Effect of 21-Gene Recurrence Score Results on Treatment Recommendations in Patients with Lymph Node-Positive, Estrogen Receptor-Positive Breast Cancer

Cost effectiveness of a 21-gene recurrence score assay versus Canadian clinical practice in post-menopausal women with early-stage estrogen or progesterone-receptor-positive, axillary lymph-node positive breast cancer

BACKGROUND

A 21-gene recurrence score (RS) assay provides a method of guiding treatment decisions in women with early-stage breast cancer (ESBC). We investigated the cost effectiveness of using the RS assay versus current clinical practice (CCP) in post-menopausal women with estrogen- or progesterone-receptor-positive, one to three positive axillary lymph-node ESBC from the perspective of the Canadian public healthcare system.

METHODS

We developed a decision analytic model to project the lifetime clinical and economic consequences of ESBC. We assumed that the RS assay would classify patients among risk levels (low, intermediate and high) and corresponding adjuvant treatment regimens. The model was parameterized using 7-year follow-up data from the Manitoba Cancer Registry, cost data from Manitoba Health administrative databases and secondary sources. Costs are presented in 2012 Canadian dollars, and future costs and benefits were discounted at 5 %.

RESULTS

In the base case analysis, the RS assay compared with CCP led to an increase of 0.08 quality-adjusted life-year (QALY) and an increase in cost of Can$36.2 per person, resulting in an incremental cost-effectiveness ratio (ICER) of Can$464/QALY gained. The ICER was most sensitive to the proportion of women classified to intermediate risk by the RS assay who received adjuvant chemotherapy, and absolute risk of relapse among patients receiving the RS assay.

CONCLUSIONS

The RS assay is likely to be cost effective in the Canadian healthcare system. Field evaluations of the assay in this patient population will help reduce uncertainty in clinical guidelines for intermediate-range RS-assay values and specific disease outcomes by the RS assay, which are important drivers of ICER.

Cost-effectiveness of a 21-gene recurrence score assay versus Canadian clinical practice in women with early-stage estrogen- or progesterone-receptor-positive, axillary lymph-node negative breast cancer

BACKGROUND

A 21-gene recurrence score (RS) assay may inform adjuvant systematic treatment decisions in women with early stage breast cancer. We sought to investigate the cost effectiveness of using the RS-assay versus current clinical practice (CCP) in women with early-stage estrogen- or progesterone-receptor-positive, axilliary lymph-node negative breast cancer (ER+/ PR + LN- ESBC) from the perspective of the Canadian public healthcare system.

METHODS

We developed a Markov model to project the lifetime clinical and economic consequences of ESBC. We evaluated adjuvant therapy separately in post- and pre-menopausal women with ER+/ PR + LN- ESBC. We assumed that the RS-assay would reclassify pre- and post-menopausal women among risk levels (low, intermediate and high) and guide adjuvant systematic treatment decisions. The model was parameterized using 7 year follow up data from the Manitoba Cancer Registry, cost data from Manitoba administrative databases, and secondary sources. Costs are presented in 2010 CAD. Future costs and benefits were discounted at 5%.

RESULTS

The RS-assay compared to CCP generated cost-savings in pre-menopausal women and had an ICER of $60,000 per QALY gained in post-menopausal women. The cost effectiveness was most sensitive to the proportion of women classified as intermediate risk by the RS-assay who receive adjuvant chemotherapy and the risk of relapse in the RS-assay model.

CONCLUSIONS

The RS-assay is likely to be cost effective in the Canadian healthcare system and should be considered for adoption in women with ER+/ PR + LN- ESBC. However, ongoing assessment and validation of the assay in real-world clinical practice is warranted.