Characterising the impact of pneumonia on outcome in non-small cell lung cancer: identifying preventative strategies

Background: Infections remain a part of the natural course of cancer, and lung cancer patients often present with some form of respiratory infection that can lead to their ultimate demise. Methods: Data was gathered concerning all unplanned hospital admissions (UHAs) to our centre from three separate patient cohorts; non-small cell lung cancer (NSCLC) patients (cohort 1), “other cancer” patients (breast, prostate, colon) (cohort 2) and all non-cancer patients (cohort 3). Results: Across the three cohorts, there were 455, 1,190 and 54,158 individual patient UHAs to our centre respectively. Within the NSCLC cohort, 164 UHAs were as a direct result of pneumonia (36.0%), compared to 1.3% and 2.2% in the other two cohorts (P<0.0001). In-hospital mortality and length of hospital stay were significantly higher in the pneumonia sub-group of NSCLC patients only compared with the other two patient cohorts (P<0.0001 and P=0.011 respectively). Within the NSCLC cohort, Patient age, pneumococcal vaccination status, pneumonia admission, smoking status and specific tumour stages were identified as significant independent risk factors for in-hospital mortality. Odds ratios of 0.160 for positive vaccination status and 9.522 for pneumonia admission indicate that for NSCLC patients admitted to hospital with a pneumonia without previous pneumococcal vaccination in the last 5 years, the odds of death were almost 60-fold higher. Conclusions: Vigilance for infection, early diagnosis with adequate assessment and efforts to identify a culprit organism should be a priority when faced with these patients. Infection prevention strategies should be further explored to address this high mortality risk in NSCLC.