Nationwide Analysis of Treatment Patterns for Korean Breast Cancer Survivors Using National Health Insurance Service Data

Abstract

BackgroundThe National Health Insurance Service (NHIS) established a healthcare claim database for all Korean citizens. This study aimed to analyze the NHIS data and investigate the patterns of breast cancer treatments.MethodsWe constructed a retrospective female breast cancer cohort by analyzing annual incident cases. The annual number of newly diagnosed female breast cancer was compared between the NHIS data and Korea National Cancer Incidence Database (KNCIDB). The annual treatment patterns including surgery, chemotherapy, radiation therapy, endocrine therapy and targeted therapy were analyzed.ResultsA total of 148,322 women with newly diagnosed invasive breast cancer during 2006–2014 was identified. The numbers of newly diagnosed invasive breast cancer cases were similar between the NHIS data and KNCIDB, which demonstrated a strong correlation (r = 0.995; P < 0.001). The age distribution of the breast cancer cases in the NHIS data and KNCIDB also showed a strong correlation (r = 1.000; P < 0.001). About 85% of newly diagnosed breast cancer patients underwent operations. Although the proportions of chemotherapy use have not changed during 2006–2014, the total number of chemotherapy prescriptions sharply increased during this period. The proportions of radiotherapy and anti-hormonal therapy increased. Among the anti-hormonal agents, tamoxifen was the most frequently prescribed medication, and letrozole was the most preferred endocrine treatment in patients aged ≥ 50 years.ConclusionAlong with the increased breast cancer incidence in Korea, the frequencies of breast cancer treatments have increased. The NHIS data can be a feasible data source for future research.

Association between Post-Diagnosis Particulate Matter Exposure among 5-Year Cancer Survivors and Cardiovascular Disease Risk in Three Metropolitan Areas from South Korea

“…On the other hand, the Korea National Cancer Incidence Database (KNCIDB) is a hospital-based cancer registry system that has the stages of cancer. However, the overall cancer prevalence rates using the two data are quite similar in the previous studies, and this study suggests that NHIS data are a feasible data source for cancer survivorship [50,51]. Second, operationally defined CVD may be incorrectly coded.…”

Long‐term risk of congestive heart failure in younger breast cancer survivors: A nationwide study by the SMARTSHIP group

“…Because we considered the first 2 years (2005‐2006) as a washout period to exclude prevalent breast cancer cases, subjects were excluded from the cohort if they had already been coded as C50 from 2005 to 2006 . The operational definition is similar to a previous algorithm that we reported in previous studies . Patients were excluded from the cohort if they had already been diagnosed with CHF between 2005 and 2006 (to exclude prevalent CHF cases) or if they had been newly diagnosed with CHF within the 2 years after their breast cancer diagnosis.…”

“…15 The operational definition is similar to a previous algorithm that we reported in previous studies. 14 Patients were excluded from the cohort if they had already been diagnosed with CHF between 2005 and 2006 (to exclude prevalent CHF cases) or if they had been newly diagnosed with CHF within the 2 years after their breast cancer diagnosis. Male subjects, patients younger than 20 years, and patients who did not undergo breast cancer surgery were also excluded from this study.…”

“…The National Health Insurance Service (NHIS) is a governmental institution for health care insurance in Korea and provides a complete set of medical information on almost 97% of Korean citizens. Many studies have been conducted with the NHID, the feasibility of which for research on breast cancer survivors we previously reported …”

“…Many studies have been conducted with the NHID, 12,13 the feasibility of which for research on breast cancer survivors we previously reported. 14 This nationwide, retrospective study was aimed at investigating the incidence of late CHF more than 2 years after the breast cancer diagnosis in comparison with the general population and at assessing the risk factors for late CHF in breast cancer survivors.…”