Infection burden is high among cancer inpatients suggesting that targeted surveillance and infection prevention measures may be needed in high-risk groups, according to Australian researchers.
Hospitalised patients with haematological cancers have higher rates of infection than patients with solid tumours, but are at a lower risk of death according to a cohort study of more than 21,000 inpatients at the Peter MacCallum Cancer Centre, Melbourne.
Conducted between 2007 and 2017 it found rates of infection were 67% in blood cancer patients and 29% in solid tumour patients. Haematology patients undergoing autologous-HSCT had an 88% infection rate.
Gastrointestinal, bloodstream and lower respiratory tract infections were the most common infections.
The study, published in Supportive Care in Cancer, found the risk of in-hospital mortality was higher in patients with coded infections than those without – with a higher risk for solid tumour patients (HR 1.61) than for haematological cancer patients (HR 1.30).
Lead author Mr Jake Valentine, from the National Centre for Infections in Cancer at Peter Mac, told the limbic the difference in risk required further research.
“We think it might be due to improvements in the supportive care of patients with haematological malignancies over the last 5-10 years compared to patients with solid tumours.”
He said contributing factors included the highly protocolised use of antimicrobial prophylaxis regimens in patients with blood cancers.
“What this study has certainly demonstrated is that we may want to revisit some of the protocols in terms of treating patients with solid tumours.”
The study also provided stratified data on infections by cancer type.
For example, in haematology patients, GI infections were most common in multiple myeloma (192/10,000 occupied bed days), bloodstream infections in Hodgkin’s lymphoma (123/10,000 OBD) and lower respiratory tract infections in CML (143/10,000 OBD).
GI infections comprised 24% of infections in patients with solid cancers and were most common in patients with pancreatic cancer (138/10,000 OBD) and patients with lip and oral cancer (124/10,000 OBD).
Age-specific infection incidence rates were highest in the 60–69 years group among the haematology patients (741 infections per 1000 persons) and in the 18–29 years group among the solid tumour group (386 infections per 1000 persons).
“I think this information will certainly inform clinical and, more so, infection prevention staff as to how they may want to direct some of the infection prevention resources now that we have a better idea of where these infections are popping up,” Mr Valentine said.
The study also found increasing rates of some infections over the study period and noted there may be some misattribution such as recording immunotherapy-related colitis as a GI infection.
Mr Valentine said while the findings need to be validated at another centre, they provided some indication of the relative burden of infection in cancer patients.
“What this study demonstrated is that we really need to ensure our infection prevention measures are watertight in cancer wards to mitigate and prevent these infections.”