Table 1.
Clinical and tumor characteristics of patients with early-onset and average-onset colorectal cancer
| Characteristic | EO-CRC, ≤35 years (n = 151) | EO-CRC, 36-49 years (n = 608) | AO-CRC (n = 687) | ≤35 years vs AO |
36-49 years vs AO |
||
|---|---|---|---|---|---|---|---|
| P a | q | P a | q | ||||
| Age at diagnosis, y | |||||||
| Mean (SD) | 30.8 (3.8) | 43.8 (3.8) | 62.1 (8.5) | — | — | — | — |
| Median (range) | 31 (14-35) | 44 (36-49) | 61 (50-93) | — | — | — | — |
| Sex, No. (%) | |||||||
| Male | 74 (49) | 347 (57.1) | 370 (53.9) | .28 | — | .26 | — |
| Female | 77 (51) | 261 (42.9) | 317 (46.1) | — | — | — | — |
| Race, No. (%) | |||||||
| White | 113 (74.8) | 475 (78.1) | 561 (81.7) | .07 | 0.266 | .13 | 0.204 |
| Black or African American | 11 (7.3) | 29 (4.8) | 46 (6.7) | .86 | 0.858 | .15 | 0.204 |
| Asian or Indian subcontinent | 14 (9.3) | 59 (9.7) | 40 (5.8) | .14 | 0.266 | .01 | 0.046 |
| Other | 13 (8.6) | 45 (7.4) | 40 (5.8) | .20 | 0.266 | .26 | 0.263 |
| BMI, No. (%) | |||||||
| Normal | 81 (53.6) | 233 (38.3) | 211 (30.7) | <.001 | <0.001 | .006 | 0.023 |
| Underweight | 4 (2.6) | 13 (2.1) | 11 (1.6) | .33 | 0.325 | .54 | 0.539 |
| Overweight | 39 (25.8) | 192 (31.6) | 248 (36.1) | .02 | 0.023 | .08 | 0.155 |
| Obese | 25 (16.6) | 168 (27.6) | 211 (30.7) | <.001 | <0.001 | .22 | 0.294 |
| Unknown | 2 (1.4) | 2 (0.4) | 6 (0.9) | — | — | — | — |
| Median BMI | 24.3 | 26.5 | 27.0 | <.001 | — | .07 | — |
| Smoking history, No. (%) | |||||||
| Ever | 25 (16.6) | 194 (31.9) | 310 (45.1) | <.001 | — | <.001 | — |
| Never | 124 (82.1) | 414 (68.1) | 367 (53.4) | — | — | — | — |
| Unknown | 2 (1.3) | 0 (0) | 10 (1.5) | — | — | — | — |
| Hypertension, No. (%) | |||||||
| Yes | 2 (1.3) | 69 (11.3) | 300 (43.7) | <.001 | — | <.001 | — |
| No | 148 (98) | 531 (87.3) | 385 (56) | — | — | — | — |
| Unknown | 1 (0.7) | 8 (1.4) | 2 (0.3) | — | — | — | — |
| Diabetes, No. (%) | |||||||
| Yes | 4 (2.6) | 33 (5.4) | 80 (11.6) | <.001 | — | <.001 | — |
| No | 146 (96.7) | 574 (94.4) | 605 (88.1) | — | — | — | — |
| Unknown | 1 (0.7) | 1 (0.2) | 2 (0.3) | — | — | — | — |
| Family history of CRC, No. (%) | |||||||
| Yes | 74 (49) | 306 (50.3) | NA | — | — | — | — |
| No | 76 (50.3) | 295 (48.5) | NA | — | — | — | — |
| Unknown | 1 (0.7) | 7 (1.2) | NA | — | — | — | — |
| Stage, No. (%) | |||||||
| I | 2 (1.3) | 22 (3.6) | 29 (4.2) | .10 | 0.131 | .67 | 0.668 |
| II | 12 (7.9) | 53 (8.7) | 93 (13.5) | .08 | 0.131 | .006 | 0.025 |
| III | 47 (31.1) | 165 (27.1) | 161 (23.4) | .06 | 0.131 | .14 | 0.28 |
| IV | 90 (59.7) | 368 (60.6) | 404 (58.9) | .93 | 0.927 | .53 | 0.668 |
| Primary tumor location, No. (%) | |||||||
| Cecum | 15 (9.9) | 39 (6.4) | 120 (17.5) | .02 | 0.091 | <.001 | <0.001 |
| Ascending colon | 9 (6) | 37 (6.1) | 80 (11.6) | .04 | 0.123 | <.001 | <0.001 |
| Hepatic flexure | 1 (0.7) | 11 (1.8) | 23 (3.3) | .10 | 0.184 | .08 | 0.125 |
| Transverse colon | 6 (4) | 18 (3) | 30 (4.4) | 1.00 | 1.000 | .19 | 0.209 |
| Splenic flexure | 5 (3.3) | 18 (3) | 9 (1.3) | .15 | 0.227 | .05 | 0.092 |
| Descending colon | 9 (6) | 41 (6.7) | 39 (5.7) | .85 | 0.956 | .49 | 0.489 |
| Sigmoid | 47 (31.1) | 197 (32.4) | 160 (23.3) | .06 | 0.139 | <.001 | <0.001 |
| Rectosigmoid | 8 (5.3) | 41 (6.7) | 60 (8.7) | .19 | 0.243 | .18 | 0.209 |
| Rectum | 51 (33.7) | 205 (33.7) | 155 (22.6) | .007 | 0.061 | <.001 | <0.001 |
| Colon, NOS | 0 (0) | 1 (0.2) | 11 (1.6) | — | — | — | — |
| Metastasectomy, No. (%) | |||||||
| Yes | 78 (51.7) | 280 (46.1) | 338 (49.2) | .41 | — | .69 | — |
| No | 68 (45) | 303 (49.8) | 348 (50.7) | — | — | — | — |
| Unknown | 5 (3.3) | 25 (4.1) | 1 (0.1) | — | — | — | — |
| Molecular subtype, No. (%) | |||||||
| MSS | 139 (92.1) | 583 (95.8) | 626 (91.1) | .87 | 0.873 | <.001 | <0.001 |
| MSI | 8 (5.3) | 21 (3.5) | 56 (8.2) | .31 | 0.464 | <.001 | <0.001 |
| POLE | 4 (2.6) | 4 (0.7) | 5 (0.7) | .06 | 0.182 | 1.00 | 1.000 |
| Tumor grade (MSS only), No. (%)b | |||||||
| Well differentiated | 1 (0.7) | 10 (1.7) | 1 (0.2) | .34 | 0.344 | .005 | 0.016 |
| Moderately differentiated | 116 (83.5) | 454 (77.9) | 477 (76.2) | .34 | 0.344 | .72 | 0.827 |
| Poorly differentiated | 22 (15.8) | 114 (19.6) | 122 (19.5) | .28 | 0.344 | .83 | 0.827 |
| Unknown | 0 (0) | 5 (0.8) | 26 (4.1) | — | — | — | — |
| Symptoms | |||||||
| BRBPR | 62 (41.1) | 249 (41.0) | 178 (25.9) | <.001 | 0.002 | <.001 | <0.001 |
| Abdominal pain, bloating, pelvic pain | 56 (37.1) | 207 (34.0) | 184 (26.8) | .01 | 0.049 | .005 | 0.011 |
| Change in bowel habits | 36 (23.8) | 114 (18.8) | 188 (27.4) | .42 | 0.626 | <.001 | <0.001 |
| Weight loss | 12 (7.9) | 40 (6.6) | 66 (9.5) | .64 | 0.803 | .07 | 0.099 |
| Anemia | 3 (2.0) | 22 (3.6) | 100 (14.6) | <.001 | <0.001 | <.001 | <0.001 |
| Fatigue | 3 (2.0) | 25 (4.1) | 47 (6.9) | .02 | 0.064 | .04 | 0.072 |
| Screening colonoscopy | 3 (2.0) | 17 (2.8) | 33 (4.8) | .18 | 0.338 | .08 | 0.105 |
| Upper GI symptoms | 3 (2.0) | 8 (1.3) | 26 (3.8) | .34 | 0.558 | .005 | 0.011 |
| Rectal pain | 22 (15.8) | 114 (19.6) | 122 (19.5) | .28 | 0.344 | .83 | 0.827 |
| Back, shoulder, bone pain | 1 (0.7) | 12 (2.0) | 6 (0.9) | 1.00 | 1.00 | .10 | 0.117 |
| Obstruction | 0 (0.0) | 4 (0.7) | 13 (1.9) | .14 | 0.302 | .08 | 0.105 |
a
A 2-sided Fisher exact test was used. AO = average-onset; BMI = body mass index; CRC = colorectal cancer; EO = early-onset; GI = gastrointestinal; MSI = microsatellite instability; MSS = microsatellite stable; NA = not available; NOS = not otherwise specified; POLE = polymerase epsilon; BRBPR = bright red blood per rectum.
b
For tumor grade, only MSS tumors were compared, given that MSI tumors are known to be associated with a higher prevalence of poorly differentiated tumors (35 years and younger, n = 139; 36-49 years, n = 583; AO, n = 626). For classification of tumor grade, tumors were categorized according to the most aggressive differentiation exhibited within any given tumor.