How many sentinel lymph nodes are enough during sentinel lymph node dissection for breast cancer?

BACKGROUND.: It remains unclear how many sentinel lymph nodes (SLNs) must be removed to accurately predict lymph node status during SLN dissection in breast cancer. The objective of this study was to determine how many SLNs need to be removed for accurate lymph node staging and which patient and tumor characteristics influence this number. METHODS.: The authors reviewed data for all patients in their prospective database with clinical tumor, lymph node, metastasis (TNM) T1 through T3, N0, M0 breast cancer who underwent lymphatic mapping at their institution during the years 1994 through 2006. There were 777 patients who had at least 1 SLN that was positive for cancer. Simple and multiple quantile regression analyses were used to determine which patient and tumor characteristics were associated with the number of positive SLNs. The baseline number of SLNs that needed to be dissected for detection of 99% of positive SLNs in the total group of patients also was determined. RESULTS.: The mean number of SLNs removed in the 777 lymph node-positive patients was 2.9 (range, 1-13 SLNs). Greater than 99% of positive SLNs were identified in the first 5 lymph nodes removed. On univariate analysis, tumor histology, patient race, tumor location, and tumor size significantly affected the number of SLNs that needed to be removed to identify 99% of all positive SLNs. On multivariate analysis, mixed ductal and lobular histology, Caucasian race, inner quadrant tumor location, and T1 tumor classification significantly increased the number of SLNs that needed to be removed to achieve 99% recovery of all positive SLNs. CONCLUSIONS.: In general, the removal of a maximum of 5 SLNs at surgery allowed for the recovery of >99% of positive SLNs in patients with breast cancer. The current findings indicated that tumor histology, patient race, and tumor size and location may influence this number.     

What is new about sentinel lymph node biopsy in breast cancer?

Sentinel lymph node biopsy concept was described in several reports since 1994. Technical and identification procedure, false negative risk, learning curve criteria and benefits concerning cancer stadification and postoperative morbidity were assessed. Peroperative and postoperative pathologic examination procedures are improving progressively but remains still under debate. Classification for micro-metastasis, isolated cells and macro-metastasis in sentinel lymph node was suggested but their immunohistochimic detection and prognostic impact are unclear. These parts are discussed in this article.     

How can sentinel navigation surgery abbreviate mediastinal lymph node dissection for lung cancer?

Sentinel nodes (SNs) were examined for 101 patients who had peripheral type non-small cell lung cancer less than 5 cm and had undergone systemic mediastinal lymph node dissection. The surgical procedure was lobectomy in 91, pneumonectomy in 3, and segmentectomy with lymph node dissection in 7. In the CT room, the site for RI injection was marked on the skin, and the angle and depth of the needle required to reach the peritumoral region was determined. The RI was then injected in the RI room. The radioactivity in the lymph nodes was counted before dissection (in vivo counting), and after dissection that (ex vivo counting). SNs were defined as any node for which the count was > or = 10 times than the background count. SN identification was finally based on ex vivo data. Of the 101 patients, SNs could be identified in 80 patients (80%). Patients whose SNs could not be identified had a significantly lower FEV1/FVC than those with identifiable SNs (p=0.025). Twenty six patients (33%) had SN in the mediastinum, the distribution of which depended on the lobe, ie the #4 lymph node station in the right upper lobe, the #4 in the right middle lobe, the #4 and 7 in the right lower lobe, the #5 in the left upper lobe, and the #7 in the left lower lobe. One false negative SN was detected in 25 patients with N 1 or N 2 disease (4%). In vivo and ex vivo counting showed 73% concurrence for the identification of SNs in mediastinal lymph node stations, of which rate was significantly higher than 40% in hilar lymph node stations (p<0.001). Conclusion: The SNs were identifiable in 80% of lung cancer patients, with 4% false negative by using a Tc-99 m tin-colloid. SNs were difficult to identify in patients with a low level of FEV1/FVC, such as those with chronic obstructive pulmonary disease. The in vivo identification of mediastinal SNs was reliable as much as the ex vivo. Therefore, the in vivo identification of SNs in the mediastinum could be useful approach to guide mediastinal lymph node sampling or dissection.     

Predictive factors for non-sentinel lymph node involvement in breast cancer patients with a positive sentinel node: should we consider sentinel node-related factors?

Introduction  Sentinel node (SN) biopsy to predict axillary involvement in breast cancer patients is a common practice. After a positive SN, additional metastases are present in an unpredictable percentage, as variable as 13–66%, of axillary clearances. Our aim is to define variables associated with non-sentinel node (NSN) metastases and to determine the predictive value of a derived clinical decision rule. Methods  A consecutive series of patients with a positive SN submitted to SN biopsy plus axillary dissection was evaluated from June 1999 to December 2004 (n=143). Patient-, tumour- and SN-related variables were analysed in relation to the presence of additional metastasis. Univariate and multivariate analyses were done and predictive values of a clinical decision rule based on significant variables were estimated. Results  A total of 66 patients had metastasis in non-sentinel axillary nodes. No significant differences were present between this group and those with only the SN metastasised. Significant and independent association was found between NSN positivity and increasing tumour size, the presence of multifocality and the presence of peritumoral lymph channel invasion. Conclusions  A first derivation of a simple rule based on tumour-related variables concurs to define the presence of NSN metastasis. Care should be taken when including SN-related variables in these algorithms.     

Is there any role for sentinel node mapping in colorectal cancer staging? Personal experience and review of the literature

BACKGROUND: We explored the role of lymphatic mapping and sentinel lymphadenectomy (originally described for melanoma and breast cancer) in colon cancer. Pathologic techniques can successfully identify micrometastatic disease in lymph nodes, but they are not suitable for clinical routine use. We evaluated the role of sentinel node (SN) mapping in refining the staging of colorectal cancer. METHODS: A total of 56 open colorectal resections were performed, and Patent Blue V dye was injected under the serosa surrounding the tumor immediately after opening the abdomen. SNs were analysed by immunohistochemistry to find micrometastatic disease. A literature search for the role of SNs in colorectal cancer was also performed. RESULTS: We identified the SN in 100% of patients, with a mean of 2.02 SNs/patient (range 1-5). After immunohistochemical staining, we could upstage 21 out of 56 patients (37.5%), and we observed 10.7% false negative SNs (6/56 patients). Fewer than half of the articles described false negative rates of <15%, and most articles showed an upstaging rate of >5% of patients. These differences are probably the result of different sensitivities of the methods used in identifying the lymph node micrometastases. CONCLUSIONS: SN mapping is an easy and cost-effective technique that holds promise and warrants further investigations.     

Internal mammary lymph drainage and sentinel node biopsy in breast cancer – A study on 1008 patients

Introduction

Nowadays, axillary sentinel node (SN) biopsy is a standard procedure in the staging of breast cancer. Although the internal mammary (IM) lymph node status is a major independent prognostic factor in breast cancer patients, sampling of IM sentinel nodes (IMSNs) is not performed routinely. The aim of this study was to determine the likelihood of finding IM lymph node metastases in case of IM hotspots on lymphoscintigraphy and evaluate the relevance of IMSN biopsy as a method to improve staging.

Patients and methods

Between April 1997 and May 2006, a total of 1008 consecutive patients with clinically node-negative operable primary breast cancer were enrolled in a prospective study on SN biopsy. Both axillary and IMSNs were sampled, based on lymphoscintigraphy, intraoperative gamma probe detection and blue dye mapping, using 10 mCi (370 MBq) ^99mTc-nanocolloid injected peritumorally, and 0.5–1.0 ml Patent Blue V injected intradermally.

Results

Lymphoscintigraphy showed axillary sentinel nodes in 98% (989/1008) and IMSNs in 20% of the patients (196/1008). Sampling the IM basin, as based on the results of lymphoscintigraphy, was successful in 71% of the patients (139/196) and revealed metastases in 22% (31/139). In 29% of the patients with positive IMSNs (9/31) no axillary metastases were found.

Conclusion

Evaluation of IMSNs improves nodal staging in breast cancer. Patients with IM hotspots on lymphoscintigraphy have a substantial risk (22%) of metastatic involvement of the IM chain. In addition, true IM node-negative patients can be spared the morbidity associated with adjuvant radiotherapy.     

What is a sentinel node? Re‐evaluating the 10% rule for sentinel lymph node biopsy in melanoma

INTRODUCTION: Many surgeons use the "10% rule" to define whether a lymph node is a sentinel node (SLN) when staging malignant melanoma. However, this increases the number of SLN removed and the time and cost of the procedure. We examined the impact of raising this threshold on the accuracy of the procedure. METHODS: We reviewed the records of 561 patients with melanoma (624 basins) who underwent SLN with technetium Tc99 labeled sulfur colloid using a definition of a SLN as 10% of that of the node with the highest counts per minute (CPM). RESULTS: Of the 624 basins, 154 (25%) were positive for metastases. An average of 1.9 nodes per basin were removed (range 1-6). Metastases were found in the hottest node in 137 cases (89% of positive basins, 97% of basins overall). Increasing the threshold above 10% decreased the number of nodes excised and the costs involved, but incrementally raised the number of false negative cases above baseline (a 4% increase for a "20% rule," 5% for a "30% rule," 6% for a "40% rule," and 7% for a "50% rule"). Taking only the hottest node would raise the false negative rate by 11%. CONCLUSIONS: Although using thresholds higher than 10% for the definition of a SLN will minimize the extent of surgery and decrease the costs associated with the procedure, it will compromise the accuracy of the procedure and is not recommended.     

Current trends of sentinel lymph node biopsy for breast cancer —A surgeon’s perspective

Sentinel lymph node biopsy (SLNB) is standard care for patients with early-stage breast cancer, and axillary lymph node dissection (ALND) is considered unnecessary when sentinel lymph nodes (SLNs) are tumor-free. Additional non-SLN metastasis in patients with positive SLNs can be estimated using several risk factors such as primary tumor size, metastatic tumor size in SLNs, lymphatic vessel invasion, and so on. All patients with positive SLNs may be treated with further ALND based on their own risk for nonSLN metastasis. Recent randomized clinical trials have already proved less surgical morbidity and better QOL for SLNB alone compared with ALND. However, trials concerning the efficacy of ALND in positive SLNB patients in preventing local regional recurrence and improving overall survival compared with no ALND, and also, concerning the effectiveness of ALND compared with axillary radiation therapy (RT), have not yielded clear results. The prognostic significance of micrometastasis in SLNs or bone marrow also remains to be determined. So far SLNB is not acceptable for patients with positive nodes in the axilla at initial diagnosis even if their axillary metastases are down-staged to negative by neoadjuvant chemotherapy. Although basically SLNB does not need to be performed for patients with pure ductal carcinoma in situ (DCIS), it is recommended for patients with an initial diagnosis of DCIS which is large, palpable, high grade, or found in younger patients. Because these types of DCIS have higher incidences of accompanying invasive lesions. In addition if patients will undergo mastectomy, SLNB is recommended because of the inability to perform SLNB after mastectomy. SLNB may be acceptable for patients with T3 or T4b tumors, even though SLN identification is lower yet SLN involvement is higher compared with T1 or T2 tumors, and systemic adjuvant therapy is more important for patients with T3 or T4b tumors. SLNB is a bridge to further axillary treatment such as ALND or axillary RT, and which strategy, including no further treatment, is best considered individually based on recurrence risk, treatment responsiveness and use or non-use of systemic therapy.     

Timing of the sentinel lymph node biopsy in breast cancer patients receiving neoadjuvant therapy – Recommendations for clinical guidance

Neoadjuvant chemotherapy (NAC) is an increasingly important component in the treatment of both locally advanced and early-stage breast cancer. With this, a debate on the timing of the sentinel lymph node biopsy (SLNB) has emerged. At the end of the last century, the SLNB was introduced as an axillary staging modality, and this paper aims to further elucidate this issue in the context of NAC. We compiled available data on the SLNB after NAC and provide clinical guidance for timing the SLNB in this context. On the basis of our findings, we recommend that the SLNB can be performed after NAC in all cases. In patients with a clinically node-negative (cN0) status prior to NAC, the SLNB should be performed after NAC, and in case of a histologically confirmed negative SLNB, a completion axillary lymph node dissection (ALND) has no added value and can be omitted. In patients with clinically positive nodal involvement (cN+) prior to NAC, all axillary surgery can also be performed after NAC.     

What is the accuracy of sentinel lymph node biopsy for gastric cancer? A systematic review

Background

In gastric cancer, the utility of sentinel lymph node (SLN) biopsy has not been established. SLN may be a good predictor of the pathological status of other lymph nodes and thus the necessity for more extensive surgery or lymph node dissection. We aimed to identify and synthesize findings on the performance of SLN biopsies in gastric cancer.

Methods

Electronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from 1998 to 2009. Titles and abstracts were independently rated for relevance by a minimum of two reviewers. Techniques, detection rates, accuracy, sensitivity, specificity, and false-negative rates (FNRs) were analyzed. Analysis was performed based on the FNR.

Results

Twenty-six articles met our inclusion criteria. SLN detection using the dye method (DM) was reviewed in 18 studies, the radiocolloid method (RM) was used in 12 studies, and both dye and radiocolloid methods (DUAL) were used in 5 studies. The DM had an overall calculated FNR of 34.7% (95% confidence interval [CI] 21.2, 48.1). The RM had an overall calculated FNR of 18.5% (95% CI 9.1, 28.0). DUAL had an overall calculated FNR of 13.1% (95% CI −0.9, 27.2).

Conclusion

Application of the SLN technique may be practical for early gastric cancer. The use of DUAL for identifying SLN may yield a lower FNR than either method alone, although statistical significance was not met.

     

Intraoperative sentinel node imaging versus SPECT/CT in oral cancer – A blinded comparison

Introduction

Sentinel node biopsy (SNB) is gaining popularity as a staging tool in oral cancer. Protocol mandates radiotracer injection and pre-operative imaging (LSG?±?SPECT/CT) in the nuclear medicine department. This approach limits application to accessible tumours and to centres with nuclear medicine. New technology, freehand single photon emission computed tomography (fhSPECT), has proved a useful adjunct in intraoperative imaging and localisation of sentinel nodes. This study investigates fhSPECT as an alternative to traditional imaging, an approach that would widen the remit of SNB.