.85 μmol/L | 267 | 27.6 | 214 | 22.1 | |
| Cysteine | 967 | 283.9 ± 1.15 | 967 | 284.0 ± 1.15 | 0.39 |
| ≤260.0 μmol/L | 247 | 25.5 | 224 | 23.2 | |
| >260–282.0 μmol/L | 235 | 24.3 | 258 | 26.7 | |
| >282.0–309.0 μmol/L | 250 | 25.9 | 236 | 24.4 | |
| >309.0 μmol/L | 235 | 24.3 | 249 | 25.8 | |
1
All values in the “Value” column are means ± SDs or percentages. Differences between cases and controls were compared by t tests (continuous variables) and chi-square tests (categorical variables). CRC, colorectal cancer; SEER, Surveillance Epidemiology and End Results.
2
Measured at baseline.
3
Hispanic, Asian or Pacific Islander, American Indian or Alaskan Native, or missing.
4
Two individuals are listed as having both colon cancer and CRC, so information on both tumors is reported here.
5
Values are geometric means ± SDs.