OBJECTIVE: To evaluate the cost-effectiveness of 70-gene MammaPrint signature 
(Agendia Inc, Huntington Beach, CA) vs Adjuvant! Online software (AS) 
(http://www.adjuvantonline.com) in patients 60 years or younger with early-stage 
breast cancer.
STUDY DESIGN: Cost-effectiveness and cost-utility analyses from a US payer 
perspective.
METHODS: A Markov model with 3 health states was constructed. In the base case 
model, risk classification and patient outcomes were based on a 70-gene 
signature validation study. Efficacy of chemotherapy was derived from a 
published meta-analysis of clinical trials. An alternative model using data from 
AS and from the Surveillance, Epidemiology and End Results registry was built to 
examine the external validity of the base case model. The incremental benefits, 
costs, and cost-effectiveness of treatment guided by 70-gene signature were 
calculated.
RESULTS: In the base case model, 70-gene signature reclassified 29% of patients 
and spared 10% of patients from chemotherapy. Compared with the AS strategy, the 
70-gene signature strategy was associated with $1440 higher total cost per 
patient and with 0.14 additional life-year or 0.15 additional quality-adjusted 
life-year. Overall, the incremental cost-effectiveness ratios were approximately 
$10,000 per life-year or quality-adjusted life-year in the base case model and 
$700 in the alternative model. The model results were sensitive to estrogen 
receptor status, the proportion of patients classified as high risk vs low risk, 
and the overall survival in each risk group.
CONCLUSION: A 70-gene signature is likely to be a cost-effective strategy to 
guide adjuvant chemotherapy treatment in younger patients with early-stage 
breast cancer.