The American Society of Clinical Oncology (ASCO) has issued new guidelines for the use of sentinel node biopsy (SNB) in patients with early-stage breast cancer (Lyman GH, et al. J Clin Oncol. 2014;32:1365-1383. The newer version expands the use of SNB to a larger group of patients, based on evidence from 9 randomized trials and 13 cohort studies conducted since 2005, when the first SNB guidelines were published.
By expanding these guidelines, more women with early-stage breast cancer will be spared the more invasive procedure, axillary lymph node dissection (ALND), which is associated with increased morbidity.
“The updated guidelines broaden the indications for use of SNB for staging patients with early-stage breast cancer based on recent clinical trials and greater experience in a range of clinical settings. As in the previous guidelines, routine complete ALND is not recommended in patients with negative SNB,” Gary H. Lyman, MD, MPH, FASCO, Codirector, Hutchinson Institute for Cancer Outcomes Research, Seattle, WA, told Value-Based Cancer Care. “However…, it is now considered safe for most patients with only 102 positive lymph nodes on SNB to avoid complete lymph node biopsy if they will undergo breast-sparing surgery followed by locoregional radiation therapy,” he said. Dr Lyman was Cochair of the ASCO Expert Panel that updated the guideline.
ALND entails removal of most of the lymph nodes in the axilla on the same side as the breast tumor, and analyzing the nodes for cancer positivity. This procedure can cause long-term adverse events, including pain, numbness, and lymphedema, which is associated with compromised quality of life.
SNB was hailed as a breakthrough when it was first introduced, because it promised to spare many women from having to undergo ALND. SNB involves removing a few lymph nodes and analyzing them for signs of cancer. If the SNBs are cancer-free, this usually means that the cancer has not spread to the other lymph nodes. SNB does have side effects, but these are fewer and less severe than those associated with ALND.
The Updated Guidelines
Based on 9 randomized controlled trials, the updated guidelines include 3 new recommendations:
- Women without SNB metastases should not receive ALND
- Most women with 1 or 2 metastatic SNBs planning to receive breast-conserving surgery and whole-breast irradiation should not undergo ALND
- Women with SNB metastases who will be treated with mastectomy may be offered ALND.
In addition, 2 groups of recommendations were updated based on cohort studies and/or informed consensus, stating that:
- Women with operable breast cancer and multicentric tumors, and/or ductal carcinoma in situ (DCIS) who are planning to have mastectomy and/or had previous breast and axillary surgery, and/or had preoperative neoadjuvant systemic therapy, may be offered SNB
- Women who have large or locally advanced invasive breast cancer (tumor size, T3/T4), and/or inflammatory breast cancer, and/or DCIS, when breast-conserving surgery is planned, and/or are pregnant, should not have SNB.
Finally, the Expert Panel that updated the guidelines had insufficient evidence on chronologic age, body mass index and body surface area, and some other factors to change some of the previous recommendations.
As in all decision-making processes, appropriate communication between patient and clinician is a critical component for optimizing patient compliance and outcome, the Expert Panel noted. “We strongly encourage patients to talk with their surgeon and other members of their multidisciplinary team to understand their options and make sure everybody’s on the same page,” Dr Lyman said upon the release of the guidelines. “The most critical determinant of breast cancer prognosis is still the presence and extent of lymph node involvement and, therefore, the lymph nodes need to be evaluated so we can understand the extent of the disease.”
The discussions should consider the patient’s perspective, set realistic expectations by discussing potential benefits and harms of SNB, explain potential outcomes, and take the time to understand what quality of life means to each individual patient.
“Certainly, improving patient quality of life is an important reason for avoiding unnecessary full lymph node dissection. However, it is important to note that it is essential that patients discuss with their surgeon and oncologist whether they are appropriate candidates for SNB, and what the possible outcomes and subsequent management is likely to look like. It is important to place the decision of local regional surgery in the context of the entire patient clinical setting and other therapies likely to be administered, including radiation, chemotherapy, and hormonal therapy,” Dr Lyman told Value-Based Cancer Care.