{"paper_id":"220176e4-8a93-4deb-afb2-b79d5a381c7b","body_text":"INTRODUCTION \nReview question / Objective: Increased risk \no f o v a r i a n c a n c e r ( O C ) a m o n g \nendometriosis patients has been proposed. \nHowever, the association between \nendometriosis and prognosis of OC \nremains controversial. This study evaluated \nwhether endometriosis had influence on \nthe survival outcomes of OC through a \nmeta-analysis. \nCondition being studied: Relevant studies \nwere retrieved from PubMed, Embase, and \nWeb of Science databases and were \nevaluated using the Newcastle-Ottawa \nQuality Assessment Scale. Effect size was \npresented as hazard ratio (HR) and 95% \nINPLASY 1\nInternational Platform of Registered Systematic Review and Meta-analysis Protocols\nINPLASY\nPROTOCOL Association between endometriosis \nand prognosis of ovarian cancer: an \nupdated meta-analysis\nChen, P1; Zhang, CY2.\nTo cite: Chen et al. Association \nbetween endometriosis and \nprognosis of ovarian cancer: \nan updated meta-analysis. \nInplasy protocol 202230109. \ndoi: \n10.37766/inplasy2022.3.0109\nReceived: 21 March 2022\nPublished: 21 March 2022\nReview question / Objective: Increased risk of ovarian cancer \n(OC) among endometriosis patients has been proposed. \nHowever, the association between endometriosis and \nprognosis of OC remains controversial. This study evaluated \nwhether endometriosis had in fluence on the survival \noutcomes of OC through a meta-analysis. \nEligibility criteria: (1) non-original articles, such as reviews, \nconference abstracts and comments; (2) the studies that \nprovide only a figure but not a detailed HR (95% CI) to show \nthe results of survival analysis; (3) duplicate studies or \nmultiple studies involving the same data, with only the one \nwith the most complete information included. \nINPLASY registration number: This protocol was registered with \nthe International Platform of Registered Systematic Review and \nMeta-Analysis Protocols (INPLASY) on 21 March 2022 and was \nlast updated on 21 March 2022 (registration number \nINPLASY202230109). \nCorresponding author: \nChi-Yuan Zhang \nzcysjcmu@163.com \nAuthor Affiliation:                  \nDepartment of Obstetrics and \nGynecology, Shengjing \nHospital of China Medical \nUniversity. \nSupport: The Natural Science \nFoundation. \nReview Stage at time of this \nsubmission: Completed and \npublished. \nConflicts of interest:          \nNone declared.\nChen et al. Inplasy protocol 202230109. doi:10.37766/inplasy2022.3.0109\nChen et al. Inplasy protocol 202230109. doi:10.37766/inplasy2022.3.0109 Downloaded from https://inplasy.com/inplasy-2022-3-0109/\n\nconfidence interval (CI). Heterogeneity test \nevaluation was performed using Cochran’s \nQ test and I2 statistics. Publication bias \nwas determined using Egger’s test. \nStatistical analysis was performed using \nStata 12.0 software. \nMETHODS \nSearch strategy: According to a pre-\nestablished retrieval strategy, the relevant \nstudies were systematically retrieved from \nPubMed, Embase, Web of Science \ndatabases with the retrieval time up to May \n11, 2021 and without language restrictions. \nThe search terms contained three \ncategories: research object (\"ovarian \nneoplasm\", \"ovarian cancer\", \"ovary \nneoplasm\", \"ovary cancer\", \"ovarian \ncarcinoma\", \"ovary carcinoma\"), exposure \nfactors (“endometriosis”, “endometrioses”) \nand outcomes (\"mortality\", \"survival\", \n\"prognosis\"). Two search terms in the same \ncategory are combined with \"OR\", while \n\"AND\" was used between two search \nterms of different categories. The detailed \nretrieval strategies for different databases \nare listed in Table S1. Additionally, manual \nretrieval was carried out for the paper \nversion of the relevant studies, and the \nreferences of the relevant reviews and \nincluded studies were also retrieved. \nParticipant or population: Patients who \nwere pathologically and histologically \ndiagnosed as epithelial ovarian cancer \nwere included. \nI n t e r v e n t i o n : P a t i e n t s w h o w e r e \npathologically and histologically diagnosed \nas epithelial ovarian cancer were included. \nComparator: Patients with or without \nendometriosis. \nS t u d y d e s i g n s t o b e i n c l u d e d : \nRetrospective or prospective cohort \nstudies or nested case-control studies. \nEligibility criteria: (1) non-original articles, \nsuch as reviews, conference abstracts and \ncomments; (2) the studies that provide only \na figure but not a detailed HR (95% CI) to \nshow the results of survival analysis; (3) \nduplicate studies or multiple studies \ninvolving the same data, with only the one \nwith the most complete information \nincluded. \nInformation sources: The relevant studies \nwere systematically retrieved from \nPubMed, Embase, Web of Science \ndatabases. \nMain outcome(s): EAOC patients tended to \nhave better OS and PFS than non-EAOC \npatients. Conducting higher quality \nprospective cohort studies with large \nsample sizes is recommended to confirm \nthe authenticity of the current study’s \nresults. \nQuality assessment / Risk of bias analysis: \nOn the basis of the above selection criteria, \nstudy retrieval was carried out by two \nindependent investigators. \nStrategy of data synthesis: All statistical \nanalyses were completed using Stata 12.0 \nsoftware. HR and 95% CI were utilized as \neffect size indicators to evaluate the \ndifferences on PFS and OS of EAOC vs. \nnon-EAOC. Cochran’s Q test and I2 test \nwere used to assess the heterogeneity \namong studies. Significant heterogeneity \nwas determined with P50%, and a random-\neffects model was utilized. A fixed-effects \nmodel was utilized when no signi ficant \nheterogeneity was observed (P≥0.05 and \nI2≤50%). The effect of region, confounding \nfactors adjusted or not for heterogeneity, \nand the pooled results were evaluated with \na subgroup analysis. Publication bias \nevaluation was conducted using Egger’s \ntest. If there was significant publication \nbias, the stability of the results of the meta-\nanalysis was evaluated using the trim-and-\nfill method. The stability of the results was \nalso evaluated using the method of \nelimination one by one. \nSubgroup analysis: All statistical analyses \nwere completed using Stata 12.0 software. \nHR and 95% CI were utilized as effect size \nindicators to evaluate the differences on \nPFS and OS of EAOC vs. non-EAOC. \nCochran’s Q test and I2 test were used to \nassess the heterogeneity among studies. \nINPLASY 2Chen et al. Inplasy protocol 202230109. doi:10.37766/inplasy2022.3.0109\nChen et al. Inplasy protocol 202230109. doi:10.37766/inplasy2022.3.0109 Downloaded from https://inplasy.com/inplasy-2022-3-0109/\n\nSignificant heterogeneity was determined \nwith P50%, and a random-effects model \nwas utilized. A fixed-effects model was \nutilized when no significant heterogeneity \nwas observed (P≥0.05 and I2≤50%). The \neffect of region, confounding factors \nadjusted or not for heterogeneity, and the \npooled results were evaluated with a \nsubgroup analysis. Publication bias \nevaluation was conducted using Egger’s \ntest. If there was significant publication \nbias, the stability of the results of the meta-\nanalysis was evaluated using the trim-and-\nfill method. The stability of the results was \nalso evaluated using the method of \nelimination one by one. \nSensitivity analysis: All statistical analyses \nwere completed using Stata 12.0 software. \nHR and 95% CI were utilized as effect size \nindicators to evaluate the differences on \nPFS and OS of EAOC vs. non-EAOC. \nCochran’s Q test and I2 test were used to \nassess the heterogeneity among studies. \nSignificant heterogeneity was determined \nwith P50%, and a random-effects model \nwas utilized. A fixed-effects model was \nutilized when no significant heterogeneity \nwas observed (P≥0.05 and I2≤50%). The \neffect of region, confounding factors \nadjusted or not for heterogeneity, and the \npooled results were evaluated with a \nsubgroup analysis. Publication bias \nevaluation was conducted using Egger’s \ntest. If there was significant publication \nbias, the stability of the results of the meta-\nanalysis was evaluated using the trim-and-\nfill method. The stability of the results was \nalso evaluated using the method of \nelimination one by one. \nCountry(ies) involved: China. \nKeywords: endometriosis, ovarian cancer, \nprognosis, meta-analysis. \nContributions of each author: \nAuthor 1 - Peng Chen. \nAuthor 2 - Chi-Yuan Zhang. \nINPLASY 3Chen et al. Inplasy protocol 202230109. doi:10.37766/inplasy2022.3.0109\nChen et al. Inplasy protocol 202230109. doi:10.37766/inplasy2022.3.0109 Downloaded from https://inplasy.com/inplasy-2022-3-0109/","source_license":"CC0","license_restricted":false}