Table 1.
Clinical and demographic characteristics of patients by radiotherapy receipt status (n = 2247)
| Variable | Irradiated (n = 622) No. (%) | Unirradiated (n = 1625) No. (%) | P* |
|---|---|---|---|
| Procedure type | |||
| Implant | 386 (62.1) | 1218 (75.0) | <.001 |
| Autologous | 236 (37.9) | 407 (25.0) | |
| Age, y | |||
| <30 | 19 (3.1) | 24 (1.5) | .003 |
| 30–39 | 99 (15.9) | 181 (11.1) | |
| 40–49 | 211 (33.9) | 586 (36.1) | |
| 50–59 | 191 (30.7) | 542 (33.4) | |
| ≥60 | 102 (16.4) | 292 (18.0) | |
| Extent of disease | |||
| Local | 124 (20.1) | 1392 (85.8) | <.001 |
| Regional | 490 (79.3) | 216 (13.3) | |
| Metastatic | 4 (0.6) | 14 (0.9) | |
| Laterality | |||
| Unilateral | 342 (55.0) | 754 (46.4) | <.001 |
| Bilateral | 280 (45.0) | 871 (53.6) | |
| Timing | |||
| Immediate | 516 (83.0) | 1555 (95.7) | <.001 |
| Delayed | 106 (17.0) | 70 (4.3) | |
| Chemotherapy | |||
| Yes | 585 (94.1) | 588 (36.2) | <.001 |
| No | 37 (5.9) | 1037 (63.8) | |
| Lymph node biopsy | |||
| SLNB | 130 (20.9) | 995 (61.2) | <.001 |
| ALND | 367 (59.0) | 326 (20.1) | |
| None | 125 (20.1) | 304 (18.7) | |
| Obesity status by BMI, kg/m2 | |||
| <30 | 431 (69.3) | 1251 (77.0) | <.001 |
| ≥30 | 191 (30.7) | 374 (23.0) | |
| Smoking status | |||
| Nonsmoker | 387 (62.8) | 1049 (65.2) | .46 |
| Previous smoker | 213 (34.6) | 513 (31.9) | |
| Current smoker | 16 (2.6) | 47 (2.9) | |
| Diabetes | |||
| Yes | 34 (5.5) | 63 (3.9) | .10 |
| No | 588 (94.5) | 1562 (96.1) | |
| Race | |||
| White | 545 (89.1) | 1399 (87.0) | .17 |
| Black | 39 (6.4) | 101 (6.3) | |
| Other | 28 (4.6) | 108 (6.7) | |
| Ethnicity | |||
| Hispanic/Latino | 39 (6.3) | 89 (5.6) | .50 |
| Non-Hispanic/Latino | 576 (93.7) | 1502 (94.4) | |
| Education | |||
| No college | 196 (31.7) | 415 (25.6) | .004 |
| College | 422 (68.3) | 1204 (74.4) | |
| Employment status | |||
| Full-time (include student) | 353 (57.6) | 924 (57.6) | .31 |
| Part-time | 72 (11.7) | 223 (13.9) | |
| Unemployed | 188 (30.7) | 456 (28.4) | |
| Household annual income | |||
| <$50 000 | 123 (20.3) | 273 (17.3) | .13 |
| $50 000–$99 999 | 202 (33.4) | 507 (32.1) | |
| ≥$100 000 | 280 (46.3) | 798 (50.6) |
*
Based on a two-sided chi-square test. ALND = axillary lymph node dissection; BMI = body mass index; SLNB = sentinel lymph node biopsy.