According to a recent article published in the Annals of Surgical Oncology, age is an independent predictor of cancer spread to the lymph nodes under the arm in early breast cancer. Patients who were 66 years or older had a significantly reduced risk of this cancer spread.
Staging involves determining the extent of cancer spread from the site of origin; cancer stage often dictates treatment options.
For over 30 years, the standard for early breast cancer staging has included the removal of approximately 10 to 25 axillary (under the arm) lymph nodes to help determine whether the cancer has spread. This procedure, called an axillary lymph node dissection (ALND), can be associated with chronic side effects, including pain, limited shoulder motion, numbness, and swelling.
A more recent approach to evaluate whether cancer has spread to the lymph nodes is sentinel lymph node biopsy (SNB). The advantage of this procedure is that only a small number of sentinel nodes (or even a single node) are removed.
Sentinel nodes are the first lymph nodes to which cancer is likely to spread. Sentinel lymph node biopsy is becoming more widely adopted in the clinical setting in order to determine whether cancer has spread to the lymph nodes in women with localized breast cancer.
If the sentinel node is removed and cancer cells are present within the node, patients often will undergo an ALND since cancer has likely spread to other axillary lymph nodesl. If the sentinel node is removed and there are no cancer cells present, patients are typically considered “node-negative”, meaning there has been no cancer spread to the axillary nodes. The difference between having cancer cells in the sentinel node versus being node-negative often influences treatment options.
It has been determined that younger patients tend to have more aggressive breast cancer than their elderly counterparts. However, the influence of age on the rate of cancer spread (metastasis) to the sentinel lymph node has not been established.
Researchers from the Mayo Clinic recently analyzed data to evaluate the potential association between age and sentinel lymph node metastasis in women with early breast cancer. Data were evaluated for 810 patients whose ages ranged from 29 to 95 years, with a median age of 66 years. Several variables were analyzed during this study. Overall, patients who were elderly had a significantly lower risk of metastasis to axillary nodes.
- Patients who were 66 years or older had a significantly lower rate of metastasis to the sentinel node than those who were younger.
- Among patients without angiolymphatic invasion (signs that cancer cells seen through laboratory processes may have invaded nearby blood or lymph vessels), metastasis to the sentinel node was nearly twice as common among younger patients than their elder counterparts.
- Including multiple variables that are often associated with different cancer characteristics, age was an independent predictor of cancer spread to the sentinel lymph node.
The researchers concluded that women who are 66 years or older with early breast cancer have a significantly lower rate of metastasis to the sentinel lymph node. This could possibly be one reason why younger women tend to have a worse prognosis than older women with breast cancer. Furthermore, physicians should be aware of the increased risk in their younger patients.
Reference: Caywood J, Gray R, Hentz J, Pockaj B. Older Age Independently Predicts a Lower Risk of Sentinel Lymph Node Metastasis in Breast Cancer. Annals of Surgical Oncology. 2005; 12: 1061–1065.