Data abstraction
Data abstraction was done using a standardized spreadsheet designed for
the study. Data include study characteristics (authors, year of
publication, study setting, type of the study, comparison arms, and
sample size), patient characteristics (selection frame, patient
demographics, disease stage, pathological grade, histologic type, serum
CA125), surgical management, tumor size, intraoperative findings, number
of removed lymph nodes, lymph nodes status, residual disease after
surgery, adjuvant or neoadjuvant treatment and duration of follow up.
The data were abstracted from article text, tables, and figures. Quality
assessment of included studies was assessed using US National Heart,
Lung and Blood Institute Quality Assessment Tool (9).