Low-dose aspirin and incidence of lung carcinoma in patients with chronic obstructive pulmonary disease in Hong Kong: A cohort study

Background Evidence suggests that chronic obstructive pulmonary disease (COPD) is associated with a higher risk of lung carcinoma. Using a territory-wide clinical electronic medical records system, we investigated the association between low-dose aspirin use (≤160 mg) among patients with COPD and incidence of lung carcinoma and the corresponding risk of bleeding. Methods and findings This is a retrospective cohort study conducted utilizing Clinical Data Analysis Reporting System (CDARS), a territory-wide database developed by the Hong Kong Hospital Authority. Inverse probability of treatment weighting (IPTW) was used to balance baseline covariates between aspirin nonusers (35,049 patients) with new aspirin users (7,679 patients) among all eligible COPD patients from 2005 to 2018 attending any public hospitals. The median age of the cohort was 75.7 years (SD = 11.5), and 80.3% were male. Competing risk regression with Cox proportional hazards model were performed to estimate the subdistribution hazard ratio (SHR) of lung carcinoma with low-dose aspirin and the associated bleeding events. Of all eligible patients, 1,779 (4.2%, 1,526 and 253 among nonusers and users) were diagnosed with lung carcinoma over a median follow-up period of 2.6 years (interquartile range [IQR]: 1.4 to 4.8). Aspirin use was associated with a 25% lower risk of lung carcinoma (SHR = 0.75, 95% confidence interval [CI] 0.65 to 0.87, p =
In a cohort study, Si-Yeung Yu and colleagues investigate the association between low-dose aspirin and incidence of lung carcinoma in patients with chronic obstructive pulmonary disease in Hong Kong.
Author summary Why was this study done? Lung carcinoma is the most common malignancy worldwide, and chronic obstructive pulmonary disease (COPD), for which no curative treatments exist, is a prevalent risk factor of lung carcinoma. Aspirin is a medication with potential anticancer effects. Its effect on lung cancer, however, remains controversial. To our knowledge, its effect in patients in COPD remains unstudied. Aspirin is also known to cause bleeding. However, its effects in COPD patients, again to our knowledge, also remains unstudied. What did the researchers do and find? Using a territory-wide database, the risk of lung carcinoma was assessed in patients with COPD defined as aspirin nonusers (35,049) and aspirin users (7,679 patients). A mathematical model was used, which balances the 2 cohorts by their comorbidities, drug uses, demographic variables, and proxy variables for their socioeconomic status. Aspirin use was associated with a 25% lower risk of lung carcinoma, implying that within our cohort, every 125 patients treated for 5 years is associated with one fewer case of lung carcinoma. We found, additionally, that aspirin use was associated with an increased risk of coughing up blood, although the overall risk of gastrointestinal bleeding is not increased. What do these findings mean? Aspirin may be implicated as a potential preventative treatment for lung carcinoma in COPD patients, but the increased risk of adverse effects merits further evaluation. The current study design was unable to eliminate the possibility that aspirin users were more likely to seek additional treatment, although this is mitigated through design choices in developing the mathematical model. The observational nature of the study prevents causality from being established. The use of aspirin in COPD should depend on the benefits and harms associated with its usage, when they have been thoroughly studied in randomized trials.