Women diagnosed with isolated cancer cells in the sentinel lymph node often are considered node-negative and likely don't receive any additional treatment after surgery such as chemotherapy, hormonal therapy, or radiation therapy (treatment after surgery is called adjuvant therapy). A fairly large Danish study suggests that this treatment approach may need to change.
In this study, women diagnosed with node-negative, early-stage breast cancer -- but who actually had isolated cancer cells in the sentinel lymph node -- were 56% less likely to survive without the breast cancer coming back in the 5 years after treatment compared to women who were truly node negative (no cancer cells at all in the sentinel lymph node). This suggests that classifying cancers as node-negative when there are isolated cancer cells in the sentinel node may result in inadequate treatment and a higher risk of breast cancer coming back (recurrence).
During surgery to remove early-stage breast cancer, the lymph node closest to the cancer -- called the sentinel node -- often is removed and sent to a pathologist for evaluation. Removing just this one node is called sentinel node biopsy, or sentinel node dissection.
Clusters of cancer cells -- called micrometastases -- found in the sentinel lymph node mean that the cancer has spread beyond the breast. If there are micrometastases in the sentinel node, the cancer is considered node-positive. Other research has shown that when micrometastases are found in the sentinel lymph node, the risk of the cancer coming back is higher compared to node-negative cancer. To lower the risk of node-positive breast cancer coming back, doctors may recommend one or more of the treatments below after surgery:
- removing other underarm lymph nodes (axillary node dissection)
- radiation therapy to the underarm lymph nodes
- hormonal therapy if the cancer is hormone-receptor-positive
In this study, women diagnosed with node-positive breast cancer who got treatment after surgery were 43% more likely to survive without breast cancer coming back 5 years after treatment compared to women diagnosed with node-positive breast cancer who didn't get treatment after surgery.
Based on the results of this study, the same treatments after surgery used for node-positive early-stage breast cancer (micrometastases in the sentinel node) also may be needed when only isolated cancer cells are found in the sentinel node -- even though isolated cancer cells in the sentinel node often is considered node-negative.
If you've been diagnosed with early-stage breast cancer and a sentinel lymph node biopsy was done, ask your doctor about the specific results of the biopsy. If any cancer micrometastases were found, your doctor will likely recommend an axillary lymph node dissection. Your doctor also may recommend axillary lymph node radiation.
If the cancer was classified as node-negative, ask your doctor if there were any isolated cancer cells in the sentinel node. If isolated cancer cells were found, talk to your doctor about the results of this study and whether your treatment plan should include adjuvant radiation, chemotherapy, or hormonal therapy. Together you and your doctor can decide on a treatment plan that makes the most sense for your specific situation.