How Does Breast Cancer Return to the Lymph Nodes?
Breast Cancer Recurrence
- Breast cancer, even when successfully treated, may recur. Recurrence is rare, happening in approximately two percent of all breast cancer cases. The recurrent cancer may be detected at the site of the original tumor (local recurrence), in the lymph nodes near the affected breast (regional recurrence) or in organs located away from the breast area, such as the lungs, liver or bone (distant recurrence). Recurrence may happen at any time, but most often occurs within three to five years after the initial treatment of breast cancer.
Breast Cancer and Lymph Nodes
- Lymph is a clear fluid that circulates through the body, cleansing tissues. Foreign bodies such as viruses and bacteria are filtered out by the lymph nodes and the fluid drains through the lymphatic system. Lymph travels to all tissues, including organs affected by cancer. As the lymph passes through the affected breast, cancer cells can be carried away by the lymph to the nodes. Even when initial breast cancer treatment is mastectomy, cancer cells may remain and resume growing.
Breast Cancer Metastasis
- Once cancer cells enter the lymphatic system, they can migrate throughout the body. The lymph nodes located in the underarm area are typically the first site of cancer metastasis. After the lymph nodes, cancer most frequently spreads to the bone.
Risk for Recurrence
- Certain factors raise a woman's risk for breast cancer recurrence. If the original cancer involved the lymph nodes in addition to the breast tissue, the risk of recurrence is higher than if no lymph node involvement is detected. Lymph node involvement also predicts the aggressiveness of the cancer, with more aggressive cancers affecting the lymph nodes earlier than less aggressive cancers. Larger tumors more often recur than smaller tumors; tumors that are estrogen-receptor negative (only one third of all breast cancers) are more aggressive and more likely to recur. Specific characteristics of the cancer cells, such as the rate of growth and the appearance of the cells, also indicate whether a woman is at high risk for recurrence.
- Treatment for recurrent breast cancer depends on the type of treatment initially administered. For example, if the initial tumor was treated with lumpectomy and radiation therapy, mastectomy would be recommended for the treatment of the recurrent. Radiation therapy cannot be used twice at the same site. If the original treatment was mastectomy, recurrent treatment would be surgical removal of the tumor followed by radiation therapy. Chemotherapy or hormone therapy would also be administered with either approach.