The cost-effectiveness of primary prophylaxis with granulocyte colony-stimulating factor in docetaxel-containing adjuvant chemotherapy in early breast cancer: The impact of risk of febrile neutropenia and its mortality.

Abstract

6086 Background: Studies have shown higher rates of febrile neutropenia (FN) with docetaxel (D) containing chemotherapy (C) in early breast cancer (BC) patients than those in clinical trials (CTs). Previous cost-effectiveness analyses (CEA) on FEC-D vs FEC and primary prophylaxis (PP) of granulocyte colony stimulating factor (GCSF) were based on FN risk from CTs that may not reflect the real world. These CEA lacked the complexity to model the risk of FN per cycle, address use of PP vs secondary prophylaxis (SP) & examine long term efficacy of FEC-D vs FEC jointly. Methods: A 2-stage Markov model was developed for a hypothetical cohort of patients age 50 with early BC. First stage modeled costs/outcomes of 6 cycles C (FEC or FEC-D), including events related to FN, complications and G-CSF use (either PP or SP). Second stage modeled costs/outcomes of local/distant relapse, and death from BC (10 year horizon). Efficacy data of C and G-CSF, and utility were obtained from published data. Model was based on 3rd party payer (2010 Canadian dollars - 3% discounting rate). 4 strategies were used: (S1) FEC x 6 with SP, (S2) FEC x 3 with SP → D x 3 with SP, (S3) FEC x 3 with SP → D x 3 with PP, (S4) FEC x 3 with PP → D x 3 with PP. Results: At a willingness-to-pay (WTP) threshold of $50,000/QALY, S2 is preferred to S1 when risk of FN with D per cycle without G-CSF is < 9%, 6% or 4% if risk of death from FN is 1%, 5% or 10% respectively. S3 may be preferred if the risk of death from FN is > 14%. At a WTP of $100,000/QALY, S3 is preferred to S2 when risk of FN with D per cycle is > 12%, 4% or 2% if the risk of death from FN is 1%, 5% or 10% respectively. S4 is preferred to S3 only if risk of death from FN is > 18%. S1 is preferred only if risk of FN with D per cycle is much > 40%. Conclusions: We developed an economic model to determine the cost-effectiveness of different C/GCSF strategies in early BC, calibrated to the efficacies reported in CTs. In the “real world”, the most cost-effective strategy will depend on accurate understanding of the risk of developing/dying from FN in the non CTs setting. Societal WTP threshold will have a significant impact on defining the optimal systemic approach.