Pulmonary tuberculosis in COPD may increase risk of lung cancer

The studies of pulmonary tuberculosis (PTB) affecting lung cancer development in chronic obstructive pulmonary disease (COPD) patients is limited.

A new study by Dr Hye Yun Park MD and team has found that Pulmonary TB was associated with an increased risk of developing lung cancer among COPD patients in our country with an intermediate tuberculosis (TB )burden.

The study is published in Annals of American Thoracic Society.

The objective of the study was to evaluate whether a history of PTB is associated with an increased risk of lung cancer development in a population with COPD.

The study was a cohort study which included a nationwide representative sample of 13,165 Korean men and women with COPD, aged between 50–84 years. In addition, to assess whether the relationship between PTB and lung cancer risk differs between participants with and without COPD, a matched cohort without COPD was included. Participants were matched 1:3 for age, sex, smoking history, and PTB status based on the index health screening exam of corresponding participants with COPD. The two cohorts were followed up for 13 years (January 1st, 2003, to December 31st, 2015). PTB was diagnosed based on the results of chest radiography, and incident lung cancer was identified from hospitalization and outpatient visit claims (International Classification of Diseases, Tenth Revision diagnosis code C33 or C34).

The results of the study were found to be

• Out of 370,617 person-years (PY) of follow-up (median follow-up, 7.7 years), in the COPD group, they observed 430 incident cases of lung cancer in participants without a history of PTB (incidence rate 524 per 100,000 PY).

• Out of which 148 cases were those with a history of PTB (incidence rate 931 per 100,000 PY). The fully adjusted subdistribution hazard ratio was (95% confidence interval) for lung cancer in those with a history of PTB was 1.24 (1.03, 1.50) when compared to participants without a PTB history,.

• The association of PTB history and lung cancer development was more evident in never-smokers with COPD. In contrast, among participants without COPD, the corresponding hazard ratio (95% confidence interval) was 0.98 (0.78, 1.22).

• There was no interaction between PTB, smoking status, and COPD.

Dr Park and team concluded that "The history of PTB was associated with an increased risk of developing lung cancer among COPD patients in our country with an intermediate TB burden. COPD patients with a history of PTB, particularly the never-smokers, might benefit from periodical screening or assessment for lung cancer development."

For further information: https://doi.org/10.1513/AnnalsATS.202010-1240OC