A Systematic Review of Sex Differences of Incidence and Overall Survival in 15 Non-Reproductive Cancers

ABSTRACT

Sex is an important factor that influences disease development, progression, and treatment. In multiple non-reproductive cancers, sex differences in incidence, progression, treatment response, survival, and other clinical outcomes are observed. Overall, males have a 20% higher chance of developing cancer over their lifetime, and experience worse clinical outcomes when compared with females. The NIH recognizes the importance of sex as a biologic variable and addressing sex as a biological variable is now required for all researchers submitting NIH grants. While more researchers are investigating the role of sex differences in cancer, a systematic review that examines the patterns of sex differences in incidence and survival across 15 non-reproductive cancers has not yet been published. We performed a systematic review by searching five databases using keywords and controlled vocabulary terms for each concept of interest and limited to English language. Records were included if it reported sex differences in human adults (18+), addressed incidence, mortality, or survival, at least one of the 15 cancers of interest, and were a cohort, cross-sectional, RCT, or case control study. Covidence was used for screening and two reviewers independently screened each record at title/ and then full text. Two reviewers independently completed data extraction using Microsoft Excel and the Cochrane RoB 2.0, and JBI tools were used for risk of bias assessment. The searches and pilot of the methods are underway. Understanding the role sex-differences play on incidence and survival are important for adding to our understanding of advances in diagnosis and treatment of individuals with cancer.