An ongoing debate in breast cancer research involves deciding which patients should have their axillary (underarm) lymph nodes surgically removed and examined for evidence that their cancer has spread past the breast. In a recent study on the subject, researchers say that even women with small breast tumors (one centimeter or less in diameter) should have their lymph nodes evaluated. According to the researchers, age, increasing tumor size, and the aggressiveness of the cancer are all factors that may determine which patients are likely to have cancerous lymph nodes.
Because breast cancer most commonly spreads first to the axillary lymph nodes, removing 10 to 30 lymph nodes can help physicians stage a patient’s breast cancer and determine treatment and prognosis (expected outcome). However, standard axillary node dissection has potentially serious side effects for some patients. Between 10% and 20% of patients who have their lymph nodes removed develop lymphedema (chronic swelling) of the arm.
Physicians have argued that patients with small tumors whose lymph nodes are found to be free of cancer essentially undergo axillary node dissection unnecessarily. Between 3% and 37% of women with breast tumors that are one centimeter or less in size are found to have cancerous lymph nodes.
However, in the July 2000 issue of the Journal of the American College of Surgeons, researchers say that when women with small tumors are found to have cancer in their lymph nodes, their treatment is modified accordingly. For instance, post-surgical chemotherapy may be necessary for patients with cancerous lymph nodes, according to lead researcher David E. Rivadeneira, MD.
In the study, the researchers evaluated 919 patients with small breast tumors (one centimeter or less in diameter) who underwent breast surgery and axillary node dissection. Cancer was found in the lymph nodes of 165 of these patients. Of the 165 patients, 32 had breast tumors that were 0.5 centimeters (cm) or less in size while 133 patients had breast tumors between 0.6 cm and 1.0 cm in size.
The researchers say that with every millimeter increase in breast tumor size, patients were 3.5 times more likely to have cancer in their lymph nodes. Also, younger women were at higher risk of having cancerous lymph nodes. According to the researchers, women over 50 years of age with small breast tumors were 40% less likely to have cancerous lymph nodes than women younger than 50.
The aggressiveness of a patient’s breast cancer was another factor involved in indicating which patients have cancer in their lymph nodes. Women with grade 3 (aggressive) breast cancers were 2.5 times more likely to have cancerous lymph nodes than women with grade 1 (slow growing) breast cancers.
Based on the results of their study, the researchers say that even women with small breast tumors should have their lymph nodes removed and examined for evidence of cancer. Because standard axillary node dissection can cause lymphedema in some patients, the researchers say sentinel node biopsy may be a “reasonable alternative” for lymph node examination since it is a less invasive procedure.
Sentinel node biopsy is a new surgical technique that involves removing only one to three “sentinel” nodes (the first nodes in the lymphatic chain) and examining them for evidence of cancer. If the sentinel nodes do not contain cancerous cells, this may eliminate the need to remove additional lymph nodes in the axillary area. Several clinical trials have shown that sentinel node biopsy may help reduce the risk for lymphedema.
Though the researchers of this study recommend lymph node removal and testing for women with small breast tumors, other physicians do not believe all women should undergo lymph node surgery. Additional studies on lymph nodes and sentinel node biopsy will likely offer new dimensions on this debate.
- The study, “Predictive Factors Associated With Axillary Lymph Node Metastases in
T1a and T1b Breast Carcinomas: Analysis in More Than 900 Patients,” is published in
the July 2000 issue of the Journal of the American
College of Surgeons. An abstract of the study is available at
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_
uids=10898177&dopt= Abstract - The July 25, 2000 Oncology.com report by Heather
Lindsey, “Women With Small Breast Cancers Should Have Their
Underarms Checked,” is available at
http://www.oncology.com/v2_MainFrame/1,1614,_21|004|00_12|00290|
00_04|001|00_17|002|00_03|00548850|00_18|005701|00_19|005702|00_20|001,00.asp - To learn more about lymph nodes, including the importance of lymph nodes in staging breast cancer, please visit http://www.imaginis.com/breasthealth/lymph_nodes.asp
- To learn more about axillary node dissection, please visit http://www.imaginis.com/breasthealth/mastectomy.asp#axillary
- To learn more about sentinel node biopsy, please visit http://www.imaginis.com/breasthealth/sentinelnode.asp
