Ovarian cancer in the world: epidemiology and risk factors

Zohre Momenimovahed,1,2 Azita Tiznobaik,2,3 Safoura Taheri,4 Hamid Salehiniya5,61Department of Midwifery and Reproductive Health, School of Nursing and Midwifery, Qom University of Medical Sciences, Qom, Iran; 2Department of Midwifery and Reproductive Health, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran; 3Department of Midwifery and Reproductive Health, School of Nursing and Midwifery, Hamedan University of Medical Sciences, Hamedan, Iran; 4Department of Midwifery and Reproductive Health, School of Nursing and Midwifery, Ilam University of Medical Sciences, Ilam, Iran; 5Social Determinants of Health Research Center, Birjand University of Medical Sciences, Birjand, Iran; 6Epidemiology and Biostatistics Department, School of Public Health, Tehran University of Medical Sciences, Tehran, IranAim: Ovarian cancer is one of the most common gynecologic cancers that has the highest mortality rate. Considering the fact that knowledge on the incidence, mortality of ovarian cancer, as well as its risk factors is necessary for planning and preventing complications, this study was conducted with the aim of examining the epidemiology and risk factors of ovarian cancer in the world.Materials and methods: In order to access the articles, Medline, Web of Science Core Collection, and Scopus databases were searched from their start to the year 2018. Full-text, English observational studies that referred to various aspects of ovarian cancer were included in the study.Results: In total, 125 articles that had been published during the years 1925–2018 were entered into the study. Ovarian cancer is the seventh most common cancer among women. Increased risk factors of cancer have led to an upward trend in the incidence of cancer around the world. In 2018, 4.4% of entire cancer-related mortality among women was attributed to ovarian cancer. Although the incidence of cancer is higher among high Human Development Index (HDI) countries, the trend of mortality rate tends to be reversing. Various factors affect the occurrence of ovarian cancer, from which genetic factor are among the most important ones. Pregnancy, lactation, and oral contraceptive pills play a role in reducing the risk of this disease.Conclusion: This study provides significant evidence about ovarian cancer. Considering the heavy burden of ovarian cancer on women’s health, preventive measures as well as health education and early detection in high risk groups of women are highly recommended. Although some risk factors cannot be changed, a focus on preventable risk factors may reduce the risk of ovarian cancer. More studies are needed to explore the role of unclear risk factors in ovarian cancer occurrence.Keywords: Ovarian cancer, epidemiology, risk facto