Pathologic analysis of sentinel lymph nodes

Ultrastaging methods of sentinel lymph nodes in endometrial cancer - a systematic review

OBJECTIVE

Sentinel lymph node mapping has emerged as an alternative to lymphadenectomy in evaluating the lymph node status in endometrial cancer. Several pathological methods to examine the sentinel lymph node are applied internationally. The aim of this study was to determine the value of ultrastaging and to assess the ultrastaging method with the highest detection rate of metastases.

METHODS

A systematic review was conducted. Inclusion criteria were: pathologically-confirmed endometrial cancer with sentinel lymph node mapping, report of the histological outcomes, metastases found by hematoxylin and eosin staining and metastases found by ultrastaging were separately mentioned, and description of the ultrastaging method. The primary outcome was the detection of metastases found by ultrastaging that were not detected by routine hematoxylin and eosin staining. The secondary outcome was the difference in detection rate of metastases between several ultrastaging methods. Random effects meta-analyses were conducted.

RESULTS

Fifteen studies were selected, including 2259 patients. Sentinel lymph nodes were examined by routine hematoxylin and eosin staining. Subsequently, multiple ultrastaging methods were used, with differences in macroscopic slicing (bread-loaf/longitudinal), number of microscopic slides, and distance between slides, but all used immunohistochemistry. A positive sentinel lymph node was found in 14% of patients. In 37% of these, this was detected only by ultrastaging. Using more ultrastaging slides did not result in a higher detection rate. Bread-loaf slicing led to a higher detection rate compared with longitudinal slicing (mean detection rates 53% and 33%, respectively).

CONCLUSION

Pathological ultrastaging after routine hematoxylin and eosin staining in endometrial cancer patients has led to an increased detection rate of sentinel lymph node metastases. Different ultrastaging methods are used, with a preference for bread-loaf slicing. However, due to the large heterogeneity of the studies, assessing which ultrastaging method has the highest detection rate of sentinel lymph node metastases was not possible.

Sentinel lymph node detection for gastric cancer: Promise or pitfall?

At present, optimal surgery for gastric cancer is still under debate, especially the extent of lymph node dissection. Gastrectomy with D1/D2 lymphadenectomy is standard treatment for resectable advanced gastric cancer. However, in early gastric cancer without lymph node metastasis, gastrectomy with D1/D2 lymphadenectomy may not be unnecessary, which could increases morbidity and mortality and reduces the quality of life (QOL). Therefore, the concept of sentinel lymph node could be applied in gastric cancer. But due to the complexity of gastric lymphatic drainage, there are still many issues under debate, such as suitable tracers, the method of mapping and collecting and the oncologic safety of sentinel node navigation surgery (SNNS). In addition, skip metastasis and unreliability of intraoperative pathological diagnosis are two main reasons for false negative cases. In this review, we summarize the current status and controversy of sentinel lymph node detection in gastric cancer, attempting to help with practical application. Further, we hold opinion that we should be cautious about performing sentinel lymph node detection in gastric cancer before an accurate and effective method occurs.

Practical intraoperative pathologic evaluation of sentinel lymph nodes during sentinel node navigation surgery in gastric cancer patients - Proposal of the pathologic protocol for the upcoming SENORITA trial

Over the last decade, as the number of patients with early gastric cancer increased and the subsequent survival rate improved, there has been a consistent effort to verify the applicability of the sentinel node concept in gastric cancer in a bid to improve postoperative quality of life in these patients. During sentinel node navigation surgery in gastric cancer patients, intraoperative pathologic examination of the retrieved sentinel nodes plays a critical role in determining the extent of surgery, but the optimal method is still under debate. Currently, a multicenter, phase III clinical trial is underway to compare laparoscopic sentinel basin dissection with stomach preserving surgery and standard laparoscopic gastrectomy in terms of oncologic outcomes in patients with clinical stage T1N0 gastric cancer. Herein, the currently available intraoperative pathologic techniques are reviewed and their clinical significance and applicability are appraised based on the published literature. The proper pathologic examination of the sentinel lymph nodes in an upcoming clinical trial (SENORITA trial) is also proposed here based on this review.

Accuracy of microRNAs as markers for the detection of neck lymph node metastases in patients with head and neck squamous cell carcinoma

BACKGROUND

The presence of metastatic disease in cervical lymph nodes of head and neck squamous cell carcinoma (HNSCC) patients is a very important determinant in therapy choice and prognosis, with great impact in overall survival. Frequently, routine lymph node staging cannot detect occult metastases and the post-surgical histologic evaluation of resected lymph nodes is not sensitive in detecting small metastatic deposits. Molecular markers based on tissue-specific microRNA expression are alternative accurate diagnostic markers. Herein, we evaluated the feasibility of using the expression of microRNAs to detect metastatic cells in formalin-fixed paraffin-embedded (FFPE) lymph nodes and in fine-needle aspiration (FNA) biopsies of HNSCC patients.

METHODS

An initial screening compared the expression of 667 microRNAs in a discovery set comprised by metastatic and non-metastatic lymph nodes from HNSCC patients. The most differentially expressed microRNAs were validated by qRT-PCR in two independent cohorts: i) 48 FFPE lymph node samples, and ii) 113 FNA lymph node biopsies. The accuracy of the markers in identifying metastatic samples was assessed through the analysis of sensitivity, specificity, accuracy, negative predictive value, positive predictive value, and area under the curve values.

RESULTS

Seven microRNAs highly expressed in metastatic lymph nodes from the discovery set were validated in FFPE lymph node samples. MiR-203 and miR-205 identified all metastatic samples, regardless of the size of the metastatic deposit. Additionally, these markers also showed high accuracy when FNA samples were examined.

CONCLUSIONS

The high accuracy of miR-203 and miR-205 warrant these microRNAs as diagnostic markers of neck metastases in HNSCC. These can be evaluated in entire lymph nodes and in FNA biopsies collected at different time-points such as pre-treatment samples, intraoperative sentinel node biopsy, and during patient follow-up. These markers can be useful in a clinical setting in the management of HNSCC patients from initial disease staging and therapy planning to patient surveillance.

Sentinel-lymph-node procedure in colon and rectal cancer: a systematic review and meta-analysis

BACKGROUND

No consensus exists on the validity of the sentinel-lymph-node procedure for assessment of nodal status in patients with colorectal cancer. We aimed to assess the diagnostic performance of this procedure.

METHODS

We searched Embase and PubMed databases for studies published before March 20, 2010. Eligible studies had a prospective design, a sample size of at least 20 patients, and reported the rate of sentinel-lymph-node positivity. Individual patient data were requested for localisation and T-stage stratification. A subset of reports with high methodological quality was selected and analysed.

FINDINGS

We identified 52 eligible studies, which included 3767 sentinel-lymph-node procedures (2961 [78·6%] colon and 806 [21·4%] rectal carcinomas). Most tumours 2339 (62·1%) were stage T3 or T4. 1887 (50·1%) of patients were male, 1880 (49·9%) female. Mean overall weighted-detection rate was 0·94 (95% CI 0·92-0·95), at a pooled sensitivity of 0·76 (0·72-0·80) with limited heterogeneity (χ(2)=286·08, degrees of freedom=51; p=0·003). A mean weighted upstaging of 0·15 (95% CI 0·12-0·19) was noted. Individual patient data were available from 19 studies that included 1168 patients. Analysis of these data showed no significant difference in sensitivity between colon (0·86 [95% CI 0·83-0·90]) and rectal cancer (0·82 [0·77-0·88]; p=0·23). Also, there was no dependency of sensitivity on T stage for both colon (pT1: 0·79 [95% CI 0·73-0·84], pT2: 0·76 [0·62-0·90], pT3: 0·73 [0·59-0·87], pT4: 0·73 [0·53-0·93]) and rectal cancer (T1 or T2: 0·81 [0·52-0·94] vs T3 or T4: 0·80 [0·51-0·93]). The subgroup of eight studies with high methodological quality showed a mean detection rate of 0·96 (95% CI 0·90-0·99) for colonic tumours and 0·95 (0·75-0·99) for rectal tumours, and a mean sensitivity of 0·90 (95% CI 0·86-0·93) for colonic tumours and 0·82 (0·60-0·93) for rectal tumours.

INTERPRETATION

The sentinel-lymph-node procedure shows a low sensitivity, regardless of T stage, localisation, or pathological technique. For every patient diagnosed with colon or rectal cancer without clinical evidence of lymph-node involvement or metastatic disease, this procedure in addition to conventional resection should be considered, since the prognostic information provided by this technique could be clinically significant.

FUNDING

Cancer Center Amsterdam Foundation, Amsterdam, Netherlands.

Neck restaging with sentinel node biopsy in T1-T2N0 oral and oropharyngeal cancer: Why and how?

Objective: To evaluate the lack of accuracy in neck staging with the classical technique (i.e., neck dissection and routine histopathology) with the sentinel node (SN) biopsy in oral and oropharyngeal T1-T2N0 cancer.

Study Design: Cross-sectional study with planned data collection.

Setting: Tertiary center care.

Subjects and Methods: In 50 consecutive patients, the pathological stage of sentinel node (pSN) was established after analyzing SN biopsies (n = 148) using serial sectioning and immunohistochemistry. Systematic selective neck dissection was performed. The pN stage was established with routine histopathologic analysis of both the non-SN (n = 1075) and the 148 SN biopsies.

Results: The sensitivity and negative predictive value of pSN staging were 100 percent. Conversely, if one considers pSN staging procedure as the reference test for micro- and macro-metastasis diagnosis, the sensitivity of the classical pN staging procedure was 50 percent (9/1; 95% CI 26.9-73.1) and its negative predictive value was 78 percent (95% CI 61.9-88.8). Fifteen patients (30%) were upstaged, including nine cases from pN0 to pSN ≥ 1 and six cases from pN1 to pSN2. Two of the pN0-pSN1 upstaged patients died with relapsed neck disease.

Conclusion: The SN biopsy technique appeared to be the best staging method in cN0 patients and provided evidence that routinely undiagnosed lymph node invasion may have clinical significance.

Sentinel Lymph Node Biopsy in Breast Cancer

The axillary lymph node status is the most reliable prognostic indicator of recurrence and overall survival in patients with breast cancer. The current standard surgical procedure for the management of invasive breast cancer is the complete removal of the cancer with total axillary clearance. However, recently, selective sentinel lymph node mapping and biopsy is gaining acceptance as a useful and accurate staging procedure, as it is minimally invasive. The sentinel lymph node is the first node into which a primary cancer drains, and is thus the first node to be involved by metastases. Patients whose sentinel nodes are negative for breast cancer metastases, can be spared a more extensive axillary lymph node dissection, with reduction in the postoperative morbidity. Sentinel node mapping is usually performed by intradermal or peritumoral injection of a combination of blue dye and radiotracer. Sentinel node examination is sometimes done intraoperatively, by imprint cytology and frozen sections, for an immediate assessment, to plan the extent of surgery at a single sitting. Permanent sections of the sentinel node are studied by serial sectioning, and immunohistochemistry for cytokeratin is done to detect micrometastases which are frequently missed on hematoxylin and eosin (H&E)-stained sections. The various aspects of sentinel node examination, and its role to decide further management in patients with ductal carcinoma-in-situ, and in other clinical settings, are discussed in this review.

Pemphigus vulgaris antigen mRNA quantification for the staging of sentinel lymph nodes in head and neck cancer

Background:

Molecular diagnosis has been proposed to enhance the intra-operative diagnosis of sentinel lymph node (SLN) invasion in head and neck squamous cell carcinoma (HNSCC). Although cytokeratin (CK) mRNA quantification with real-time reverse transcriptase-PCR (QRT–PCR) has produced encouraging results, the more discriminating markers remain to be identified.

Methods:

Pemphigus vulgaris antigen (PVA), squamous cell carcinoma antigen (SCCA), and CK17 mRNA were quantified using QRT–PCR, and the results were compared with an extensive histopathological examination of the entire SLNs on 78 SLNs harvested from 22 patients with HNSCC.

Results:

SCCA and CK17 quantification showed significantly higher mRNA values for macrometastases (MAs) than for either negative or isolated tumour cell (ITC) SLNs (P<0.01). Pemphigus vulgaris antigen allowed the discrimination of all MAs and micrometastases from both negative and ITC SLNs (P<0.001). For the neck staging of patients, considering metastatic vs non-metastatic status, receiver-operating characteristic curve analysis found areas under the curve of 93.8, 97.9, and 100% for CK17, SCCA, and PVA, respectively. With PVA, a cutoff value of 562 copies per 100 ng of cDNA permitted the correct distinction between patients with positive as opposed to negative neck nodes in all cases.

Conclusion:

PVA seems to be a highly promising marker for accurate intra-operative SLN staging in HNSCC by QRT–PCR.

Lymphatic mapping and sentinel node biopsy in gynecological cancers: a critical review of the literature

Although it does not have a long history of sentinel node evaluation (SLN) in female genital system cancers, there is a growing number of promising study results, despite the presence of some aspects that need to be considered and developed. It has been most commonly used in vulvar and uterine cervivcal cancer in gynecological oncology. According to these studies, almost all of which are prospective, particularly in cases where Technetium-labeled nanocolloid is used, sentinel node detection rate sensitivity and specificity has been reported to be 100%, except for a few cases. In the studies on cervical cancer, sentinel node detection rates have been reported around 80–86%, a little lower than those in vulva cancer, and negative predictive value has been reported about 99%. It is relatively new in endometrial cancer, where its detection rate varies between 50 and 80%. Studies about vulvar melanoma and vaginal cancers are generally case reports. Although it has not been supported with multicenter randomized and controlled studies including larger case series, study results reported by various centers around the world are harmonious and mutually supportive particularly in vulva cancer, and cervix cancer. Even though it does not seem possible to replace the traditional approaches in these two cancers, it is still a serious alternative for the future. We believe that it is important to increase and support the studies that will strengthen the weaknesses of the method, among which there are detection of micrometastases and increasing detection rates, and render it usable in routine clinical practice.

Intra-operative rapid diagnostic method based on CK19 mRNA expression for the detection of lymph node metastases in breast cancer

Staging by sentinel node (SN) biopsy is the standard procedure for clinically node-negative breast cancer patients. Intra-operative analysis of the SN allows immediate axillary lymph node (ALN) dissection in SN positive patients, but a quick, reliable and reproducible method is lacking. We tested the suitability of a quantitative cytokeratin 19 (CK19) mRNA one step nucleic acid amplification (OSNA#) technique (OSNA-CK19) for intra-operative SN analysis. OSNA-CK19 involves a short manual sample preparation step and subsequent fully automated amplification of CK19 mRNA based on reverse transcription loop-mediated isothermal amplification, with results available within 30–40 min. OSNA-CK19 was compared to histological staining (Hematoxylin&Eosin and CAM5.2 and CK19 immunostaining) of 346 frozen ALNs from 32 breast cancer patients, using half of the lymph node for each method. 267 samples were negative and 61 positive by both methods. Three samples were histology positive and OSNA-CK19 negative. Fifteen samples were histology negative and OSNA-CK19 positive, 11 of which had copy numbers close to the cut-off level of OSNA-CK19. Seven of these 15 samples were RT-PCR positive for epithelial markers and/or showed CK19 protein expression by Western blot suggesting the presence of tumor deposits in the lymph node part investigated by OSNA-CK19. Concordance with histology was 94.8%, and 96.8% after exclusion of the latter 7 discordant cases. Sensitivity was 95.3% and specificity was 94.7% before and 97.1% after discordant case investigation. Our results indicate that OSNA-CK19 can potentially be useful in an intra-operative clinical setting to detect SN tumor involvement in breast cancer patients.

The microanatomic location of metastatic breast cancer in sentinel lymph nodes predicts nonsentinel lymph node involvement

BACKGROUND

The majority of sentinel node (SN) positive breast cancer patients do not have additional non-SN involvement and may not benefit from axillary lymph node dissection (ALND). Previous studies in melanoma have suggested that microanatomic localization of SN metastases may predict non-SN involvement. The present study was designed to assess whether these criteria might also be used to be more restrictive in selecting breast cancer patients who would benefit from an ALND.

METHODS

A consecutive series of 357 patients with invasive breast cancer and a tumor-positive axillary SN, followed by an ALND, was reviewed. Microanatomic SN tumor features (subcapsular, combined subcapsular and parenchymal, parenchymal, extensive localization, multifocality, and the penetrative depth from the SN capsule) were evaluated for their predictive value for non-SN involvement.

RESULTS

Non-SN metastases were found in 136/357 cases (38%). Microanatomic location and penetrative depth of SN metastases were significant predictors for non-SN involvement (<0.001); limited penetrative depth was associated with a low frequency of non-SN involvement with a minimal of 10%.

CONCLUSIONS

Microanatomic location and penetrative depth of breast cancer SN metastases predict non-SN involvement. However, based on these features no subgroup of patients could be selected with less than 10% non-SN involvement.

Sentinel node staging for breast cancer: intraoperative molecular pathology overcomes conventional histologic sampling errors

BACKGROUND

When sentinel node dissection reveals breast cancer metastasis, completion axillary lymph node dissection is ideally performed during the same operation. Intraoperative histologic techniques have low and variable sensitivity. A new intraoperative molecular assay (GeneSearch BLN Assay; Veridex, LLC, Warren, NJ) was evaluated to determine its efficiency in identifying significant sentinel lymph node metastases (>.2 mm).

METHODS

Positive or negative BLN Assay results generated from fresh 2-mm node slabs were compared with results from conventional histologic evaluation of adjacent fixed tissue slabs.

RESULTS

In a prospective study of 416 patients at 11 clinical sites, the assay detected 98% of metastases >2 mm and 88% of metastasis greater >.2 mm, results superior to frozen section. Micrometastases were less frequently detected (57%) and assay positive results in nodes found negative by histology were rare (4%).

CONCLUSIONS

The BLN Assay is properly calibrated for use as a stand alone intraoperative molecular test.

Is there an indication for sentinel node biopsy in patients with ductal carcinoma in situ of the breast? A review

Ductal carcinoma in situ (DCIS) of the breast is defined as a proliferation of malignant epithelial cells within breast ducts without evidence of invasion through the basement membrane. The detection rate of DCIS of the breast has dramatically increased since the mid-1980s as the result of the widespread use of screening mammography. DCIS currently represents about 15-25% of all breast cancers detected in population screening programmes. Although inherently a non-invasive disease, occult invasion with the potential of lymph node metastases may occur. Where performing an axillary lymph node dissection-or-not for DCIS used to be an important dilemma, the same now holds for the sentinel node biopsy. This article reviews the potential role of the sentinel node biopsy (SNB) in patients with DCIS. We conclude that based on the current literature, there is in general no role for a SNB in DCIS. A SNB should only be considered in patients with an excisional biopsy diagnosis of high risk DCIS (grade III with palpable mass or large tumour area by imaging) as well as in patients undergoing mastectomy after a core or excisional biopsy diagnosis of DCIS, although SNB may be contraindicated in many of the latter patients because of lesion size and/or multifocality. Even in these patients the value of a positive SN, containing mostly isolated tumour cells, is questionable.

The Diagnostic Accuracy of Reverse Transcription-PCR Quantification of Cytokeratin mRNA in the Detection of Sentinel Lymph Node Invasion in Oral and Oropharyngeal Squamous Cell Carcinoma: A Comparison with Immunohistochemistry

PURPOSE

The main goal of sentinel lymph node (SLN) detection in head and neck squamous cell carcinomas is to limit neck dissections to pN+ cases only. However, intraoperative + diagnosis cannot be routinely done using the current gold standard, serial step sectioning with immunohistochemistry. Real-time quantitative reverse transcription-PCR (RT-PCR) is potentially compatible with intraoperative use, proving highly sensitive in detecting molecular markers. This study postoperatively assessed the accuracy of quantitative RT-PCR in staging patients from their SLN.

EXPERIMENTAL DESIGN

A combined analysis on the same SLN by serial step sectioning with immunohistochemistry and quantitative RT-PCR targeting cytokeratins 5, 14, and 17 was done in 18 consecutive patients with oral or oropharyngeal squamous cell carcinoma and 10 control subjects.

RESULTS

From 71 lymph nodes examined, mRNA levels (KRT) were linked to metastasis size for the three cytokeratins studied (Pearson correlation coefficient, r = 0.89, 0.73, and 0.77 for KRT 5, 14, and 17 respectively; P < 0.05). Histopathology-positive SLNs (macro- and micrometastases) showed higher mRNA values than negative SLNs for KRT 17 (P < 10(-4)) and KRT 14 (P < 10(-2)). KRT 5 showed nonsignificant results. KRT 17 seemed to be the most accurate marker for the diagnosis of micrometastases of a size >450 mum. Smaller micrometastases and isolated tumor cells did not provide results above the background level. Receiver operating characteristic curve analysis for KRT 17 identified a cutoff value where patient staging reached 100% specificity and sensitivity for macro- and micrometastases.

CONCLUSION

Quantitative RT-PCR for SLN staging in cN(0) patients with oral and oropharyngeal squamous cell carcinoma seems to be a promising approach.

Intraoperative sentinel lymph node examination by frozen section, immunohistochemistry and imprint cytology during breast surgery – A prospective study

The aim of this study was to compare the sensitivity of intraoperative frozen section with hematoxyllin-eosin (H&E) staining, immunohistochemistry (IHC) or imprint cytology (IC) in the analysis of sentinel node (SN) in breast cancer. Towards this end, a prospective study of 102 patients undergoing mastectomy or sector resection with SN biopsy was conducted. Frozen sections of SN with H&E, IHC staining and IC had sensitivities of 73.5%, 75.5% and 51.0%, respectively. The combination of H&E and IHC raised the overall sensitivity to 83.7%. Macrometastases (>2 mm) were detected in 100% of the cases with H&E, 92.6% with IHC and 81.5% with IC; and micrometastases (2 mm) in 35.0%, 45.0% and 5.0%, respectively. The combination of H&E and IHC staining raised the sensitivity to 55.0%. Frozen-section analysis with H&E staining showed high sensitivity in detecting macrometastases but not micrometastases. The sensitivity for detection of micrometastases was not substantially increased by the use of intraoperative IHC. Imprint cytology did not provide any additional information.

Rapid Intraoperative Immunohistochemical Evaluation of Sentinel Lymph Nodes for Metastatic Breast Carcinoma

OBJECTIVE

Sentinel lymph node (SLN) biopsy is an integral part of the surgical management of patients with breast cancer. Rapid immunohistochemistry (RIHC) has the potential to increase detection of metastatic carcinoma at the time of frozen section consultation. The authors assessed the accuracy and turnaround time of a newly developed RIHC method for pancytokeratin (RIHC-CK).

METHODS

Sixty-six SLNs from 32 patients with breast carcinoma were examined for metastasis using the Zymed Sentinel Lymph Node Rapid IHC Kit. Intraoperative frozen sections (6 mum) of the SLNs were incubated with Zymed anti-pan-cytokeratin/HRP conjugate, diaminobenzidine (DAB), and stained with hematoxylin. Slides were ready within 8 minutes and were interpreted as positive or negative for metastatic carcinoma. Results were compared with previous intraoperative touch preparations, frozen sections, hematoxylin and eosin (Perm H&E), and AEl/3-immunostained permanent sections (Perm CK).

RESULTS

Fourteen lymph nodes (19%) in 13 patients tested positive for metastatic carcinoma in Perm H&E, the gold standard. RIHC-CK had the highest sensitivity (92%) of the intraoperative tests, compared with touch preparations (64%) and frozen sections (80%). RIHC-CK showed 94% accuracy, compared with 96% (frozen section) and 93% (touch preparation). The RIHC technique took 8 minutes and was easy to perform and interpret.

CONCLUSIONS

Zymed RIHC is a sensitive method for detecting breast cancer metastases in SLNs. The speed, accuracy, and ease of interpretation of the test allow for recognition of micrometastases (<2 mm) that might otherwise be undetectable by current methods of intraoperative evaluation. The prognostic significance and effect on surgical management of micrometastases in SLNs have yet to be determined.

The value of intraoperative imprint cytology in the assessment of lymph node status in gastric cancer surgery

BACKGROUND

The intraoperative assessment of lymph node status is important when performing limited surgery in gastric cancer patients. Currently available techniques for this assessment are frozen section, imprint cytology, and other molecular methods; most current studies use the frozen-section method. In the present study, we focused on the accuracy and feasibility of imprint cytology as a tool to assess lymph node status intraoperatively in gastric cancer surgery.

METHODS

Between April 2001 and March 2003, we performed imprint cytology of the sentinel nodes in 260 consecutive patients. After review by an experienced cytopathologist, the sensitivity, specificity, and overall accuracy of the method were determined.

RESULTS

The time required for the intraoperative imprint cytology was 8 min, and the sensitivity, specificity, and overall accuracy were 52.2%, 88.8%, and 73.8%, respectively.

CONCLUSION

Imprint cytology could be a useful technique for the assessment of lymph node status intraoperatively if the sensitivity and specificity can be improved to an acceptable level.

Clinical outcome of patients with lymph node-negative breast carcinoma who have sentinel lymph node micrometastases detected by immunohistochemistry

BACKGROUND

The ideal pathologic assessment of sentinel lymph nodes (SLNs) in patients with breast carcinoma remains controversial. The authors evaluated how detailed assessment of SLNs using immunohistochemistry (IHC) and serial sectioning would affect treatment decisions and outcomes in patients with breast carcinoma who had negative SLNs on standard hematoxylin and eosin staining.

METHODS

The SLNs from patients who were treated between June 1998 and June, 1999 and who had negative lymph node status determined by hematoxylin and eosin staining (n = 84 patients) were evaluated further with serial sectioning and cytokeratin IHC. Patients were offered adjuvant therapy based on primary tumor factors.

RESULTS

The median patient age was 57 years, and the median tumor size was 1.2 cm. At a median follow-up of 40.2 months, 81 patients (96%) were alive with no evidence of disease, 1 patient was alive with disease, 1 patient had died of disease, and 1 patient had died of other causes. Fifteen patients (18%) had micrometastases identified on IHC. Of the total 84 patients, information regarding adjuvant therapy was not available for 5 patients. Of the remaining 79 patients, 10 patients (13%) were not offered adjuvant chemotherapy but had positive SLN status determined by IHC. SLN status based on IHC evaluation did not correlate with age (P = 0.077), tumor size (P = 0.717), grade (P = 0.148), estrogen receptor status (P = 1.000), or lymphovascular invasion (P = 0.274). Furthermore, IHC-detected positive SLN status did not correlate with distant metastasis (P = 0.372) or overall or distant metastasis-free survival (P = 0.543 and P = 0.540, respectively).

CONCLUSIONS

Although the finding of SLN micrometastases by IHC may change management in > 12% of patients, preliminary results suggested that such micrometastases do not affect outcomes significantly.

Sentinel Lymph Node Tumor Load: An Independent Predictor of Additional Lymph Node Involvement and Survival in Melanoma

BACKGROUND

Even though 60% to 80% of melanoma patients with a positive sentinel lymph node (SLN) have no positive additional lymph nodes (ALNs), all these patients are subjected to an ALN dissection (ALND) with its associated morbidity. The aim of this study was to predict the absence of ALN metastases in patients with a positive SLN by using features of the primary melanoma and SLN tumor load.

METHODS

Of 71 SLN-positive patients, 52 had metastasis limited to the SLN (group 1), and 19 had > or =1 positive ALN after ALND (group 2). The tumor load of the SLN was assessed by measuring the total surface area by computerized morphometry. Breslow thickness, ulceration and lymphatic invasion of the primary tumor, and total SLN metastatic area were tested as covariates predicting the absence of positive ALNs.

RESULTS

The mean SLN metastatic area was 1.18 mm(2) (group 1) and 3.39 mm(2) (group 2) (P = .003) and was the only significant and independent factor after multivariate analysis (P = .02). None of the patients with both a Breslow thickness <2.5 mm and an SLN metastatic area <.3 mm(2) had a positive ALN.

CONCLUSIONS

SLN metastatic area can be used to predict the absence of positive ALNs in melanoma patients. In this study, patients with a Breslow thickness <2.5 mm and an SLN tumor load <.3 mm(2 )seemed to have no positive ALN and had excellent survival. We hypothesize that this subgroup might not benefit from ALND. Prospective larger trials, using this model and randomizing between ALND and no ALND, should confirm this hypothesis.

Improved Staging of Cervical Metastases in Clinically Node-Negative Patients With Head and Neck Squamous Cell Carcinoma

BACKGROUND

The management of the N0 neck in oral and oropharyngeal cancer is often determined by the risk of metastases related to features of the primary tumor. Where the risk of metastases is >20%, elective neck dissection (END) has been advocated. This study reviewed clinical staging, surgical staging, pathologic staging, and histopathologic parameters to determine the prediction of nodal metastases and micrometastases in patients with head and neck squamous cell carcinoma.

METHODS

A prospective series of 61 clinically neck node-negative patients undergoing surgical resection of a T1/2 intraoral or oropharyngeal invasive squamous cell carcinoma and surgical staging of the neck, with sentinel node biopsy (SNB) alone or SNB-assisted END, between June 1998 and March 2002 were included in this study.

RESULTS

Pathologic upstaging of the clinically N0 neck occurred in 27 (44%) of 61 patients. Routine pathology with hematoxylin and eosin upstaged disease in 22 of 27 patients (sensitivity of 81%). Five patients with micrometastasis were staged pN1mi after stepped serial sectioning and immunohistochemistry. Tumor thickness, a noncohesive invasive front, and perineural and bone invasion were all histological predictors for cervical metastases. Five patients with micrometastases were staged pN1mi.

CONCLUSIONS

Both clinical staging and routine pathologic staging underestimate the presence of nodal metastases. Staging with either SNB alone or SNB-assisted END shows promise in the management of the N0 neck by identifying patients with micrometastases (pN1mi).

False-negative frozen section of sentinel lymph node biopsy for breast cancer

A prospective study is presented of frozen section examinations (FS) performed in parallel with 265 consecutive sentinel lymph node procedures (SLNP) over a 20-month period. The final pathological study included immunohistochemistry (IHC) for keratin if the haematoxylin-eosin (HE)-stained section was tumour free. FS correctly identified node-positive or node-negative axillae in 235 cases. In 28 SLNPs the final examination gave a positive result not detected in the FS, resulting in reoperation. In 21 of these false-negative (FN) cases micrometastases (MIM) were present. There were no false-positive cases, but in two cases of lobular carcinoma the findings in the FS were equivocal, the final reports recording metastases in one but not in the other. Lobular carcinoma and other less common subtypes of carcinoma were overrepresented, ductal carcinoma not otherwise specified (NOS) being less likely to affect the FN findings.

Towards reasonable workload in diagnosis of sentinel lymph nodes: comparison of two frozen section methods

AIMS

To compare two methods of histological assessment with intraoperative diagnosis of sentinel node metastases in breast cancer.

METHODS AND RESULTS

A total of 204 consecutive breast cancer cases with lymphatic mapping, sentinel node biopsy and intraoperative diagnosis were included. The sentinel nodes in the first 102 cases (method A) were bisected and serially sectioned. In the other 102 cases (method B) the nodes were sliced thinly with a razor blade. All 1-1.5 mm thick slices were mounted on prechilled mounting medium on frozen section buttons. Cytological imprints were also made of the attached tissue slices. Postoperative diagnosis of sentinel lymph node metatases was taken as gold standard. Sentinel node metastases were found in 28 (27%) cases in group A and in 42 (40%) cases in group B (P = 0.05). The median size of the sentinel node metastases was 4.3 mm in group A and 3.3 mm in group B (P < 0.05).

CONCLUSION

Method B finds more and smaller metastases and takes less time and effort in the laboratory. When using method A, many small metastases are not detected at all.

The feasibility of intraoperative diagnosis of sentinel lymph node metastases in breast cancer

BACKGROUND AND OBJECTIVES

The aim of the study was to analyse in detail the feasibility of intraoperative assessment of sentinel lymph nodes in breast cancer.

METHODS

Altogether 139 consecutive breast cancer patients with metastases in axillary sentinel nodes were included in a prospective study. A combination of imprint cytology and frozen section was used as the method of intraoperative diagnosis of sentinel node metastases. The definite postoperative evaluation of the sentinel nodes was taken as the gold standard.

RESULTS

The overall sensitivity of intraoperative diagnosis was 83%, reaching 81% if the intraoperative assessment had been limited to the two first retrieved sentinel nodes. False negative (FN) findings were more common in connection with invasive lobular carcinoma (28%) than with invasive ductal carcinoma (8%) (P < 0.01) as well as in connection with micro-metastases, in 38% of the cases, compared to the larger metastases, 6% (P < 0.00005).

CONCLUSIONS

Intraoperative examination of sentinel lymph nodes enables breast surgery, axillary staging, and treatment in the same operation in a substantial proportion of breast cancer patients. Hospital costs as well as workload in the pathology laboratory may be reduced, limiting the intraoperative assessment to the two first retrieved nodes.

Laparoscopic detection of sentinel lymph nodes followed by lymph node dissection in patients with early stage cervical cancer

OBJECTIVE

The purpose of this study was to investigate the feasibility of sentinel node detection through laparoscopy in patients with early cervical cancer. Furthermore, the results of laparoscopic pelvic lymph node dissection were studied, validated by subsequent laparotomy.

METHODS

Twenty-five patients with early stage cervical cancer who planned to undergo a radical hysterectomy and pelvic lymph node dissection received an intracervical injection of technetium-99m colloidal albumin as well as blue dye. With a laparoscopic gamma probe and with visual detection of blue nodes, the sentinel nodes were identified and separately removed via laparoscopy. If frozen sections of the sentinel nodes were negative, a laparoscopic pelvic lymph node dissection, followed by radical hysterectomy via laparotomy, was performed. If the sentinel nodes showed malignant cells on frozen section, only a laparoscopic lymph node dissection was performed.

RESULTS

One or more sentinel nodes could be detected via laparoscopy in 25/25 patients (100%). A sentinel node was found bilaterally in 22/25 patients (88%). Histological positive nodes were detected in 10/25 patients (40%). One patient (11%) had two false negative sentinel nodes in the obturator fossa, whereas a positive lymph node was found in the parametrium removed together with the primary tumor. In seven patients (28%), the planned laparotomy and radical hysterectomy were abandoned because of a positive sentinel node. Bulky lymph nodes were removed through laparotomy in one patient, and in six patients only laparoscopic lymph node dissection and transposition of the ovaries were performed. These patients were treated with chemoradiation. In two patients, a micrometastasis in the sentinel node was demonstrated after surgery. Ninety-two percent of all lymph nodes was retrieved via laparoscopy, confirmed by laparotomy. Detection and removal of the sentinel nodes took 55 +/- 17 min. Together with the complete pelvic lymph node dissection, the procedure lasted 200 +/- 53 min.

CONCLUSION

Laparoscopic removal of sentinel nodes in cervical cancer is a feasible technique. If radical hysterectomy is aborted in the case of positive lymph nodes, sentinel node detection via laparoscopy, followed by laparoscopic lymph node dissection, prevents potentially harmful and unnecessary surgery.

Groin surgery and the sentinel lymph node

Vulvar cancer is a rare disease. Squamous-cell carcinomas account for 90% of vulvar cancers. The main mode of spread is lymphogenic to the inguinofemoral lymph nodes. Therefore, elective uni- or bilateral inguinofemoral lymphadenectomy is part of the standard treatment in combination with radical (wide) local excision of the vulvar tumour. Lymph drainage studies in relation to the biological behaviour of vulvar cancer are presented, as well as the anatomy and surgery of the groin. The sentinel lymph node procedure is a relatively new method of staging in vulvar cancer which may lead to the omission of inguinofemoral lymphadenectomy in those patients identified as not having inguinofemoral lymph node metastases. The accuracy of this technique appears to be high, but its safety still has to be proven. Moreover, the role of additional histopathological techniques for the examination of the sentinel lymph nodes needs to be established.

Cytokeratin staining and other sentinel node controversies

Sentinel lymph node (SLN) biopsy for breast cancer staging has been widely accepted because it is more sensitive and less morbid than axillary dissection. Sentinel nodes can be thoroughly scrutinized using a variety of techniques increasing the detection of micrometastases; however, the clinical relevance of micrometastases has been challenged. The available data suggest that the prognostic significance of axillary metastases is related to the size of the metastases, and the best data suggest that outcome for patients with metastases < 0.2 mm is similar to patients with node-negative disease. This would argue against the use of ultrasensitive tests such as reverse transcriptase polymerase chain reaction. Immunohistochemistry upstages 2%-20% of hematoxylin and eosin-negative sentinel nodes, and additional nodal metastases are identified in approximately 10% of completion axillary dissections prompted by an immunohistochemistry (IHC)-positive sentinel node. This would appear to be a good reason to perform IHC and act on the results. Because micrometastases can be artifactual, SLN biopsy in ductal carcinoma in situ can lead to harmful overtreatment and is best performed in the context of clinical trials. Lymphoscintigraphy has allowed the detection of alternate drainage patterns to internal mammary, infraclavicular, and supraclavicular lymph nodes. Although patients are occasionally identified who have metastases to these basins but not the axilla, this information will not impact the decision for chemotherapy in most cases. Internal mammary SLN biopsy may have value in patients with tumors < 1 cm, but requires additional evaluation in clinical trials.

How morphometric analysis of metastatic load predicts the (un)usefulness of PET scanning: the case of lymph node staging in melanoma

BACKGROUND

In primary cutaneous melanoma, the sentinel node (SN) biopsy is an accurate method for the staging of the lymph nodes. Positron emission tomography (PET) has been suggested as a useful alternative. However, the sensitivity of PET may be too low to detect SN metastases, which are often small.

AIM

To predict the value of PET for initial lymph node staging in melanoma based on morphometric analysis of SN metastatic load, without exposing patients to PET.

MATERIALS AND METHODS

In 59 SN positive patients with melanoma, the sizes of tumour deposits in the SNs and subsequent dissection specimens were measured by morphometry and correlated with the detection limits of current and future PET scanners.

RESULTS

The median tumour volume within the basin was 0.15 mm(3) (range, 0.0001-118.86). Seventy per cent of these deposits were smaller than 1 mm(3). State of the art PET scanners that have a resolution of about 5 mm would detect only 15-49% of positive basins. Logistic regression analysis revealed no pretest indicators identifying patients expected to have a positive PET. However, the SN tumour load was a significant and single predictor of the presence of PET detectable residual tumour.

CONCLUSION

Morphometric analysis of metastatic load predicts that PET scanning is unable to detect most metastatic deposits in sentinel lymph nodes of patients with melanoma because the metastases are often small. Therefore, the SN biopsy remains the preferred method for initial regional staging.

Combined MR lymphangiography and MR imaging-guided needle localization of sentinel lymph nodes using Gadomer-17

OBJECTIVE

The goals of our study were to determine the technical feasibility of dynamic MR lymphangiography for detecting sentinel lymph nodes using Gadomer-17 contrast material to compare these results to the clinically standardized blue dye contrast agent, and to show MR imaging-guided needle localization marking of the sentinel nodes.

MATERIALS AND METHODS

Six anesthetized swine underwent MR imaging before and for 1 hr after interstitial injection of Gadomer-17 in the posterior tongue and intradermally in the stifle (knee). Using MR imaging guidance, we percutaneously placed a histology needle into the sentinel node or nodes. A standardized intraoperative sentinel node detection procedure was then performed using isosulfan blue contrast agent. Sentinel nodes identified on the MR images were compared with and matched to those identified by biopsy needle localization and the isosulfan blue contrast agent. RESULTS. Interstitial and intradermal injection of Gadomer-17 resulted in a lasting, increased MR signal in the regional lymph nodes. Seven sentinel nodes were identified in both the neck and the groin, with one pig showing two sentinel nodes in the neck and another showing two sentinel nodes in the groin. In all cases, the isosulfan blue contrast agent agreed with the location of the sentinel node determined by Gadomer-17 and marked with the needle.

CONCLUSION

In this large animal model, dynamic MR angiography of sentinel lymph nodes is technically feasible using a contrast agent (Gadomer-17) and can be easily combined with MR imaging-guided needle localization.

Sentinel lymph node biopsy in breast cancer

The concept of sentinel lymph node (SLN) biopsy in breast cancer patients is simple, attractive and rapidly emerging as a new standard of care. Several aspects of the technique of lymphatic mapping, case selection, pathologic analysis and the finding of micrometastases, and the accuracy of the technique are important subjects of study and debate in the literature and will be discussed in this review. High identification rates can be attained by the use of both radioguided and blue dye lymphatic mapping. Intradermal injection of tracers has reported to be successful, suggesting that dermal and parenchymal lymphatics drain to the same SLN. Extra axillary drainage is only seen after peri- or intratumoural injection. SLN biopsy is most widely used for both palpable and non-palpable T1 and T2 tumours, and limited experience exists for other indications. Accuracy is high only in experienced hands. The impact of failure of the procedure on regional disease control and survival will be assessed in a trial of the NSABP (National Adjuvant Breast and Bowel Project). The influence of a positive SLN biopsy with and without axillary dissection on survival and local control will be studied in trials of the BASO (British Association of Surgical Oncology), ACOSOG (American College of Surgeons Oncology Group) and EORTC (European Organisation for Research and Treatment of Cancer). These phase III trials and related studies on the importance of micrometastases in the SLN will give new insights in the safety of the SLN procedure and in the importance of treatment of regional lymph nodes in relation to local disease control and survival.

Sentinel node biopsy: the technique and the feasibility in head and neck cancer

Management of the clinically N(0) neck in head and neck squamous cell carcinoma is still under debate. Tumour spread to the neck is the most important prognostic factor in head and neck cancer patients. The sentinel node technique comprises the identification of the sentinel node by means of dye or isotope or a combination, and surgical removal followed by histological examination. We have reviewed the preliminary reports indicating that sentinel node identification is technically feasible in head and neck cancer surgery, i.e. in solitary and unilaterally oral and pharyngeal cancer stages T1 and T2 with clinical N(0). However, the existing reports enrole observational studies, thus randomised trials should be considered to gain maximum valid data to prove that sentinel node biopsy has an effect on parameters such as loco-regional control and survival.