Table 1. Selection criteria.
| Study type | Key search string(s) | Inclusion | Exclusion |
|---|---|---|---|
| Surgical | “Breast spine metastatic surgery” | • Publication date: 1990 or later • Language: English or with a complete English translation • Articles describing operative techniques used to treat spinal metastases in patients with breast cancer • Fully published, peer-reviewed, retrospective or prospective studies including randomized controlled trials, nonrandomized trials, cohort studies, case control studies, and case series |
• Articles that did not provide clinical outcomes and statistics specific to the patients with breast spinal metastases • Articles that lumped all breast spinal metastases cohort outcomes with that of other primary tumor types • Study size: <6 patients in the breast spinal metastases cohort with respect to surgical techniques • Articles that did not specify the operative procedure used |
| Cement augmentation procedure | “Kyphoplasty breast cancer”; “vertebroplasty breast cancer” | • Articles that did not provide clinical outcomes and statistics specific to the patients with breast spinal metastases • Articles that lumped all breast spinal metastases cohort outcomes with that of other primary tumor types • Study size: <2 patients with breast cancer related spinal metastases • Articles that did not specify the operative procedure used |
|
| Supplementary prognostic variable studies | “Metastatic free interval prognostic breast” | • Publication date: 2000 or later • Language: English or with a complete English translation • Articles evaluating statistical significance of prognostic variables in metastatic breast cancer patients • Fully published, peer-reviewed, retrospective or prospective studies including randomized controlled trials, nonrandomized trials, cohort studies, case control studies, and case series • MFI or DFI exclusively defined as time between diagnosis of primary disease and first metastasis |
• Study size: ≤300 patients • Studies not investigating MFI/DFI prognostic variable as defined in the inclusion criteria |
Abbreviations: DFI, disease-free interval; MFI, metastatic-free interval.