Epidemiological characteristics of breast cancer in Koreans

ABSTRACT

In the ranking of cancer incidence in the year, female breast cancer was the highest cancer after thyroid cancer in 2004–2015, and became the most common cancer in 2016, exceeding the cases of thyroid cancer. The incidence rates of breast cancer have increased steadily over the past two decades and are expected to continue to increase in the next decades, although the incidence rates of all other cancers has declined in Korea. Most of the established risk factors of breast cancer are primarily related to female sex hormones. Other known risk factors are alcohol drinking, a family history of breast cancer, genetic predisposition, and benign breast conditions. Some risk factors, such as physical activity, breastfeeding, and number of children, are modifiable factors that can be targeted for risk reduction. This article summarizes the descriptive epidemiological characteristics of breast cancer in Korea that have been reported and identifies the specific characteristics and secular trends in incidence, mortality, and survival rates of breast cancer up to the present day. It is uncertain whether the risk factors established in western populations will also be valid for the Korean population. To explore this question, we summarize the results from international collaborative studies and meta-analyses of risk factors of breast cancer published to date. The results for Koreans are summarized and described based on results from population-based or nested case-control studies, hospital case-community control studies, cohort studies, and meta-analyses conducted in Korea. This study will be helpful for risk assessment, interventions, and prevention of breast cancer.