From the Guidelines
Cancers that typically metastasize to left axillary lymph nodes include left breast cancer, as it is the most common malignancy to spread to these nodes, with approximately 40-50% of breast cancer patients having axillary lymph node involvement at diagnosis 1.
Key Points to Consider
- Left breast cancer is the primary source of metastasis to left axillary lymph nodes due to the lymphatic drainage pattern of the breast, which flows primarily to the ipsilateral axillary lymph nodes.
- Melanomas of the left upper extremity and left chest wall can also metastasize to left axillary nodes, following lymphatic drainage patterns.
- Less commonly, left lung cancers, particularly those in the upper lobe, may metastasize to these nodes.
- Rare instances of metastases from more distant primary sites like gastrointestinal cancers can occur through retrograde lymphatic flow when normal pathways are blocked.
Diagnostic Approach
- The presence of left axillary lymphadenopathy in patients without a known cancer history should prompt a thorough examination of potential primary sites, with particular attention to the left breast and left upper extremity skin.
- Imaging studies such as mammography, ultrasound, or PET/CT may be necessary to identify the primary tumor.
- Breast MRI has been shown to identify the primary tumor in around two-thirds of patients with negative clinical examination and negative mammography, making it a crucial diagnostic tool 1.
Management
- Patients with breast-like cancer of unknown primary (CUP) should be managed under the presumption of an occult breast primary and receive treatment according to primary breast cancer protocols.
- Axillary lymph node dissection is recommended, with additional ipsilateral breast-targeting treatment using either mastectomy or radiation therapy (RT) to reduce the risk of recurrence and improve survival 1.
- Systemic therapy should be given analogous to the equivalent nodal-positive breast cancer, aligning with current treatment standards for breast cancer.
From the Research
Cancers that Metastasize to Left Axillary Lymph Nodes
- Breast cancer is the most common cancer to metastasize to axillary lymph nodes, including the left axillary lymph nodes 2, 3
- The metastasis of breast cancer to axillary lymph nodes is a crucial factor in the staging and treatment of the disease 3
- Other types of cancer can also metastasize to axillary lymph nodes, but breast cancer is the most common and well-studied example 4
Factors that Influence Metastasis to Axillary Lymph Nodes
- Tumor size and grade are significant factors in the risk of axillary lymph node metastases, with larger and higher-grade tumors being more likely to metastasize 5
- Lymphovascular invasion is also a significant predictor of axillary lymph node metastases, with tumors that exhibit lymphovascular invasion being more likely to metastasize 5
- The presence of lymph node metastases is a significant prognostic factor in breast cancer, and accurate assessment of axillary lymph node status is crucial for staging and treatment 3, 4
Clinical Management of Axillary Lymph Node Metastases
- Surgical treatment, including axillary lymph node dissection, is a common approach to managing axillary lymph node metastases, particularly in patients with breast cancer 2, 6, 4
- Sentinel lymph node biopsy is a less invasive alternative to axillary lymph node dissection and may be suitable for patients with smaller tumors or lower-risk disease 5
- Adjuvant therapy, including chemotherapy and radiation, may also be used to manage axillary lymph node metastases, particularly in patients with more advanced disease 6