Studies have shown that having COPD puts you at a higher risk of developing lung cancer. One reason is that both diseases share common risk factors, such as exposure to environmental pollutants. The most common risk factor of COPD is smoking cigarettes — however, exposure to other irritants, such as air pollution, chemical fumes, and dust, can also contribute to developing the disease, according to Mayo Clinic. In some rare cases, genetic factors may play a role in the development of COPD. People with a genetic condition called alpha-1 antitrypsin deficiency are at higher risk for developing COPD, as their bodies cannot produce a protein that helps protect the lungs from damage, per the National Heart, Lung, and Blood Institute.
Like COPD, lung cancer is also strongly associated with cigarette smoking, but other risk factors include exposure to arsenic, asbestos, and other carcinogens, per the Centers for Disease Control and Prevention (CDC). Certain genetic mutations have also been linked to an increased risk of developing lung cancer. For example, mutations in the EGFR (epidermal growth factor receptor) gene have been found in some lung cancers, explains a 2010 study published in the Journal of Thoracic Disease. Other genetic mutations linked to an increased risk of lung cancer include mutations in the KRAS and TP53 genes, according to a 2019 study published in the journal Oncology Letters).