There is a substantial negative impact of multidrug-resistant Gram-negative bacteria on empirical antibiotic therapy in cancer patients—in many cases resulting in mortality, explained Dr Carlota Gudiol at the ECCMID 2019.1
From the literature, the overall mortality rates for cancer patients with bacteraemia can vary country-to-country, but can reach up to 45% with K. pneumoniae infections. In the case of P. aeruginosa infections, nearly 65% mortality rate has been observed. Mortality rates for haematological disease patients with carbapenem-resistant Enterobacteriaceae range from 50%–100%.
According to Gudiol, the difficulty in applying empirical antibiotic therapy is whether to escalate or de-escalate treatments based on individual patient cases. In her view, the escalation strategy should be used for uncomplicated presentations: those without specific risk for resistant pathogens, and in centres where resistance rates are low. For the escalation strategy, anti-pseudomonal cephalosporin, piperacillin-tazobactam, and several other options are available (e.g. Ticarcillin-clavulanate and cefoperazone-sulbactam, though these are not available in some European countries).
On the other hand, the de-escalation strategy should be used for patients with complicated presentations: those with individual risk factors for resistant pathogens and in centres where resistance rates are high based on the local epidemiology. For the de-escalation strategy, patients can be treated with carbapenem monotherapy; a combination of anti-pseudomonal β-lactam + aminoglycoside or quinolone, with carbapenems as the β -lactam in seriously ill patients; colistin + β-lactam ± rifampin (for P. aeruginosa, A. baumannii, and S. maltophilia); or early coverage of resistant Gram-positive if there are risk factors.
Gudiol noted that surveillance should be performed in high-risk haematological patients in centres and units with high rates of carbapenem-resistant and Extended-Spectrum Beta-Lactamase-Producing (ESBL-P) bacteria.
In summary, the individual clinical situations are the key determinants for empirical treatment strategies.