Which Factors Are Linked to Lower Risk of Lung Cancer in Patients With COPD?

It is already known that patients with chronic obstructive pulmonary disease (COPD) face a greater risk of dying of lung cancer than age and gender matched controls. According to new research, a concurrent asthma diagnosis and the use of inhaled corticosteroids may be associated with a decreased risk of lung cancer in patients with COPD, while the use of acetylsalicylic acid may be linked to an increased risk.

The study aimed to analyze whether age, gender, socioeconomic factors, comorbidity, and medication may affect the risk of lung cancer in patients with COPD. Data was collected from primary care medical records and national patient registries in Sweden.

“Both COPD and lung cancer are closely related to the chronic inflammation and oxidative stress induced by smoking,” the study explained. “However, it has been shown that patients with emphysema who have never smoked also have an increased risk of developing lung cancer. Hence, it is likely that the inflammatory process driving the formation of emphysema contributes as a risk factor for lung cancer.”

A total of 19,894 patients were included in the study and 594 lung cancer cases were diagnosed. The analysis revealed that the risk of lung cancer was lower if the patients with COPD had a concurrent asthma diagnosis, while the risk of lung cancer was higher with increasing age.

“Data concerning lung cancer risk in asthma patients are contradictory. It has been suggested that an atopic constitution including asthma is linked to an increased risk of lung cancer. However, there is also evidence of a decreased risk, as well as studies where no relationship is confirmed,” the study noted on its unexpected results regarding asthma and COPD.

Also, the researchers observed a decreased lung cancer risk in an exposure-dependent manner in patients who were prescribed inhaled corticosteroids, while the opposite was observed for the use of acetylsalicylic acid.

The study noted the correlation between COPD and lung cancer, however, the authors emphasized the need to understand the additive risks, as well as protective measures for both diseases.

“The finding in the present study that pharmacological treatment may modify the risk relation between these two diseases should be seen as hypothesis generating and needs to be confirmed in prospective studies,” concluded the study.

The authors acknowledge that the results are limited because smoking and lung function were not considered in the analysis. Additionally, the researchers lacked data on pharmacological treatment before 2005 and because the observational period does not cover recent years, the results may not reflect all potential changes in COPD management.

Reference

Sandelin M, Mindus S, Thuresson M, Lisspers K, Ställberg B, Johansson G, et al. Factors associated with lung cancer in COPD patients.

Int J Chron Obstruct Pulmon Dis. 2018:13;1833-1839. doi: 10.2147/COPD.S162484