Influenza Among Breast Cancer Survivors in South Korea: A Nationwide Population-Based Study

Abstract

Abstract. Background Worldwide, breast cancer is the most commonly diagnosed malignancy among women (1). Especially in traditionally low-risk areas, where changes in lifestyle have been significant, breast cancer incidence rates have nearly doubled in recent decades (2). In South Korea, the number of patients diagnosed with breast cancer has rapidly increased, reaching 12,206 in 2012, which was 3-fold higher than 10 years earlier (3). As the number of breast cancer survivors has increased, managing quality of life had become increasingly important over time (4).Influenza infection is a major cause of acute respiratory disease. Influenza epidemics are associated with economic burden to medical finance, in addition to mortality (5). Those with medical conditions such as chronic disease, metabolic syndrome, or underlying malignancy are susceptible to influenza infection (6). In particular, cancer survivors could experience reduced immunity due to chemotherapy, disease, or medications such as corticosteroids (7). To prevent influenza infection, annual vaccination for influenza is recommended for cancer survivors (8).However, despite recommendations there are some cancer survivors who tend to be reluctant to undergo vaccination (9). These attitudes towards vaccination were attributed to anxiety to complication after vaccination, lack of awareness of necessity, and lack of proper advice by medical staff (10). In a previous study, the influenza vaccination rates for cancer survivors and non-cancer survivors were 50.3% and 31.5%, respectively, in South Korea (11). However, vaccination for influenza varies based on age. More than 75% of people over 65 years old were vaccinated and only 26% of cancer survivors aged 19-44 years were vaccinated (12).Although studies have examined influenza vaccination rates among cancer survivors in South Korea, there are no studies about the prevalence of influenza disease among cancer survivors based on nationwide data. In this study, we analyzed the prevalence of influenza disease among breast cancer survivors using claims data from the Health Insurance Review and Assessment Service (HIRA) in South Korea. Patients and MethodsSouth Korea has the National Health Insurance (NHI) system and every resident in South Korea is obligated to join NHI. Claim data in HIRA were generated during patient visits to medical institutions. Based on NHI, the HIRA database consisted of four subgroup 967

Prevalence of COVID-19-related risk factors and risk of severe influenza outcomes in cancer survivors: a matched cohort study using linked English electronic health records data

“…The few previous studies in this area have reported high rates of influenza among cancer survivors, consistent with our findings, but have lacked a cancer-free comparison group. [18][19][20][21] Hermann et al investigated outcomes among patients with a history of cancer presenting with influenza, and found no difference in mortality according to haematological or non-haematological cancer type, or activity of the cancer. 18 Our results showed considerably higher risks of hospitalisation or death among haematological cancer survivors, which could be consistent with the findings in Hermann et al if haematological cancer survivors are at increased risk of infection, but not mortality once infected, compared to non-haematological cancer survivors.…”

“…Other studies have investigated vulnerability to influenza infection of any severity; two studies using administrative claims data in South Korea found a high rate of claims for influenza among both breast cancer survivors and survivors of childhood cancers. 19,20 Similarly, Australian survey data found that a large proportion (38%) of hematopoietic stem cell transplant survivors had had influenza-like illnesses in the time (median 5 years) since their transplant suggesting potentially high vulnerability to infection, but there was no control group or information on severity of infection. 21 Direct evidence on how COVID-19 affects cancer patients and survivors is immature.…”

“…As of 7 July 2020, the novel Coronavirus disease 2019 (COVID- 19) has been diagnosed in over 11.6 million individuals with more than 539,000 deaths reported worldwide. 1 Around 20% of individuals contracting the virus are estimated to develop severe disease requiring hospitalisation, with a high risk of mortality.…”

Dyslipidemia in breast cancer patients increases the risk of SAR-CoV-2 infection

“…Studies have shown that BC patients treated with chemotherapy stay immuno-compromised for more than a year after treatment ( Carreira et al, 2020 ). A higher prevalence rate of viral infection was reported among BC survivors compared to cancer-free people ( Heo et al, 2017 ).…”

Cardiovascular Vulnerability to COVID-19 in Cancer Survivors

“…Radiation therapy can also lead to cardiovascular complications including coronary artery disease, cardiomyopathy, and myocardial fibrosis [31,32]. Cancer survivors are at increased risk for morbidity and mortality from infections and infection-related complications [33,34]. Indeed, influenza-induced exacerbation of pre-existing cardiovascular diseases is more common among high-risk populations, including cancer survivors [35].…”