Breast cancer staging: one lymph node or several?

This paper compares the benefits and risks of axillary lymph node dissection compared to sentinel lymph node dissection.

Breast cancer can spread to nearby lymph nodes (organ that is involved in the immune system that is found throughout the body). Generally, for patients with no cancer in their lymph nodes, sentinel lymph node dissection is performed to stage the cancer. This involves removal of only the first lymph node to which the cancer is most likely to spread, to determine the severity of cancer. For patients with early invasive breast cancer and metastatic disease (cancer that has spread to other parts of the body), axillary lymph node dissection is undertaken. This involves removal of several lymph nodes to determine the severity of cancer.

The authors studied women with breast cancer that had spread to the sentinel lymph node. Data from 10 previous articles were combined and studied.

From three studies, there were similar survival rates between patients who had sentinel lymph node dissection alone and complete axillary lymph node dissection.

In one study, 1.6% of patients who had sentinel lymph node dissection compared with 3.1% of patients who had axillary lymph node dissection experienced return of breast cancer. However, another study reported that significantly more women who underwent a sentinel lymph node dissection alone had higher rates of cancer return. Women who had sentinel lymph node dissection alone had similar disease-free-survival (period without symptoms of disease) rates compared with women who had complete axillary lymph node dissection.

The studies also evaluated the risks associated with each option. Compared to patients who had complete axillary lymph node dissection, those who had sentinel lymph node dissection alone had a 70% lower risk of lymphedema (swelling in the limbs) after 6 months, 74% lower risk of limited range of motion, 75% lower risk of pins and needles in arms and a 42% lower risk of wound infections. 

The authors concluded that for some women with early invasive breast cancer, sentinel lymph node dissection can be an alternative to axillary lymph node dissection. 

There could be publication bias and some studies had low strength of evidence. 

\Discuss with your doctor the advantages and disadvantages of both treatment methods.