Optimising treatment of patients with hormone receptor-positive breast cancer

This thesis investigated whether extending the duration of endocrine therapy improves the prognosis of postmenopausal women with hormone receptor-positive breast cancer. The findings indicate that not all women benefit equally from prolonged treatment. Women with luminal A tumours experienced a significantly lower risk of recurrence with extended therapy, whereas women with luminal B tumours experienced no measurable benefit. This thesis also demonstrates that specific risk factors, such as ovarian function recovery and higher body weight, negatively impact the prognosis of postmenopausal women with hormone receptor-positive breast cancer receiving aromatase inhibitor therapy. Furthermore, this thesis evaluated treatment patterns and survival outcomes of patients with high-risk HR+/HER2- breast cancer in the Netherlands. Results revealed that one in four women with high-risk disease will die from breast cancer within ten years of diagnosis. These findings help to raise awareness and provide valuable insights for predicting individual patient outcomes.