Patient Selection, Staging, Treatment, and Follow-Up

Multidisciplinary management of patients undergoing preoperative therapy by an experienced team is essential to optimize the following:

The tumor histology, grade, and hormone receptor status are carefully evaluated before preoperative therapy is initiated. Patients whose tumors have a pure lobular histology, low grade, or high hormone receptor expression and HER2-negative status are less likely to respond to chemotherapy and should consider primary surgery, especially if the nodes are clinically negative. Even if adjuvant chemotherapy is given after surgery in these cases, a third-generation regimen (anthracycline/taxane based) may be avoided.

Before beginning preoperative therapy, the extent of the disease within the breast and regional lymph nodes should be assessed. Staging of systemic disease may include:[6]

When breast-conserving therapy is desired, baseline breast imaging is performed to identify the tumor location and exclude multicentric disease. Suspicious abnormalities are usually biopsied before beginning treatment, and a marker is placed at the center of the breast tumor(s). When possible, suspicious axillary nodes should be biopsied before initiation of systemic treatment.

In patients with clinically negative nodes who receive neoadjuvant chemotherapy, a sentinel lymph node (SLN) biopsy is typically performed at the time of surgery. In patients presenting with positive lymph nodes, detected by either clinical examination or imaging, SLN biopsy may be performed in a patient who becomes clinically node negative after preoperative therapy.[7] The use of dual mapping with both radiocolloid and blue dye and retrieval of at least three negative lymph nodes was associated with a lower false-negative rate and ALND may be omitted in these patients.[8][Level of evidence B4]; [9][Level of evidence C2]; [10][Level of evidence C3]

When considering preoperative therapy, treatment options include:

Regular clinical assessment of response to therapy is necessary after beginning preoperative therapy. Repeat radiographic assessment is also required if breast conservation is the surgical goal. Patients with progressive disease during preoperative therapy may either transition to a non–cross-resistant regimen or proceed to surgery, if feasible.[11,12] Although switching to a non–cross-resistant regimen results in a higher pCR rate than continuing the same therapy, there is no clear evidence that other breast cancer outcomes are improved with this approach.