BACKGROUND: The 70-gene signature (MammaPrint) is a prognostic test used to 
guide adjuvant treatment decisions in patients with node-negative breast cancer. 
In order to decide upon its use, a systematic comparative analysis of the 
effects of the 70-gene signature, the Sankt Gallen guidelines and the Adjuvant 
Online Software for these patients on survival, quality of life and costs is 
warranted.
METHODS: A Markov decision model was used to simulate the 20-year costs and 
outcomes (survival and quality-of-life adjusted survival (QALYs)) in a 
hypothetical cohort of node-negative, estrogen receptor positive breast cancer 
patients. Sensitivity and specificity of the three prognostic tools were based 
on 5 and 10 years breast cancer specific survival and distant metastasis as 
first event, derived from a pooled analysis consisting of 305 tumour samples 
from 3 previously reported validation studies concerning the 70-gene signature.
RESULTS: Small differences in survival, but substantial differences in 
quality-adjusted survival between the prognostic tools were observed. 
Quality-adjusted survival was highest when using the 70-gene signature. Based on 
costs per QALY, the 70-gene has the highest probability of being cost-effective 
for a willingness to pay for a QALY higher than euro12.000. Sankt Gallen showed 
the highest survival rates compared to the 70-gene signature, but leads to a 
substantial larger amount of adjuvant chemotherapy and lower cost-effectiveness, 
thus demanding a high willingness to pay to save a life year.
CONCLUSIONS: When deciding upon the cost-effectiveness of the prognostic tests, 
the 70-gene signature improves quality-adjusted survival and has the highest 
probability of being cost-effective.