Epidemiological characteristics of and risk factors for breast cancer in the world

Aim: Breast cancer is the most common cancer among women and one of the most important causes of death among them. This review aimed to investigate the incidence and mortality rates of breast cancer and to identify the risk factors for breast cancer in the world. Materials and methods: A search was performed in PubMed, Web of Science, and Scopus databases without any time restrictions. The search keywords included the following terms: breast cancer, risk factors, incidence, and mortality and a combination of these terms. Studies published in English that referred to various aspects of breast cancer including epidemiology and risk factors were included in the study. Overall, 142 articles published in English were included in the study. Results: Based on the published studies, the incidence rate of breast cancer varies greatly with race and ethnicity and is higher in developed countries. Results of this study show that mortality rate of breast cancer is higher in less developed regions. The findings of this study demonstrated that various risk factors including demographic, reproductive, hormonal, hereditary, breast related, and lifestyle contribute to the incidence of breast cancer. Conclusion: The results of this study indicated that incidence and mortality rates of breast cancer is rising, so design and implementation of screening programs and the control of risk factors seem essential.