Clinical predictors of Pseudomonas aeruginosa bacteremia among Gram-negative bacterial infections in non-neutropenic patients with solid tumor

Objectives: This study was performed to identify risk factors in Pseudomonas aeruginosa bacteremia among Gram-negative bacterial infections in non-neutropenic patients with solid tumor. Methods: A case-control study was performed to identify clinical predictors for P. aeruginosa bacteremia among non-neutropenic patients with Gram-negative bacteremia. Each case of P. aeruginosa bacteremia was matched to one or two controls with Escherichia coli, Klebsiella, Enterobacter or Citrobacter species in non-neutropenic patients with solid tumor. Results: Seventy-eight patients with P. aeruginosa bacteremia were compared with 98 control patients who had other Gram-negative bacteremias. The most common types of cancer were biliary tract cancer (49/176, 27.8%) and hepatocellular carcinoma (38/176, 21.6%), followed by gastric and bladder cancer. Factors associated with development of P. aeruginosa bacteremia were the presence of lung cancer, percutaneous tubes, nosocomial exposure, an invasive procedure and previous antimicrobial therapy (all P < 0.05). Independent risk factors for P. aeruginosa bacteremia included the presence of lung cancer and previous antimicrobial therapy. In the subgroup analysis including 90 patients with community-onset bacteremia, the previous use of antimicrobial agents and presence of bladder cancer were independent factors significantly associated with P. aeruginosa bacteremia. Conclusions: Underlying lung cancer and previous antimicrobial treatment were significantly associated with P. aeruginosa bacteremia in non-neutropenic patients with solid tumor. P. aeruginosa should be considered as a probable cause of Gram-negative bacteremia in this patient group.