Lymph node micrometastases in head and neck cancer: a review

Evaluation of micrometastasis and isolated tumor cells in node-negative early-stage oral tongue squamous cell carcinoma: a cross-sectional study in tertiary-level hospitals in eastern India

OBJECTIVE

The present study aimed to investigate the incidence of micrometastasis (MMs) and isolated tumor cells (ITCs) in node-negative early-stage oral tongue squamous cell carcinoma (T1-T2 N0). The secondary objective was to correlate the incidence with the clinicopathologic parameters of age, sex, depth of invasion, pattern of invasion, host lymphocytic response, and size and grade of primary tumor.

STUDY DESIGN

Micrometastasis and ITCs in cervical nodes of 30 patients with early-stage oral tongue squamous cell carcinoma were detected and compared using 3 methods: routine hematoxylin and eosin staining, serial-sectioning at intervals of 150 microns employing hematoxylin and eosin, and serial sectioning pan-cytokeratin immunostaining. Associations with clinicopathological variables were analyzed.

RESULTS

Metastatic tumor cells were detected in the cervical nodes of 2 patients using serial sectioning and immunohistochemistry, resulting in upstaging of 6.6% of all cases. Level I and II lymph nodes were primarily involved.

CONCLUSIONS

Early-stage oral tongue squamous cell carcinoma has a significant potential for MMs that frequently go undetected in routine histopathologic examination. However, laborious and technique-sensitive, serial sectioning in combination with pan-cytokeratin staining (AE1/AE3) may aid in detecting MMs and ITCs in patients with early-stage OTSCC.

Intraoperative Detection of Micrometastases in Whole Excised Lymph Nodes Using Fluorescent Paired-Agent Imaging Principles: Identification of a Suitable Staining and Rinsing Protocol

PURPOSE

Correctly identifying nodal status is recognized as a critical prognostic factor in many cancer types and is essential to guide adjuvant treatment. Currently, surgical removal of lymph nodes followed by pathological examination is commonly performed as a standard-of-care to detect node metastases. However, conventional pathology protocols are time-consuming, yet less than 1 % of lymph node volumes are examined, resulting in a 30-60 % rate of missed micrometastases (0.2-2 mm in size).

PROCEDURES

This study presents a method to fluorescently stain excised lymph nodes using paired-agent molecular imaging principles, which entail co-administration of a molecular-targeted imaging agent with a suitable control (untargeted) agent, whereby any nonspecific retention of the targeted agent is accounted for by the signal from the control agent. Specifically, it was demonstrated that by dual-needle continuous infusion of either an antibody-based imaging agent pair (epidermal growth factor receptor (EGFR) targeted agent: IRDye-800CW labeled Cetuximab; control agent: IRDye-700DX-IgG) or an Affibody-based pair (EGFR targeted Affibody® agent: ABY-029; control agent IRDYe-700DX carboxylate) at 0.3 ml/min.

RESULTS

The results demonstrated the possibility to achieve >99 % sensitivity and > 95 % specificity for detection of a single micrometastasis (~0.2 mm diameter) in a whole lymph node within 22 min of tissue processing time.

CONCLUSION

The detection capabilities offer substantial improvements over existing intraoperative lymph node biopsy methods (e.g., frozen pathology has a micrometastasis sensitivity <20 %).

Circulating tumour cells in head and neck cancers: Biological insights

Tumour metastasis is one of the leading cause of cancer-related mortality. Circulating tumour cells (CTCs) have been implicated in loco-regional and distant metastasis and its role is being extensively studied in various malignancies, including those from the head and neck region. The main challenge in understanding their significance lies in the rarity of these cells in the blood. However, newer technologies have attempted to overcome these pitfalls. This review explores the evolution of CTC research and other related areas, including its biological significance, sustainability within the circulating vascular environment and possible clinical implications.

Surgical nodal management in hypopharyngeal and laryngeal cancer

Objective

The aim of this study is to compare pre-therapeutic staging of the loco-regional lymphatic basin and subsequent surgical management in cN0 versus cN+ hypopharyngeal and laryngeal cancer patients.

Methods

We analyzed all hypopharyngeal and laryngeal carcinoma patients treated surgically at a single quaternary medical care and cancer center between 2004 and 2014. We established two groups for patients who underwent neck dissection comparing patients with a low LNR (lymph node ratio) to one with a high LNR. Regarding the cN0 cohort, elective neck dissection was evaluated as a secondary predictor variable. Comorbidities, such as anemia and renal insufficiency, were analyzed as potentially influencing disease-free (DFS) and overall survival (OS).

Results

A total of 310 patients (185 glottic and 125 supraglottic/hypopharyngeal carcinoma) were included. Pre-therapeutic neck MRI-/CT-scan and concomitant neck ultrasound revealed cN+ status in 144 patients resulting in a significant over-staging in 63 patients (44%) who were rated as being pN0 after histological examination. 166 patients were staged cN0 and 21 underwent elective neck dissection (11 local advanced glottic and 10 supraglottic/hypopharyngeal carcinoma). Two cN0 patients showed occult cervical lymph node metastases (10%). Furthermore, we could detect a significant negative impact of the LNR divided by the number of dissected lymph nodes and OS.

Conclusion

The pre-therapeutic clinical evaluation of lymphatic outgrowth is over-staged. OS decreases with increasing LNR divided by the number of dissected lymph nodes. Renal insufficiency and anemia are significant negative factors, decreasing both OS and DFS.

Postoperative radiotherapy is dispensable for OSCC patients with micrometastases in lymph nodes

Lymph node metastasis is a decisive factor for performing postoperative radiotherapy for oral squamous cell carcinoma (OSCC). However, whether OSCC patients with only micrometastasis need postoperative radiotherapy is unclear. In this study, OSCC patients (n = 311) with negative (n = 247), only micrometastasis (n = 44) and macrometastasis (n = 20) were detected and selected by HE staining. Micrometastasis was re-assessed using immunohistochemical staining of cytokeratin (CK) in HE-negative patients to find out the false negative cases. The results indicated that, among the negative lymph node cases (n = 247), the positive rate of CK was 4.94% (n = 12). Besides, the clinical features of the primary tumor in relation to the only micrometastatic status and the value of the postoperative radiotherapy on the only micrometastasis patients were evaluated. Patients with only micrometastasis had higher T stage and inferior worst pattern of invasion (WPOI) than patients without micrometastasis, but they had longer overall survival (OS), metastasis-free survival (MFS), and disease-free survival (DFS) than macrometastasis patients. However, the survival time of only micrometastasis patients with or without postoperative radiotherapy was comparable, even in patients with inferior WPOI. Radiotherapy, however, may only benefit patients with IV/V levels of micrometastasis. These data indicated that postoperative radiotherapy is dispensable for only micrometastasis OSCC patients.

Development of comprehensive nomograms for evaluating overall and cancer-specific survival of laryngeal squamous cell carcinoma patients treated with neck dissection

Background

Neck dissection for laryngeal squamous cell carcinoma (LSCC) patients could provide complementary prognostic information for AJCC N staging, like lymph node ratio (LNR). The aim of this study was to develop effective nomograms to better predict survival for LSCC patients treated with neck dissection.

Results

2752 patients were identified and randomly divided into training (n = 2477) and validation (n = 275) cohorts. The 3- and 5-year probabilities of cancer-specific mortality (CSM) were 30.1% and 37.2% while 3- and 5-year death resulting from other causes (DROC) rate were 6.2% and 11.3%, respectively. 13 significant prognostic factors including LNR for overall (OS) and 12 (except race) for CSS were enrolled in the nomograms. Concordance index as a commonly used indicator of predictive performance, showed the nomograms had superiority over the no-LNR models and TNM classification (Training-cohort: OS: 0.713 vs 0.703 vs 0.667, CSS: 0.725 vs 0.713 vs 0.688; Validation-cohort: OS: 0.704 vs 0.690 vs 0.658, cancer-specific survival (CSS): 0.709 vs 0.693 vs 0.672). All calibration plots revealed good agreement between nomogram prediction and actual survival.

Materials and Methods

We identified LSCC patients undergoing neck dissection diagnosed between 1988 and 2008 from Surveillance, Epidemiology, and End Results (SEER) database. Optimal cutoff points were determined by X-tile program. Cumulative incidence function was used to analyze cancer-specific mortality (CSM) and death resulting from other causes (DROC). Significant predictive factors were used to establish nomograms estimating overall (OS) and cancer-specific survival (CSS). The nomograms were bootstrapped validated both internally and externally.

Conclusions

Comprehensive nomograms were constructed to predict OS and CSS for LSCC patients treated with neck dissection more accurately.

Droplet digital PCR for detection and quantification of circulating tumor DNA in plasma of head and neck cancer patients

Background

During posttreatment surveillance of head and neck cancer patients, imaging is insufficiently accurate for the early detection of relapsing disease. Free circulating tumor DNA (ctDNA) may serve as a novel biomarker for monitoring tumor burden during posttreatment surveillance of these patients. In this exploratory study, we investigated whether low level ctDNA in plasma of head and neck cancer patients can be detected using Droplet Digital PCR (ddPCR).

Methods

TP53 mutations were determined in surgically resected primary tumor samples from six patients with high stage (II-IV), moderate to poorly differentiated head and neck squamous cell carcinoma (HNSCC). Subsequently, mutation specific ddPCR assays were designed. Pretreatment plasma samples from these patients were examined on the presence of ctDNA by ddPCR using the mutation-specific assays. The ddPCR results were evaluated alongside clinicopathological data.

Results

In all cases, plasma samples were found positive for targeted TP53 mutations in varying degrees (absolute quantification of 2.2–422 mutational copies/ml plasma). Mutations were detected in wild-type TP53 background templates of 7667–156,667 copies/ml plasma, yielding fractional abundances of down to 0.01%.

Conclusions

Our results show that detection of tumor specific TP53 mutations in low level ctDNA from HNSCC patients using ddPCR is technically feasible and provide ground for future research on ctDNA quantification for the use of diagnostic biomarkers in the posttreatment surveillance of HNSCC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3424-0) contains supplementary material, which is available to authorized users.

Immunohistochemical detection of lymph node-DTCs in patients with node-negative HNSCC

This study was performed to systematically assess the prevalence, topography and prognostic impact of disseminated tumor cells (DTCs) in lymph nodes (LN) of patients with primary, regional and distant metastasis-free head and neck squamous cell carcinoma (HNSCC) who underwent resection with elective neck dissection. From the routinely processed resection specimen, we could prospectively analyze a total of 1.137 exactly mapped LNs of 50 pN0-HNSCC patients, classified as tumor free by routine histopathology. Three immunohistochemistry (IHC) assays using antibodies directed against CK5/14, a broad spectrum of CKs (1-8, 10, 14-16 and 19), and CD44v6, respectively, were applied on 4.190 LN sections to detect DTCs. The IHC results were correlated with clinicopathologic parameters and clinical follow-up data. We detected seven micrometastases (MM) in five patients and 31 DTCs in 12 patients. Overall, 15 (30%) patients were positive for DTCs or MMs. Strikingly, the anatomical distribution of LN affected with DTCs was not random, but was dependent on the lateralization of the primary tumor and clustered significantly most proximal to the primary tumor. None of the investigated patients developed loco-regional lymphatic or distant metastasis during the mean follow-up period of 71 months. Our results reveal clinically occult tumor cell dissemination as an early and frequent event in HNSCC. Considering that higher rates of recurrences in therapeutic LN dissection concepts have been reported than in elective neck dissection strategies, our DTC-data support to perform elective neck dissections, since they appear to be effective in preventing loco-regional lymphatic recurrence from LN DTCs or MMs.

Relevance of level IIb neck dissection in oral squamous cell carcinoma

Background

The purpose of this study was to determine the prevalence of level IIb metastasis in patients with oral squamous cell carcinomas (OSCCs).

Material and Methods

A prospective analysis of 56 patients with OSCC who underwent surgical treatment of the primary lesion with simultaneous neck dissection was performed. During neck dissection, level IIb lymph nodes were separately removed and processed. Neck dissection was bilateral in 26 patients (46%) and unilateral in 30 patients (54%).

Results

The mean number of nodes found in the level IIb specimens was 4.7 (range: 0-8 nodes). The prevalence of metastasis at level IIb was 0% in pN0 necks and 3.4% in pN+ necks, with an overall prevalence of 1.8%. A significant association between metastasis to level IIb and type of neck dissection was observed. There were no isolated metastases to level IIb without the involvement of other nodes in the remaining neck specimen. Four regional recurrences were observed during follow-up.

Conclusions

Based on our findings, we suggest that dissection of the level IIb region in patients with OSCC may be required only in patients with multilevel neck metastasis or if level IIa metastasis is found intraoperatively.

Key words: Oral squamous cell carcinoma, neck dissection, level IIb, metastasis, spinal accessory nerve.

Detection of Cervical Lymph Node Micrometastases in Patients with Squamous Cell Carcinoma of the Oral Cavity, Pharynx and Larynx

Background: The goal of this prospective study was to determine the frequency of micrometastases in patients with squamous cell carcinoma (SCC) of the oral cavity, pharynx and larynx in whom elective neck dissection was indicated (cN0). Patients and Methods: A total of 12 patients (10 males and 2 females) were enrolled in the study. The age ranged 42–73 years (median 62 years). Elective neck dissection was performed in all patients (8 ipsilateral, 4 bilateral) and a total of 256 lymph nodes were removed and sent for microscopic examination. Results: The presence of tumor cells in cervical lymph nodes was found in 5/12 (42%) patients. Micrometastases of SCC were found in two patients and isolated tumor cells (ITC) in two other patients. In the remaining one patient with oropharyngeal SCC, a micrometastasis of papillary thyroid carcinoma (PTC) was detected. Positive lymph nodes were localized in level II in three patients with SCC of larynx, hypopharynx and tongue base, respectively, in level I in one patient with SCC of oral tongue and in level III in one patient with PTC. Conclusion: Our results indicate that SCC of head and neck has a high potential for creating micrometastases which frequency is higher compared to clinically detected macrometastases. Therefore, elective neck dissection or radiotherapy of the neck should be considered in patients with high risk of occult metastases or micrometastases.

Primary cN0 lip squamous cell carcinoma and elective neck dissection: Systematic review and meta-analysis

BACKGROUND

Management of clinically negative lymph nodes (cN0) in primary lip squamous cell carcinoma (SCC) has always been a controversial topic.

METHODS

A systematic review of English-language electronic databases using Medline, Embase, Cochrane library, Google Scholar, SCI, and specific journals on the subject matter was done. Only the studies mentioning primary nonmetastatic lip SCC with cN0 neck treated by surgery only and having at least 2 years of follow-up data were selected. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews and meta-analysis was followed.

RESULTS

The pooled estimate of occult metastasis in neck dissected specimen was 0.17 (95% confidence interval [CI], 0.10-0.28) and that of delayed nodal metastasis in patients without neck dissection was 0.08 (95% CI, 0.01-0.18).

CONCLUSION

The results do not prove sufficient to justify elective treatment of the neck in primary cN0 lip SCC and close observation would be a viable option in such cases. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1392-1400, 2015.

Detection of micrometastasis in lymph nodes of oral squamous cell carcinoma: A comparative study

Background:

The annual mortality rate from head and neck squamous cell carcinoma (HNSCC) is over 11,000 worldwide. Squamous cell carcinoma of the head and neck (SCCHN) frequently metastasizes to the regional lymph nodes which are the first site of arrest of tumor cells that have invaded the peritumoral lymphatics, hence the strongest predictor of disease prognosis and outcome.

Aim:

The present study aims to compare the efficacy of frozen sections (cryosection), step-serial sectioning conventional H and E staining, immunohistochemistry (IHC) and RT-PCR analysis in detection of lymph node micrometastasis.

Materials and Methods:

A prospective series of 30 patients who were diagnosed with primary squamous cell carcinoma of the oral cavity and underwent surgical treatment including unilateral or bilateral selective neck dissection were considered for the study.

Result:

Metastatic carcinomatous cells were observed in H and E staining of frozen section in 18 lymph nodes (54%) and in 19 lymph nodes (57%) in step-serial sectioned H and E-stained sections of the 78 lymph nodes from 30 patients. Carcinomatous cells were immunolabeled with pancytokeratin in 18 lymphnodes (54%). CK19 mRNA was detected in 33 lymph nodes of 16 patients. RT-PCR gave positive signals for 24% and 23% of lymph nodes positive by histopathology and immunohistochemistry.

Conclusion:

Our study demonstrated that RT-PCR is far more sensitive in detection of micrometastasis than any other technique used in routine procedures and immunohistochemistry. Fifty-three percent patients with micrometastasis detected by RT-PCR had large T3/T4 tumors. Prognosis was poor for patients who were positive for micrometastasis detected only by RT-PCR, among which two patients died within a period of 6 months.

Immunohistochemistry, a valuable tool in detection of cervical lymph node micrometastases in head and neck squamous cell carcinoma: a prospective study

The regional failure after comprehensive clearance of neck metastasis and consequent pathological report of N0 disease has been reported fairly frequently. The role of recurrence of disease in the neck in the cases has been variously reported by different authors. The light microscopy does not detect the micrometastasis and the specimen is reported negative for metastasis. The presence of micrometastasis (the reason for neck failure) has been reported by many studies as 5-58 % (mean 19.6 %). These figures are significantly high. The present study was done to ascertain the micrometastasis after comprehensive neck clearance (pN0 report). Two groups of patients were included in this study. (1) Group I included patients with N0 necks (80 patients). (2) Group II included Patients with N+ necks (107 patients). We found that 20 % case were reported N0 (Group I) in light microscopy but on immunohistochemistry these were positive for disease. 15 % upstaging was reported in N+ cases (Group 2). Immunohistochemistry has been more sensitive for cancer detection and has significantly changed the tumor staging and its consequent management.

Metastatic esthesioneuroblastoma secreting adrenocorticotropic hormone in pediatric patients

The purpose of this article was to report a pediatric case of secondary cervical esthesioneuroblastoma involving the parapharyngeal lymph nodes. A 3-year-old boy came to our clinical observation because of a right lymphonodal mass evidenced by nuclear magnetic resonance and a diagnosis of Cushing syndrome associated with ectopic adrenocorticotropic hormone secretion, moon face, central obesity, asthenia, and hirsutism. At the age of 10 months, the patient underwent endoscopic surgery for asportation of the World Health Organization stage IV esthesioneuroblastoma. At 38 months of age, the patient underwent right parapharyngeal lymphadenectomy with surgical access by a double mandibulectomy. After surgery, serum ACTH, cortisolemia, and urinary excretion of cortisol were within the reference range. Blood pressure was recorded at 110/70 mm Hg. Moon face disappeared, as well as central obesity and hirsutism. Clinical report is presented together with brief review of literature.

Detection of metastatic head and neck squamous cell carcinoma using the relative expression of tissue-specific mir-205

The presence of cervical lymph node metastases in head and neck squamous cell carcinoma (HNSCC) is the strongest determinant of patient prognosis. Owing to the impact of nodal metastases on patient survival, a system for sensitive and accurate detection is required. Clinical staging of lymph nodes is far less accurate than pathological staging. Pathological staging also suffers limitations because it fails to detect micrometastasis in a subset of nodal specimens. To improve the sensitivity of existing means of diagnosing metastatic disease, many advocate the use of molecular markers specific for HNSCC cells. MicroRNA (miRNA) are short noncoding segments of RNA that posttranscriptionally regulate gene expression. Approximately one third of all miRNA will exhibit substantial tissue specificity. Using a quantitative reverse transcription-polymerase chain reaction-based assay, we examined the expression of microRNA-205 (mir-205) across tissues and demonstrated that its expression is highly specific for squamous epithelium. We applied this assay to tissue samples, and we could detect metastatic HNSCC in each positive lymph node specimen, whereas benign specimens did not express this marker. When compared to metastases from other primary tumors, HNSCC-positive lymph nodes were distinguishable by the high expression of this marker. Using an in vitro lymphoid tissue model, we were able to detect as little as one squamous cell in a background of 1 million lymphocytes. By combining the sensitivity of quantitative reverse transcription-polymerase chain reaction with the specificity of mir-205 for squamous epithelium, we demonstrate a novel molecular marker for the detection of metastatic HNSCC.

Pathologic evaluation of sentinel lymph nodes in oral squamous cell carcinoma

BACKGROUND

The objective of this study was to determine the relative efficacy of different methods of pathologic evaluation of sentinel lymph nodes.

METHODS

In this prospective study, sentinel nodes were evaluated for occult metastasis using frozen section, imprint-cytology, hematoxylin-eosin staining, serial step sectioning (SSS) with hematoxylin-eosin, and immunohistochemistry (IHC). Metastases were classified into macrometastasis (>2.0 mm), micrometastasis (0.2 mm-2.0 mm), isolated tumor cells (<0.2 mm).

RESULTS

Occult metastasis was detected in 20 of 80 patients. Frozen section and imprint cytology identified metastasis in 10 of 20 patients, hematoxylin-eosin stain in 13 patients; SSS upstaged the disease in a further 7 patients (9%). Frozen section detected macrometastasis in 7 of 8 cases but failed to detect smaller metastases (missed micrometastasis in 4 of 7 and isolated tumor cells in 5 of 5). SSS upstaged the disease by 10%, and sensitivity and negative predictive value of SSS with hematoxylin-eosin stain were 90% and 97%, respectively.

CONCLUSION

Frozen section and imprint cytology are not effective in identifying occult metastasis. IHC and SSS are required to identify micrometastasis and isolated tumor cells.

Long-term surgical complications in the oral cancer patient: a comprehensive review. Part I

OBJECTIVES

Oral and oropharyngeal cancer remains among the top ten most common malignancies in the United States and worldwide. Over the last several decades the approach to treatment of oral cancer has changed very little with regards to primary tumour extirpation while the approach to the "at risk" lymph nodes has evolved significantly. Perhaps the most significant change in the surgical treatment of cancer is the introduction of free flap for reconstruction post resection. Despite these surgical advances, oral cancer ablation, still results in the sacrifice of several functional and aesthetic organs. The aim of this article was to provide a comprehensive review of the potential long-term complications associated with surgical treatment of oral cancer and their management.

MATERIAL AND METHODS

The available English language literature relevant to long-term surgical complications associated with surgical treatment of oral cancer was reviewed. The potential common as well as rarer complications that may be encountered and their treatment are summarized.

RESULTS

In total 50 literature sources were obtained and reviewed. The topics covered in the first part of this review series include ablative surgery complications, issues with speech, swallowing and chewing and neurologic dysfunction.

CONCLUSIONS

The early complications associated with oncologic surgery for oral cancer are similar to other surgical procedures. The potential long-term complications however are quite challenging for the oncologic team and the patient who survives oral cancer, primarily due to the highly specialized regional tissues involved in the surgical field.

Identification of tetranectin as a potential biomarker for metastatic oral cancer

Lymph node involvement is the most important predictor of survival rates in patients with oral squamous cell carcinoma (OSCC). A biomarker that can indicate lymph node metastasis would be valuable to classify patients with OSCC for optimal treatment. In this study, we have performed a serum proteomic analysis of OSCC using 2-D gel electrophoresis and liquid chromatography/tandem mass spectrometry. One of the down-regulated proteins in OSCC was identified as tetranectin, which is a protein encoded by the CLEC3B gene (C-type lectin domain family 3, member B). We further tested the protein level in serum and saliva from patients with lymph-node metastatic and primary OSCC. Tetranectin was found significantly under-expressed in both serum and saliva of metastatic OSCC compared to primary OSCC. Our results suggest that serum or saliva tetranectin may serve as a potential biomarker for metastatic OSCC. Other candidate serum biomarkers for OSCC included superoxide dismutase, ficolin 2, CD-5 antigen-like protein, RalA binding protein 1, plasma retinol-binding protein and transthyretin. Their clinical utility for OSCC detection remains to be further tested in cancer patients.

Micrometastases and isolated tumour cells in sentinel lymph nodes in oral and oropharyngeal squamous cell carcinoma

BACKGROUND

The occurrence of micrometastases (MMs) and isolated tumour cells (ITCs) in oral sentinel lymph node (SLN) biopsy is poorly known, and the definitions and clinical significance of MMs and ITCs in SLN biopsy are controversial. We compared the UICC/TNM definitions of MMs and ITCs with our previously published sentinel node protocol to assess how the adoption of the UICC/TNM criteria would affect the staging of nodal micrometastatic disease.

METHODS

Of 107 patients who had a SLN biopsy and pathology at 150 microm intervals, 35 with metastatic tumour were included. Eighty-six SLNs were reassessed using the UICC/TNM definitions for MMs and ITCs. Findings were linked to the final pathology in the subsequent neck dissection.

RESULTS

Initial H&E sections showed metastases in 24 patients (in 34 out of 61 SLN), 8 of whom (9 SLNs) had MMs. Additional step serial sections revealed metastatic deposits in a further 11 patients (15 out of 25 SLNs were positive) which were reassessed as MMs (6 patients) or ITCs (5 patients). Subsequent neck dissection revealed additional metastases in 46% of patients with MM, whilst one of the ITC patients had subsequent neck metastases (20%).

CONCLUSION

Despite some limitations, the UICC/TNM classification provides an objective, uniform method of detecting MMs and ITC's. Unlike in cases with ITC, metastases in other non-SLNs were common when a micrometastasis was detected in a SLN, indicating need for further treatment of the neck.

Elective management of the neck in oral cavity squamous carcinoma: current concepts supported by prospective studies

The incidence of occult cervical metastasis in oral cavity cancer, even in early stages, is significant, necessitating elective treatment of the neck in a majority of cases. There is no method of imaging or other examination that will detect microscopic foci of metastatic disease in cervical lymph nodes. Immunohistochemical and molecular analysis of neck specimens reveals the incidence of occult metastases to be higher than revealed by light microscopy with ordinary hematoxylin and eosin staining. The neck may be treated electively by surgery or irradiation. Surgery has the advantage of permitting pathological staging of the neck, avoiding unnecessary radiation treatment and indicating cases where adjuvant therapy should be employed. As oral cavity cancer rarely metastasizes to level V, a radical or modified radical neck dissection of all five node levels is not necessary. Selective dissection of levels I-III ("supraomohyoid neck dissection") is the usual procedure of choice for elective dissection of the neck. Most of the relatively small number of isolated metastasis to level IV are from primary tumours of the tongue, which are known to produce "skip" metastases. Thus an "extended supraomohyoid neck dissection" of levels I-IV is recommended by some authors for elective treatment of the neck in tongue cancer. A number of recent prospective multi-institutional studies have demonstrated that sublevel IIB is rarely involved with isolated metastasis from oral cavity primary tumours, except from some tongue cancers. Thus it is justifiable to omit dissection of sublevel IIB in elective treatment of most cases of oral cavity cancer. Bilateral neck dissection should be performed in elective treatment of tumours involving midline structures, and in patients with ipsilateral neck metastasis.

Ki-67 expression predicts locoregional recurrence in stage I oral tongue carcinoma

Oral tongue squamous cell carcinoma (OTSCC) is an aggressive cancer associated with poor prognosis. Methods for determining the aggressiveness of OTSCC from analysis of the primary tumour specimen are thus highly desirable. We investigated whether genomic instability and proliferative activity (by means of Ki-67 activity) could be of clinical use for prediction of locoregional recurrence in 76 pretreatment OTSCC paraffin samples (stage I, n=22; stage II, n=33; stage III, n=8; stage IV, n=13). Eleven surgical tumour specimens were also analysed for remnants of proliferative activity after preoperative radiotherapy. Ninety-seven percent of cases (n=72) were characterised as being aneuploid as measured by means of image cytometry. Preoperative radiotherapy (50–68 Gy) resulted in significant reduction of proliferative activity in all patients for which post-treatment biopsies were available (P-value=0.001). Proliferative activity was not associated with response to radiation in stage II patients. However, we report a significant correlation between high proliferation rates and locoregional recurrences in stage I OTSCC patients (P-value=0.028). High-proliferative activity is thus related to an elevated risk of recurrence after surgery alone. We therefore conclude that Ki-67 expression level is a potentially useful clinical marker for predicting recurrence in surgically treated stage I OTSCC.

Detection of lymph node micrometastases in patients with squamous carcinoma of the head and neck

While the significance of large cervical node metastases in patients with head and neck squamous carcinomas is well established, the import of a finding of regional nodal micrometastases (where a micrometastasis is defined as a metastatic deposit greater than 0.2 mm and not greater than 2.0 mm in greatest dimension) or isolated tumor cells in those patients is less clearly understood. Some earlier investigators have suggested that finding micrometastases does not have an impact on prognosis; some later investigators, however, have taken issue with this position, arguing that finding either micrometastases or isolated tumor cells might portend a poorer prognosis for head and neck cancer patients. At this juncture, it is difficult to advance a single recommendation for handling a finding of micrometastases or isolated tumor cells. It would be helpful if two courses of action were followed: first, while the detection of micrometastases and isolated tumor cells remains an investigatory practice, data should be collected and analyzed with an eye to discerning whether such findings are indeed of significance to the individual head and neck cancer patient. Second, rigorous definitions of micrometastases and isolated tumor cells (such as the definitions suggested here) should be developed and widely employed so as to permit ready comparison between the results as they are reported by different investigators.

Management of the clinically negative neck (N0) of supraglottic laryngeal carcinoma: a systematic review

AIM

The most effective therapeutic approach for patients with supraglottic laryngeal carcinoma (SGLC) and clinically negative neck (cN0) remains a subject of much debate. The purpose of this systematic review was to answer the following question: among patients with SGLC and cN0 neck, are the survival and occurrence of neck metastases significantly different between patients that received neck dissection and those that had another therapeutic treatment (radiotherapy, combined therapy, 'wait and see' policy)?

MATERIALS AND METHODS

An electronic literature search was performed in MEDLINE, EMBASE, Cochrane Library and CENTRAL databases, followed by extensive hand-searching for the identification of relevant studies. The following inclusion criteria were established: the study should (a) include a comparison of neck dissection with one of the other therapeutic procedures for cN0 of SGLC; (b) report the therapy for the initial supraglottic cancer; and (c) use time-to-event analysis of its results. Six studies were eventually identified and systematically reviewed.

RESULTS

All studies included in the systematic review were retrospective (n=792 patients). The survival (overall, disease-specific and neck disease-free) and the site of neck recurrence of the patients with N0 supraglottic cancer were not significantly different between patients in the neck dissection treatment group and those of the rest of the therapeutic strategies examined (neck radiotherapy, combined therapy and 'wait and see' policy).

CONCLUSIONS

The present systematic review highlights the need for further well-designed prospective studies that will provide more reliable answers to the debatable issue of the management of cN0 of SGLC. Currently, based on the best available evidence, it seems that neck dissection is not superior to radiotherapy or combined therapy or a 'wait and see' policy in terms of survival and control of neck disease.

Sentinel lymph node biopsy as an alternative to wait and see policy in patients with small T1 oral cavity squamous cell carcinoma

CONCLUSION

Although sentinel lymph node (SLN) biopsy is not yet validated for clinical use to replace elective neck dissection in patients with oral squamous cell carcinoma, it can be recommended for patients who do not fulfil the criteria for elective neck treatment according to current treatment protocols.

OBJECTIVE

To examine the benefits of SLN biopsy in oral cancer patients who have a small risk for occult metastasis and therefore are not considered candidates for elective neck treatment.

PATIENTS AND METHODS

Thirteen consecutive patients with a small T1 oral cavity squamous cell carcinoma, clinically staged NO, and who did not meet the indications for elective neck treatment, underwent SLN biopsy. The SLNs were cut at 1-2 mm intervals and stained with haematoxylin and eosin and cytokeratin AE1/AE3.

RESULTS

Histopathological examination of SLNs revealed micrometastases in two patients. A selective neck dissection was performed on these patients and no further metastases were encountered. All patients had a minimum follow-up of 12 months and no cervical or other recurrences were encountered.

The role of ultrasound in the detection of cervical lymph node metastases in clinically N0 squamous cell carcinoma of the head and neck

Nodal involvement is the most important prognostic factor in head and neck squamous cell carcinoma (HNSCC) of mucosal origin. The presence of a single ipsilateral or contralateral metastatic node reduces survival by 50% and bilateral disease by a further 50%. The management of N+ HNSCC is relatively clear-cut. By contrast, the investigation and treatment of patients with clinically N0 disease is controversial. Most institutions electively treat the neck with surgery or radiotherapy because the risk of occult metastases is over 20%, even though it will be unnecessary in the majority of cases. In this situation the main purpose of staging would be to assess those nodes that are not going to be removed. However, the optimal management of the clinically N0 neck remains controversial and there is growing interest in a more conservative approach. Research is now directed toward finding a method of staging sensitive enough to bring the risk of occult metastases below 20%. High spatial resolution, ease of multiplanar scanning, power Doppler and the ability to perform guided fine-needle aspiration for cytology give ultrasound (US) an advantage over other imaging techniques.

Micrometastases in cervical lymph nodes from patients with squamous carcinoma of the head and neck: should they be actively sought? Maybe

Techniques are now being developed, which allow ever smaller metastatic deposits in regional lymph nodes to be detected; the question is, should they be sought, or does their presence convey no additional information for treatment of head and neck carcinoma patients at this time? Preliminary findings have suggested that the presence of micrometastases may carry with it some prognostic information, and as a consequence, the search for micrometastases would, for the foreseeable future, appear to be a fertile ground for investigation. To bring some uniformity to this project, it is suggested that these definitions be adopted: a micrometastasis measures greater than 0.2 mm but less than 2.0 mm in diameter, and smaller deposits should be designated as isolated tumor cells, which, in turn, are subdivided into those isolated tumor cells detected by light microscopy, immunohistochemistry, or molecular methods. At this juncture, the import of such micrometastases remains in the realm of the clinical investigator--it remains an open question whether the identification of micrometastases (however they may ultimately come to be defined) will prove to have an impact on the care of head and neck cancer patients.

Elective and therapeutic selective neck dissection

Selective neck dissection is a modification of the more comprehensive modified radical or radical neck dissection that is designed to remove only those nodal levels considered to be at risk for harboring nodal metastases. The role of selective neck dissection continues to evolve: while initially designed as a staging and diagnostic procedure for patients without clinical evidence of nodal disease, a growing body of literature suggests that selective neck dissection has a therapeutic role in patients with clinical and histologic evidence of nodal metastases. The rationale behind selective neck dissection, its application in the clinically negative but histologically node-positive neck and the extended application of selective neck dissection in patients with clinical evidence of nodal disease are discussed.

Importance of molecular analysis in detecting cervical lymph node metastasis in head and neck squamous cell carcinoma

BACKGROUND

Because of the impact of nodal status on treatment and survival in squamous cell carcinoma of the head and neck, accurate staging of cervical lymph nodes is critical. This article explores the value of molecular analyses in the detection of cervical lymph node metastasis.

METHODS

A review of the literature was carried out and combined with our own experience regarding the role of molecular analyses in detecting cervical lymph node metastasis.

RESULTS

Few studies have demonstrated the diagnostic and prognostic relevance of molecular analysis in detecting tumor cells in lymph nodes. Nodal staging was improved by the use of molecular techniques; when compared with histopathologic examination, however, the small sample size of these studies did not allow definitive conclusions.

CONCLUSIONS

Molecular analysis is exquisitely sensitive in detecting very small cancer deposits within lymph nodes. It provides an oncologic basis that may be used to guide therapy and influence outcomes. It should be recommended for diagnostic use in controlled studies of patients without evidence of lymph node metastasis on routine hematoxylin-eosin-stained sections. The clinical significance of these types of metastases, however, must be determined with carefully designed and controlled prospective clinical trials.

Level IIb lymph nodes metastasis in elective supraomohyoid neck dissection for oral cavity squamous cell carcinoma: a molecular-based study

OBJECTIVES

To identify the incidence of level IIb lymph nodes metastasis in elective supraomohyoid neck dissection (SOHND) as a treatment for patients with squamous cell carcinoma (SCC) of the oral cavity.

STUDY DESIGN

Prospective analysis of a case series.

METHODS

Forty-eight patients with SCC of the oral cavity and with no palpable lymph nodes at the neck who underwent an elective SOHND were prospectively studied. The incidence of micrometastasis to level IIb lymph nodes after performing elective SOHND was evaluated by pathologic examination and molecular analysis.

RESULTS

Of the 48 patients, 15 (31%) by pathologic analysis and 22 (46%) by molecular analysis had lymph nodes positive for metastatic SCC. By molecular analysis, 5 (10%) of the 48 patients had involvement of level IIb lymph nodes. All patients with metastasis to level IIb lymph nodes have their primary lesions in the tongue and constituted 22% of patients with tongue lesions. There was no instance of isolated metastasis to level IIb lymph nodes without involvement of other nodes in the SOHND specimens.

CONCLUSIONS

In this study, level IIb lymph node metastasis was only found in association with tongue carcinoma. Although this region may be preserved in elective SOHND in patients with SCC of the oral cavity, it should be included whenever the tongue is the primary site.

Management of the N0 neck--reference or preference

For patients with squamous cell carcinoma of the upper aerodigestive tract, appropriate management of the regional lymph nodes is an important and often controversial issue that has significant influence on survival. Over the years radical treatment either by surgery or radiotherapy contributed to improvement in prognosis. Recently, a more conservative approach has achieved a similar level of cancer control with less morbidity. This review considers the issues of selection of patients for treatment of the neck, choice of modality and extent of therapy, treatment of the contralateral neck, management of recurrence and influence of the site and status of the primary lesion.

New molecular diagnostic methods in head and neck cancer

Initial cancer evaluation includes assessment of histologic appearance, tumor grading, assessment of lymph node status, and presence of metastasis. However, traditional diagnostic methods such as histopathology and radiology are not sensitive enough to detect small numbers of cancer cells and are limited in their ability to predict response to treatment. Recently, there has been considerable progress in molecular diagnostics in these areas. Using molecular-based technologies, it is now possible to detect cancer early in asymptomatic individuals, identify minimal residual disease at histopathologic normal surgical margins, more precisely assess tumor burden in cancer patients, and more accurately assess the prognosis of the patients. Examples of these applications in the evaluation of head and neck cancer are reviewed here. However, despite the great promise of these new molecular approaches for cancer detection, much of the current technology limits their implementation into routine clinical use.

Molecular markers for diagnosis and prognosis

A plethora of aberrations are associated with progress and outcome for head and neck cancer patients and some have been shown to provide prognostic information independent of the TNM staging system. These findings justify future studies that will harness recent advances in technologies to refine the range of molecular markers available. Important lessons have been learnt during the last two decades, particularly the need to perform multivariate analysis and to combine information derived from several molecular markers. At present the overall evidence is insufficient to alter clinical practice or to consider restricting clinical trials of new adjuvant to subsets of patients, identified on the basis of the use of molecular markers. However, a number of key prospective clinical studies are in progress and we can be optimistic that in the near future clinical research incorporating specific markers may provide new criteria for defining risk of relapse or of developing a new primary tumour, and guide the choice of optimal adjuvant treatment after surgery. The only way to truly validate a marker is to incorporate it into large clinical trials, and it is anticipated that the new treatment options that are on the horizon, that are likely to be an improvement on radiotherapy alone, will provide opportunities to help translate this laboratory research into clinical practice.

Immunohistochemical Studies in the Identification of Lymph Node Micrometastases in Patients with Squamous Cell Carcinoma of the Head and Neck

In the prediction of likely disease-free and overall survival intervals in patients with squamous carcinomas of the head and neck, cervical lymph node status assumes a prime role, and patients with cervical node metastases have diminished survivals, as a group, compared with patients whose cervical nodes are reported as negative for metastatic carcinoma. Conventional means of pathologic examination of cervical node biopsy specimens include examination of a single section through each individual node identified on gross examination, a process which, of necessity, leaves a significant portion of the node unexamined by microscopy. Recently, it has become apparent that more exhaustive pathologic sampling techniques, such as examining multiple sections of each lymph node, or staining each lymph node with antibodies to keratin via immunohistochemistry, will reliably yield a greater incidence of positive cervical lymph nodes ("micrometastases") than do conventional pathologic techniques. This suggests that the next line of inquiry should answer this question: just because micrometastases can be detected, should they be? Does the identification of (otherwise likely to be overlooked) tiny microscopic foci of spread of tumor in regional nodes by more sophisticated techniques yield additional data of real import to the patients, or is such information of lesser value? Should a role be defined in the care of head and neck cancer patients for the use of such advanced inquiries in the structuring of therapies, then the best approach to finding such elusive micrometastases (intraoperative immunohistochemistry? immunohistochemistry using routinely fixed tissues? polymerase chain reaction?) may subsequently be established.

Upper aerodigestive tract squamous cell carcinoma: distribution of extracapsular spread and soft tissue deposits in the neck

OBJECTIVE

Extracapsular spread (ECS) and soft tissue deposits (STD) of squamous cell carcinoma (SCC) in the neck of patients with metastatic SCC of the upper aerodigestive tract have been shown to adversely affect actuarial and disease-free survival. No studies to date have detailed the distribution of ECS and STD within the neck.

MATERIAL AND METHODS

A total of 215 neck dissections from 155 patients were prospectively collected and analysed for the presence of both STD and ECS. As no classification for STD exists, their distribution was classified according to the nodal levels used for classification of cervical lymph nodes as described by the Memorial Sloan-Kettering Cancer Center.

RESULTS

A total of 81 neck dissections from 59 patients were found to have either metastatic lymph nodes with ECS, STD or both. The distribution of lymph node metastasis, ECS and STD was very similar. Level II was most frequently affected, with Levels III and IV being affected less frequently. There were very few lymph node metastases to Level V, and this level contained no evidence of either ECS or STD.

CONCLUSION

The method of pathological assessment of neck dissection specimens and reporting on the presence of ECS and STD has not been formalized. By analysing neck dissection specimens in the manner described we can report on the presence or absence of ECS and STD with increased accuracy. This has considerable implications for patient management.

Neck disease and distant metastases

While the implementation of multi-modality neoadjuvant therapy for the treatment of head and neck cancer has resulted in an improvement in local regional control, there has been a resultant increase in the reported incidence of distant metastasis. This shift in the pattern of patient treatment failure highlights the importance of identifying patients at high risk of developing metastasis, accurately detecting metastasis, and improving treatment strategies for advanced disease. Currently, metastatic lesions from head and neck primaries portend a poor prognosis; however, molecular biologic techniques offer a promising approach to the diagnosis and treatment of micrometastasis and distant metastatic lesions. The identification of tumor-specific gene mutations and the cell surface antigens may play a key role in the future management of head and neck cancer. The following review outlines just several of the current issues related to the contemporary diagnosis and management of metastatic lesions of the head and neck.