Seong Cheol Min

This retrospective cohort study included patients with breast cancer diagnosed between 2008 and 2015, and their survival was tracked until 2017. The index date of follow-up was the date of diagnosis of new-onset breast cancer, whereas the end date was the date of loss to follow-up, death, or the end of the study period (December 31, 2017), whichever occurred first [29].

This nationwide, population-based cohort study included all adult patients diagnosed with breast cancer in South Korea between 2006 and 2017, based on data from the National Health Insurance Service (NHIS) and the Korea National Cancer Incidence Database (KNCI DB). De-identified data were obtained from the claims database of the National Health Insurance Service (NHIS) of the Republic of Korea [16].