Table 1 Baseline patient characteristics in the entire cohort and by receipt of radiation therapy.
Entire Cohort (N = 6897) | Had RT (N = 6388) | RT omission (N = 509) | p Value | |
|---|---|---|---|---|
Age | ||||
Mean (standard deviation) | 59.6 (10.4) | 59.2 (10.2) | 64.0 (11.6) | <0.0001 |
≥70 yrs, N (%) | 1204 (17.5%) | 996 (15.6%) | 208 (40.9%) | <0.0001 |
Comorbidities | <0.0001 | |||
0 | 5845 (84.8%) | 5445 (85.2%) | 400 (78.6%) | |
≥1 | 1052 (15.2%) | 943 (14.8%) | 109 (21.4%) | |
Laterality | 0.1962 | |||
Left | 3564 (51.7%) | 3315 (51.9%) | 249 (48.9%) | |
Right | 3333 (48.3%) | 3073 (48.1%) | 260 (51.1%) | |
Hormone status | 0.4174 | |||
ER+ or PR+ | 5264 (76.3%) | 4883 (76.4%) | 381 (74.9%) | |
ER−/PR− | 1633 (23.7%) | 1505 (23.6%) | 128 (25.1%) | |
Tumor size | 0.2204 | |||
≤1 cm | 2504 (36.3%) | 2332 (36.5%) | 172 (33.8%) | |
>1–2 cm | 4393 (63.7%) | 4056 (63.5%) | 337 (66.2%) | |
Tumor grade | 0.3196 | |||
Grade 3 | 3346 (48.5%) | 3088 (48.3%) | 258 (50.7%) | |
Grade 1–2 | 3277 (47.5%) | 3050 (47.8%) | 227 (44.6%) | |
Unknown | 274 (4.0%) | 250 (3.9%) | 24 (8.8%) | |
Facility type | 0.3496 | |||
Academic | 2224 (32.3%) | 2074 (32.5%) | 150 (29.5%) | |
Other | 4499 (65.2%) | 4152 (65.0%) | 347 (7.7%) | |
Unknown | 174 (2.5%) | 162 (2.5%) | 12 (6.9%) | |
Race/ethnicity | 0.3428 | |||
Non-Hispanic White | 5459 (79.2%) | 5063 (79.3%) | 396 (77.8%) | |
Non-Hispanic Black | 765 (11.1%) | 714 (11.2%) | 51 (10.0%) | |
Hispanic | 331 (4.8%) | 300 (4.7%) | 31 (6.1%) | |
Non-Hispanic Other | 299 (4.3%) | 273 (4.2%) | 26 (5.1%) | |
Unknown | 43 (0.6%) | 38 (0.6%) | 5 (1.0%) | |
Income status | 0.0016 | |||
<$46,000/yr | 3432 (49.8%) | 3145 (49.2%) | 287 (56.4%) | |
≥$46,000/yr | 3269 (47.4%) | 3066 (48.0%) | 203 (39.9%) | |
Unknown | 196 (2.8%) | 177 (2.8%) | 19 (3.7%) | |
No HSD | 0.0467 | |||
≥20% | 2196 (31.8%) | 2014 (31.5%) | 182 (35.8%) | |
<20% | 4505 (65.3%) | 4197 (65.7%) | 308 (60.5%) | |
Unknown | 196 (2.8%) | 177 (2.8%) | 19 (3.7%) | |
Distance to facility | 0.8743 | |||
≥8.9 miles | 3465 (50.2%) | 3211 (50.3%) | 254 (49.9%) | |
<8.9 miles | 3432 (49.8%) | 3177 (49.7%) | 255 (50.1%) | |
Chemotherapy | 0.0022 | |||
Single-agent | 2341 (33.9%) | 2140 (33.5%) | 201 (39.5%) | |
Multi-agent | 4449 (64.5%) | 4154 (65.0%) | 295 (58.0%) | |
Not specified | 107 (1.6%) | 94 (1.5%) | 13 (2.5%) | |
Receipt of ETa | <0.0001 | |||
Yes | 4520 (85.9%) | 4338 (88.8%) | 182 (47.8%) | |
No | 744 (14.1%) | 545 (11.2%) | 199 (52.2%) | |
