Open Access Research article

Societal cost-effectiveness analysis of the 21-gene assay in estrogen-receptor–positive, lymph-node–negative early-stage breast cancer in Japan

Hideko Yamauchi1, Chizuko Nakagawa1, Shinji Yamashige2, Hiroyuki Takei3, Hiroshi Yagata1, Atsushi Yoshida1, Naoki Hayashi1, John Hornberger45*, Tiffany Yu4, Calvin Chao6, Carl Yoshizawa6 and Seigo Nakamura17

Author Affiliations

1 Department of Breast Surgery, St. Luke’s International Hospitalcph, Tokyo, Japan

2 Graduate School of Economics, Hitotsubashi University, Tokyo, Japan

3 Division of Breast Surgery, Saitama Cancer Center, Saitama, Japan

4 Cedar Associates LLC, Menlo Park, CA, USA

5 School of Medicine, Stanford University, Stanford, CA, USA

6 Genomic Health, Inc, Redwood City, CA, USA

7 Department of Breast Surgery, Showa University, Tokyo, Japan

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BMC Health Services Research 2014, 14:372  doi:10.1186/1472-6963-14-372

Published: 5 September 2014



Breast-cancer incidence and mortality have been increasing in Japan. Japanese-specific clinical validity and utility data for the 21-gene assay (Oncotype DX® Breast Cancer Assay; Genomic Health, Inc., Redwood City, USA) are now available. The objective of this study was to evaluate the cost-effectiveness of the 21-gene assay for the guidance of adjuvant chemotherapy decisions in estrogen-receptor–positive, lymph-node–negative, early-stage breast cancer patients, from the Japanese societal perspective.


The recurrence risk group distribution by the 21-gene assay result and the assay’s influence on adjuvant chemotherapy recommendations were obtained from a study of 104 patients. A state-transition cohort (Markov) model tracked time from surgery until distant recurrence and from distant recurrence to death. Adjuvant chemotherapy benefit by 21-gene assay risk group was based on published clinical validation studies. Direct and indirect medical costs were obtained from the referral centers. Utilities associated with progression and chemotherapy-related adverse events were extracted from literature. Sensitivity analyses assessed the key drivers and robustness of the primary outcomes.


The 21-gene assay identified 48% of patients as low-risk, 36% as intermediate-risk, and 16% as high-risk. Total acute chemotherapy-related costs decreased by ¥154,066 due to less adjuvant chemotherapy usage. In the high-risk group, adjuvant chemotherapy use increased 18%, leading to survival benefits. Chemotherapy use overall decreased by 19%. Monitoring costs increased by ¥3,744 but recurrence costs declined by ¥46,113 per patient. Use of the 21-gene assay increased quality-adjusted–life-years (QALYs) by 0.241 per patient on average; the net cost per QALY gained was ¥636,752 ($6,368).


The 21-gene assay for women with estrogen-receptor–positive, lymph-node–negative, early-stage breast cancer is projected to be cost-effective in Japan.

Breast cancer; Cost-effectiveness; Cost-benefit; Molecular diagnostic testing; Genetic testing