Table 1.
The characteristics of patients in chemotherapy and nonchemotherapy subgroups.
| Risk factors | n (%) | Nonchemotherapy n (%) | Chemotherapy n (%) |
p * |
|---|---|---|---|---|
| Total | 58,133 | 43,216 (74.34) | 14,917 (25.66) | |
| Age | <0.001 | |||
| ⩽60 years | 18,885 | 11,437 (26.46) | 7448 (49.93) | |
| >60 years | 39,248 | 31,779 (73.54) | 7469 (50.07) | |
| Gender | <0.001 | |||
| Female | 28,820 | 21,647 (50.09) | 7173 (48.09) | |
| Male | 29,313 | 21,569 (49.91) | 7744 (51.91) | |
| Marital status | <0.001 | |||
| Married | 35,203 | 25,562 (59.15) | 9641 (64.63) | |
| Unmarried | 8056 | 5905 (13.66) | 2151 (14.42) | |
| Divorced | 14,874 | 11,749 (27.19) | 3125 (20.95) | |
| Race | 0.011 | |||
| White | 46,664 | 34,666 (80.22) | 11,998 (80.43) | |
| Black | 6519 | 4928 (11.40) | 1591 (10.67) | |
| Other | 4950 | 3622 (8.38) | 1328 (8.90) | |
| Location$ | <0.001 | |||
| Left colon | 27,564 | 19,255 (44.56) | 8309 (55.70) | |
| Right colon | 30,569 | 23,961 (55.44) | 6608 (44.30) | |
| Histology | <0.001 | |||
| Adenocarcinoma | 50,390 | 37,578 (86.95) | 12,812 (85.89) | |
| Mucinous adenocarcinoma | 7452 | 5444 (12.60) | 2008 (13.46) | |
| Signet ring cell carcinoma | 291 | 194 (0.45) | 97 (0.65) | |
| Differential grade | <0.001 | |||
| Grade I | 4775 | 3693 (8.55) | 1082 (7.25) | |
| Grade II | 44,445 | 33,313 (77.08) | 11,132 (74.63) | |
| Grade III | 8913 | 6210 (14.37) | 2703 (18.12) | |
| T classification‡ | <0.001 | |||
| T3 | 48,883 | 37,689 (87.21) | 11,194 (75.04) | |
| T4 | 9250 | 5527 (12.79) | 3723 (24.96) | |
| nLN | <0.001 | |||
| 0 | 1346 | 905 (2.09) | 441 (2.96) | |
| 0–3 | 1879 | 1373 (3.18) | 506 (3.39) | |
| 3–6 | 5004 | 3716 (8.60) | 1288 (8.63) | |
| 6–12 | 14,479 | 10,770 (24.92) | 3709 (24.86) | |
| ⩾12 | 35,425 | 26,452 (61.21) | 8973 (60.15) | |
| Year of diagnosis | 0.741 | |||
| 1988–2004 | 32,386 | 24,093 (55.75) | 8293 (55.59) | |
| 2005–2013 | 25,747 | 19,123 (44.25) | 6624 (44.41) |
nLN, number of lymph nodes.
*
p values obtained from the χ2 test. All statistical tests were two-sided.
$
Left colon includes rectosigmoid junction, sigmoid colon, descending colon and splenic flexure; right colon includes transverse colon, hepatic flexure, ascending colon, cecum, and appendix.
‡
T classification according to 7th AJCC staging system.