Positive Nodes, But Axillary Dissection Not Needed

Patients only had 1 or 2 positive nodes

Nick Mulcahy

February 09, 2011

February 9, 2011 — In certain women with early-stage breast cancer and positive nodes, sentinel lymph node dissection (SLND) does not result in inferior survival, compared with axillary lymph node dissection (ALND), according to the authors of a major clinical trial from the American College of Surgeons Oncology Group.

The practice-changing finding has been widely covered by the media, including the New York Times, Washington Post, and television networks.

Dr. Armando Giuliano

The women in the study all had clinical T1/T2 invasive breast cancer and 1 or 2 sentinel lymph nodes (SLNs). They also received breast-conserving surgery, whole-breast irradiation, and adjuvant systemic therapy, said the authors, led by Armando E. Giuliano, MD, from the John Wayne Cancer Institute at Saint John's Health Center, in Santa Monica, California.

The 5-year overall survival was 91.8% for ALND and 92.5% for SLND alone, with a median follow-up of 6.3 years, report Dr. Giuliano and colleagues in the February 9 issue of the Journal of the American Medical Association. The results were first presented at the 2010 American Society of Clinical Oncology (ASCO) meeting, and were reported as practice-changing by Medscape Medical News at that time.

There was also no benefit of ALND in terms of local control or disease-free survival.

"The results of this trial definitely showed that ALND is not beneficial [in these circumstances]," write Grant Walter Carlson, MD, and William Wood, MD, from the Winship Cancer Institute of Emory University in Atlanta, Georgia, in an accompanying editorial.

Many clinicians have already stopped using ALND in such patients because of the apparent lack of utility and the frequent additional morbidity, write the editorialists.

Nevertheless, at the ASCO meeting, a breast cancer expert noted that "the majority of doctors are still doing axillary node dissection when sentinel lymph node biopsy is positive."

At ASCO, Dr. Giuliano admitted that it is counterintuitive to leave behind any cancer, even very small amounts.

In their editorial, Dr. Carlson and Dr. Wood attempt to explain why the residual disease is not problematic. "Adjuvant radiation and systemic therapy likely treated the low-volume nodal metastasis in this study."

Dr. Giuliano and colleagues hope that surgeons embrace the findings and the recommendation to forgo ALND in this set of patients.

"Implementation of this practice change would improve clinical outcomes in thousands of women each year by reducing the complications associated with ALND and improving quality of life with no diminution in survival," they write.

The study authors note that the trial did not include patients who were treated with mastectomy, lumpectomy without radiotherapy, partial-breast irradiation, neoadjuvant therapy, or whole-breast irradiation in the prone position (in which the low axilla is not treated).

For patients who are treated in these ways, "ALND remains standard practice when SLND identifies a positive SLN," write the authors.

However, at the ASCO meeting, Dr. Giuliano said that axillary dissection should no longer be performed routinely in all women with positive sentinel nodes. "The role of this operation needs to be reconsidered," he summarized at the time.

The new study is the second major clinical trial to publish results within the past year that reinforce the value of sentinel node dissection alone in the presence of minimal sentinel node involvement. The National Surgical Adjuvant Breast and Bowel Project (NSABP) B-32 study found that women who have sentinel node dissection alone have no survival or recurrence disadvantage, compared with those who undergo axillary dissection, when there is a small amount disease found in the initial sentinel node biopsy (Lancet Oncol. 2010;11:927-933).

Trial Details and Results

The American College of Surgeons Oncology Group Z0011 trial was a phase 3 noninferiority trial conducted at 115 sites and enrolling patients from May 1999 to December 2004.

In addition to having T1/T2 invasive breast cancer and only 1 or 2 sentinel lymph nodes containing metastases, patients had no palpable adenopathy or enlarged lymph nodes.

Patients with SLN metastases identified by SLND were randomized to undergo either ALND (n = 445) or no further axillary treatment (SLND-alone group; n = 446). Those randomized to ALND underwent dissection of 10 or more nodes.

The median number of nodes removed was 17 in the ALND group and 2 in the SLND-alone group. There were 94 deaths (42 in the SLND-alone group and 52 in the ALND group). As noted above, SLND alone ALND resulted in similar survival; 5-year disease-free survival was 83.9% with SLND alone and 82.2% with ALND. The axillary recurrence rates for both groups were also similar: 0.9% with ALND and 0.5% with SLND (= .45).

Will different outcomes be seen over the long term? Not likely, say the authors.

"The low rates of locoregional recurrence at 5 years and the nearly identical overall and disease-free survival between treatment groups in Z0011 would suggest that differences in survival between study groups are unlikely to emerge with longer follow-up, because ALND would only affect survival by virtue of improved locoregional control," they write.

The authors have disclosed no relevant financial relationships.

JAMA. 2011;305:569-575, 606-607. Abstract Extract

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