Abstract
Although various studies have demonstrated that growth differentiation factor 15 (GDF15) might be a potential diagnostic and prognostic marker in colorectal cancer (CRC) patients, the results are inconsistent and the statistical power of individual studies is also insufficient. An original study was conducted to explore the diagnostic and prognostic value of serum GDF15 in CRC patients. We also conducted a meta-analysis study which aimed to summarize the diagnostic and prognostic performance of serum GDF15 in CRC. We searched PubMed and ISI Web of Knowledge up to 1 November 2014 for eligible studies. In order to explore the diagnostic performance of GDF15, standardized mean difference (SMD) and their 95% confidence intervals (CI) were estimated and receiver-operating characteristic (ROC) curves were constructed. For prognostic meta-analysis, study-specific hazard ratios (HRs) of serum GDF15 for survival were summarized. A total of eight studies were included in the meta-analyses. Our results revealed that serum GDF15 levels in CRC patients were higher than those in healthy controls (SMD = 1.08, 95% CI: 0.56-1.59, P < 0.001). For discriminating CRC from healthy controls, the AUC of GDF15 was 0.816 (95% CI: 0.792-0.838). The sensitivity and specificity were 58.9% (95% CI: 55.0-62.8) and 92.08% (95% CI: 89.2-94.4), respectively, when a cut-off value of 1099 pg/ml was established. Besides, higher GDF15 expression level was associated with worse overall survival for CRC patients (pooled HR = 2.09, 95% CI: 1.47-2.96). In conclusion, the present meta-analysis suggests that serum GDF15 may be a useful diagnostic and prognostic biomarker for CRC.