Increasing Interest in Neoadjuvant Endocrine Treatment for Locally Advanced Breast Cancer

Although overall mortality related to breast cancer in women is declining, patients with locally advanced breast cancer (LABC) still pose a challenge to oncologists.

LABC patients fall into 2 distinct categories: women with large clinical stage tumors who need mastectomies rather than breast-conserving surgeries, and women with inflammatory breast cancer for whom surgery is unlikely to successfully remove all existing disease.

Those in the latter category have poor prognoses as a result of their diseases’ aggressive nature, advanced stage at diagnosis, and difficulty in obtaining complete surgical margins. Such challenges redirect the oncologist’s attention to neoadjuvant chemotherapy as a method for reducing tumor burden enough to permit successful surgery.

Neoadjuvant endocrine therapy originated as an intervention for elderly or frail patients with hormone receptor—positive LABC. However, shared clinical knowledge on endocrine intervention in breast cancer has exploded over the last 15 years. Today, oncologists understand differential responses to chemotherapy and endocrine therapy in various subtypes of breast cancer. For this reason, neoadjuvant endocrine therapy now offers hope to women with LABC.

A multinational team of researchers published a review of neoadjuvant endocrine therapy in the February 2014 issue of Current Oncology. Their 7 points address the entire treatment continuum, which include:

• Establishing endocrine therapy’s safety before surgery
• Comparing neoadjuvant chemotherapy to endocrine therapy
• Deciding whether to use aromatase inhibitors or tamoxifen
• Identifying the optimal duration of therapy
• Comparing aromatase inhibitors in the neoadjuvant setting
• Addressing human epidermal growth factor receptor 2—positive disease
• Using biomarkers and genomic evaluations to formulate prognoses

The review presented a concise summary of the current medical knowledge on neoadjuvant endocrine therapy for LABC and directly discussed many factors that muddy patients’ clinical pictures. The researchers looked to the POETIC trial, which has exposed 4,000 postmenopausal estrogen receptor—positive breast cancer patients to 2 weeks of preoperative adjuvant endocrine treatment, in order to clarify the treatment’s role and identify the biomarkers associated with best response.