Table 1.
Patient demographics and disease characteristics of the endocrine and chemotherapy groups.
| Characteristics | Initial chemotherapy, N = 277, n (%) | Initial endocrine therapy, N = 280, n (%) | P |
|---|---|---|---|
| Age at MBC diagnosis | |||
| Median in years (IQR) | 61 (50–69) | 73 (61–80) | <0.0001a |
| <65 years | 170 (61) | 97 (35) | <0.0001 |
| ≥65 years | 107 (39) | 183 (65) | |
| Menopausal status | <0.0001 | ||
| Premenopausal | 83 (30) | 35 (12) | |
| Postmenopausal | 194 (70) | 245 (88) | |
| Charlson Comorbidity Index (CCI) | |||
| CCI = 0 | 178 (64) | 130 (46) | <0.0001 |
| CCI > 0 | 99 (36) | 150 (54) | |
| Primary tumour diagnostic year | |||
| <2008 | 97 (35) | 119 (42) | 0.07 |
| ≥2008 | 180 (65) | 161 (58) | |
| Primary tumour type | 0.2543 | ||
| Ductal | 231 (83) | 223 (80) | |
| Lobular | 46 (17) | 57 (20) | |
| Hormone receptor status | |||
| ER positive | 269 (97) | 276 (99) | 0.2355 |
| PR positive | 199 (72) | 208 (74) | 0.2388 |
| Primary tumour stageb | 0.1053 | ||
| T1–T2 | 187 (67) | 172 (61) | |
| T3–T4 | 88 (32) | 108 (39) | |
| Unknown | 2 (1) | 0 | |
| Node statusb | 0.9667 | ||
| Node negative | 139 (50) | 140 (50) | |
| Node positive | 132 (48) | 132 (48) | |
| Unknown | 6 (2) | 8 (2) | |
| Adjuvant systemic therapyc | |||
| Endocrine therapy | 164 (91) | 105 (74) | <0.0001 |
| Chemotherapy | 141 (78) | 82 (58) | <0.0001 |
| None | 6 (3) | 24 (17) | <0.0001d |
| Adjuvant radiotherapyc | 0.3244 | ||
| Yes | 163 (90) | 122 (87) | |
| No | 18 (10) | 19 (13) | |
| Primary metastatic disease | |||
| Yes | 96 (35) | 139 (50) | 0.0002 |
| No | 181 (65) | 141 (50) | |
| Metastasis-free intervalc | 0.1423 | ||
| <24 months | 26 (14) | 29 (21) | |
| ≥24 months | 155 (86) | 112 (79) | |
| Initial metastatic sites | <0.0001 | ||
| Bone only | 62 (22) | 136 (49) | |
| Visceral | 90 (33) | 66 (23) | |
| Multiple | 125 (45) | 78 (28) | |
| Endocrine resistance | 0.0003 | ||
| Primary | 50 (18) | 35 (13) | |
| Secondary | 74 (27) | 45 (16) | |
| Hormone responsive | 153 (55) | 200 (71) | |
Bold values indicate statistically significant results.
n number, IQR interquartile range, MBC metastatic breast cancer, ER oestrogen receptor, PR progesterone receptor.
aWilcoxon rank-sum test.
bFifth edition before 2008 and sixth edition since 2008 of the TNM classification of malignant tumours.
cOnly on secondary metastatic diseases.
dFisher’s exact test.