The Effects of Short-term Preoperative Treatment With Hormonal Therapy on Gene Profiles in Breast Cancer

The Effects of Short-term Preoperative Treatment With Hormonal Therapy on Gene Profiles in Breast Cancer

The investigators would like to study the genetic and molecular outcomes that results after a short term neoadjuvant hormonal therapy on patients with breast cancer.

Breast cancer is among the most common malignancies in women in the United States. Over the years breast cancer management have dramatically developed from the extensive surgical approach toward the breast conservative approach. This was mainly due to the introduction of chemotherapy and hormonal therapy. Hormonal therapy in particular has been shown to improve the oncological outcomes of the breast cancer. However, while this is well documented in the clinical outcomes. Little is known in regards what happens on the genetic level. As such in this study the investigators would like to study the genetic and molecular outcomes that results after a short term neoadjuvant hormonal therapy on patients with breast cancer.

The hypothesis of this study is that short-term, preoperative hormonal treatment will induce genetic changes associated with reduced proliferation, including lower Ki67 expression, and changes in Estrogen Receptor (ER) and Progesterone Receptor (PR) expression. The data from such investigation will be very helpful in advancing the individualized care to women with breast cancer.

Inclusion criteria

• Treatment-naïve, histologically confirmed invasive ductal breast cancer between stages 1 to 3.
• Co-enrollment in the FLEX Registry
• Estrogen Receptor Positive (ER+) Progesterone Receptor Positive (PR+) confirmed hormone receptor status measured by immunohistochemistry (IHC)
• Patients should understand patients' condition and be able to give informed consent to participate

Exclusion criteria

• History of hormonal therapy, chemotherapy, radiation therapy, or novel therapy to treat the current breast cancer.
• Allergic reactions/hypersensitivity to tamoxifen, letrozole, or exemestane or any of the ingredients of these drugs.
• Any contraindication to hormonal therapy, such as history of thromboembolic disease or uterine cancer.
• Patients without invasive disease (stage 0)
• Patients with metastatic breast cancer(stageIV)
• Patients that are Human Epidermal Growth Factor 2+(HER2+) by IHC/Fluorescence in situ hybridization (FISH).