Cost-effectiveness of the 21-gene assay for guiding adjuvant chemotherapy decisions in early breast cancer.
OBJECTIVE
Adjuvant chemotherapy decisions in early breast cancer are complex. The 21-gene assay can potentially aid such decisions, but costs US $4175 per patient. Adjuvant! Online is a freely available decision aid. We evaluate the cost-effectiveness of using the 21-gene assay in conjunction with Adjuvant! Online, and of providing adjuvant chemotherapy conditional upon risk classification.


METHODS
A probabilistic Markov decision model simulated risk classification, treatment, and the natural history of breast cancer in a hypothetical cohort of 50-year-old women with lymph node-negative, estrogen receptor- and/or progesterone receptor-positive, human epidermal growth factor receptor 2/neu-negative early breast cancer. Cost-effectiveness was considered from an Ontario public-payer perspective by deriving the lifetime incremental cost (2012 Canadian dollars) per quality-adjusted life-year (QALY) for each strategy, and the probability each strategy is cost-effective, assuming a willingness-to-pay of $50,000 per QALY.


RESULTS
The 21-gene assay has an incremental cost per QALY in patients at low, intermediate, or high Adjuvant Online! risk of $22,440 (probability cost-effective 78.46%), $2,526 (99.40%), or $1,111 (99.82%), respectively. In patients at low (high) 21-gene assay risk, adjuvant chemotherapy increases (reduces) costs and worsens (improves) health outcomes. For patients at intermediate 21-gene assay risk and low, intermediate, or high Adjuvant! Online risk, chemotherapy has an incremental cost per QALY of $44,088 (50.59%), $1,776 (77.65%), or $1,778 (82.31%), respectively.


CONCLUSIONS
The 21-gene assay appears cost-effective, regardless of Adjuvant! Online risk. Adjuvant chemotherapy appears cost-effective for patients at intermediate or high 21-gene assay risk, although this finding is uncertain in patients at intermediate 21-gene assay and low Adjuvant! Online risk.
Toronto Health Economics and Technology Assessment (THETA) Collaborative, University of Toronto, Toronto, ON, Canada. mike.paulden@theta.utoronto.ca
Mike
M
Paulden
Jacob
J
Franek
Ba'
B
Pham
Philippe L
PL
Bedard
Maureen
M
Trudeau
Murray
M
Krahn
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage* / Q000009:adverse effects / Q000191:economics; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D008390:Markov Chains; D008875:Middle Aged; D018803:Models, Economic; D017410:Practice Guidelines as Topic; D019057:Quality-Adjusted Life Years; D018570:Risk Assessment; D059467:Transcriptome
breast cancer; chemotherapy; cost-effectiveness analysis; decision making; pharmacogenetics