Search results and study selection
385 researches were obtained from the original search,21 duplicate
records were removed. Following screening title and abstract, 291
publications were excluded owing to case reports, case series, comments,
reviews, letters, editorials, animal models. The remaining 46 records
were obtained for full-text assessment. Whereafter,32 publications were
removed according to the items of exclusion criteria after checking the
full-text. Such as veteran studies were excluded for its very high male
proportion (almost 100%) which may cause bias to the result. Besides,
publications without enough data for calculating pooled HRs for PFS and
OS were also excluded. Eventually, 14 studies were eligible for this
meta-analysis. A PRISMA flow chart
describing the process of study screen and selection was presented in
Figure 1.