Table 3.

Base-case results

A. Baseline recurrence risk from a Japan-based validation study
Main analysis	Without 21-gene assay	With 21-gene assay	Difference
Proportion receiving adjuvant chemotherapy	46.2%	26.9%	−19.2%
10-year recurrence-free survival, %	94.5%	95.0%	0.5%
QALYs
Adjuvant chemotherapy (immediate)	−0.246	−0.144	0.103
Recurrence (long-term)	21.093	21.231	0.139
Total	20.847	21.088	0.241
Costs*
21-gene assay		¥350,000	¥350,000
Acute costs
Chemotherapy drugs	¥259,298	¥151,257	-¥108,041
Adverse events	¥78,845	¥45,993	-¥32,852
Patient time and transportation	¥31,615	¥18,442	-¥13,173
Monitoring costs until recurrence	¥520,493	¥524,238	¥3,744
Costs after recurrence	¥347,446	¥301,333	-¥46,113
Total	¥1,237,698	¥1,391,263	¥153,565
Cost per QALY gained		JPY	¥636,752
		USD	$6,368
B. Baseline recurrence risk from US- and UK-based validation studies
Alternative analysis	Without 21-gene assay	With 21-gene assay	Difference
Proportion receiving adjuvant chemotherapy	46.2%	26.9%	−19.2%
10-year recurrence-free survival, %	89.4%	89.6%	0.3%
QALYs
Adjuvant chemotherapy (immediate)	−0.246	−0.144	0.103
Recurrence (long-term)	19.533	19.590	0.057
Total	19.287	19.447	0.160
Costs*
21-gene assay		¥350,000	¥350,000
Acute costs
Chemotherapy drugs	¥259,298	¥151,257	-¥108,041
Adverse events	¥78,845	¥45,993	-¥32,852
Patient time and transportation	¥31,615	¥18,442	-¥13,173
Monitoring costs until recurrence	¥478,260	¥479,798	¥1,537
Costs after recurrence	¥899,695	¥882,593	-¥17,102
Total	¥1,747,715	¥1,928,084	¥180,369
Cost per QALY gained		JPY	¥1,129,442
		USD	$11,294

Abbreviations: QALY quality-adjusted–life-year, ¥, JPY Japanese Yen, $, USD United States Dollar.

*Per patient on average. Reported in 2013 currency.