Adjuvant Trastuzumab Therapy for Early HER2-Positive Breast Cancer in Iran: A Cost-Effectiveness and Scenario Analysis for an Optimal Treatment Strategy.

INTRODUCTION

Clinical guidelines have recommended a 1-year trastuzumab regimen as standard care for early human epidermal growth factor receptor 2 (HER2)-positive breast cancer; however, this recommendation can have a dramatic impact on total drug expenditures in middle-income countries (MICs). We performed a cost-effectiveness analysis from the Iranian healthcare perspective to find an optimum duration of trastuzumab use in Iran.

METHOD

We compared four treatment strategies comprising chemotherapy and varying durations of trastuzumab use (no trastuzumab, 6, 9 months, and 1 year), and a Markov model and probabilistic sensitivity analysis were used to estimate the costs and effects of the strategies. We then examined the cost effectiveness of the strategies at different willingness-to-pay (WTP) thresholds and ages at onset of treatment.

RESULTS

Incremental costs (versus no trastuzumab) were €8826 (6 months), €13,808 (9 months) and €18,588 (12 months), while incremental quality-adjusted life-years (QALYs) were 0.65 (6 months), 0.87 (9 months) and 1.14 (12 months). At a threshold of 3 × gross domestic product (GDP)/capita (€21,000/QALY) and for patients younger than 59 years, the 6-month protocol was most likely to be cost effective (probability of 42%). At a threshold of 4 × GDP/capita (€28,000/QALY), the 6-month and 1-year regimens were essentially equal in cost effectiveness (37 and 35%, respectively). At this WTP threshold, the 6-month and 1-year regimens were optimal strategies only for patients up to 66 and 44 years of age, respectively.

CONCLUSION

In contrast to clinical guidelines, 6 months of trastuzumab may be the most cost-effective option for Iran. The lower absolute WTP threshold and lower life expectancy compared with high-income countries are two crucial parameters in the cost effectiveness of interventions in MICs. It is therefore necessary to strike a balance between maximum population health and maintaining affordability in these countries.