J Cancer 2016; 7(9):1105-1113. doi:10.7150/jca.14801 This issue
1. Department of Gastrointestinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China;
2. Department of Research Administration, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.
Background: Circulating cell-free DNA (cfDNA) is a promising candidate biomarker for detection, monitoring and survival prediction of colorectal cancer (CRC). However, its prognostic significance for patients with CRC remains controversial. To derive a precise estimation of the prognostic significance of cfDNA, a meta-analysis was performed.
Methods: We made a systematic search in data base of the Science Citation Index Embase and Pubmed for studies reporting prognostic data of cfDNA in CRC patients. The data of cfDNA on recurrences-free survival (RFS) and overall survival (OS) were extracted and measured in hazard rates (HRs) and 95% confident intervals (CIs). Subgroup analyses were carried out as well. Finally, the meta-analysis is accompanied with nine studies including 19 subunits.
Results: The pooled HRs with 95% CIs revealed strong associations between cfDNA and RFS (HR [95%CI]=2.78[2.08-3.72], I2=32.23%, n=7) along with OS (HR [95%CI]=3.03[2.51-3.66], I2=29.24%, n=12) in patients with CRC. Entire subgroup analyses indicated strong prognostic value of cfDNA irrespective tumor stage, study size, tumor markers, detection methods and marker origin.
Conclusions: All the results exhibits that appearance of cfDNA in blood is an indicator for adverse RFS and OS in CRC patients.
Keywords: Plasma DNA, cell-free DNA, colorectal cancer, prognosis, meta-analysis.