ABSTRACT
<b>Purpose and Methods</b>: Infection and neoplastic fever is one of the common complication in patients with advanced cancer. To develop a novel method to differentiate neoplastic fever from infection, we performed a retrospective study of hospitalized terminally ill cancer patients at Seirei Hospice from April 2009 to August 2011. <b>Results</b>: We identified a consecutive sample of 12 patients with neoplastic fever and 12 patients with infection as a control. We extracted demographic data, laboratory data, vital signs and symptoms from medical charts. We found significant differences in difference in C-reacive protein value between afebrile and febrile period (<i>p</i>＜0.001), difference of white blood cell count between afebrile and febrile period (<i>p</i>=0.0017), percentages in neutrophil counts (<i>p</i>=0.023), percentages in lymphocyte counts at base line (<i>p</i>=0.011) and the presence of delirium (<i>p</i>=0.012). <b>Conclusion</b>: These findings suggest that we might differentiate neoplastic fever from infection with common laboratory data and their longitudinal change.