Infection-related deaths not uncommon among cancer survivors

Many patients living with cancer die of infection, and early identification of those at risk is important to prevent infection-related mortality, according to a study.

Researchers identified 7,529,481 US cancer survivors from 1992 to 2015 using the Surveillance, Epidemiology, and End Results database. They calculated standardized mortality ratios (SMRs) and performed fine-gray survival analysis to calculate hazard ratios by adjusting for the effects of competing risks (eg, deaths due to causes other than infection).

Of the survivors, 101,167 (1.3 percent) died of infection, with a rate of 27.19 per 10,000 person-years (SMR, 3.29, 95 percent confidence interval [CI], 3.26–3.32; p<0.001). The risk of fatal infection was higher among those who were male, older, unmarried, and Black.

The risk of infection-specific mortality for patients living with cancer, compared with the general population, was greatest at 1 year after diagnosis (SMR, 8.68, 95 percent CI, 8.53–8.84; p<0.0001). This risk, however, was attenuated during follow-up (SMR at >10 years after diagnosis, 2.93, 95 percent CI, 2.87–3.00; p<0.0001).

Moreover, 9.2 percent of patients with Hodgkin lymphoma, 11.5 percent of those with non-Hodgkin lymphoma, and 82.2 percent of Kaposi sarcoma patients who died within the first year of cancer diagnosis were due to acute infectious disease.

On the other hand, the relative percentage of infection-specific death rose from 3.5 percent at <1 year after cancer diagnosis to 10.4 percent at 10+ years of follow-up for patients with liver cancer.

“The results of this study characterize infection mortality in patients living with cancer, which can guide more targeted research and interventions in this population,” the researchers said.