Table 6: [Summary of Findings of Included Studies]. - Gene Expression Tests for Women with Early Stage Breast Cancer: A Review of Clinical Utility and Cost-Effectiveness

Main Study Findings	Author’s Conclusion
Node-negative Subgroup: For the 0 to 5 year subgroup, both EP and EPclin performance were very similar to that of RS (EP LR chi-square = 15.5; EPclin LR chi-square = 17.0; RS LR chi-square = 18.7) For the 5 to 10 year subgroup, RS was weak compared to the EP and EPclin (EP LR chi-square = 22.7; EPclin LR chi-square = 15.5; RS LR chi-square = 4.8). The RS low group (RS < 18) had a DR rate of 5.3% (95% CI, 3.5 to 8.2), compared to the EP low group (EP < 5) that had a DR rate of 3.0% (95% CI, 1.5 to 6.6) and the EPclin low group (EPclin < 3.3) that had a DR rate of 5.9% (95% CI, 4.0 to 8.6). The RS non-low group (RS ≥ 18) had a DR rate of 17.1% (95% CI: 12.8 to 22.7), compared to the EP high group (EP ≥ 5) that had a DR rate of 14.6% (95% CI: 11.3 to 18.8) and the EPclin high group (EPclin ≥ 3.3) that had a DR rate of 20.0% (95% CI: 14.6 to 27.0). The hazard ratio between the high/non-low vs low risk groups was similar for RS and EPclin at 3.72 (95% CI, 2.17 to 6.39) and 3.90 (95% CI, 2.33 to 6.52), respectively. The hazard ratio was the highest for EP at 5.15 (95% CI, 2.44 to 10.85).	“In summary, this study has confirmed the independent prognostic ability of EP and EPclin in postmenopausal women with ER+/HER2- primary disease.” p.7 The authors did not provide any specific conclusions for the node-negative subgroup.
Economic Study
Mislick, 2014¹⁰
The base-costs for the use of Mammostrat were $15,782, compared with $18,051 for the use of Oncotype DX. The cost savings of $2,268 resulted from using Mammostrat over Oncotype DX. Both assays resulted in similar life years (9.880 and 9.882) and quality-adjusted life years (7.935 and 7.940) for Mammostrat and Oncotype DX, respectively.	“We found that survival and QALYs were similar when using either assay; however, costs were lower for patients assessed using Mammostrat” p.44

Main Study Findings

Author’s Conclusion

Clinical Study

Buus, 2016²

Node-negative Subgroup:
For the 0 to 5 year subgroup, both EP and EPclin performance were very similar to that of RS (EP LR chi-square = 15.5; EPclin LR chi-square = 17.0; RS LR chi-square = 18.7)
For the 5 to 10 year subgroup, RS was weak compared to the EP and EPclin (EP LR chi-square = 22.7; EPclin LR chi-square
= 15.5; RS LR chi-square = 4.8).
The RS low group (RS < 18) had a DR rate of 5.3% (95% CI, 3.5 to 8.2), compared to the EP low group (EP < 5) that had a DR rate of 3.0% (95% CI, 1.5 to 6.6) and the EPclin low group
(EPclin < 3.3) that had a DR rate of 5.9% (95% CI, 4.0 to 8.6).
The RS non-low group (RS ≥ 18) had a DR rate of 17.1% (95% CI: 12.8 to 22.7), compared to the EP high group (EP ≥ 5) that had a DR rate of 14.6% (95% CI: 11.3 to 18.8) and the EPclin high group (EPclin ≥ 3.3) that had a DR rate of 20.0% (95% CI: 14.6 to 27.0).
The hazard ratio between the high/non-low vs low risk groups was similar for RS and EPclin at 3.72 (95% CI, 2.17 to 6.39) and
3.90 (95% CI, 2.33 to 6.52), respectively. The hazard ratio was the highest for EP at 5.15 (95% CI, 2.44 to 10.85).

“In summary, this study has confirmed the independent prognostic ability of EP and EPclin in postmenopausal women with ER+/HER2- primary disease.” p.7
The authors did not provide any specific conclusions for the node-negative subgroup.

Economic Study

Mislick, 2014¹⁰

The base-costs for the use of Mammostrat were $15,782, compared with $18,051 for the use of Oncotype DX.
The cost savings of $2,268 resulted from using Mammostrat over Oncotype DX.
Both assays resulted in similar life years (9.880 and 9.882) and quality-adjusted life years (7.935 and 7.940) for Mammostrat and Oncotype DX, respectively.

“We found that survival and QALYs were similar when using either assay; however, costs were lower for patients assessed using Mammostrat” p.44

From: Gene Expression Tests for Women with Early Stage Breast Cancer: A Review of Clinical Utility and Cost-Effectiveness

Cover of Gene Expression Tests for Women with Early Stage Breast Cancer: A Review of Clinical Utility and Cost-Effectiveness

Gene Expression Tests for Women with Early Stage Breast Cancer: A Review of Clinical Utility and Cost-Effectiveness [Internet].

Narain T, Adcock L.

Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; 2017 Oct 16.

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