Breast cancer is the most common type of cancer in women in Switzerland. In 15–20% of cases, tumour growth is accelerated as a result of overexpression of the HER2 receptor in breast cancer cells. This is to be prevented by starting treatment with trastuzumab or trastuzumab in combination with pertuzumab either before or after surgery. This report assesses the effects of a reduction in treatment duration from 12 to 6 months on overall survival, disease-free survival and adverse events. Also analysed were cost-effectiveness and the budget impact, as well as ethical, legal, social and organisational issues.
A systematic review of clinical trials involving over 11,000 women showed that 6 months of trastuzumab treatment is likely non-inferior to 12 months with regard to overall survival. For disease-free survival, the evidence is inconclusive. With the reduced treatment duration, health-related quality of life may be similar or higher. The risk of congestive heart failure is likely lower, and the risk of severe adverse events may be lower and of discontinuation due to adverse events is likely lower. No studies could be found investigating a reduced duration of combination treatment with trastuzumab and pertuzumab. The cost-effectiveness analysis conducted for Switzerland suggests that a reduced treatment duration resulted in cost savings of CHF 15,047 per patient but, at the same time, also led to a total decrease of 0.62 quality-adjusted life years (QALYs) per patient.These findings mean that the amount of money saved per QALY lost is rather small. However, additional analysis indicated that the results are highly uncertain. There is thus a similar likelihood that the result will be lower costs with a decrease or lower costs with an increase in QALYs. Published cost-effectiveness analyses from other countries indicate cost savings with a reduced treatment duration, but report both increases and decreases in QALYs gained. The budget impact analysis for Switzerland suggests that reducing the treatment duration would lead to a decrease in costs ranging between CHF 13.6 million in 2024 and CHF 14.1 million in 2028. With regard to ethical, legal, social and organisational issues, very little literature is available on reductions in cancer treatment duration. Application of the principles of biomedical ethics showed that a reduced treatment duration is largely compatible with these principles. Important aspects include the need to inform patients and to respect their autonomy with regard to treatment choice.
The report concludes that overall survival with 6 months or less of trastuzumab treatment is likely non-inferior to 12 months of treatment. As regards disease-free survival, the evidence is inconclusive. With a reduced treatment duration, health related quality of life may be similar or higher. The risk of congestive heart failure is likely lower, and the risk of any severe adverse events may be lower. The cost-effectiveness analysis suggests that while 6 months of trastuzumab treatment results in lower costs than 12 months’ treatment, it may also lead to a decrease in QALYs gained.
