Cigarette Smoking Is Associated with Increased Risk of Malignant Gliomas: A Nationwide Population-Based Cohort Study

Abstract

The association between cigarette smoking and the risk of developing malignant glioma (MG) remains unclear. We aimed to evaluate this potential association in a large general population, using a well-established and validated longitudinal nationwide database. Using data from the Korean National Health Insurance System cohort, 9,811,768 people over 20 years old without any cancer history in 2009 were followed until the end of 2017. We documented 6100 MG cases (ICD-10 code C71) during the median follow-up period of 7.31 years. Current smokers had a higher risk of developing MG (HR = 1.22, CI: 1.13–1.32) compared with never-smokers, after adjusting for confounders. This association was stronger for those who smoked ≥ 20 cigarettes daily (HR = 1.50, CI: 1.36–1.64). Furthermore, having 30 or more pack-years of smoking over the course of one’s lifetime was associated with an increased risk of developing MG in a dose-dependent manner, compared with never-smokers (HR = 1.31, CI: 1.16–1.48 for 30–39 pack-years of smoking; HR = 1.36, CI: 1.17–1.59 for 40–49 pack-years of smoking; HR = 1.68; CI: 1.44–1.95 for ≥ 50 pack-years of smoking). These results suggest that cigarette smoking may be associated with developing MG. Further prospective studies could help elucidate this association.

Clinicopathological Features and Prognosis of Indonesian Patients with Gliomas with IDH Mutation: Insights into Its Significance in a Southeast Asian Population

“…Nicotine has also been shown to enhance the proliferation and migration of human glioma cells. Recently, the role of cigarette smoking in breaching the blood-brain barrier via the impairment of endothelial tight junctions has also been shown, possibly facilitating penetration of environmental carcinogens to the brain (Ahn et al, 2020). To the best of our knowledge, our study is the first study showing an association between IDH1 mutation and smoking in patients with glioma.…”

“…They did find a small but statistically significant association in female smokers (Li et al, 2016). A more recent study from Korea, however, reported that current smokers had a higher risk to have malignant glioma compared to those who never smoked (Ahn et al, 2020). Several mechanisms have been proposed to explain this association.…”

“…Several mechanisms have been proposed to explain this association. Smoking may induce multiple distinct mutational signatures, including IDH mutation, in tissues directly and indirectly exposed to smoking (Ahn et al, 2020;Madanat et al, 2017). Nicotine has also been shown to enhance the proliferation and migration of human glioma cells.…”

Associations of General and Abdominal Obesity with the Risk of Glioma Development

“…This retrospective nationwide population-based study was conducted using the database of the National Health Insurance Service (NHIS) of Korea, which is a mandatory health insurance system operated by the Korean government that covers almost all Koreans (97%, approximately 50 million people) [28,42,43]. The NHIS database includes 10 demographic information as well as medical information such as clinical diagnoses, prescribed medications including chemotherapy, surgical procedures, and radiotherapy.…”

“…The medical code "C71" represents intracranial gliomas according to the International Classification of Disease, Tenth Revision (ICD-10), and includes diffuse astrocytomas, anaplastic astrocytomas, ependymomas, anaplastic ependymomas, oligodendrogliomas, anaplastic oligodendrogliomas, and glioblastoma multiforme. Because all C71 patients received an additional cost coverage service from the NHIS for rare and incurable diseases, called the "benefit extension policy for rare incurable diseases (BEP)," we defined patients with gliomas as those who were diagnosed both with C71 and who are registered as having a BEP to ensure more accurate identification of glioma patients [42].…”