
A systematic review and meta-analysis found a high level of antimicrobial resistance (AMR) in bacteria isolated from cancer patients, researchers reported late last week in BMC Infectious Diseases.
Although cancer patients are known to be at increased risk of infections caused by drug-resistant pathogens, there has been no systematic review of the global prevalence of AMR in the common pathogenic bacteria known to cause infections in cancer patients. To address this gap in knowledge, researchers from the University of Ghana Medical School reviewed studies published from 2000 to 2024 on cancer patients with infections caused by Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacter spp.
The review identified 132 articles involving 49,638 cancer patients in 39 countries. Most studies (67%) reported AMR in multiple pathogens, while 33% reported resistance in single pathogens. For E coli, resistance prevalence was highest for penicillins (81.8%), followed by cotrimoxazole (65.8%) and monobactams (61.6%). For K pneumoniae, the highest prevalence of resistance was observed for penicillins (99.0%) and cotrimoxazole (70.9%), while A baumannii had high resistance prevalence to multiple antimicrobial classes, including third-generation cephalosporins (84.1%), fourth-generation cephalosporins (80.8%), carbapenems (82.6%), fluoroquinolones (80.4%), beta-lactam/beta-lactamase inhibitors (79.2%), cotrimoxazole (75.8%), and aminoglycosides (64.1%).
Enterobacter spp and E faecium showed high resistance prevalence to penicillins, at 91.8% and 90.6% respectively, while P aeruginosa had a high prevalence of resistance to third-generation cephalosporins (49.4%), and S aureus showed high prevalence to macrolides (55.6%) and methicillin (45.3%).
Better infection prevention, antimicrobial stewardship needed
The study authors suggest possible underlying factors for high AMR levels among cancer patients include immunosuppression, prolonged antibiotic exposure, invasive medical devices, and intensive treatments such as chemotherapy and radiation therapy.
"These procedures and treatments can weaken their immune system, increasing their susceptibility to infections," they wrote. "Moreover, the acquisition of resistant bacteria from healthcare settings is significant, considering that cancer patients spend a substantial amount of time in these facilities."
"The pronounced resistance prevalence observed, especially among ESKAPE pathogens, underscores the urgent need to improve infection prevention and antimicrobial stewardship in cancer care globally," they added.