Table 1 Demographic and treatment characteristics for 818 patients undergoing mastectomy and receiving postmastectomy radiotherapy
Total | IBR+ | IBR- | ||
|---|---|---|---|---|
Characteristics | n = 818 (%) | n = 162 (%) | n = 656 (%) | P- value¶ |
Age at mastectomy, years | ||||
Median [min-max] | 58 [21-90] | 45 [21-69] | 58 [21-90] | <0.001 |
≤55 | 363 (44.4) | 136 (84.0) | 227 (34.6) | |
>55 | 455 (55.6) | 26 (16.0) | 429 (65.4) | <0.001 |
Calendar year mastectomy | ||||
2009 | 260 (31.8) | 61 (37.7) | 199 (30.3) | |
2010 | 292 (35.7) | 47 (29.0) | 245 (37.4) | |
2011 | 266 (32.5) | 54 (33.3) | 212 (32.3) | 0.093 |
Side# | ||||
Right | 391 (47.8) | 90 (55.6) | 301 (45.9) | |
Left | 427 (52.2) | 72 (44.4) | 355 (54.1) | 0.027 |
Tumor size | ||||
pT1 | 309 (37.8) | 72 (44.4) | 237 (36.1) | |
pT2 | 333 (40.7) | 57 (35.2) | 276 (42.1) | |
pT3 | 125 (15.3) | 25 (15.4) | 100 (15.2) | 0.15 |
Missing* | 51 (6.2) | 8 (4.9) | 43 (6.6) | |
Lymph nodes | ||||
pN0 | 295 (36.1) | 83 (51.2) | 212 (32.3) | |
pN+ | 511 (62.5) | 77 (47.5) | 434 (66.2) | <0.001 |
Missing* | 12 (1.5) | 2 (1.2) | 10 (1.5) | |
Adjuvant chemotherapy | ||||
Yes | 388 (47.4) | 91 (56.2) | 297 (45.3) | |
No | 415 (50.7) | 70 (43.2) | 345 (52.6) | 0.020 |
Missing* | 15 (1.8) | 1 (0.6) | 14 (2.1) | |
Neoadjuvant chemotherapy | ||||
No | 559 (68.3) | 130 (80.2) | 429 (65.4) | |
Yes | 259 (31.7) | 32 (19.8) | 227 (34.6) | <0.001 |
Endocrine therapy | ||||
Yes | 643 (78.6) | 110 (67.9) | 533 (81.3) | |
No | 164 (20.1) | 49 (30.2) | 115 (17.5) | <0.001 |
Missing* | 11 (1.3) | 3 (1.9) | 8 (1.2) | |
RT target | ||||
Chest wall | 242 (29.6) | 80 (49.4) | 162 (24.7) | |
Chest wall plus lymph nodes | 576 (70.4) | 82 (50.6) | 494 (75.3) | <0.001 |
Boost dose | ||||
Yes | 27 (3.3) | 3 (1.9) | 24 (3.7) | |
No | 791 (96.7) | 159 (98.1) | 632 (96.3) | 0.33 |
Bolus field | ||||
Yes | 34 (4.2) | 3 (1.9) | 31 (4.7) | |
No | 784 (95.8) | 159 (98.1) | 625 (95.3) | 0.12 |
Breast implant | ||||
Permanent expander | 92 (56.8) | 92 (56.8) | - | |
Permanent implant | 40 (24.7) | 40 (24.7) | - | |
Temporary expander with a magnetic port | 30 (18.5) | 30 (18.5) | - | - |