Grade 4 Neutropenia Frequency as a Binary Risk Predictor for Adverse Clinical Consequences of Chemotherapy‑Induced Neutropenia: A Meta-analysis.

Neutropenia is the major toxicity of myelosuppressive cancer chemotherapy. Grade 4 neutropenia (Gr4N) is a measure of chemotherapy-induced neutropenia (CIN) severity. We conducted a meta-analysis of CIN data. Gr4N incidence was significantly correlated with febrile neutropenia (FN), days of severe neutropenia (DSN), and nadir absolute neutrophil count (ANC), which are all important predictors of morbidity. With a Gr4N threshold of 65%, both FN and DSN were below levels for low risk of adverse CIN outcomes. Gr4N was highly predictive for adverse CIN outcomes, and a 65% threshold demarcated low vs. high risk for FN and other adverse CIN outcomes.