Risk and healthcare costs of chemotherapy-induced neutropenic complications in women with metastatic breast cancer.

Background: The burden of chemotherapy-induced neutropenic complications (CINC) in women with metastatic breast cancer (MBC) is largely unknown and may differ across cancer populations due to variation in the characteristics of patients, their disease and their treatment.

Methods: This study employed a retrospective cohort design and US healthcare claims data (2003-2009). For each woman in the study database who received myelotoxic chemotherapy for MBC, the first observed course and each cycle within the course were characterized. Risk and healthcare costs of CINC - by care setting - were descriptively analyzed on an overall basis by chemotherapy cycle and chemotherapy regimen.

Results: Among 2,620 study subjects, most received chemotherapy with cyclophosphamide/doxorubicin (25%), docetaxel (20%) or paclitaxel (12%). Thirty-one percent of subjects received colony-stimulating factors (CSF) prophylactically in their first chemotherapy cycle and an additional 13% first received CSF prophylaxis after cycle one. CINC developed in 11% of subjects; among these subjects, 88% required inpatient care and 45% experienced CINC in the first cycle of chemotherapy. For CINC requiring inpatient care, costs averaged USD 12,869 (95% CI: USD 12,622-13,116), and for CINC requiring outpatient care only, USD 2,030 (CI: USD 1,925-2,135).

Conclusion: CINC is a clinically and economically important threat among women with MBC, and should be an important consideration in the treatment of this population.