Economic analysis of prophylactic granulocyte colony-stimulating factor (G-CSF) use based on a risk model for neutropenic complications in breast cancer patients receiving adjuvant chemotherapy

Abstract

6107 Background: Although recent economic analyses of prophylactic G-CSF provide cost saving febrile neutropenia (FN) risk estimates of approximately 20%, many regimens have reported rates <20%. A prospective nationwide cohort study was undertaken to develop risk models for neutropenic complications (NC) including severe and febrile neutropenia in patients receiving cancer chemotherapy (Lyman ASCO 2005). A cost-effectiveness model is presented to evaluate the economic impact of G-CSF prophylaxis based on the model. Methods: Data on 974 consecutive breast cancer patients receiving adjuvant chemotherapy at 115 randomly selected practice sites were analyzed. The clinical and cost impact of G-CSF prophylaxis in high-risk patients based on the model was compared with: 1) no G-CSF; 2) primary prophylaxis; and 3) secondary prophylaxis. Pegfilgrastim costs were based on Medicare pricing while hospitalization costs and mortality on national hospitalization data. Results: Independent predictors of first cycle NC included: type and schedule of chemotherapy, diabetes, elevated bilirubin, planned RDI >85%, low glomerular filtration rate and low neutrophil count. Prophylactic G-CSF was associated with a decreased risk. Model R2=0.327 and c-statistic=0.80 [95% CI: 0.78–0.83; P<.001]. At a baseline FN risk of 8.4% per cycle, the expected costs over four cycles of chemotherapy were: no pegfilgrastim: $1,285; primary prophylaxis: $2,573; secondary prophylaxis: $2,040 and model-targeted G-CSF: $1,527. Expected cost varied with FN risk and model performance. Primary prophylaxis was associated with lower cost than no prophylaxis at FN risk >18%, while the model outperformed both strategies at an FN risk >10%. At a baseline cycle risk of FN of 8.4%, model-guided G-CSF was associated with an expected cost of $44,980 per life saved. Cost savings increased as model discrimination increased. The model was consistently associated with lower cost compared to secondary prophylaxis. Conclusions: A risk model for NC has been developed in breast cancer patients receiving adjuvant chemotherapy. Use of the model to guide G-CSF support appears to be cost-effective at an overall FN risk of 10%. [Table: see text]