Background: Chemotherapy-induced neutropenia and associated fever and infection are the most common complications of systemic chemotherapy. In this retrospective analysis, the authors evaluated the incidence of neutropenic fever, infection, and mortality in relation to the level of neutropenia, performance status, course number of chemotherapy, bone marrow metastasis, and age among patients with metastatic breast carcinoma receiving salvage chemotherapy.
Methods: A total of 174 patients with previously treated metastatic breast carcinoma enrolled on 4 consecutive Phase II protocols were evaluated.
Results: Twenty-three percent of the patients had an episode of neutropenic fever (41 episodes among 40 patients). The incidence of neutropenic fever did not increase until the absolute neutrophil count (ANC) had decreased to less than 500/microL, and then fever incidence had a linear relationship with decreasing ANC (linear trend, P < 0.01). A source of infection was documented in 59% of the neutropenic fever episodes. The incidence of infection did not increase significantly until the ANC had decreased to less than 250/microL (P < 0.01). The risk of neutropenic fever and infection was also significantly higher when patients had poor performance status or were undergoing the initial courses of chemotherapy. Patients with bone marrow metastases also had a higher frequency of fever, infection, and death, but these differences were not statistically significant.
Conclusions: For patients with metastatic breast carcinoma receiving salvage chemotherapy, the risk of fever increases with decreasing ANC, but the risk of infection does not increase significantly until ANC decreases to less than 250/microL. Poor performance status, initial courses of chemotherapy, and bone marrow metastases further increase the risk of fever, infection, and death.