I have written three prior articles on lymphedema associated with axillary dissection and Sentinel Lymph Node biopsy. A recent presentation at the American Society of Oncology (ASCO) Breast Cancer Symposium was very interesting and so now is a good time to revisit that topic.
Cells from cancers of the breast will break off from the cancer and migrate through the lymphatic channels to the regional lymph nodes. As a result, removal of the lymph nodes serves two functions. First, the nodes can be studied under the microscope. If there are no cancer cells in the lymph nodes, the risk of recurrence of the cancer is much lower than if there is metastatic cancer in the lymph nodes and less aggressive treatment is required to control the cancer. Patients with cancer in their lymph nodes will require additional treatment and their chance of recurrence of the cancer is higher. Second, if the cancer does involve the lymph nodes, removal of as much of the cancer as possible is important prior to further treatment with radiation or chemotherapy.
Lymphedema is associated with surgical removal of lymph nodes during the process of axillary dissection or with radiation to the regional lymph nodes. Other factors associated with lymphedema include obesity, limb infections, trauma to the limb and age. We have previously reported on the association of obesity (<a href="obesity1.htm"><B>Obesity Survey Results</B></a>) with lymphedema and numerous reports have established a relationship between infection, trauma and age.
At the recent ASCO meeting, Dr. Bevilacqua and colleagues presented data from their study of the incidence of lymphedema following axillary dissection. The objective of the study was to determine the risk of developing lymphedema over a 5 year period after axillary lymph node dissection for breast cancer. The study was conducted at the Cancer Hospital of the Brazilian National Cancer Institute. Detailed measurements were made of both arms and patients were evaluated 30 days after axillary dissection surgery and then every 6 months for 5 years. A total of 1054 patients were followed and all but about 6% of the patients remained in the study so that a true measure of the incidence of lymphedema could be determined.
In this study, they found that the incidence of lymphedema, defined as an increase of more than 200ml of fluid in the arm, was 30.3% over the 5 years of the study. Essentially, 1 in 3 women undergoing axillary dissection will get lymphedema following axillary dissection. They evaluated what factors were most strongly associated with the occurrence of lymphedema and they divided the risk factors into those predicting lymphedema at the time of surgery, then 1-6 months after surgery and more than 6 months after surgery.
They confirmed previously identified risk factors for lymphedema including that obesity, advanced age, more extensive axillary dissection and treatment with radiation. In addition, they found that the number of cycles of chemotherapy and the development of swelling in the arm or early edema was highly correlated with the development of lymphedema. This is the first study to identify exposure to chemotherapy before surgery, particularly in the arm on the side where the surgery was performed, was a factor associated with lymphedema.
This is a very important study because these doctors and researchers followed a large group of women very carefully for a period of 5 years after the surgery and checked some key factors that could be associated with lymphedema. These results demonstrate that the incidence of lymphedema may be higher than previously thought, highlighting the need for careful evaluation of these patients over many years. This report also emphasizes the need for careful monitoring of patients and early intervention to prevent and control lymphedema.