A study has shown that tobacco is particularly dangerous for lung cancer and laryngeal cancer. If a person has smoked for more than 30 years and has a smoking quantity of over 20 pack-years (one pack a day for 20 years), then 98.2% of the cause of being diagnosed with small cell lung cancer can be attributed to tobacco.
The National Health Insurance Service announced on the 11th that a research team led by Professor Ji Seon-ha at Yonsei University analyzed health examination records of 136,965 individuals and obtained these results. Factors contributing to cancer include smoking, drinking, genetics, and environmental factors. The research team measured how much smoking contributes to cancer development compared to other factors under the same conditions.
When smokers develop squamous cell laryngeal cancer and squamous cell lung cancer, 88% and 86.2%, respectively, were found to be caused by tobacco. Liver cancer was 57.2%, stomach cancer was 50.8%, and colorectal cancer was 28.6%, all attributed to tobacco.
Genetics contributed to the occurrence of squamous cell carcinoma in only 0.4% of cases. For stomach cancer, it was 5.1%, and for colorectal cancer, it was significantly higher at 7.3%. An official from the National Health Insurance Service noted, "When controlling for factors other than smoking, 98.2% of the cause of small cell lung cancer is due to smoking," adding, "This research clarifies the causal relationship between tobacco and lung cancer and laryngeal cancer."
The results of this study could serve as evidence supporting the claims of the National Health Insurance Service in the ongoing 53.3 billion won tobacco lawsuit that has continued for 12 years. The National Health Insurance Service filed a damages lawsuit against tobacco companies KT&G, Philip Morris Korea, and BAT Korea in April 2014, claiming that citizens developed lung cancer and laryngeal cancer from smoking and that medical costs arose from the health insurance budget, so the tobacco companies should be held accountable.
The first trial ruled in favor of the tobacco companies, and the National Health Insurance Service has appealed, with a verdict in the second trial expected soon. The first trial court stated, "Lung cancer may have developed not only due to smoking but also due to other factors." The National Health Insurance Service believes that this study proves the causal relationship between smoking and lung and laryngeal cancer.