Table 4. Inclusion criteria for eligible studies.

Study types	observational studies (prospective or retrospective)
Language	English, Chinese
Databases	PubMed, Wiley Online Library, Science Direct, EMBASE, Cochrane Central Register of Controlled Trials, ISI Web of Science, China National Knowledge Infrastructure (CNKI) and Wanfang database
Tumor type	female reproduction malignancies
Sample	tissue
Sample size	>50
Tumor stage	unlimited
Examined method	IHC
Follow-up	unlimited
Outcome	OS, CSS, DFS and metastasis
Analysis	presenting the HRs/ORs value and its 95% CIs, Kaplan-Meier survival curves or relevant data to calculate HRs/ORs

IHC: immunohistochemistry; OS: overall survival; CSS: cancer-specific survival; DFS: disease-free survival.