Roderick R. Turner

PURPOSE: To develop a guideline for the use of sentinel node biopsy (SNB) in early stage breast cancer. METHODS: An American Society of Clinical Oncology (ASCO) Expert Panel conducted a systematic review of the literature available through February 2004 on the use of SNB in early-stage breast cancer. The panel developed a guideline for clinicians and patients regarding the appropriate use of a sentinel lymph node identification and sampling procedure from hereon referred to as SNB. The guideline was reviewed by selected experts in the field and the ASCO Health Services Committee and was approved by the ASCO Board of Directors. RESULTS: The literature review identified one published prospective randomized controlled trial in which SNB was compared with axillary lymph node dissection (ALND), four limited meta-analyses, and 69 published single-institution and multicenter trials in which the test performance of SNB was evaluated with respect to the results of ALND (completion axillary dissection). There are currently no data on the effect of SLN biopsy on long-term survival of patients with breast cancer. However, a review of the available evidence demonstrates that, when performed by experienced clinicians, SNB appears to be a safe and acceptably accurate method for identifying early-stage breast cancer without involvement of the axillary lymph nodes. CONCLUSION: SNB is an appropriate initial alternative to routine staging ALND for patients with early-stage breast cancer with clinically negative axillary nodes. Completion ALND remains standard treatment for patients with axillary metastases identified on SNB. Appropriately identified patients with negative results of SNB, when done under the direction of an experienced surgeon, need not have completion ALND. Isolated cancer cells detected by pathologic examination of the SLN with use of specialized techniques are currently of unknown clinical significance. Although such specialized techniques are often used, they are not a required part of SLN evaluation for breast cancer at this time. Data suggest that SNB is associated with less morbidity than ALND, but the comparative effects of these two approaches on tumor recurrence or patient survival are unknown.

PURPOSE: To provide evidence-based recommendations to practicing oncologists, surgeons, and radiation therapy clinicians to update the 2005 clinical practice guideline on the use of sentinel node biopsy (SNB) for patients with early-stage breast cancer. METHODS: The American Society of Clinical Oncology convened an Update Committee of experts in medical oncology, pathology, radiation oncology, surgical oncology, guideline implementation, and advocacy. A systematic review of the literature was conducted from February 2004 to January 2013 in Medline. Guideline recommendations were based on the review of the evidence by Update Committee. RESULTS: This guideline update reflects changes in practice since the 2005 guideline. Nine randomized clinical trials (RCTs) met systematic review criteria for clinical questions 1 and 2; 13 cohort studies informed clinical question 3. RECOMMENDATIONS: Women without sentinel lymph node (SLN) metastases should not receive axillary lymph node dissection (ALND). Women with one to two metastatic SLNs planning to undergo breast-conserving surgery with whole-breast radiotherapy should not undergo ALND (in most cases). Women with SLN metastases who will undergo mastectomy should be offered ALND. These three recommendation are based on RCTs. Women with operable breast cancer and multicentric tumors, with ductal carcinoma in situ (DCIS) who will undergo mastectomy, who previously underwent breast and/or axillary surgery, or who received preoperative/neoadjuvant systemic therapy may be offered SNB. Women who have large or locally advanced invasive breast cancer (tumor size T3/T4), inflammatory breast cancer, or DCIS (when breast-conserving surgery is planned) or are pregnant should not undergo SNB. These recommendations are based on cohort studies and/or informal consensus. In some cases, updated evidence was insufficient to update previous recommendations.

OBJECTIVE: The authors evaluated the effect of intraoperative lymphatic mapping and sentinel lymphadenectomy (SLND) on the axillary staging of patients with carcinoma of the breast. SUMMARY BACKGROUND DATA: The accurate staging of patients with breast cancer is essential to guide management and determine prognosis. The authors previously reported the feasibility and accuracy of SLND in breast carcinoma. Sentinel lymphadenectomy identifies the first ("sentinel") axillary lymph node draining the site of a primary tumor; because this node is the most likely site of axillary metastasis, histopathologic examination of the sentinel node correlates well with examination of the entire axillary contents. The current study compares SLND with standard axillary lymphadenectomy (ALND) for the staging of breast carcinoma. METHODS: The incidence of axillary node metastasis and micrometastasis in SLND and ALND specimens from patients undergoing operative treatment of a primary breast carcinoma was compared prospectively. Multiple sections of each sentinel lymph node in SLND specimens were examined by hematoxylin and eosin (H&E) staining and by immunohistochemical techniques using antibodies to cytokeratin. One or two sections of each nonsentinel lymph node in ALND specimens were examined by routine H&E staining. RESULTS: One hundred thirty-four patients underwent ALND (ALND group), and 162 underwent successful SLND followed by completion ALND (SLND group). Both groups were similar with respect to age (median, 55 and 54 years, respectively), palpable primary tumors (54.5% and 59.3%, respectively), palpable axillary nodes (5.2% and 7.4%, respectively), size of primary tumor (median, 1.5 cm in each group), and total number of axillary lymph nodes examined (median, 19 and 21, respectively). The number of patients with axillary metastasis was 39 (29.1%) in the ALND group and 68 (42.0%) in the SLND group (p < 0.03). Of these, 4 of 39 (10.3%) ALND patients (3.0% of all ALND patients) and 26 of 68 (38.2%) SLND patients (16.0% of all SLND patients) had micrometastasis (< or = 2 mm), a highly significant difference (p < 0.0005) CONCLUSIONS: Sentinel lymphadenectomy with multiple sectioning and immunohistochemical staining of sentinel nodes increases the accuracy of axillary staging in breast cancer and can identify significantly more patients with lymph nodes metastases, especially micrometastases, than can ALND with routine histopathologic processing of lymph nodes.

BACKGROUND AND OBJECTIVE: The sentinel node hypothesis assumes that a primary tumor drains to a specific lymph node in the regional lymphatic basin. To determine whether the sentinel node is indeed the node most likely to harbor an axillary metastasis from breast carcinoma, the authors used cytokeratin immunohistochemical staining (IHC) to examine both sentinel and nonsentinel lymph nodes. METHODS: From February 1994 through October 1995, patients with breast cancer were staged with sentinel lymphadenectomy followed by completion level I and II axillary dissection. If the sentinel node was free of metastasis by hematoxylin and eosin staining (H&E), then sentinel and nonsentinel nodes were examined with IHC. RESULTS: The 103 patients had a median age of 55 years and a median tumor size of 1.8 cm (58.3% T1, 39.8% T2, and 1.9% T3). A mean of 2 sentinel (range, 1-8) and 18.9 nonsentinel (range, 7-37) nodes were excised per patient. The H&E identified 33 patients (32%) with a sentinel lymph node metastasis and 70 patients (68%) with tumor-free sentinel nodes. Applying IHC to the 157 tumor-free sentinel nodes in these 70 patients showed an additional 10 tumor-involved nodes, each in a different patient. Thus, 10 (14.3%) of 70 patients who were tumor-free by H&E actually were sentinel node-positive, and the IHC lymph node conversion rate from sentinel node-negative to sentinel node-positive was 6.4% (10/157). Overall, sentinel node metastases were detected in 43 (41.8%) of 103 patients. In the 60 patients whose sentinel nodes were metastasis-free by H&E and IHC, 1087 nonsentinel nodes were examined at 2 levels by IHC and only 1 additional tumor-positive lymph node was identified. Therefore, one H&E sentinel node-negative patient (1.7%) was actually node-positive (p < 0.0001), and the nonsentinel IHC lymph node conversion rate was 0.09% (1/1087; p < 0.0001). CONCLUSIONS: If the sentinel node is tumor-free by both H&E and IHC, then the probability of nonsentinel node involvement is <0.1%. The true false-negative rate of this technique using multiple sections and IHC to examine all nonsentinel nodes for metastasis is 0.97% (1/103) in the authors' hands. The sentinel lymph node is indeed the most likely axillary node to harbor metastatic breast carcinoma.

PURPOSE: Immediate complete axillary lymphadenectomy (ALND) after sentinel lymphadenectomy (SLND) has confirmed that tumor-negative sentinel nodes accurately predict tumor-free axillary nodes in breast cancer. Therefore, we hypothesized that SLND alone in patients with tumor-negative sentinel nodes would achieve axillary control, with minimal complications. PATIENTS AND METHODS: Between October 1995 and July 1997, 133 consecutive women who had primary invasive breast tumors clinically </= 4 cm in diameter and no axillary lymphadenopathy were prospectively entered onto a trial of SLND using vital blue dye. Sentinel nodes were examined by standard microscopy or immunohistochemistry. SLND was the only axillary surgery if sentinel nodes were tumor-free. Completion ALND was performed only if sentinel nodes contained metastases or if they were not identified. Excluded from subsequent analysis were patients with unsuspected multifocal carcinoma and those who refused completion ALND. The complication and axillary recurrence rates after SLND without ALND were determined. RESULTS: Sentinel nodes were identified in 132 (99%) of 133 patients. Eight patients were excluded from further analysis. Of the 125 assessable patients, 57 had tumor-positive sentinel nodes and one had an unsuccessful mapping procedure; these patients underwent completion ALND. In the remaining 67 patients (54%), SLND was the only axillary procedure. Complications occurred in 20 patients (35%) undergoing ALND after SLND but in only two patients (3%) undergoing SLND alone (P =.001). There were no local or axillary recurrences at a median follow-up of 39 months. CONCLUSION: Complication rates are negligible after SLND alone. An absence of axillary recurrences supports SLND as an accurate staging alternative for breast cancer and suggests that routine ALND can be eliminated for patients with histopathologically negative sentinel nodes.