Adjuvant ET is the cornerstone treatment of localized hormone-receptor positive breast cancer, with demonstrated benefits on overall survival (30-40% relative decrease in mortality) but also on the risk of local and contralateral relapse (43-50% relative decrease). While the relative benefit of 5 years ET is identical for small tumors as compared to larger ones, the absolute benefit is much lower, and the risk-benefit ratio may therefore become very questionable given the frequent and impactful side effects of ET. If recent trials tested longer durations as compared to 5 years for high-risk cancers, older trials have tested shorter durations. Five years appeared at that time as the gold standard because of optimal benefit-risk ratios of tamoxifen among rather high-risk patients. However shorter treatments of 2-3 years were already associated with substantial benefits and may be enough for very low risk patients. The purpose of this study is to demonstrate that adjuvant hormone therapy limited to 2 years of antiaromatase in postmenopausal women with a good prognosis can ensure very high survival without metastatic relapse and allows a reduction of side effects and a better quality of life. The 5-year DMFS was excellent in patients with low risk Luminal A tumors who received endocrine therapy.
Hormone therapy is recommended for five years in all patients with hormone receptor-positive breast cancer, but there is no consensus on its duration in low-risk tumours and especially in postmenopausal women. Adjuvant endocrine therapy (ET) is associated with substantial side effects and long-term decreased quality of life.~Moreover, while it has been shown that ET provides a real benefit in reducing the relapse rate over time, the deterioration in quality of life may also have a negative effect on patient adherence to treatment. It is therefore important to offer treatment to women with low-risk cancer less intensive treatment strategies. If recent trials tested longer durations as compared to 5 years for high-risk cancers, older trials have tested shorter durations. The 5-year duration appeared at that time as the gold standard because of optimal benefit-risk ratios of tamoxifen among high-risk patients. However shorter treatments of 2-3 years were already associated with substantial benefits and may be enough for very low risk patients.