Fluoroquinolone resistance in bacteremic and low risk febrile neutropenic patients with cancer.

Background: The low risk febrile neutropenic patients with Multinational Association for Supportive Care in Cancer (MASCC) score of more than 20 are recommended to be treated with fluoroquinolone-based oral treatment by the National Comprehensive Cancer Network (NCCN) guideline. This recommendation relies, at least partially, on the high sensitivity of the blood culture isolates to fluoroquinolone in clinical trials conducted in Western countries. Whether this also applies in middle or low income countries like China where antibiotic resistance is becoming prevalent recently has not been evaluated.

Methods: All the positive blood culture results from January 2010 to December 2013 in the 2 large Chinese cancer centers were reviewed. The patients were included into the study with the following criteria: febrile neutropenia, solid tumor or lymphoma, MASCC score >20, positive blood cultures within two days of the onset of fever, and detailed treatment history.

Results: A total of 38 patients were included in this analysis. Two patients had polymicrobial bacteremia (Enterococcus faecalis and Flavimonas oryzihabitans). Other isolates included coagulase-negative staphylococcus, micrococcal species, viridans streptococci, Klebsiella pneumoniae, and Escherichia coli. The majority of the monomicrobial isolates from these 36 patients was Escherichia coli (28 patients, 74%). Notably, in contrast to the high sensitivity to fluoroquinolone from blood culture of the low risk patients in previous reports in Westen countries, a very high drug resistance was observed: 13 out of 28 Escherichia coli isolates (46%) or 14 out of all 38 positive cultures (37%).

Conclusion: The results warrant further validations in prospective clinical trials in countries where antibiotic resistance is prevalent to ensure appropriate antibiotic administration.