Selection and eligibility
Rayyan software (Qatar Computing Research Institute, HBKU, Doha, Qatar) was used for title and abstract screening for eligibility (R.V.), and subsequent duplicate removal9. A second reviewer (J.H.) double-checked study eligibility with discrepancies solved by consensus discussion. Studies were included in our meta-analysis if they met the following predefined criteria: (1) randomized controlled trial, prospective or retrospective cohort study; (2) patients with clinically FIGO stage I or II EOC defined according to the FIGO guidelines. In most studies CT, MRI and/or ultrasound were used in the preoperative workup to detect or exclude metastatic disease; (3) comprehensive surgical staging adhering to the FIGO guideline at the time of surgery, completed in all included patients and with a full description of the performed surgery; (4) results presented on tumor status and upstaging rate for the various components of the staging surgery.
Studies were excluded when they were: (1) not written in English, non-human, or if the full-text version was not available; (2) patients with other malignancies in present or past.