Aromatase inhibitors in the extended treatment of early-stage breast cancer
In the "extended" treatment approach, tamoxifen is used for five years, and then an aromatase inhibitor is taken.
In 2016, the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) looked into the advantages and disadvantages of aromatase inhibitors in the extended treatment of early-stage breast cancer in women.
The Institute compared the effects of aromatase inhibitors used in this way with the effects of no treatment or a placebo treatment. The Institute only found one relevant study, looking at the aromatase inhibitor letrozole. A total of 5,187 women participated in this study. They had all already been through the menopause. Half of the women were given 2.5 mg letrozole per day for five years, and the other half took a placebo (fake medication). All of the women had previously been treated with tamoxifen for five years. The results are described below.