Abstract P4-12-05: Cost-effectiveness analysis of second-generation multi-gene expression prognostic assays compared with the standard 21-gene recurrence score assay to guide adjuvant therapy decisions in women with early stage breast cancer
Authors: Hannouf MB , Zaric GS , Brackstone M 
Published: February 2018

Second-generation multi-gene expression assays can generate comprehensive molecular risk scores which may inform adjuvant chemotherapy decisions in women with early breast cancer. The 12-gene EPclin score assay (EndoPredict®) and 50-gene PAM50-risk of recurrence (ROR) score assay (Prosigna®) appeared to have better prognostic value when compared to the current north American standard 21-gene recurrence score (RS) assay (Oncotype DX®). We sought to investigate the cost-effectiveness of using EPclin and ROR score assays versus RS assay in women with axillary lymph node-negative (LN−), hormone receptor–positive (HR+), and human epidermal growth factor receptor 2–negative (HER2−) early-stage operable breast cancer (ESBC) from the perspective of the Canadian public healthcare system.

We developed a Markov model to project the lifetime clinical and economic consequences of operable LN- HR+ HER2− ESBC. We assumed that women within each risk category by RS assay (low, intermediate and high) would be reclassified to binary risk categories (low and high) by EPclin score assay and to three risk categories (low, intermediate and high) by ROR score assay. The decision model was parameterized using 10-year follow up data from retrospective analyses of the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial, cost data from the London Regional Cancer Program (Ontario, Canada) and secondary sources. Costs are presented in 2017 Canadian dollars. Future costs and benefits were discounted at 5%.

EPclin and ROR score-based strategies led to an increase of 0.04 and 0.02 quality adjusted life years (QALY)/person and a decrease in cost of $917 and $600/person respectively, resulting in both strategies being cost-saving compared to RS-based strategy. Incorporating the EPclin and ROR score assays in place of the current standard RS-assay for operable LN- HR+ HER2− ESBC patients in Canada would result in total gains of 469 and 250 QALYs/year and total savings of $11.5 and $7.5 million/year, respectively. EPclin compared to ROR score-based strategy led to an increase of 0.02 QALY/person and a decrease in cost of $317/person, resulting in EPclin score-based strategy being dominant. Our results were most sensitive to the proportion of women classified by EPclin and ROR score assays to different risk categories and who received adjuvant chemotherapy. A value-of-information analysis revealed that the total expected value of perfect information about the EPclin and ROR score assays' clinical impact was $95 and $55 million/year, respectively.

Our results indicate that the EPclin and ROR score assays are both clinically and economically attractive for patients with operable LN- HR+ HER2− ESBC in the Canadian healthcare setting. Both assays should be considered for adoption in place of the current standard RS-assay for this patient population. The EPclin compared to the ROR score assay appears to be clinically more promising and provides greater value for money in the Canadian healthcare system. Field evaluations of the EPclin and ROR score assays in real-world Canadian clinical practice are associated with a large societal benefit and warranted.

Citation Format: Hannouf MB, Zaric GS, Brackstone M. Cost-effectiveness analysis of second-generation multi-gene expression prognostic assays compared with the standard 21-gene recurrence score assay to guide adjuvant therapy decisions in women with early stage breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-12-05.