Table 3. Prognostic factors for which univariate analyses were reported in at least two cohorts.
| Prognostic factors | Number/significant* |
|---|---|
| DFI | 15/9 (12,19,21,22,26,27,29,30,32) |
| <5 years | 1/0 |
| <3 years | 8/7 (19,21,26,27,29,30,32) |
| <2 years | 5/1 (12) |
| <1 year | 1/1 (22) |
| Resection of metastases (incomplete vs. complete) | 8/4 (23,27,29,31) |
| No. of pulmonary metastases (multiple vs. solitary) | 14/3 (19,23,25) |
| The HR status of metastases (negative vs. positive) | 9/3 (12,23,24) |
| Size of the largest metastasis (≥2 vs. <2 cm) | 6/2 (23,32) |
| Site of metastases (bilateral vs. unilateral) | 6/2 (19,29) |
| Stage of breast cancer at breast surgery | 5/1 (21) |
| No. of metastasectomies (redo vs. primary) | 3/1 (29) |
| Pleural invasion (yes vs. no) | 2/1 (23) |
| Additional adjuvant therapy | 6/0 |
| Age at metastasectomy | 6/0 |
| Type of surgical procedures | 4/0 |
| Nodal status of primary tumor | 4/0 |
| Other recurrence site before lung surgery | 2/0 |
| Histologic grade of breast cancer | 2/0 |
*, number of cohorts in which the factor was reported/number of cohorts in which a significant association with poor outcome was reported (log-rank test, α<0.05). DFI, disease-free interval.