Cost-effectiveness of the 70-gene signature versus St. Gallen guidelines and Adjuvant Online for early breast cancer

Background: The 70-gene signature (MammaPrint (R)) 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 (sic)4600. Sankt Gallen showed the highest survival rates compared to the 70-gene signature, but leads to a substantial larger amount of adjuvant chemotherapy and hence higher costs, thus demanding a willingness to pay of (sic)29.326 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.