Spectrum of the initial antibiotic treatment for cancer patients with fever and low leukocyte counts

Background: cancer patients develop neutropenia, a decrease in the subset of leukocytes responsible for protection against bacteria, as a result of chemotherapy or cancer. Neutropenia predisposes the patients to severe bacterial infections. Standard antibiotic regimens for cancer patients with neutropenia and fever are directed at most of the bacteria that can cause infections. However, a subset of resistant bacteria belonging to the the Gram-positive group (Staphylococcus aureus and Streptococci) remain untreated unless specific antibiotics are added to the treatment.

Review question: we assessed whether the addition of specific antiGram-positive antibiotics prior to identification of a causative bacteria improves survival and cure among cancer patients with fever and neutropenia.

Search dates: the evidence is current to August 2013.

Study characteristics: we included randomised controlled trials that compared a standard antibiotic regimen to the same regimen with an antibiotic directed at Gram-positive bacteria. Overall, 13 randomised controlled trials were included with 2392 patients or episodes of infection. The antibiotics were given to cancer patients with neutropenia and fever as first-line treatment (11 trials) or for recurrent fever (two trials).

Study funding sources: in 8/13 of the trials the trial received funding from the industry.

Key results: mortality did not differ significantly between patients groups. Antibiotic treatment was more frequently modified among patients who did not initially receive specific antibiotics against Gram-positive bacteria, but overall treatment failures were not significantly different. We attempted to examine the durations of fever and hospital stay, but these were not consistently reported. The addition of specific antibiotics against Gram-positive bacteria resulted in more adverse events, mainly rash. We conclude that antibiotic treatment directed against resistant Gram-positive bacteria can await identification of bacteria and need not be given routinely prior to bacterial identification.

Quality of the evidence: overall the quality of the evidence was good since it relied on randomised controlled trials, most of which were at low risk of bias. A limitation of the results for mortality was that all-cause mortality was not reported and could not be obtained in 6/13 of the studies. The trials did not examine specific circumstances that might mandate empirical use of antibiotics against Gram-positive bacteria and thus the evidence is relevant to cancer patients with fever, without low blood pressure, or a focus of infection that might be caused by Gram-positive bacteria.

Authors' conclusions: 

Current evidence shows that the empirical routine addition of antiGP treatment, namely glycopeptides, does not improve the outcomes of febrile neutropenic patients with cancer.

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Background: 

The pattern of infections among neutropenic cancer patients has shifted in the last decades to a predominance of Gram-positive infections. Some of these Gram-positive bacteria are increasingly resistant to beta-lactams and necessitate specific antibiotic treatment.

Objectives: 

To assess the effectiveness of empirical antiGram-positive (antiGP) antibiotic treatment for febrile neutropenic cancer patients in terms of mortality and treatment failure. To assess the rate of resistance development, further infections and adverse events associated with additional antiGP treatment.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 7), MEDLINE (1966 to 2013), EMBASE (1982 to 2013), LILACS (1982 to 2013), conference proceedings, and the references of the included studies. First authors of all included and potentially relevant trials were contacted.

Selection criteria: 

Randomised controlled trials (RCTs) comparing one antibiotic regimen to the same regimen with the addition of an antiGP antibiotic for the treatment of febrile neutropenic cancer patients.

Data collection and analysis: 

Two review authors independently assessed trial eligibility and risk of bias, and extracted all data. Risk ratios (RR) with 95% confidence intervals (CI) were calculated. A random-effects model was used for all comparisons showing substantial heterogeneity (I2 > 50%). Outcomes were extracted by intention to treat and the analysis was patient-based whenever possible.

Main results: 

Thirteen trials and 2392 patients or episodes were included. Empirical antiGP antibiotics were tested at the onset of treatment in 11 studies, and for persistent fever in two studies. The antiGP treatment was a glycopeptide in nine trials. Seven studies were assessed in the overall mortality comparison and no significant difference was seen between the comparator arms, RR of 0.82 (95% CI 0.56 to 1.20, 852 patients). Ten trials assessed failure, including modifications as failures, while six assessed overall failure disregarding treatment modifications. Failure with modifications was significantly reduced, RR of 0.76 (95% CI 0.68 to 0.85, 1779 patients) while overall failure was the same, RR of 1.00 (95% CI 0.79 to 1.27, 943 patients). Sensitivity analysis for allocation concealment and incomplete outcome data did not change the results. Both mortality and failure did not differ significantly among patients with Gram-positive infections, but the number of studies in the comparisons was small. Data regarding other patient subgroups likely to benefit from antiGP treatment were not available. Glycopeptides did not increase fungal superinfection rates and were associated with a reduction in documented Gram-positive superinfections. Resistant colonisation was not documented in the studies.