The three studies reviewed here suggest that routinely removing the underarm (axillary) lymph nodes during early-stage breast cancer surgery may not make sense for most women. These results were presented at the 2010 American Society of Clinical Oncology (ASCO) annual meeting.
When early-stage breast cancer is removed, the lymph node closest to the cancer -- called the sentinel node -- often is removed and sent to a pathologist for evaluation. Removing just this one node is called sentinel node biopsy or sentinel node dissection.
If cancer cells are in the sentinel node, it means the cancer has spread beyond the breast. So more treatment may be needed to reduce the risk of the cancer coming back (recurrence). Treatment choices to reduce the risk of recurrence if cancer is in the sentinel node include:
In the first study, 856 women diagnosed with early-stage breast cancer had:
After radiation, the women were split into two groups. One group had axillary node dissection and the other group had no more surgery.
After about 6 years, the researchers found no differences in treatment outcomes between the two groups:
In the second study, almost 4,000 women had surgery to remove early-stage breast cancer. None of the women had cancer cells in their lymph nodes. The women were split into to groups. One group had axillary node dissection and the other group had no more surgery.
After about 8 years of follow-up, the researchers found that overall survival, disease-free survival, and the risk of recurrence were the same in both groups. Still, the women who had axillary node dissection were more likely to have shoulder and arm problems:
These results suggest that if the sentinel node is negative, axillary node dissection may not offer any more benefits and may increases the risk of arm and shoulder problems. Most doctors don't routinely recommend axillary node dissection in women diagnosed with early-stage breast cancer if the sentinel node is negative. For doctors that still routinely recommend axillary node dissection if the sentinel node is negative in women diagnosed with early-stage breast cancer, these results suggest that may not make sense.
Some women diagnosed with early-stage breast cancer have no signs of cancer spread but later are diagnosed with metastatic breast cancer (cancer that has spread to locations away from the breast, such as the bones, liver or brain). So the third study was designed to see if a more sensitive test to detect cancer cells in the lymph nodes or bone marrow might help better predict prognosis. Being able to so could help a woman and her doctor make more informed treatment choices.
All 5,539 women in the third study had:
If the traditional way of looking for cancer cells in the sentinel lymph node and bone marrow (staining the samples and looking for cancer cells with a microscope) found no cancer, the researchers used a newer and more sophisticated method, called immune system assay or immunohistochemistry test to look at the sentinel node and bone marrow samples.
The traditional staining method found cancer in the sentinel node in 24% of the women. The more sensitive immunohistochemistry test found cancer in the sentinel node that staining didn't detect in another 10% of the women. Still, this better detection of cancer in the sentinel node didn't help predict which women were likely to survive after a breast cancer diagnosis.
The immunohistochemistry test found cancer in 3% of the bone marrow samples. In these cases, the immunohistochemistry test did help predict which women were likely to survive; women with cancer in their bone marrow were less likely to survive.
These results suggest that the immunohistochemistry test may help determine prognosis if it's used on bone marrow samples, but not sentinel node samples.
If you've been diagnosed with early-stage breast cancer, sentinel node biopsy may be done as part of your surgery. If cancer cells are found in the sentinel node, your doctor will consider all the details of your situation, including your age and the characteristics of the cancer (size, stage, etc.) before recommending treatments to reduce the risk of the cancer coming back. Axillary node dissection is one possibility.
The studies reviewed here suggest that axillary node dissection may not be beneficial for many women. Still, each woman's situation is unique. For some women, the advantages of axillary node dissection may outweigh the risks. If your doctor recommends axillary node dissection, you may want to ask about these studies and how the results may apply to your situation. With the most up-to-date information, you and your doctor can make the best decisions for YOU.
You can learn more by visiting the Breastcancer.org Lymph Node Removal pages.
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CHICAGO (MedPage Today) -- Routine removal of axillary nodes in breast cancer patients with lymph node involvement does not improve survival or lessen the risk of relapse, a researcher said here.
A randomized clinical trial involving more than 800 women found that performing axillary lymph node dissection in early-stage breast cancer patients whose sentinel node showed evidence of cancer spread had no impact on the risk of dying of the disease, according to Armando Giuliano, MD, of the John Wayne Cancer Institute in Santa Monica, Calif.
The procedure, widely viewed as necessary after cancer has been detected in the sentinel node, also made no difference in the risk of relapse, Giuliano told reporters at a press conference during the annual meeting here of the American Society of Clinical Oncology.
"The role of this operation should be reconsidered," said Giuliano, who was one of the pioneers of sentinel node biopsy in breast cancer.
Another major clinical trial looking at axillary node dissection, this one conducted among nearly 4,000 node-negative women, showed that node removal does not improve outcomes for those patients, said David Krag, MD, of the Vermont Cancer Center in Burlington.
In a third clinical trial reported at the press conference, researchers found that using more sensitive tests to detect sentinel node micrometastases in women with early stage breast cancer -- using an immune system assay, rather than chemical staining -- also did not predict survival.
On the other hand, women with such small metastases found by immunohistochemistry in the bone marrow were significantly more likely to die within five years of diagnosis, A. Marilyn Leitch, MD, of the University of Texas Southwestern Medical Center, told reporters.
Giuliano's axillary node study included 856 patients who had breast-conserving surgery and whole-breast radiation, with cancer found in the sentinel node by hematoxylin and eosin (H&E) staining after the surgery. They were randomized to get a further complete axillary node dissection or no surgery, Giuliano said, and followed for a median of 6.2 years.
The researchers found:
"We should be doing axillary node dissection much more selectively," Giuliano told reporters.
One limitation of the study was that it did not reach its accrual goals and thus was underpowered to detect differences, Giuliano said, although he told MedPage Today it's the largest such analysis ever performed in node-positive women.
Nonetheless, he said, it's unlikely that axillary node dissection -- which has significant morbidity -- is beneficial in all cases.
Many centers for years have avoided axillary node dissections in some patients, such as older women or those who would prefer to avoid the procedure, noted Eric Winer, MD, of Harvard Medical School. Winer was not part of the studies but moderated the press conference at which some of the data was presented.
"This study gives us more confidence to do that," he said, adding, "I don't think we should use this study to abandon node dissection in all patients."
"You can't say that this is a new standard," he told MedPage Today.
Krag's trial -- the National Surgical Adjuvant Breast and Bowel Project B-32 study -- looked at results from 3,986 women with node-negative early stage breast cancer who were randomized to either axillary node dissection or no further surgery.
The average time in study was 95 months, he said, but there were no significant differences in overall survival, disease-free survival, or regional control. On the other hand, there was significant residual morbidity at the end of follow-up:
The implication, Krag said, is that when the sentinel node is negative, no further surgery needs to be done.
Indeed, Krag's co-investigator, Thomas Julian, MD, of Allegheny General Hospital in Pittsburgh, said that the finding confirms what is becoming standard practice. Since the 1990s, he told MedPage Today, physicians have been moving away from routine axillary node dissection in node-negative early stage breast cancers, although some procedures are still done.
Researchers in the third study were intrigued by the observation that some women with what seems like early stage breast cancer still develop distant metastases, Leitch said. They wondered if more sensitive testing might identify those at risk by finding tiny deposits of cancer cells in the sentinel node or in bone marrow.
To find out, they enrolled 5,539 women undergoing breast-conserving surgery, who had bone marrow aspiration and a sentinel node biopsy. If the sentinel node was negative after H&E staining, she said, the investigators used the immune system assay to look deeper.
They found that 24% of the nodes were positive for metastases on staining, and a further 10% came up positive on immunohistochemistry. At the same time, 3% of the bone marrow tests using the immune system approach came up positive, she said.
However, when the results were correlated with survival, there was little effect of using the immune system assay to retest the sentinel nodes, she said. On the other hand, the presence of bone micrometastases was significantly associated with an increased risk of death (at P<0.01).
"One of the surprises was the overall excellent survival in both groups," she said -- about 93% overall.
The practice among pathologists in the U.S. has been variable, Winer said, with many doctors opting to use the more sensitive tests.
The node-positive study was supported by the American College of Surgeons Oncology Group. Giuliano did not report any potential conflicts.
The node-negative study was supported by the National Cancer Institute. Krag reported no potential conflicts.
The immunohistochemistry study was supported by the American College of Surgeons Oncology Group. Leitch did not report any potential conflicts.
Winer reported financial links with Genentech.
Primary source: Journal of Clinical Oncology Source reference: Giuliano AE, et al "ACOSOG Z0011: A randomized trial of axillary node dissection in women with clinical T1-2 N0 M0 breast cancer who have a positive sentinel node" J Clin Oncol 2010; 28(7s): Abstract CRA506.Additional source: Journal of Clinical OncologySource reference: Krag DN, et al "Primary outcome results of NSABP B-32, a randomized phase III clinical trial to compare sentinel node resection (SNR) to conventional axillary dissection (AD) in clinically node-negative breast cancer patients" J Clin Oncol 2010; 28(7s): Abstract LBA505.Additional source: Cote R, et al "ACOSOG Z0010: A multicenter prognostic study of sentinel node (SN) and bone marrow (BM) micrometastases in women with clinical T1/T2 N0 M0 breast cancer" J Clin Oncol 2010; 28(7s): Abstract CRA504. Source reference: Cote R, et al "ACOSOG Z0010: A multicenter prognostic study of sentinel node (SN) and bone marrow (BM) micrometastases in women with clinical T1/T2 N0 M0 breast cancer" J Clin Oncol 2010; 28(7s): Abstract CRA504.
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