Table 1.
Patient characteristics and treatment according to gBRCA1/2 mutation status defined at baseline (treatment initiation).
| gBRCAm | gBRCAwt | Not Tested | ||
|---|---|---|---|---|
| (N = 170) | (N = 676) | (N = 12,930) | p-value | |
| Age at metastatic disease diagnosis (years) | <0.0001 | |||
| Median | 47.0 | 51.0 | 62.0 | |
| (Range) | (26.0;82.0) | (26.0;88.0) | (22.0;103.0) | |
| Age at metastatic disease diagnosis | <0.0001 | |||
| <50 years | 101 (59.4%) | 314 (46.4%) | 2358 (18.2%) | |
| 50–70 years | 57 (33.5%) | 306 (45.3%) | 6947 (53.7%) | |
| >70 years | 12 (7.1%) | 56 (8.3%) | 3625 (28.0%) | |
| Gender | 0.0163 | |||
| Female | 166 (97.6%) | 663 (98.1%) | 12,801 (99.0%) | |
| Male | 4 (2.4%) | 13 (1.9%) | 129 (1.0%) | |
| Germline BRCA mutation — no. (%) | ||||
| BRCA1 | 51 (30.0%) | NR | NR | |
| BRCA2 | 117 (68.8%) | NR | NR | |
| BRCA1 and BRCA2 | 2 (1.2%) | NR | NR | |
| Histological grade of primary tumour | <0.0001 | |||
| Grade I | 7 (4.9%) | 74 (13.1%) | 1541 (14.4%) | |
| Grade II | 74 (51.4%) | 319 (56.6%) | 6532 (60.9%) | |
| Grade III | 63 (43.8%) | 171 (30.3%) | 2661 (24.8%) | |
| Missing | 26 | 112 | 2196 | |
| Histological type of primary tumour | <0.0001 | |||
| Invasive ductal carcinoma | 134 (79.3%) | 505 (75.3%) | 9146 (72.2%) | |
| Invasive lobular carcinoma | 13 (7.7%) | 76 (11.3%) | 2177 (17.2%) | |
| Other | 22 (13.0%) | 90 (13.4%) | 1351 (10.7%) | |
| Missing | 1 | 5 | 256 | |
| Primary tumour surgery | <0.0001 | |||
| No | 18 (10.7%) | 55 (8.1%) | 3214 (25.3%) | |
| Yes | 151 (89.3%) | 620 (91.9%) | 9484 (74.7%) | |
| Missing | 1 | 1 | 232 | |
| Metastasis-free interval (months) | <0.0001 | |||
| <6 months | 10 (5.9%) | 26 (3.8%) | 3904 (30.3%) | |
| [6–24] months | 21 (12.4%) | 72 (10.7%) | 1002 (7.8%) | |
| >24 months | 139 (81.8%) | 578 (85.5%) | 7991 (62.0%) | |
| Missing | 0 | 0 | 33 | |
| De novo metastatic disease | <0.0001 | |||
| No | 160 (94.1%) | 650 (96.2%) | 8997 (69.8%) | |
| Yes | 10 (5.9%) | 26 (3.8%) | 3900 (30.2%) | |
| Missing | 0 | 0 | 33 | |
| Number of metastatic sites at MBC diagnosis | 0.0034 | |||
| 1 site | 78 (45.9%) | 366 (54.1%) | 7252 (56.1%) | |
| 2 sites | 37 (21.8%) | 165 (24.4%) | 3036 (23.5%) | |
| ≥3 sites | 55 (32.4%) | 145 (21.4%) | 2642 (20.4%) | |
| Type of Metastases at MBC diagnosis | 0.0003 | |||
| Visceral | 115 (67.6%) | 383 (56.7%) | 6910 (53.4%) | |
| Non-visceral | 55 (32.4%) | 293 (43.3%) | 6020 (46.6%) | |
| Bone metastases only | <0.0001 | |||
| No | 136 (80.0%) | 507 (75.0%) | 8898 (68.8%) | |
| Yes | 34 (20.0%) | 169 (25.0%) | 4032 (31.2%) | |
| Adjuvant endocrine therapy | <0.0001 | |||
| No | 40 (23.0%) | 115 (17%) | 5356 (41.5%) | |
| Yes | 130 (76.5%) | 561 (83.0%) | 7543 (58.5%) | |
| Aromatase inhibitor | 56 | 240 | 4343 | |
| Tamoxifen | 100 | 434 | 4006 | |
| LHRH analogues | 11 | 89 | 369 | |
| Others | 1 | 2 | 63 | |
| Missing | 3 | 11 | 628 | |
| Chemotherapy or Endocrine therapy within first treatment line | <0.0001 | |||
| Chemotherapy alone | 55 (32.4%) | 153 (22.6%) | 2463 (19.0%) | |
| Endocrine therapy alone | 46 (27.1%) | 266 (39.3%) | 6092 (47.1%) | |
| Chemotherapy + Endocrine therapy | 69 (40.6%) | 257 (38.0%) | 4375 (33.8%) | |
| HR status derived from a metastasis biopsy by subgroup of treatment | ||||
| Endocrine therapy alone (subgroup n = 6404) | ||||
| Yes | 24 (52.2%) | 125 (47.0%) | 2111 (34.7%) | |
| No | 22 (47.8%) | 141 (53.0%) | 3981 (65.3%) | |
| Chemotherapy +/− Endocrine therapy (subgroup n = 7372) | ||||
| Yes | 27 (21.8%) | 135 (32.9%) | 2010 (29.4%) | |
| No | 97 (78.2%) | 275 (67.1%) | 4828 (70.6%) | |
| CDK4-6 inhibitors within first treatment line | ||||
| No | 170 (100.0%) | 667 (98.7%) | 12,808 (99.1%) | 0.2858 |
| Yes | 0 (0.0%) | 9 (1.3%) | 122 (0.9%) | |
| PARP inhibitor within first treatment line | ||||
| No | 163 (95.9%) | 676 (100.0%) | 12,927 (100.0%) | |
| Yes | 7 (4.1%) | 0 (0.0%) | 3 (0.0%) | |
Statistically significant p-values are in bold.