Enterobacteriaceae bacteremias among cancer patients: an observational cohort study

Enterobacteriaceae bacteremia is a common complication in patients with neoplasm. The cancer itself, chemotherapy-induced immunosuppression, and other cancer-related procedures play a role as predisposing factors for this condition. However, despite the clear association between cancer and Enterobacteriaceae bacteremia, the distinctive clinical characteristics of patients with cancer presenting with Enterobacteriaceae bacteremia have not been well established.

The population studied was a prospective cohort of adult hospitalized patients with Enterobacteriaceae bacteremia in a tertiary care hospital. We compared the clinical variables and microbiological features between patients with an underlying neoplasm (n=203) and those without (n=259). STATA software was used for statistical association analysis.

In a bivariate analysis, older age, prior exposure to aminopenicillins, fewer days of symptoms, biliary source of bacteremia, greater severity of APACHE II score, lower white blood cell and platelet counts, and the presence of Klebsiella pneumoniae were more common in the neoplasm group. In a multivariable analysis, K. pneumoniae bacteremia (odds ratio (OR) 6.13, 95% confidence interval (CI) 1.65-22.71; p=0.007), APACHE II score (OR 1.18, 95% CI 1.05-1.34; p=0.007), and exposure to aminopenicillins (OR 28.84, 95% CI 1.94-429.3; p=0.015) were associated with neoplasm. K. pneumoniae bacteremia was more commonly present in patients with lung and gastrointestinal cancers.

We have confirmed the association of K. pneumoniae bacteremia with underlying neoplastic disease, especially with gastrointestinal malignancies, which may allow stratification for initial empiric antibiotic therapy in this subset of patients. Prior exposure to aminopenicillins in the neoplasm group might contribute to this finding.