Patient characteristics
| Characteristic | No adjuvant treatment n=248 (22.1%) | Chemotherapy n=286 (25.5%) | Radiation n=201 (18.0%) | Chemoradiation n=385 (34.4%) | P value |
| Age at diagnosis (years) | <0.001 | ||||
| <50 | 50 (20.2%) | 65 (22.7%) | 28 (13.9%) | 80 (20.8%) | |
| 50–69 | 133 (53.6%) | 190 (66.4%) | 107 (53.2%) | 274 (71.2%) | |
| ≥70 | 65 (26.2%) | 31 (10.8%) | 66 (32.8%) | 31 (8.1%) | |
| Race | 0.52 | ||||
| White | 223 (89.9%) | 247 (86.4%) | 185 (92.0%) | 335 (87.0%) | |
| Black | 11 (4.4%) | 18 (6.3%) | 7 (3.5%) | 24 (6.2%) | |
| Other/multiple | 14 (5.7%) | 21 (7.3%) | 9 (4.5%) | 26 (6.8%) | |
| Ethnicity | 0.56 | ||||
| Non-Hispanic/unknown | 226 (91.1%) | 269 (94.1%) | 185 (92.0%) | 352 (91.4%) | |
| Hispanic | 22 (8.9%) | 17 (5.9%) | 16 (8.0%) | 33 (8.6%) | |
| Charlson–Deyo comorbidity score | 0.56 | ||||
| 0 | 175 (70.6%) | 213 (74.5%) | 154 (76.6%) | 295 (76.6%) | |
| 1 | 58 (23.4%) | 59 (20.6%) | 37 (18.4%) | 66 (17.1%) | |
| ≥2 | 15 (6.1%) | 14 (4.9%) | 10 (5.0%) | 24 (6.2%) | |
| Income | 0.81 | ||||
| <$40 227 | 43 (17.4%) | 38 (13.4%) | 33 (16.5%) | 51 (13.3%) | |
| $40 227–$50 353 | 62 (25.1%) | 73 (25.7%) | 52 (26.0%) | 89 (23.2%) | |
| $50 354–$63 332 | 57 (23.1%) | 71 (25.0%) | 52 (26.0%) | 106 (27.6%) | |
| ≥$63 333 | 85 (34.4%) | 102 (35.9%) | 63 (31.5%) | 138 (35.9%) | |
| Insurance | <0.001 | ||||
| Private | 134 (54.7%) | 192 (67.6%) | 87 (43.9%) | 258 (67.7%) | |
| Medicare | 83 (33.9%) | 53 (18.7%) | 94 (47.5%) | 74 (19.4%) | |
| Medicaid/Government other | 15 (6.1%) | 23 (8.1%) | 10 (5.1%) | 30 (7.9%) | |
| Uninsured | 13 (5.3%) | 16 (5.6%) | 7 (3.5%) | 19 (5.0%) | |
| Location | 0.001 | ||||
| Northeast | 37 (15.4%) | 46 (17.2%) | 47 (23.9%) | 79 (21.6%) | |
| South | 91 (37.8%) | 72 (27.0%) | 64 (32.5%) | 90 (24.6%) | |
| Midwest/Central | 65 (27.0%) | 92 (34.5%) | 60 (30.5%) | 139 (38.0%) | |
| West | 48 (29.9%) | 57 (21.4%) | 26 (13.2%) | 58 (15.9%) | |
| Rurality | 0.15 | ||||
| Metro | 201 (84.5%) | 232 (83.8%) | 150 (78.1%) | 316 (84.0%) | |
| Urban | 36 (15.1%) | 38 (13.7%) | 40 (20.8%) | 53 (14.1%) | |
| Rural | 1 (0.4%) | 7 (2.5%) | 2 (1.0%) | 7 (1.9%) | |
| Facility type | 0.73 | ||||
| Non-academic | 154 (62.1%) | 165 (57.7%) | 117 (58.2%) | 232 (60.3%) | |
| Academic | 94 (37.9%) | 121 (42.3%) | 84 (41.8%) | 153 (39.7%) | |
| Distance to treatment center | 0.04 | ||||
| <50 miles | 197 (79.8%) | 243 (85.6%) | 175 (87.5%) | 336 (87.5%) | |
| ≥50 miles | 50 (20.2%) | 41 (14.4%) | 25 (12.5%) | 48 (12.5%) | |
| Year of diagnosis | <0.001 | ||||
| 2004–2009 | 118 (47.6%) | 101 (35.3%) | 121 (60.2%) | 98 (25.5%) | |
| 2010–2016 | 130 (52.4%) | 185 (64.7%) | 80 (39.8%) | 287 (74.6%) | |
| Lymphovascular space invasion status | <0.001 | ||||
| + | 27 (10.9%) | 31 (10.8%) | 18 (9.0%) | 84 (21.8%) | |
| – | 87 (35.1%) | 136 (47.6%) | 54 (26.9%) | 167 (43.4%) | |
| Missing | 134 (54.0%) | 119 (41.6%) | 129 (64.2%) | 134 (34.8%) | |
| Tumor size | 0.18 | ||||
| <2 cm | 13 (5.2%) | 21 (7.3%) | 12 (6.0%) | 21 (5.5%) | |
| ≥2 cm | 167 (67.3%) | 199 (69.6%) | 135 (67.2%) | 290 (75.3) | |
| Unknown | 68 (27.4%) | 66 (23.1%) | 54 (26.9%) | 74 (19.2%) | |
| Lymph node dissection | 0.03 | ||||
| No | 78 (31.7%) | 64 (22.4%) | 58 (28.9%) | 88 (22.9%) | |
| Yes | 168 (68.3%) | 222 (77.6%) | 143 (71.1%) | 297 (77.1%) |