Approach to patients with nonmetastatic breast cancer

HER2: human epidermal growth factor 2; OFS: ovarian function suppression; BRCA: breast cancer susceptibility gene.

* Hormone receptors are the estrogen receptor (ER) and progesterone receptor (PR). Threshold for hormone receptor positivity is ER and/or PR expression by immunohistochemistry of at least 1%.

¶ A reasonable cutoff is 5 cm, although it will vary depending on the size of the tumor to the breast and the location, and whether the patient desires breast conservation, all of which influences whether surgical resection with negative margins is likely. If it is not likely, neoadjuvant therapy may be considered.

Δ Ensure thorough evaluation of axilla. A suspicious node on exam or imaging is typically biopsied.

◊ Preoperative systemic therapy can be considered for triple-negative cancers that are node-negative and between 1 to 2 cm.

§ Most patients receiving neoadjuvant therapy will receive chemotherapy, although endocrine therapy is an option for select patients who wish to avoid the toxicities of chemotherapy.

§ The surgical approach to the primary tumor depends on multiple factors, including:

• The size of the tumor and the breast
• Presence of multifocal disease
• Patient preference

Options include breast-conserving surgery or mastectomy. Sentinel lymph node biopsy and/or axillary dissection is done for most patients, with the exception of some older patients with small, hormone receptor-positive, HER2-negative cancers.

‡ Select older females with small, hormone receptor-positive, HER2-negative cancers who will take endocrine therapy may have the option of omitting radiation after breast conserving surgery. For patients who have had mastectomy, reasons for radiation include lymph node involvement, or a combination of high risk features such as young age, lymphovascular invasion, etc.

† If an aromatase inhibitor is used in a patient with intact ovarian function, it must be administered with ovarian suppression.

** Examples of targeted therapy include cyclin dependent kinase inhibitors for hormone receptor-positive, HER2-negative cancers, or poly(adenosine diphosphate-ribose) polymerase inhibitors for BRCA1/2 carriers with high-risk HER2-negative breast cancer.

¶¶ The antibody drug conjugate trastuzumab emtansine is administered to those with residual disease, while trastuzumab with or without pertuzumab is administered to others.