Tailoring endocrine treatment for early breast cancer

Abstract

This thesis describes several important aspects of adjuvant endocrine therapy for postmenopausal women with endocrine-sensitive, early-stage breast cancer. In our ongoing efforts to tailor treatment so as to provide the best possible care to each of our patients, we studied the influence of various tumor- and patient-related factors on outcomes of adjuvant endocrine therapy. These factors include quantitative hormone receptor (HR) expression, body weight, age and physical activity, changes in prognosis over time, quality of life, treatment compliance, treatment-specific side effects, and single nucleotide polymorphisms (SNPs) of the aromatase gene (CYP19A1). In addition, the effect of preoperative (neoadjuvant) endocrine therapy in strong endocrine-sensitive, postmenopausal breast cancer patients is described. Finally, this thesis includes a chapter on the optimal timing of the sentinel lymph node procedure in breast cancer patients treated with neoadjuvant systemic therapy in general. The results of these studies contribute to further individualization of HR-positive early breast cancer and can improve survival outcomes while maintaining a good quality of life.