Search for distant metastasis
Prior to beginning a treatment regimen for a patient with locoregional recurrence, an evaluation for distant metastasis should be instituted, since the findings may alter the treatment plan.
Distant metastasis from the breasts
Metastatic breast cancer may be manifested by bone pain, shortness of breath secondary to a pleural effusion, parenchymal or pulmonary nodules, or neurologic deficits secondary to spinal cord compression or brain metastases. In some instances, metastatic disease is identified after abnormalities are found on routine laboratory or radiologic studies.
Assessment of disease extent
It is important to assess the extent of disease using radiography, CT, and radionulide scanning. Organ functional impairment may be determined by blood tests (liver/renal/hematologic) or may require cardiac and pulmonary function testing. Biopsy may be required to confirm the diagnosis of metastasis; this is especially important when only a single distant lesion is identified.
METASTASIS TO THE BREASTS
The most common source of metastatic disease to the breasts is a contralateral breast primary. Metastasis from a nonbreast primary is rare, representing < 1.5% of all breast malignancies. Some malignancies that could metastasize to the breast include non-Hodgkin lymphoma, leukemias, melanoma, lung cancer (particularly small-cell lung cancer), gynecologic cancers, soft-tissue sarcomas, and gastrointestinal (GI) adenocarcinomas. Metastasis to the breasts from a nonbreast primary is more common in younger women. The average age at diagnosis ranges from the late 30s to 40s. Treatment depends on the status and location of the primary site.
Mammographic findings
Mammography in patients with metastatic disease to the breasts most commonly reveals a single lesion or multiple masses with distinct or semidiscrete borders. Less common mammographic findings include skin thickening or axillary adenopathy.
FNA or biopsy
FNA cytology has been extremely useful in establishing the diagnosis when the metastatic disease has cytologic features that are not consistent with a breast primary. When cytology is not helpful, core biopsy or even open biopsy may be necessary to distinguish primary breast cancer from metastatic disease.
TREATMENT
LOCALLY ADVANCED DISEASE
The optimal treatment for patients with locally advanced breast cancer has yet to be defined due to the heterogeneity of this group. There are approximately 40 different substage possibilities with the different combinations of tumor size and nodal status. Between 66% and 90% of patients with stage III breast cancer will have positive lymph nodes at the time of dissection, and approximately 50% of patients will have four or more positive nodes.
Patients with locally advanced breast cancer have disease-free survival rates ranging from 0% to 60%, depending on tumor characteristics and nodal status. In general, the most frequent type of treatment failure is due to distant metastases, and the majority of them appear within 2 years of diagnosis.
With the increased utilization of multimodality therapy, including chemotherapy, radiation therapy, and surgery, survival for this patient population has improved significantly.
Neoadjuvant systemic therapy
Neoadjuvant therapy with cytotoxic drugs permits in vivo chemosensitivity testing, can downstage locally advanced disease and render it operable, and may allow breast-conservation surgery to be performed. Preoperative chemotherapy requires a coordinated multidisciplinary approach to plan for surgical and radiation therapy. A multimodality treatment approach can provide improved control of locoregional and systemic disease. When neoadjuvant therapy is used, accurate pathologic staging is not possible. The majority of patients receiving neoadjuvant chemotherapy and treated with either breast conservation or mastectomy will require radiation therapy following surgery.
