Presurgical (neoadjuvant) endocrine therapy is a useful model to predict response and outcome to endocrine treatment in breast cancer patients.
Endocrine therapy of breast cancer has been improved continuously during the last decades. Currently, aromatase inhibitors are dominating treatment algorithms for postmenopausal women with hormone-receptor positive breast cancer while tamoxifen still is the most widely used drug for premenopausal women. Several research tools and study designs have been used to challenge established drugs and develop the field of antihormonal therapy. One pivotal study option has been the observation of clinical responses during presurgical/neoadjuvant endocrine therapy (PSET/NET). This strategy has several major advantages. First, the breast tumor, still present in the patient's breast during therapy, can be followed by clinical observations and radiological measurements and any treatment effect will be immediately registered. Second, tumor biopsies may be obtained before initiation and following therapy allowing intra-patient comparisons. These tumor-biopsies may be used for the evaluation of intra-tumor changes associated with drug treatment. As examples, presurgical breast cancer trials have been used to evaluate intra-tumor estrogen levels during therapy with aromatase inhibitors and also to study mechanisms involved in the adaptation processes to estrogen suppression. Biomarker studies have provided information that may be used for patient selection in the future. Finally, recently published results from presurgical trials testing combinations of classical endocrine drugs and novel targeted therapies have produced promising results.
Institute of Clinical Medicine, Division of Medicine and Laboratory Sciences, University of Oslo, Oslo, Norway. juergen.geisler@medisin.uio.no
Jürgen
J
Geisler
Ian
I
Smith
William
W
Miller
D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001141:Aromatase / Q000737:chemistry / Q000378:metabolism; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D006727:Hormone Antagonists / Q000627:therapeutic use; D006801:Humans; D058990:Molecular Targeted Therapy; D020360:Neoadjuvant Therapy / Q000379:methods; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D057170:Translational Research, Biomedical; D016896:Treatment Outcome
D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D006727:Hormone Antagonists; D009363:Neoplasm Proteins; D001141:Aromatase