Prognostic factors for overall survival in patients with spinal metastasis secondary to prostate cancer: a systematic review and meta-analysis

BACKGROUND: To guide the selection of treatments for spinal metastases, the expected survival time is one of the most important determinants. Few scoring systems are fully applicable for spinal metastasis secondary to prostate cancer (PCa). This study aimed to identify the independent factors to predict the overall survival (OS) of patients with spinal metastases from PCa. METHODS: The PubMed, Embase and CENTRAL were retrieved by two reviewers independently, to identify studies analyzed the prognostic effect of different factors in spinal metastasis from PCa. A systematic review and quantitative meta-analysis was conducted with hazard ratio (HR) and 95% confidence interval (95%CI) as the effect size. RESULTS: A total of 12 retrospective cohort studies (1566 patients) were eligible for qualitative synthesis and 10 for quantitative meta-analyses. The OS was significantly influenced by performance status, visceral metastasis, ambulatory status and time from PCa diagnosis in more than half of the available studies. The meta-analyses demonstrated that OS was significantly influenced by visceral metastasis (HR = 2.24, 95%CI:1.53–3.27, p < 0.001), pre-treatment ambulatory status (HR = 2.64, 95%CI:1.82–3.83, p < 0.001), KPS (HR = 4.45, 95%CI:2.01–9.85, p < 0.001), ECOG (HR = 2.96, 95%CI:2.02–4.35, p < 0.001), extraspinal bone metastasis (HR = 2.04, 95%CI:1.13–3.68, p = 0.018), time developing motor deficit (HR = 1.57, 95%CI:1.30–1.88, p < 0.001) and time from PCa diagnosis (HR = 1.37, 95%CI:1.17–1.59, p < 0.001). CONCLUSIONS: Visceral metastasis, ambulatory status, extraspinal bone metastasis, performance status, time developing motor deficit and time interval from primary tumor diagnosis were significantly associated with the OS for spinal metastasis from PCa. When selecting the treatment modality, clinicians should fully consider the patients’ systematic status based on all potential prognostic factors. LEVEL OF EVIDENCE: I Meta-analysis.