The Association Between Overweight or Obesity and Prognosis of Kidney Cancer: A Study Protocol of An Updated Systematic Review and Meta-Analysis

Introduction: Kidney cancer is among the 10 most common cancers in both men and women. As we know, obesity and overweight is one of the confirmed risk factors. However, several studies found that overweight or obese patients with kidney cancer had a better prognosis than normal weight patients, as known as the “obesity paradox”. Therefore, in this study, we aimed to conduct a systematic meta- analysis of peer- reviewed literature to investigate the association between obesity or overweight and kidney cancer outcomes.Methods and analysis: Our review will assess case-control or cohort studies on prognosis of kidney cancer patients who are classified as obese, overweight or normal weight before 1 August 2020. Databases to be searched include PubMed/MEDLINE, Scopus, Web of Science and Embase. Two authors will independently conduct eligible studies selection process, perform data extraction and appraise the quality of included studies. Original case-control or cohort studies published in English will be considered for inclusion. The outcomes of interest will be progression-free survival, cancer- specific survival and overall survival. Meta-analyses will be performed to calculate pooled estimates. Ethics and dissemination: Our study will be based on published data, and thus there is no requirement for ethics approval. The results will be shared through publication in a peer- reviewed journal and presentations at academic conferences. PROSPERO registration number: CRD42021223347