Carcinoma of the Tongue: Pathological Considerations in Management of the Neck

In a series of 76 patients with carcinoma of the tongue the occurrence of metastasis was related to the size and histological features of the primary tumour. 64% of patients with metastasis and 10% of patients with clinically negative neck showed spread beyond the node capsule. Fast tracks (long lymphatic pathways uninterrupted by nodes) seemed to be involved in the spread of metastatic cancer in at least 20% of patients with metastasis. With surgery and adjuvant radiotherapy based on the pathological stage, metastases confined to lymph nodes did not appear to affect short-term outcome.

The sinonasal tract: another potential "hot spot" for carcinomas with transcriptionally-active human papillomavirus

While high risk human papillomavirus (HPV) is well established as causative and clinically important for squamous cell carcinoma (SCC) of the oropharynx, its role in non-oropharyngeal head and neck SCC is much less clearly elucidated. In the sinonasal region, in particular, although it is a relatively uncommon site for SCC, as many as 20 % of SCC harbor transcriptionally-active high risk HPV. These tumors almost always have a nonkeratinizing morphology and may have a better prognosis. In addition, specific variants of SCC as well as other rare carcinoma types, when arising in the sinonasal tract, can harbor transcriptionally-active HPV. This article reviews the current literature on HPV in sinonasal carcinomas, attempts to more clearly demonstrate what tumors have it and how this relates to possible precursor lesions like inverted papilloma, and discusses the possible clinical ramifications of the presence of the virus.

Molecular diagnostic alterations in squamous cell carcinoma of the head and neck and potential diagnostic applications

Head and neck squamous cell carcinoma (HNSCC) is a common malignancy that continues to be difficult to treat and cure. In many organ systems and tumor types, there have been significant advances in the understanding of the molecular basis for tumorigenesis, disease progression and genetic implications for therapeutics. Although tumorigenesis pathways and the molecular etiologies of HNSCC have been extensively studied, there are still very few diagnostic clinical applications used in practice today. This review discusses current clinically applicable molecular markers, including viral detection of Epstein-Barr virus and human papillomavirus, and molecular targets that are used in diagnosis and management of HNSCC. The common oncogenes EGFR, RAS, CCND1, BRAF, and PIK3CA and tumor suppressor genes p53, CDKN2A and NOTCH are discussed for their associations with HNSCC. Discussion of markers with potential future applications is also included, with a focus on molecular alterations associated with targeted therapy resistance.

Molecular staging of surgical margins in oral squamous cell carcinoma using promoter methylation of p16(INK4A), cytoglobin, E-cadherin, and TMEFF2

BACKGROUND

Local recurrence in oral squamous cell carcinoma (OSCC) despite clear surgical margins may indicate the presence of residual, sub-microscopic disease. Molecular assessment of surgical margins may provide a greater prognostic sensitivity compared to histopathology. We aimed to determine whether promoter methylation in deep and mucosal resection margins can predict recurrence in OSCC.

METHODS

Forty-eight consecutive OSCC cases were recruited and a 5 mm(3) tumor sample plus 5 deep and 5 mucosal margin samples were snap frozen. Clinical, pathological, adjuvant therapy, and outcome data were recorded. Tumors were informative if >5 % promoter methylation was found for ≥1 of 4 genes using qMSP. Margins were declared molecularly positive if >1 % promoter methylation was found in any margin.

RESULTS

Thirty (63 %) of 48 cases were methylation informative. Mucosal margin samples were largely positive for methylation (26 of 30, 87 %), indicating the presence of field cancerization. Methylation at ≥1 gene promoters in ≥1 deep margin correlated with the presence of close/involved mucosal margins (P = 0.027) and increased pT status (P = 0.027) but not the status of deep margins, recurrence, or survival.

CONCLUSIONS

The current gene panel did not add prognostic information to histopathological reporting of resection margins. Future efforts should concentrate on improving gene selection, informativity, and assay performance in the patient group with intermediate indications for adjuvant therapy.

Pleomorphic adenoma of the parotid: formal parotidectomy or limited surgery?

BACKGROUND

Optimal surgery for pleomorphic adenoma of the parotid is controversial. In the present review, we discuss the advantages and disadvantages of the various approaches after addressing the surgical pathology of the parotid pleomorphic adenoma capsule and its influence on surgery.

DATA SOURCES

PubMed literature searches were performed to identify original studies.

CONCLUSIONS

Almost all pleomorphic adenomas can be effectively treated by formal parotidectomy, but the procedure is not mandatory. Extracapsular dissection is a minimal margin surgery; therefore, in the hands of a novice or occasional parotid surgeon, it may result in higher rates of recurrence. Partial superficial parotidectomy may be a good compromise. The tumor is removed with a greater cuff of healthy parotid tissue than in extracapsular dissection. This may minimize the recurrence rate. On the other hand, the removal of healthy parotid tissue compared with formal parotidectomy is limited, thus minimizing complications such as facial nerve dysfunction and Frey syndrome.

First report of elective selective neck dissection in the management of squamous cell carcinoma of the maxillary sinus

Controversy remains about management of the neck in squamous cell carcinoma (SCC) of the maxillary sinus and we know of no reports of the use of elective selective neck dissection for management in this site. We retrospectively reviewed 18 consecutive patients with SCC of the maxillary sinus who were managed by primary operation with curative intent. A total of 13 patients had an elective selective neck dissection, which was invaded in one case 8%. Four patients had regional metastases, two with positive nodal disease confirmed after elective selective neck dissection, and two who developed regional recurrence (both after elective selective neck dissections which were negative (pN0)). A review of other published articles in the English language showed no cases of elective selective neck dissections reported. The mean regional recurrence rate was 12% (range 0-26%) and total mean regional metastases rate 21% (range 5-36%). Elective selective neck dissection did not contribute to an improved rate of neck control with regional recurrence of 11% (2/18) compared with 12% in the review. There is no evidence in this report to indicate that elective selective neck dissections for maxillary sinus SCC will result in better disease control. Future research may indicate fewer radiotherapy fields for necks with pathologically clear nodes after elective selective neck dissection.

Intraosseous carcinoma of the jaws--a clinicopathologic review. Part I: Metastatic and salivary-type carcinomas

This is the first part of a 3-part comprehensive review of intraosseous carcinoma of the jaws. We have outlined 4 groups of intraosseous carcinoma of the jaws (metastatic, salivary-type, odontogenic, and primary intraosseous carcinoma), emphasizing the need for accurate diagnosis and the problems associated with changing classification systems, standardization of diagnostic criteria and nomenclature, and the accuracy of existing literature. In this first part, the features of metastatic and the very rare salivary-type carcinomas of the jaws are examined with particular emphasis on histologic and immunohistochemical characteristics, diagnostic difficulties, and uncertainties.

Intraosseous carcinoma of the jaws: a clinicopathologic review. Part III: Primary intraosseous squamous cell carcinoma

This is the third part of a review of the clinicopathologic features of intraosseous carcinoma of the jaws (IOCJ). In parts 1 and 2, we discussed metastatic and salivary-type and odontogenic carcinomas, respectively. This part deals with primary intraosseous squamous cell carcinoma. Again, based on a critical approach, we emphasize histopathologic features, diagnostic difficulties, discuss histogenesis, and highlight areas of uncertainty. The 3-part review also offers speculations on how future studies may refine our understanding of the unusual and interesting IOCJ.

Intraosseous carcinoma of the jaws: a clinicopathologic review. Part II: Odontogenic carcinomas

This is the second of a 3-part review of the clinicopathologic features of intraosseous carcinoma of the jaws (IOCJ). This part deals with odontogenic carcinomas, rare entities that are difficult to evaluate because of changes in classification/nomenclature, lack of standardized diagnostic criteria, and variable consistency of the existing literature. Endorsing a critical approach, problems are addressed and areas of uncertainty are highlighted. As in part I, we emphasize histopathologic features from a diagnostic point of view and also question the existence of some "distinct" entities.

Evaluation of human papilloma virus diagnostic testing in oropharyngeal squamous cell carcinoma: sensitivity, specificity, and prognostic discrimination

PURPOSE

Human papillomavirus-16 (HPV16) is the causative agent in a biologically distinct subset of oropharyngeal squamous cell carcinoma (OPSCC) with highly favorable prognosis. In clinical trials, HPV16 status is an essential inclusion or stratification parameter, highlighting the importance of accurate testing.

EXPERIMENTAL DESIGN

Fixed and fresh-frozen tissue from 108 OPSCC cases were subject to eight possible assay/assay combinations: p16 immunohistochemistry (p16 IHC); in situ hybridization for high-risk HPV (HR HPV ISH); quantitative PCR (qPCR) for both viral E6 RNA (RNA qPCR) and DNA (DNA qPCR); and combinations of the above.

RESULTS

HPV16-positive OPSCC presented in younger patients (mean 7.5 years younger, P = 0.003) who smoked less than HPV-negative patients (P = 0.007). The proportion of HPV16-positive cases increased from 15% to 57% (P = 0.001) between 1988 and 2009. A combination of p16 IHC/DNA qPCR showed acceptable sensitivity (97%) and specificity (94%) compared with the RNA qPCR "gold standard", as well as being the best discriminator of favorable outcome (overall survival P = 0.002). p16 IHC/HR HPV ISH also had acceptable specificity (90%) but the substantial reduction in its sensitivity (88%) impacted upon its prognostic value (P = 0.02). p16 IHC, HR HPV ISH, or DNA qPCR was not sufficiently specific to recommend in clinical trials when used in isolation.

CONCLUSIONS

Caution must be exercised in applying HPV16 diagnostic tests because of significant disparities in accuracy and prognostic value in previously published techniques.

Accuracy of MRI in prediction of tumour thickness and nodal stage in oral squamous cell carcinoma

We aim to compare radiological with histological tumour thickness (RTT with HTT) for oral squamous cell carcinoma (OSCC), and the ability of both to predict cervical metastasis. The MRI images and histopathology reports of 102 consecutive OSCC cases were compared and the relationship between RTT and HTT, calculated as a "shrinkage factor" by the gradient of the best fitting regression line. Most (69%) tumours appeared thicker on MRI than was revealed by histopathology. Shrinkage factor was 0.70 (interquartile range 0.63-0.77, correlation co-efficient 0.63) for all cases, 0.87 (IQR 0.80-0.95, CC 0.88) for tongue and 0.65 (IQR 0.49-0.82, CC 0.45) for floor of mouth sub-sites. RTT did not correlate well with the presence of nodal metastases in any sub-site, i.e. there was no clinically applicable cut-off value of RTT to determine the prescription of elective neck dissection. Although RTT has some predictable relationship with HTT, this varies between sub-sites with tongue the most accurately predicted shrinkage using axial MRI. It is not possible from either the MRI staging of neck or tumour thickness to safely determine the need for neck dissection in OSCC. It is necessary to re-evaluate the benefit of MRI as a staging investigation (particularly for early stage OSCC) and further explore the contribution of molecular biomarkers and ultrasound.

Contemporary management of lymph node metastases from an unknown primary to the neck: I. A review of diagnostic approaches

In an era of advanced diagnostics, metastasis to cervical lymph nodes from an occult primary tumor is a rare clinical entity and accounts for approximately 3% of head and neck malignancies. Histologically, two thirds of cases are squamous cell carcinomas (SCCs), with other tissue types less common in the neck. With modern imaging and tissue examinations, a primary tumor initially undetected on physical examination is revealed in >50% of patients and the site of the index primary can be predicted with a high level of probability. In the present review, the range and limitations of diagnostic procedures are summarized and the optimal diagnostic workup is proposed. Initial preferred diagnostic procedures are a fine-needle aspiration biopsy (FNAB) and imaging. This allows directed surgical biopsy (such as tonsillectomy), based on the preliminary findings, and prevents misinterpretation of postsurgical images. When no primary lesion is suggested after imaging and panendoscopy, and for patients without a history of smoking and alcohol abuse, molecular profiling of an FNAB sample for human papillomavirus (HPV) and/or Epstein-Barr virus (EBV) is important.

Advances and applications of oral cancer basic research

Cancer of the oral cavity accounts for almost 3% of cancer cases in the world. The incidence varies widely reflecting geographic differences in exposure to risk factors. The recent rise in younger age groups and females seen in many countries is of particular concern. Treatment and management of complications, locoregional recurrence and further primary tumors result in high morbidity and mortality especially when the disease is advanced stage at initial diagnosis. Progress in cancer research has provided abundant new knowledge about cellular processes and molecular biology underlying oral carcinogenesis and tumor progression. The present review attempts to summarize the current most widely-used research approaches and their application in the prevention, diagnosis, effective treatment, and improved outcome of oral cancer.

Extracapsular spread in oral squamous cell carcinoma

BACKGROUND

Extracapsular spread (ECS) in the cervical lymph nodes represents the most significant adverse prognostic indicator in oral squamous cell carcinoma (OSCC).

METHODS

In a consecutive cohort of OSCC treated by primary surgery, ECS was seen in 25% (101) of 400 patients.

RESULTS

ECS doubled the incidence of local recurrence and distant metastases, but tripled regional failure. The recurrences occurred sooner in ECS than in non-ECS cases (206 vs 334 days, p = .04). Patients with macroscopic ECS had a 5-year overall survival (OS) of 19% compared with 31% in microscopic ECS. MRI neck staging offered poor sensitivity, especially in microscopic ECS. Age >75 years, smoking, and heavy use of alcohol were independent predictors of ECS, which may implicate a failure of immunosurveillance by the host as much as adverse biology of the tumor.

CONCLUSIONS

Reporting of ECS is essential in accurate prognostication, and we advocate that all patients with OSCC and ECS should be grouped as pN3 on the basis of their prognosis. (c) 2009 Wiley Periodicals, Inc. Head Neck, 2010.

Retropharyngeal lymph node metastases in head and neck malignancies

Retropharyngeal lymph node (RPLN) metastasis of primary head and neck cancer often receives less consideration than lymph node metastasis in the neck. With improvements in imaging techniques and reports of surgical pathology, there is an improved understanding of the risk and subsequently the need for treatment of RPLNs. The rates of RPLN metastasis from carcinomas of the nasopharynx, oropharynx, hypopharynx, postcricoid region, maxillary sinus, and cervical esophagus are sufficiently high to warrant routine treatment, either electively or therapeutically, of this region. Through improved diagnostic techniques and heightened awareness of RPLN metastasis, patients at risk of having these metastases can be treated more effectively.

A survey of metastatic central nervous system tumors to cervical lymph nodes

In the realm of head and neck diseases, one particularly common clinical presentation is that of the patient with a cervical mass. In children, neck masses often prove to be developmental cysts; in adults, the recent onset of a neck mass can signal a metastasis from a head and neck squamous carcinoma. Less often, both adults and children may present with cervical masses caused by either non-Hodgkin's lymphoma or Hodgkin's disease. There are, of course, less frequently encountered differential diagnostic possibilities; one of the most uncommon of all is the possibility of metastasis from an intracranial tumor. Intracranial tumors rarely give rise to cervical node metastases. The present review examines the published experience with 128 tumors that gave rise to cervical node metastases in both adult and in pediatric patients. While it is presumed that the blood-brain barrier blocks the spread of most tumors beyond the intracranial locale, this is speculative. Although many of the cervical node metastases reported here arose after craniotomy (and, presumably, after breaching of the blood-brain barrier), some arose in the absence of any preceding surgical procedure. Cervical node metastases may arise from glial tumors (including glioblastoma multiforme, in both adult and pediatric patients) and non-glial tumors (such as medulloblastoma in pediatric patients). The history of a previous intracranial lesion is often the key to correct diagnosis, since, without prompting, neither the pathologist nor the radiologist is likely to think of a cervical node metastasis from a brain tumor when assessing a cervical mass of unknown etiology.

Abstract 2148: Combined comparative genome hybridization (CGH) and pathway analysis of oral squamous cell carcinomas with respect to nodal status and extracapsular spread (ECS)

Background: Over half of the new 560,000 head and neck squamous cell carcinomas annually worldwide occur in the oral cavity (OSCC). We recently and others have reported that ECS in the cervical lymph nodes represents the most significant adverse prognostic indicator in OSCC, proving rapidly fatal in >75% of cases despite radical surgery and adjuvant chemoradiotherapy (Shaw et al., Head Neck, 2009). Increased interest in neo-adjuvant chemotherapy and targeted therapies contrasts to the neglected clinical biology of OSCC and the best strategies are unclear.

Purpose: We aimed to use CGH analysis in an initial exploratory study hypothesising significant enrichment of molecular pathways according to the presence of ECS.

Methods: Macromolecules were purified from fresh frozen samples representing T2 and T4 stage OSCC cases (n=43) having no nodal involvement, positive nodes or positive nodes plus ECS from a larger single centre series (n>200). CGH analysis was performed using 720,000 human genomic probes per array. Genomic segmentation was used to identify regional copy number changes. Genes within the segments were mapped to canonical pathways to assess significance according to metadata defining the samples.

Results: Principal component analysis grouped the samples according to gender, stage, recurrence and nodal status, listed in order of decreasing separation. Node positive status was clearly distinguished by copy number changes significantly affecting multiple pathways including cytoskeletal remodelling: TGF and WNT pathway (p = 7.78 ×10−8), keratin filaments (p = 1.377 ×10−7), transcription: receptor mediated HIF regulation (p = 4.055 × 10−7), immune response: IL9 signalling pathway (p = 1.1 × 10−6) and chemotaxis (p = 3.8 × 10−6). Other significantly altered pathways included Notch signalling and TNFs/NF-kB/IAP apoptosis for both T4 and T2 tumours (p = 9.7 ×10−5 and p = 9.95 ×10−4, respectively). Significantly affected networks included angiogenesis, protein folding and proteasome proteolysis between disease free versus recurrence (p = 6.98 × 10−3; p = 0.022; p= 0.0218, respectively). Significant associations for ECS were not found.

Discussion: This is the highest density CGH array study on specific aspects of OSCC of which we are aware. Its high resolution uniquely allowed candidate pathways associated with features of the samples to be determined. Samples with ECS could not be distinguished. This may be a result of their smaller numbers (n=11). Potentially, reduced host immune response underlying the ECS cases may be crucial, offering an alternative explanation. Future work expanding the number of samples especially with regard to ECS cases and also including expression array studies is underway. These are planned to further test the significance and examine the possibility of expression changes associated with ECS.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2148.

Determinants of outcome following surgery for oral squamous cell carcinoma

The recent changes in incidence and prevalence of oral squamous cell carcinoma in relation to gender and age mirror the changing patterns of exposure to tobacco and alcohol, the main etiological agents. Most cases of oral cancer are managed by surgery, often combined with radiotherapy. Histopathological assessment of the resection specimen provides information vital for postoperative management and prognosis. This review considers the full range of histological determinants of outcome in relation to the primary oral tumor and any metastatic involvement of the cervical lymphatic system, together with an outline of more general patient factors that may also impact on morbidity and mortality rates.

A comparison of outcomes for patients with oral squamous cell carcinoma at intermediate risk of recurrence treated by surgery alone or with post-operative radiotherapy

Controversy remains about which patients at intermediate risk of recurrence of oral squamous cell carcinoma would benefit from radiotherapy. A retrospective review of computerised database and medical records for 462 consecutive patients at the Regional Maxillofacial Unit in Liverpool who were treated with primary surgery with or without post-operative radiotherapy was carried out. We classified 29% (134) of patients as being at 'low' risk of disease recurrence (pT1-2, N0 with clear margins), 29% (135) at 'high' risk (involved margins or lymph node extracapsular spread) and the remaining 42% (193) at 'intermediate' risk. Of those at intermediate risk, 41% (80/193) received adjuvant radiotherapy and their 5 year survival (SE) was 54% (6%) compared to 71% (5%) for those with primary surgery alone (P=0.002). A higher proportion of patients having radiotherapy had loco-regional recurrence (19/80 24%) compared to those treated by surgery alone (17/113 15%). The improved salvage rate for recurrent disease in the surgery alone group (8/17 53%), compared to those receiving radiotherapy (2/19 13%, P=0.05), indicates an advantage in withholding radiotherapy for patients at intermediate risk of recurrence. This study indicates a potential disadvantage associated with the use of postoperative radiotherapy for patients at intermediate risk of recurrence. A randomised trial comparing a watch and wait policy to postoperative radiotherapy in patients with an intermediate risk of recurrence is required to confirm the trend indicated in this retrospective data.

CpG island methylation phenotype (CIMP) in oral cancer: associated with a marked inflammatory response and less aggressive tumour biology

Studies in several tumour sites highlight the significance of the CpG island methylation phenotype (CIMP), with distinct features of histology, biological aggression and outcome. We utilise pyrosequencing techniques of quantitative methylation analysis to investigate the presence of CIMP in oral squamous cell carcinoma (OSCC) for the first time, and evaluate its correlation with allelic imbalance, pathology and clinical behaviour. Tumour tissue, control tissue and PBLs were obtained from 74 patients with oral squamous cell carcinoma. Pyrosequencing was used to analyse methylation patterns in 75-200 bp regions of the CpG rich gene promoters of 10 genes with a broad range of cellular functions. Allelic imbalance was investigated using a multiplexed panel of 11 microsatellite markers. Corresponding variables, histopathological staging and grading were correlated with these genetic and epigenetic aberrations. A cluster of tumours with a greater degree of promoter methylation than would be predicted by chance alone (P=0.001) were designated CIMP+ve. This group had less aggressive tumour biology in terms of tumour thickness (p=0.015) and nodal metastasis (P=0.012), this being apparently independent of tumour diameter. Further, it seems that these CIMP+ve tumours excited a greater host inflammatory response (P=0.019). The exact mechanisms underlying CIMP remain obscure but the association with a greater inflammatory host response supports existing theories relating these features in other tumour sites. As CIMP has significant associations with other well documented prognostic indicators, it may prove beneficial to include methylation analyses in molecular risk modelling of tumours.

The topography of cervical lymph node metastases revisited: the histological findings in 526 sides of neck dissection from 439 previously untreated patients

The pathological reports, minimum datasets and topographical plots of the neck dissections from 439 cases of oral and oropharyngeal cancer reported by a single pathologist following a standard protocol were analysed. Metastasis was evident in 47% of patients including bilateral metastases in 6%, extracapsular spread in 29% and matting in 7%. The extent of metastasis (both volume and distribution) was greatest in tumours of the oropharynx followed by lateral tongue, ventral tongue and floor of mouth. The typical 'inverted-cone pattern' was seen in 67% of patients with metastasis. A single micrometastasis was seen in 14%, skip lesions in 10% and involvement of 'other' nodal groups in 4%. Contralateral neck metastases (0.4%), peppering (2%), flushing of lymph node sinuses (1%) and all nodes positive (0.4%) accounted for the remaining 'aberrant' patterns. Skip lesions were seen in tumours at all sites other than retromolar.

Salvage neck dissections in oral and oropharyngeal squamous cell carcinoma: histological features in relation to disease category

The histological findings in a series of 37 salvage neck dissections from patients who had an oral or oropharyngeal squamous cell carcinoma managed initially by primary surgery with or without neck dissection, and without postoperative radiotherapy, are described. None of the cases had an intraoral relapse. Pathological stage N2 or N3 disease was seen in 87% of the 15 salvage dissections from 'wait and watch' necks, 100% of the 10 salvage dissections of contralateral necks and 50% of the 12 salvage dissections of operated necks. The typical 'inverted-cone' pattern of metastasis was seen in 87% of 'wait and watch' necks. Skip or non-contiguous metastases to level III/IV accounted for relapse in 30% of the contralateral and 66% of the operated necks. The median time interval between original surgery and the salvage neck dissection was 15 months (range 1-48 months). In at least 15% of cases, the short time interval coupled with the histopathological features suggested that the metastatic disease suddenly became more rapidly progressive following removal of the primary tumour.

The national head and neck histopathology external quality assurance scheme: evolution, design, and analysis of 11 circulations from 1999 to 2005

The background and design of a specialised head and neck histopathology external quality assurance (assessment) scheme with optional oral and ENT arms is described. Participation (submission of response forms) exceeded 85% in eight of 11 slide circulations. In 60% of the 168 circulated cases, up to 33% (and in occasional cases, up to 56%) of respondents gave incomplete or wrong responses owing to a lack of awareness of specific diagnostic entities or to the misinterpretation of specific histological features. In all, there were 118 wrong responses, of which 58% could be considered "potentially serious". The scheme incorporates several design features which optimise the educational value. The stringent marking of cases, and the flagging of performances showing "a meaningful deviation in standard" based on the decision of peer members rather than a rigid numerical formula, encourages high standards.

Histopathological prognosticators in oral and oropharyngeal squamous cell carcinoma

Histopathological assessment of the surgical resection specimen continues to provide information that is central to determining the post-operative treatment needs and prognosis for an individual patient with oral/oropharyngeal squamous cell carcinoma. This review describes the prognostic value of histopathological features related to the primary tumour and the cervical lymph nodes, and considers their relative merits. In addition, a brief overview of more general patient factors is included. Throughout the review, guidance is offered on practical aspects of the histopathological assessment together with brief mention of potential inaccuracies. Emphasis is given also to the importance of the partnership between the surgeon and the pathologist, the need for standardisation during all stages of the histopathological assessment, and the value of accurate documentation of the findings.

The influence of the pattern of mandibular invasion on recurrence and survival in oral squamous cell carcinoma

BACKGROUND

Controversy exists over the predictive value of the presence and pattern of tumor invasion of the mandible in oral squamous cell carcinoma (SCC). Many authors have questioned increasing the classification of small tumors to T4 on the basis of mandibular invasion alone. There are little data on the influence of the pattern of invasion on prognosis.

METHODS

We prospectively reviewed 100 consecutive mandibular resections for previously untreated oral SCC. Clinical and pathologic data collected included details of soft and hard tissue histologic findings. Outcomes included recurrence (local, regional, and distant metastases), disease-specific survival, and death from other causes. The median follow-up for survivors was 65 months.

RESULTS

Of 100 cases, 65 involved segmental and 35 involved marginal resections. Sixty-two percent of mandibles were invaded by tumor. Local recurrence occurred in 21% and was strongly correlated with tumor size, nodal involvement, and pattern of soft tissue invasion. The 5-year disease-specific survival was 68%, and the crude survival was 50%. Mandibular invasion predicted for recurrence and disease-specific survival, even after correcting for the effects of other variables. The pattern of mandibular invasion (erosive/infiltrative) was also predicted for recurrence and disease-specific survival.

CONCLUSIONS

Even in the presence of mandibular invasion, soft tissue factors are the most important determinants of prognosis. Upstaging tumors on the basis of mandibular invasion is justified. An infiltrative pattern of bone invasion is a marker of aggressive tumor biology and should be included in the pTNM classification.

The prognostic implications of the surgical margin in oral squamous cell carcinoma

The prime objective of tumour ablation in oral squamous cell carcinoma (OSCC) is the removal, with a 'margin' of normal tissue, of the whole tumour. Definition of what constitutes margin involvement varies. This study aims to examine the factors associated with close and involved surgical margins in the management of OSCC. A cohort of 200 consecutive patients with previously untreated OSCC provided the material for the study. Various clinical, operative and pathological parameters were related to the status of the surgical margin, as well as time to recurrence, and survival. Cox regression analysis of the survival was also undertaken. Of the 200 patients 107 (53.5%) had clear margins, 84 (42%) close and 9 (4.5%) involved. Poor correlation was found between the status of the surgical margin and clinical factors, but in contrast high correlation between histological indicators of aggressive disease and close or involved surgical margins. These results imply that close surgical margins in OSCC could be regarded as an indictor of aggressive disease.

Cervical lymph node metastasis in oral cancer: the importance of even microscopic extracapsular spread

The prognostic significance of extracapsular spread of cervical metastases in oral cancer is still controversial. To investigate the importance of extent of extracapsular spread; the relationship between extracapsular spread and both traditional measures of metastatic disease and clinical/histological features of the primary tumour, and to determine their relative prognostic significance. The survival of 173 patients undergoing radical surgery and simultaneous neck dissection for oral/oropharyngeal squamous cell carcinoma with histologically confirmed nodal metastasis and followed for 2.2-12.3 years is reported and related to pathological features. The most predictive clinical/histopathological features were determined by Cox regression modelling. The 3-year survival probability was similar for patients with macroscopic and only microscopic extracapsular spread (33 and 36%, respectively, compared with 72% for patients with intranodal metastasis). The Cox model showed the most predictive factor was extracapsular spread followed by status of resection margins. Extracapsular spread should be incorporated into pathological staging systems. Even microscopic extracapsular spread is of critical importance and must be sought especially in small-volume metastatic disease.

Factors that influence the method of mandibular resection in the management of oral squamous cell carcinoma

The method of conservative (rim) resection of the mandible is now well established and provides good control of disease in the primary site. There are few audits of this technique in terms of margins of resection for both rim and segmental resection of the mandible. Consecutive previously untreated patients managed with resection of the mandible as part of their treatment for oral and oropharyngeal squamous cell carcinoma were recruited for the study. The presence and extent of tumour invasion of the mandible was recorded and a retrospective analysis made to establish the incidence of unnecessary segmental resections. The invasion rate was 33% (8/35) for rims and 83% (54/65) in segmental resections of the mandible, which compares favourably with previous studies and indicates a reasonable accuracy of resection. In between 6 and 11 of the 62 cases (10-17%) a rim resection could have achieved a satisfactory resection margin and retained a functioning lower border of the mandible. The accuracy of resection in terms of margins was greater for mandibular resections (94% clear margins) than soft tissues (62% clear margins). The number of compromised margins was significantly greater in the invaded rim resection group (P=0.018). This study indicates that a more conservative mandibular resection was possible in a few cases. This is unlikely to have an adverse effect on the close or involved margin rate, which depends mainly on the accuracy of the soft tissue resection. Angling the horizontal rim resection to take into account tumour entry at the point of contact will help to ensure a clear bone margin if a conservative approach to mandibular resection is an option.

Radionuclide bone imaging for detection of mandibular invasion by squamous cell carcinoma

The assessment of mandibular invasion is an important part of the pre-operative staging of oropharyngeal squamous cell carcinoma. When bone is surgically resected, histology often shows no direct bone invasion, yet such resections are associated with post-operative complication and morbidity. This prospective study of a large group of patients aims to lay down criteria for bone invasion using radionuclide bone imaging and orthopantomography, and to test their effectiveness when compared with histological analysis. 77 patients with proven squamous cell carcinoma of the oral cavity were investigated pre-operatively by radionuclide bone imaging and orthopantomography. All had bone resected as part of complete resection of the tumour. One patient had systemic bone metastases and was, therefore, excluded. In the remaining 76 patients, there were four false positive assessments for bone invasion radiologically and no false negatives. There were 48 true positive results and 24 true negatives, giving a sensitivity of 100% and specificity of 86%. It is concluded that correct application of the outlined criteria for bone invasion demonstrated that radionuclide bone imaging and orthopantomography are a sensitive test for bone invasion, with an acceptable level of specificity.

T2 carcinoma of the tongue: the histopathologist's perspective

The histological characteristics and extent of tumour spread at the primary site and in the neck are described in a series of 50 patients with a T2 squamous cell carcinoma of the oral tongue. The likely site of origin was lateral tongue in 29 cases and ventral tongue in 21 cases. Simultaneous tumours were evident in four resections and multifocal dysplasia in a further 13. Lymph node metastasis was diagnosed histologically in 27 cases, including one case with bilateral metastases. Comparison of the groups, with and without metastasis, showed significant differences in tumour thickness, tumour diameter, multifactorial histological malignancy grade, vessel invasion and nerve invasion. The number of positive lymph nodes per patient ranged from 1 to 16 (mean 3), and 17 dissections showed spread beyond the nodal capsule. Postoperative follow-up ranged from 1 to 6 years and, at the time of analysis, 18 patients had died of or with disease. Loco-regional failure was related to 'high-risk' features at the primary site and extracapsular spread in the neck.

Pathology of the N0 neck

The incidence, extent and distribution of nodal metastasis is described in 152 neck dissections from patients with an NO neck undergoing surgery for an intraoral/oropharyngeal squamous cell carcinoma. The preoperative N stage had been determined by palpation under general anaesthesia and magnetic resonance imaging. Metastasis was detected histologically in 32 (21%) of the 152 NO necks. The number of positive nodes per NO neck ranged from 1 to 6. In total, 52 positive nodes were found and 29 (56%) measured 10 mm or less in maximum dimension. Twenty-one dissections (66%) contained a single positive node and 24 (75%) showed a single positive anatomical level. Three cases showed 'skipping' of levels within the neck and one case showed 'peppering'. Seventeen (53%) of the 32 positive NO necks and 31 (60%) of the 52 positive nodes contained only 'micrometastases' (deposits < 3 mm). Microscopic extracapsular spread was evident in five NO necks including one case with extracapsular spread at multiple levels. The study concludes that preoperative staging by palpation and routine magnetic resonance imaging cannot be relied upon to detect early cervical metastatic disease, and the topographic distribution of positive nodes indicates that modified neck dissections should include level IV when the primary tumour involves the tongue.

Histological distribution of cervical lymph node metastases from intraoral/oropharyngeal squamous cell carcinomas

The histological frequency and distribution of cervical lymph node metastases was studied in 326 neck dissections from 253 patients with an intraoral/oropharyngeal squamous cell carcinoma. Metastasis was evident in 118 patients (47%) and 18 had bilateral metastasis. For primary sites other than the tongue, metastasis developed initially in a node(s) in the first drainage group (level I or II) with progressive involvement of neighbouring nodes ('overflow'). Simultaneous bilateral metastases were seen in some tumours of the floor of mouth, tongue and oropharynx which involved the midline. An erratic distribution of metastases suggestive of 'fast-tracking' (skip lesions and peppering) was only seen in tongue tumours. The pattern of metastatic spread indicates that level IV nodes must be included in staging and therapeutic neck dissections in tongue cancer. Metastasis to 'accessory' lymph nodes (lingual, buccal) occurs infrequently but may explain some 'local' recurrences.

Micrometastasis in oral/oropharyngeal squamous cell carcinoma: incidence, histopathological features and clinical implications

The prognostic importance of accurate pathological staging of oral cancer patients with established lymph node metastases is well known. The present study sought to determine the incidence and clinical significance of minimal neck disease (only micrometastases) and to evaluate clinical features of the primary tumour in relation to the pathological metastatic status. Surgical resection specimens from 178 patients with oral/oropharyngeal squamous cell carcinoma were assessed by routine techniques. Micrometastases were defined as intranodal deposits measuring in total no more than 3 mm at any level of sectioning. Fourteen patients (8%) had only micrometastases and 72 (40%) had established nodal metastases. Patients with only micrometastases were younger than those with established metastases, but there were no differences in T site, T stage or sex. The outcome (2-6 years postsurgery) of patients with only micrometastases was similar to those without cervical node metastases. Hence, the main short-term significance of micrometastases seems to be in relation to clinical staging and elective management of the NO neck.