A subgroup analysis of 444 breast cancer patients from the INC-EU Prospective Observational European Neutropenia Study has recently been published:

Schwenkglenks M, et al. Risk factors for chemotherapy-induced neutropenia occurrence in breast cancer patients: data from the INC-EU Prospective Observational European Neutropenia Study. Support Care Cancer 2010; e-pub ahead of print; doi: 10.1007/s00520-010-0840-y

Multivariate logistic regression analysis identified patient- and treatment-specific risk factors for grade IV CIN including older age, lower weight, higher planned chemotherapy dose intensity, and lower baseline white blood cell count. Protective factors against grade IV CIN were use of CSF before a neutropenic event, as well as dose delays and reductions. These findings may help target CSF prophylaxis appropriately to prevent low relative dose intensity in patients with curative treatment intent.