Medline ® Abstracts for References 77,78,83

BACKGROUND: One reason chest radiographs are recommended after pneumonia is to exclude underlying lung cancer. Our aims were to determine the incidence and correlates of new lung cancer and the diagnostic yield of new lung cancer by chest radiography in patients with pneumonia.

METHODS: We conducted a population-based cohort study of patients with chest radiography-confirmed pneumonia, who were discharged alive from hospitals and emergency departments in Edmonton, Alberta, Canada. Patients were enrolled from 2000 through 2002 and followed up for 5 years. We determined incidence of new lung cancer and receipt of chest radiographs within 90 days, 1 year, and 5 years. Multivariable proportional hazards analyses were used to determine independent correlates of lung cancer.

RESULTS: There were 3398 patients; 59% were 50 years or older, 52% were male, and 17% were smokers. Half (49%) were admitted to hospital. At 90 days, 36 patients (1.1%) had new lung cancer; at 1 year, 57 patients (1.7%); and over 5 years, 79 patients (2.3%). The median time to diagnosis was 109 days (interquartile range, 27-423 days). Characteristics independently associated with lung cancer included age 50 years or older (adjusted hazard ratio [aHR], 19.0; 95% confidence interval [CI], 5.7-63.6), male sex (aHR, 1.8; 95% CI, 1.1-2.9), and smoking (aHR, 1.7; 95% CI, 1.0-3.0). Of the patients, 1354 (40%) had follow-up chest radiographs within 90 days, and the diagnostic yield of lung cancer was 2.5%; if radiographs were restricted to patients 50 years or older, the yield would have been 2.8%.

CONCLUSIONS: The incidence of new lung cancer after pneumonia is low: approximately 1% within 90 days and 2% over 5 years. Routine chest radiographs after pneumonia for detecting lung cancer are not warranted, although our study suggests that patients 50 years or older should be targeted for radiographic follow-up.

To determine the causes of treatment failure and to evaluate the prognostic factors in patients hospitalized for community-acquired pneumonia, a prospective, observational study of 228 adult patients hospitalized for a community-acquired pneumonia in the University Hospital of Geneva and the La Chaux-de-Fonds Community Hospital, Switzerland, was conducted. The percentage of patients who failed to improve (as defined by guidelines of the Infectious Disease Society of America) and the causes of treatment failure were assessed, and patients who failed to improve under antimicrobial therapy were compared with those who did improve. In the 54 (24%) patients who failed to improve, a mean increase in length of hospitalization of 4 days was observed. Most causes of treatment failure could be attributed to host factors (61%) rather than to the pathogen (16%) or to an inappropriate antibiotic regimen (3%). After adjusting for potentially confounding variables, concomitant neoplasia (OR 3.25; 95%CI 1.11-9.56), neurological disease (OR 2.34; 95%CI 1.07-5.13), and aspiration pneumonia (OR 2.97; 95%CI 29-6.86]) were associated with failure to improve, whereas monocytosis improved prognosis (OR 0.40; 95%CI 0.20-0.80). Almost one out of four patients hospitalized for community-acquired pneumonia failed to respond to empirical antibiotic treatment. Aspiration pneumonia, concomitant neoplasia, and neurological disease were factors positively associated with failure to improve, whereas monocytosis was linked to a better prognosis.