Febrile neutropenia (FN) is a common complication of chemotherapy, associated with increased short-term morbidity and mortality. The long-term consequences of FN are poorly elucidated. We aimed to examine whether FN identifies individuals with an infectious phenotype and poor long-term outcomes.
We included patients >16 years of age, initiating first-line chemotherapy for malignant diseases at Copenhagen University Hospital, 2010-2015. Data were obtained from electronic health records. Patients were followed from the date 180 days after initiation of chemotherapy (i.e. baseline). We compared risk of infection between patients with 1 or >1 episodes of FN versus those without FN after chemotherapy (within the period 180 days before baseline). Collection of a blood culture was used as a proxy for infection. Risk of infection was assessed using competing risks regression analysis with death or new treatment with chemotherapy as competing events. Relative risks of infection and death were estimated using Poisson regression analysis adjusted for age, sex, diagnosis, calendar year and baseline leucocyte count, with infection included as a time-updated variable in risk-analyses of death.
We followed 7,210 patients with 29 types of cancers for a total of 8,523 person years; 3,666 (51%) were women and median age was 64 years (IQR, 54-71). There were 1,373 infectious events, with incidence rates of 15.3 (95%CI, 14.4-16.2), 24.3 (95%CI, 20.7-28.5) and 26.7 (95%CI, 19.2-37.2) per 100 person-years for those with no, 1 or >1 FN episode, respectively; The adjusted incidence rate ratios were 1.80 (95%CI, 1.56-2.07) and 1.95 (95%CI, 1.43-2.65) for patients with 1 or >1 episode of FN compared to those with no FN episodes. The risk of death was increased up to 6 months after an infection; adjusted mortality rate ratios were 7.65 (95%CI, 6.79-8.62) the first month, 4.21 (95%CI, 3.76-4.70) 1-3 months after, 2.26 (95%CI, 1.58-3.24) 3-6 months after and 1.02 (95%CI, 0.87-1.21) > 6 months after an infection, compared to the time before infection.
FN following chemotherapy is associated with long-term increased risk of infection. An infectious event is associated with increased mortality, persisting up to 6 months after the infection.
G. Daugaard, None
P. Brown, None
H. Sengeløv, None
J. Lundgren, None
M. Helleberg, None