AnEuropean phase III clinical trial called AMAROS, which was, in part supportedby the European Organization forResearch and Treatment of Cancer (EORTC) Charitable Trust,found that axillary radiotherapy (ART) and lymph node surgeryor axillary lymph node dissection (ALND) result in equivalent overall and disease-free survival at five years aftertreatment for women with sentinel lymph node positive early breast cancer.
However, a debilitating side effect known as lymphedema was twice as common among women who underwent surgery. The study results were presented at the 49th Annual Meeting of the American Society of Clinical Oncology (ASCO), being held in Chicago, Il, May 31 – June 4, 2013
Breast cancer cells can spread within the breast and throughout the body by different systems. One of these is the lymphatic system. When breast cancer cells travel through the lymphatic system, they may end up in a lymph node. The first draining lymph node of a breast tumor is called the sentinel node. After the sentinel node, the breast cancer cells can spread to the lymph nodes in the armpit, called axillary lymph nodes.
Study shows that women with early stage breast cancer and positive sentinel lymph nodes have equally good survival at five years after treatment with either axillary radiotherapy or lymph node surgery. However, the rates of lymphedema were substantially higher in the surgery arm compared to the radiotherapy arm.
Sentinel node biopsy (SNB) is standard in assessing axillary lymph node status for cN0 breast cancer patients. In the case of a positivesentinel node orSNB, (i.e.when the sentinel node contains breast cancer cells) anaxillarylymph node dissection or ALND, thesurgical removal of all axillary lymph nodes, is the currently the standard treatment.
Preventing breast cancer recurrence
Each year, thousands of women undergo ALND to prevent breast cancer recurrence. However, treatment with an ALND has substantial side effects, the most significant being lymphedema (long-term, painful swelling of the arm). The AMAROS study suggests that, for patients who need axillary lymph node treatment, ART is a good alternative to ALND and can reduce the risk of lymphedema, without diminishing patients? survival. ART can be combined with radiotherapy to the breast or chest wall, which most women already receive as treatment for their primary tumor.
?I am sure these findings will lead to many doctors re-thinking their strategy for treating patients who have a positive sentinel lymph node biopsy,? said lead study author Emiel J. Rutgers, MD, a surgical oncologist at the Netherlands Cancer Institute(NKI) in Amsterdam, Netherlands. ?Lymphedema is a serious concern for patients and a side effect that can affect their quality of life indefinitely.?
Four thousand eight hundred-six patients with early stage, invasive breast tumors up to five centimeters and clinically node negative (no signs of breast cancer spread to the lymph nodes before surgery based on tests, such as physical exam and imaging of the axilla), were enrolled in the study. Of those patients who had a positive sentinel lymph node biopsy, 744 were randomly assigned to ALND and 681 to ART. The median follow-up period was 6.1 years.
Five-year overall survival
The five-year breast cancer recurrence rates in the axillary nodes were very low overall ? 0.54% and 1.03% in the ALND and ART groups, respectively. There were no significant differences between the two treatment groups regarding the estimated five-year overall survival (92.5-93.3%) and disease-free survival rates (82.6-86.9%). In contrast, there were striking differences in the numbers of patients who experienced lymphedema. In the first year, 40% of patients in the ALND arm had lymphedema compared to 22% in the ART arm. In subsequent years, the number of patients with lymphedema decreased, but the trend persisted: at five years the rates were 28% and 14%.
An important non-surgical option
?While some controversy continues regarding the role of complete axillary lymph node surgery, this trial presents an important non-surgical option for selected patients to reduce breast cancer recurrence under the arm and substantially reduce the risk of arm swelling, which is too common and often debilitating for our patients,? Andrew D. Seidman, MD, ASCO spokesperson and breast cancer expert explained.
Lymphedema – poorly understood
Lymphedema of the arm on the treated side of the patient is the most common side effect of both ART and ALND. The swelling of the arm is caused by a blockage in the lymphatic system in the axilla, an important part of the immune and circulatory systems. The blockage is due to the axillary treatment (ALND and/or ART) preventing lymph fluid from draining well. And as the fluid builds up, the swelling continues. The arm feels heavier and its function is impaired.
Frequently, patients have to wear firm sleeves around the whole arm to control the increase of swelling and many patients need specialized lymphedema therapy. Other common side effects of both treatments are pain in the armpit area and shoulder function disturbances.
While lymphedema, one of the most poorly understood, relatively underestimated, and least researched complications of cancer and cancer treatment, usually affects an arm or leg, it can also affect other parts of the body. It is an important consideration for clinicians who care for patients with cancer because of its relatively high frequency and because it can cause long-term physical, psychosocial, and social problems for patients. Overall, lymphedema is an independent predictor of decreased quality of life, even when other predictive factors such as socioeconomic status, decreased range of motion, age, and obesity are taken into account.
Diminishing side effects
Researchers are working on ways to adjust radiotherapy with modern techniques to further diminish side effects of ART. In the future, complete surgical removal of lymph nodes in the armpit may no longer be necessary for most patients. Based on these findings, Rutgers noted that this invasive procedure should be reserved for patients with extensive metastases in axillary lymph nodes who do not respond to adjuvant therapy and as a salvage therapy for patients who relapse.
For more information:
Abstract #LBA1001: Radiotherapy or surgery of the axilla after a positive sentinel node in breast cancer patients: final analysis of the EORTC AMAROS trial (10981/22023).
Study Authors:Rutgers EJ, Donker M, Straver ME, Meijnen P, Van De Velde CJH, Mansel RE, Westenberg H, et al.Oral Abstract Session: Breast Cancer ? Triple-Negative/Cytotoxics/Local Therapy
Date: Monday, June 3, 2013, 10:00 ? 10:15 AM CDT
Location: Room: N Hall B1
Lymphedema (PDQ? )- Information for health professionals
NCT00014612 – Comparison of Complete Axillary Lymp
h Node Dissection With Axillary Radiation Therapy in Treating Women With Invasive Breast Cancer (AMAROS)
Photo: Emiel .J.Th. Rutgers, MD, PhD, FRCS, is surgical oncologist at the Netherlands Cancer Institute in Amsterdam, the Netherlands. Photo Courtesy: EORTC – European Organization for Research and Treatment of Cancer/? ASCO/Scott Morgan
Copyright ? 2013 InPress Media Group/Sunvalley Communication. All rights reserved. Republication or redistribution of InPress Media Group/Sunvalley Communication content, including by framing or similar means, is expressly prohibited without the prior written consent of InPress Media Group/Sunvalley Communication. InPress Media Group/Sunvalley Communication shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Onco’Zine and Oncozine are registered trademarks and trademarks of Sunvalley Communication around the world.