Table 1.
Baseline cohort characteristics.
| Characteristic, N (%) | Overall | By weight change | |||
| Gain ≥5% | Stable ±5% | Loss ≥5% | p-value^ | ||
| 993 (100) | 140 (14.1) | 668 (67.3) | 185 (18.6) | ||
| Baseline BMI, kg/m2 | |||||
| Mean (SD) | 34.5 (4.1) | 34.4 (3.8) | 34.4 (3.9) | 35.2 (4.7) | 0.185 |
| Missing | – | – | – | – | |
| Baseline BMI, WHO categories53 | |||||
| Obese class I | 640 (64.4) | 92 (65.7) | 439 (65.7) | 109 (58.9) | 0.2140 |
| Obese class II | 248 (25.0) | 34 (24.3) | 169 (25.3) | 45 (24.3) | |
| Obese class III | 105 (10.6) | 14 (10.0) | 60 (9.0) | 31 (16.8) | |
| Missing | – | – | – | – | |
| Baseline weight, continuous, kg | |||||
| Mean (SD) | 89.4 (12.8) | 89.0 (12.1) | 88.9 (12.7) | 91.5 (13.2) | 0.099 |
| Missing | – | – | – | – | |
| Age at diagnosis, years | |||||
| Mean (SD) | 59.1 (10.5) | 54.2 (10.8) | 60.1 (10.5) | 59.3 (9.2) | <.0001 |
| Missing | – | – | – | – | |
| Age at diagnosis, years | |||||
| < 50 | 194 (19.5) | 44 (31.4) | 118 (17.7) | 32 (17.3) | <.0001 |
| 50-64 | 471 (47.4) | 72 (51.4) | 302 (45.2) | 97 (52.4) | |
| ≥65 | 328 (33.1) | 24 (17.2) | 248 (37.1) | 56 (30.3) | |
| Missing | – | – | – | – | |
| Marital status | |||||
| In a relationship | 687 (74.9) | 107 (83.6) | 463 (74.4) | 117 (70.1) | 0.325 |
| Not in a relationship∗ | 230 (25.1) | 21 (16.4) | 159 (25.6) | 50 (29.9) | |
| Missing | 76 | 12 | 46 | 18 | |
| Highest education level achieved | |||||
| Primary or lower | 256 (27.9) | 34 (25.6) | 180 (29.0) | 42 (24.8) | 0.176 |
| High school | 451 (49.1) | 67 (52.3) | 308 (49.6) | 76 (45.0) | |
| College graduate or higher | 211 (23.0) | 27 (21.1) | 133 (21.4) | 51 (30.2) | |
| Missing | 75 | 12 | 47 | 16 | |
| Employment status | |||||
| Professionally active | 379 (40.3) | 72 (55.4) | 245 (38.4) | 62 (36.1) | 0.019 |
| Professionally inactive | 561 (59.7) | 58 (44.6) | 393 (61.6) | 110 (63.9) | |
| Missing | 53 | 10 | 30 | 13 | |
| Monthly total householdincome | |||||
| <1500 Euro | 185 (21.0) | 27 (22.5) | 124 (20.8) | 34 (20.7) | 0.579 |
| 1500–3000 Euro | 421 (47.8) | 55 (45.8) | 294 (49.3) | 72 (43.9) | |
| ≥3000 Euro | 274 (31.1) | 38 (31.7) | 178 (29.9) | 58 (35.4) | |
| Missing | 113 | 20 | 72 | 21 | |
| Menopausal status | |||||
| Premenopausal | 249 (25.6) | 55 (40.4) | 151 (23.1) | 43 (23.6) | 0.001 |
| Postmenopausal | 724 (74.4) | 81 (59.6) | 504 (76.9) | 139 (76.4) | |
| Missing | 20 | 4 | 13 | 3 | |
| Charlson comorbidity index | |||||
| 0 | 614 (68.9) | 91 (71.6) | 410 (68.4) | 113 (68.5) | 0.594 |
| 1+ | 277 (31.1) | 36 (28.4) | 189 (31.5) | 52 (31.5) | |
| Missing | 102 | 13 | 69 | 20 | |
| Anxiety, score | |||||
| Mean (SD) | 8.8 (4.2) | 8.6 (4.1) | 8.9 (4.4) | 8.6 (3.9) | 0.644 |
| Missing | 62 | 11 | 40 | 11 | |
| Anxiety, categorical | |||||
| Non-case | 387 (41.6) | 50 (38.8) | 269 (42.8) | 68 (39.1) | 0.769 |
| Doubtful case | 246 (26.4) | 41 (31.8) | 153 (24.4) | 52 (29.9) | |
| Case | 298 (32.0) | 38 (29.4) | 206 (32.8) | 54 (31.0) | |
| Missing | 62 | 11 | 40 | 11 | |
| Depression, score | |||||
| Mean (SD) | 4.5 (3.7) | 4.4 (3.6) | 4.4 (3.6) | 4.7 (3.9) | 0.775 |
| Missing | 62 | 11 | 40 | 11 | |
| Depression, categorical | |||||
| Non-case | 736 (79.0) | 97 (75.2) | 504 (80.2) | 135 (77.6) | 0.202 |
| Doubtful case | 131 (14.1) | 25 (19.4) | 82 (13.1) | 24 (13.8) | |
| Case | 64 (6.9) | 7 (5.4) | 42 (6.7) | 15 (8.6) | |
| Missing | 62 | 11 | 40 | 11 | |
| Smoking behavior | |||||
| Current smoker | 106 (10.8) | 28 (20.4) | 63 (9.6) | 15 (8.2) | 0.017 |
| Former smoker | 200 (20.5) | 32 (23.4) | 132 (20.1) | 36 (19.7) | |
| Never smoker | 671 (68.7) | 77 (56.2) | 462 (70.3) | 132 (72.1) | |
| Missing | 16 | 3 | 11 | 2 | |
| Baseline alcohol consumption | |||||
| Daily consumption | 859 (89.9) | 17 (12.7) | 60 (9.3) | 19 (10.6) | 0.256 |
| Less than daily consumption | 96 (10.1) | 117 (87.3) | 582 (90.6) | 160 (89.4) | |
| Missing | 38 | 6 | 26 | 6 | |
| Physical Activity, MET-hours/week | |||||
| Median (IQR) | 8.0 (0.0–26.7) | 12.0 (0.0–48.0) | 8.0 (0.0–26.0) | 8.0 (0.0–19.0) | 0.215 |
| Missing | 70 | 13 | 45 | 12 | |
| Tumor stage | |||||
| I | 438 (44.1) | 56 (40.0) | 317 (47.5) | 65 (35.1) | 0.007 |
| II | 431 (43.4) | 64 (45.7) | 272 (40.8) | 95 (51.4) | |
| III | 123 (12.4) | 20 (14.3) | 78 (11.7) | 25 (13.5) | |
| Missing | 1 | – | 1 | – | |
| Tumor subtype | |||||
| HR+/HER- | 786 (79.6) | 97 (69.3) | 557 (83.8) | 132 (72.1) | <.0001 |
| HR±/HER2+ | 127 (12.8) | 22 (15.7) | 71 (10.7) | 34 (18.6) | |
| HR-/HER2- | 75 (7.6) | 21 (15.0) | 37 (5.6) | 17 (9.3) | |
| Missing | 5 | – | 3 | 2 | |
| Breast surgery | |||||
| Partial surgery | 746 (75.1) | 107 (76.4) | 508 (76.0) | 131 (70.8) | 0.471 |
| Mastectomy | 247 (24.9) | 33 (23.6) | 160 (24.0) | 54 (29.2) | |
| Missing | – | – | – | – | |
| Axillary surgery | |||||
| Axillary dissection | 436 (43.9) | 70 (50.0) | 289 (42.3) | 77 (41.6) | 0.386 |
| Sentinel lymph node∗∗ | 557 (56.1) | 70 (50.0) | 379 (56.7) | 108 (58.4) | |
| Missing | – | – | – | – | |
| Adjuvant radiation therapy | |||||
| Yes | 908 (91.6) | 129 (92.1) | 615 (92.3) | 164 (88.6) | 0.354 |
| No | 83 (8.4) | 11 (7.9) | 51 (7.6) | 21 (11.3) | |
| Missing | 2 | – | 2 | – | |
| (Neo) adjuvant chemotherapy | |||||
| Yes∗∗∗ | 532 (53.6) | 84 (60.0) | 314 (47.0) | 134 (72.4) | <.0001 |
| No | 461 (46.4) | 56 (40.0) | 354 (53.0) | 51 (27.5) | |
| Missing | – | – | – | – | |
| Adjuvant endocrine therapy | |||||
| Yes∗∗∗∗ | 829 (83.5) | 105 (75.0) | 575 (86.1) | 149 (80.5) | 0.0008 |
| No | 164 (16.5) | 35 (25.0) | 93 (13.9) | 36 (19.5) | |
| Missing | – | – | – | – | |
| Adjuvant anti-HER2 therapy | |||||
| Yes | 97 (9.8) | 18 (12.9) | 49 (7.3) | 30 (16.2) | 0.0006 |
| No | 896 (90.2) | 122 (87.1) | 619 (92.7) | 155 (83.8) | |
| Missing | – | – | – | – | |
BMI= Body Mass Index; WHO= World Health Organization; SD= Standard Deviation; IQR = interquartile range; HR= Hormone-receptor; HER2 = Human Epidermal Growth Factor receptor 2; MET = Metabolic Equivalent of Task.
^Jonckheere-Terpstra test statistics ∗Includes separated, divorced, widowed, unmarried ∗∗Includes 7 patients who did not receive any axillary lymph node surgical procedure; ∗∗∗Includes approximately 90% women receiving an anthracycline + taxane chemotherapy combination; ∗∗∗∗Patients receiving endocrine therapy were at a median of 3.9 months (IQR 3.0–5.5 months) since treatment initiation at the time of this analysis.