De-tangling predictors of microbial colonization in lung cancer patients

Background Airway microbial colonization (AWC) can complicate lung cancer via mechanical obstruction and altered airway clearance, and possibly several other factors. Consensus over these predictors is lacking. This study explores several potential predictors of AWC in a group of lung cancer patients. Patients and methods Bronchial wash samples of 103 lung cancer patients were obtained and sent for microbiological analysis. AWC was considered positive if the culture methods yielded growth for bacterial organisms (s) that was (were) subsequently identifiable. Demographic, clinical, radiological, and histopathological profiles of the patients were examined for the potential predictability of AWC. Results Data from all enrolled patients (103) were analyzed. The oldest patients were ex-smokers (median age 70 years; IQR: 61–72). Sex significantly influenced smoking status, where ex-smokers were exclusively males ( P <0.001). AWC was detected in 25 (24.3%) patients. Though multiple factors demonstrated high odds ratio for AWC, C-reactive protein level was the only statistically significant predictor on univariate regression analysis ( P <0.001). A multivariate regression model, however, demonstrated that female sex and adenocarcinoma type were statistically significant predictors of AWC, predicting a 3.8 and 3.3-fold increase in AWC risk ( P =0.043, P =0.038, respectively). Conclusion C-reactive protein-level was a statistically significant predictor of AWC when considered in isolation, but not when considered with other more clinically relevant factors. When considered together, both female sex and adenocarcinoma type of lung cancer were statistically significant and independent predictors of AWC in lung cancer patients.