Background: Tumor fever and infection are common febrile etiologies among advanced cancer patients. To date, only few studies have been conducted to differentiate between tumor fever and infections. Objective: This study aimed to identify discriminating factors that provide rapid results and are feasible and minimally invasive for discriminating between tumor fever and infection in advanced cancer patients. Methods: This is a retrospective cohort study. Advanced cancer patients with clinically diagnosed tumor fever or infection, who received medical treatment from palliative care specialists in 10 nationwide Japanese hospitals, were consecutively identified during August 2012 and November 2014. The symptoms, physical findings, blood test results at baseline and during fever, imaging findings, and sociodemographic factors of these patients were retrospectively extracted. Results: Thirty-three patients with tumor fever and 72 patients with infection were identified. Their mean age was 68.8 years, 68 (64.8%) were men, and the median palliative performance status (PPS) was 50. Statistically significant factors predicting tumor fever by logistic regression analysis were as follows: deterioration of PPS (odds ratio, 0.078), shaking chills during fever (0.067), and change from baseline data of neutrophil/lymphocyte ratio of ≥5 (0.14). Conclusions: Shaking chills during fever, and changes from baseline of performance status and white blood cell differentiation can be useful to differentiate between tumor fever and infection among advanced cancer patients. Further confirmatory studies are needed.
Keywords: advanced cancer; infection; neutrophil to lymphocyte ratio; palliative performance status; shaking chill; tumor fever.