Clinical outcomes in patients with cancer and Gram-negative bloodstream infection: impact of carbapenem resistance.

Abstract

Purpose: To describe the outcome of cancer patients who present bloodstream infections (BSIs) by Gram-negative bacteria (GNB) and to analyze the impact of carbapenem resistance.

Methods: A retrospective study from 2021 to 2023 at a tertiary care oncologic center in Mexico. The study describes demographic, clinical, and microbiological characteristics in oncological patients with GNB-BSI.

Results: During the study period, 1348 episodes of bacteremia were included. There were 703 women (52.1%), with a mean age of 50.5 ± 16.3 years. Five hundred thirty-six (39.7%) events were reported in patients with hematological malignancies (HM) and 814 (60.3%) in patients with solid tumors, having differences between both groups in age, gender, neutropenia, and type of BSI. Polymicrobial bacteremia was documented in 111 patients; 1468 GNB were identified. Nine hundred forty-five were classified as susceptible (64.4%), 417 (28.4%) were 3rd generation cephalosporins-resistant (C3R), and 106 (7.2%) were carbapenem-resistant (CR). CR episodes were most frequent in patients with HM, with severe neutropenia, and with > 2 previous episodes of BSI. Mortality at 30 days for the whole group was 21.1% and 37.5% for patients with CR strains. Multivariate analysis for 30-day mortality revealed that age > 60 years, severe neutropenia, bloodstream infection (BSI) other than catheter-related, polymicrobial BSI, ICU admission, CR strains, and inappropriate antimicrobial treatment were identified as risk factors.

Conclusions: Oncology patients, particularly those with HM, are a high-risk group for CR-GNB. These patients have a high mortality. Appropriate antimicrobial treatment is crucial for reducing mortality.