Comorbidities among patients with cancer who do and do not develop febrile neutropenia during the first chemotherapy cycle.

Patients receiving myelosuppressive chemotherapy with certain comorbidities are at increased risk of febrile neutropenia. A comprehensive evaluation of febrile neutropenia-related comorbidities across cancers is needed. This study compared comorbidity prevalence among patients with cancer who did and did not develop febrile neutropenia during the first chemotherapy cycle. This case-control study used administrative claims from adult patients with non-Hodgkin lymphoma or breast, lung, colorectal, ovarian, or gastric cancer who received chemotherapy between 2007 and 2012. Each patient who developed febrile neutropenia (case) was matched with up to four patients without febrile neutropenia (controls) by cancer type, metastasis, chemotherapy regimen, age group, and sex. For each comorbidity (identified in the year before chemotherapy began), the adjusted odds ratio (aOR) for febrile neutropenia by cancer type was evaluated using conditional logistic regression models adjusted for potential confounding factors. Of 31,331 eligible patients, 672 developed febrile neutropenia in the first chemotherapy cycle. A total of 3312 febrile neutropenia cases and matched controls were analyzed. Across tumor types, comorbidity prevalence was higher in patients who developed febrile neutropenia than in those without febrile neutropenia. Among patients with breast cancer, osteoarthritis was more prevalent in patients with febrile neutropenia (aOR, 1.85; 95% CI, 1.07 to 3.18). Among patients with non-Hodgkin lymphoma, renal disease was more prevalent in patients with febrile neutropenia (aOR, 2.25; 95% CI, 1.23 to 4.11). Patients who developed febrile neutropenia in the first chemotherapy cycle presented with comorbidities more often than otherwise similar patients who did not develop febrile neutropenia. These findings warrant further investigation and support the inclusion of comorbidities into febrile neutropenia risk models.