Prognostic Value of Pretreatment D-Dimer Level in Small-Cell Lung Cancer: A Meta-Analysis

Purpose: Pretreatment plasma d-dimer has been reported to be a potential prognostic indicator of lung cancer. To determine the prognostic significance of pretreatment d-dimer level in predicting clinical outcomes, such as the overall survival (OS) and progression-free survival (PFS), of patients with small cell lung cancer (SCLC). Methods: A systematic search in PubMed, Web of Science, EMBASE, Cochrane Library, CNKI, SinoMed, Wanfang and VIP databases was performed to identify available studies. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were applied to assess the association of pretreatment d-dimer level with prognosis of SCLC patients. All statistical analyses were conducted via the STATA 12.0 version software. Results: A total of 7 studies involving 964 patients were included in this meta-analysis and all patients were from China. The results showed that elevated pretreatment d-dimer level was significantly correlated with worse OS (HR = 1.90, 95% CI: 1.55-2.34, P < 0.001) and PFS (HR = 1.52, 95% CI: 1.24-1.85, P<0.001). Subgroup analyses based on the treatment, d-dimer cut-off, detection method and source of HR were also performed to further verify the prognostic value of pretreatment d-dimer level in SCLC. Conclusions: Pretreatment blood concentration of d-dimer may deserve as a reliable factor to predict prognosis of Chinese patients with SCLC. More well-designed prospective studies with large samples are still needed to verify our findings.