A practice changing study, published in February 2011, in the Journal of the American Medical Association, reported the results of an important randomized trial of women with breast cancer who had metastatic involvement of their axillary sentinel lymph nodes (SLN). A procedure call a “sentinel lymph node dissection” (SLND) enables the surgeon to examine whether cancer has spread from the tumor to the lymph nodes (in particular, to the “sentinel lymph node” or SLN). Patients whose SLNs are free of cancer do not need to undergo a more extensive lymph node surgery called a “completion axillary lymph node dissection” (ALND), thereby significantly decreasing the risk of developing complications (i.e. lymphedema, infections, shoulder dysfunction, pain syndromes, etc.)
Prior to the this study, the standard of care for those patients whose SLNs were involved with cancer (“lymph node positive”) has been to perform an ALND to remove the remaining axillary lymph nodes. For years, surgeons and oncologists believed that by removing the remaining lymph nodes with an ALND in patients with a positive SLN, they would reduce the risk of cancer recurrence in the axilla and improve survival.
This study will put end to the ALND in many patients who have a positive SLN (as long as they meet the eligibility criteria below).
Randomization groups: The investigators from 115 sites (American College of Surgeons Oncology Group) randomized two groups of women with metastases detected at the time of SLND to either undergo ALND (445 patients) or no further axillary surgery (446 patients).
Eligibility criteria: Eligible women had invasive breast tumors <5 cm and one or two positive SLNs. All patients received whole-breast radiotherapy following breast-conserving surgery and SLND; 96% received adjuvant systemic therapy.
The following patients were not eligible for this study (and should therefore be recommended to undergo a completion ALND):
- palpable nodal disease at presentation
- patients who received preoperative chemotherapy
- patients who undergo mastectomies
- patients who do not receive postoperative radiotherapy or partial-breast radiotherapy
- Among patients in the ALND group, 27% were found to have additional positive nodes.
- No difference was found between the two groups in survival or recurrence rates (At median follow-up of 6.3 years):
- 5-year overall survival was 92% with ALND and 93% with SLND alone (no statistical difference)
- 5-year disease-free survival was 82% with ALND and 84% with SLND alone (no statistical difference)
The bottomline: Even though there was a 27% chance of finding additional metastatic axillary lymph nodes in the patients who underwent SLND+ALND, the OMISSION of ALND had NO EFFECT on recurrence or survival rates.
As a result of this study, many academic cancer centers in the U.S. are no longer recommending ALND in patients with positive SLNs who will be treated with subsequent adjuvant systemic therapies and whole-breast radiotherapy (learn more about “adjuvant” treatment for breast cancer here). This change in surgical management will certainly further decrease the risk of development of complications of ALND and lead to significant improvements in the lives of these patients.
If you want to learn more about lymphedema, check out my blog entry and review article (published in the American Cancer Society’s journal CA, A Cancer Journal for Clinicians)