Would you recommend 10 years instead of 5 years of tamoxifen in a premenopausal woman with early stage, node negative ER/PR/HER2 positive breast cancer?

Both the ATLAS and aTTom randomized controlled trials demonstrated that 10 years compared to 5 years of tamoxifen improves disease-free and overall survival among women with hormone receptor-positive early stage breast cancer. Most of the benefit was seen in the decrease in late breast cancer recurrences. Another option for adjuvant hormonal therapy for premenopausal women is ovarian suppression with an aromatase inhibitor for 5 years based upon the SOFT and TEXT trials. In general, HER2-positive breast cancer tends to be more refractory to hormonal therapy compared to HER2-negative disease. The decision about optimal hormonal therapy in this population should be based upon the patient's risk of breast cancer recurrence, tolerability of hor...