Risk of gynaecologic cancers in women with metabolic syndrome: A systematic review & meta-analysis

Background & objectives Metabolic syndrome may be associated with the risk of gynaecological cancers. This systematic review aims to evaluate the risk of gynaecological cancers among women with metabolic syndrome. Methods Studies published in English using a search strategy across PubMed, Google Scholar, and Scopus were identified from the earliest available indexing of the respective databases up to September 12-14, 2023. After removing duplicates and conducting a detailed screening by two independent reviewers, 25 studies were identified. Critical appraisal was conducted using JBI checklists for case-control and cohort studies and AXIS checklist for cross-sectional studies. Data extraction was conducted for information pertaining to study design, participant demographics, definition of metabolic syndrome, reported summary measures and type of gynaecological cancer. Results Random effects models were employed separately for each study design, reported summary measures and the type of gynaecological cancers. In case-control, cross-sectional, and cohort studies, presence of metabolic syndrome was associated with uterine/endometrial cancer [odds ratio (OR) 1.99, P<0.01, OR 2.64, P<0.01, hazard ratio (HR) 1.45, P=0.04], respectively. Case-control and cohort studies in ovarian cancer suggested association (OR 3.44, P<0.01, OR 1.02, P=0.79, and HR 1.02, P=0.80). Cohort studies in cervical cancer patients, yielded HR 1.26, P=0.96 and adjusted HR 1.27, P=0.83. The critical appraisal of the included studies was high. GRADE reported low-quality evidence for cervical, uterine/endometrial, and ovarian cancer. Interpretation & conclusions Women with metabolic syndrome are associated with increased risk of gynaecological cancers regardless of study design, type of gynaecological cancer and definitions of metabolic syndrome.