Prognosis of oral epithelial dysplasia in individuals with and without oral lichen planus.

OBJECTIVES: To investigate the role of oral lichen planus (OLP) on the long-term prognosis of oral epithelial dysplasia (OED). METHODS: Retrospective single-centre cohort study using the 2007-2019 database of the Head and Neck Cancer and Oral Medicine units of University College London Hospital. The exposure of interest was the presence of OLP, and the prognostic outcomes included the development of new primary episodes of OED, progression to malignancy and mortality. Cox proportional hazard and Poisson regression models were performed. RESULTS: A total of 299 patients, of whom 144 had OED arising on the background of OLP (OLP/OED) and 155 had OED without underlying OLP (non-OLP/OED), were included. A pre-existing diagnosis of OLP was significantly associated with a twofold increased risk of subsequent primary OED events (HR = 2.02, p = 0.04), which also developed faster (1.46 vs. 2.96 years, p = 0.04) and with more involvement of non-cancer-prone sites (p = 0.001) than in the non-OLP/OED group. There was no difference between groups in the progression to malignancy or mortality. CONCLUSIONS: Oral lichen planus/OED patients are at higher risk of multiple episodes of primary OED, which can develop faster and at non-cancer-prone sites as compared to non-OLP/OED individuals. Further research is needed to clarify the effects of OLP upon progression to OSCC and mortality.

Distribution and Frequency of Salivary Gland Tumours: An International Multicenter Study.

BACKGROUND: Salivary gland tumours (SGT) are a relatively rare group of neoplasms with a wide range of histopathological appearance and clinical features. To date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only. METHODS: This study aimed to mitigate these shortcomings by analysing epidemiological data including demographic, anatomical location and histological diagnoses of SGT from multiple centres across the world. The analysed data included age, gender, location and histological diagnosis from fifteen centres covering the majority of the world health organisation (WHO) geographical regions between 2006 and 2019. RESULTS: A total of 5739 cases were analysed including 65% benign and 35% malignant tumours. A slight female predilection (54%) and peak incidence between the fourth and seventh decade for both benign and malignant tumours was observed. The majority (68%) of the SGT presented in major and 32% in the minor glands. The parotid gland was the most common location (70%) for benign and minor glands (47%) for malignant tumours. Pleomorphic adenoma (70%), and Warthin's tumour (17%), were the most common benign tumours whereas mucoepidermoid carcinoma (26%) and adenoid cystic carcinoma (17%) were the most frequent malignant tumours. CONCLUSIONS: This multicentre investigation presents the largest cohort study to date analysing salivary gland tumour data from tertiary centres scattered across the globe. These findings should serve as a baseline for future studies evaluating the epidemiological landscape of these tumours.

Biphenotypic sinonasal sarcoma: European multicentre case-series and systematic literature review.

Objective: Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade cancer that was included from the 4th edition of WHO classification of head and neck tumours. The purpose of this study is to analyse clinical behaviour, pattern of recurrences and survival outcomes of this neoplasm. Methods: Retrospective review of patients affected by BSNS who were treated via an endoscopic-assisted approach in 6 European tertiary-care referral hospitals. Cases of BSNS described in literature since 2012 to date were fully reviewed, according to PRISMA guidelines. Results: A total of 15 patients were included. Seven patients were treated via an endoscopic endonasal approach, 4 with endoscopic transnasal craniectomy, and 4 via a cranio-endoscopic approach. Adjuvant treatment was delivered in 2 cases. After a mean follow-up of 27.3 months, systemic metastasis was observed in 1 case; the 5-year overall survival and disease-free survival rates were 100% and 80 ± 17.9%, respectively. Conclusions: BSNS is a locally aggressive tumour with a low recurrence rate and encouraging survival outcomes if properly treated with surgical resection and free margins followed by adjuvant radiotherapy for selected cases. Endoscopic-assisted surgery is safe and effective as an upfront treatment within a multidisciplinary care protocol.

Bioengineering the ameloblastoma tumour to study its effect on bone nodule formation.

Ameloblastoma is a benign, epithelial cancer of the jawbone, which causes bone resorption and disfigurement to patients affected. The interaction of ameloblastoma with its tumour stroma drives invasion and progression. We used stiff collagen matrices to engineer active bone forming stroma, to probe the interaction of ameloblastoma with its native tumour bone microenvironment. This bone-stroma was assessed by nano-CT, transmission electron microscopy (TEM), Raman spectroscopy and gene analysis. Furthermore, we investigated gene correlation between bone forming 3D bone stroma and ameloblastoma introduced 3D bone stroma. Ameloblastoma cells increased expression of MMP-2 and -9 and RANK temporally in 3D compared to 2D. Our 3D biomimetic model formed bone nodules of an average surface area of 0.1 mm2 and average height of 92.37 [Formula: see text] 7.96 µm over 21 days. We demonstrate a woven bone phenotype with distinct mineral and matrix components and increased expression of bone formation genes in our engineered bone. Introducing ameloblastoma to the bone stroma, completely inhibited bone formation, in a spatially specific manner. Multivariate gene analysis showed that ameloblastoma cells downregulate bone formation genes such as RUNX2. Through the development of a comprehensive bone stroma, we show that an ameloblastoma tumour mass prevents osteoblasts from forming new bone nodules and severely restricted the growth of existing bone nodules. We have identified potential pathways for this inhibition. More critically, we present novel findings on the interaction of stromal osteoblasts with ameloblastoma.

Somatostatin receptor 2 expression in nasopharyngeal cancer is induced by Epstein Barr virus infection: impact on prognosis, imaging and therapy.

Nasopharyngeal cancer (NPC), endemic in Southeast Asia, lacks effective diagnostic and therapeutic strategies. Even in high-income countries the 5-year survival rate for stage IV NPC is less than 40%. Here we report high somatostatin receptor 2 (SSTR2) expression in multiple clinical cohorts comprising 402 primary, locally recurrent and metastatic NPCs. We show that SSTR2 expression is induced by the Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) via the NF-κB pathway. Using cell-based and preclinical rodent models, we demonstrate the therapeutic potential of SSTR2 targeting using a cytotoxic drug conjugate, PEN-221, which is found to be superior to FDA-approved SSTR2-binding cytostatic agents. Furthermore, we reveal significant correlation of SSTR expression with increased rates of survival and report in vivo uptake of the SSTR2-binding 68Ga-DOTA-peptide radioconjugate in PET-CT scanning in a clinical trial of NPC patients (NCT03670342). These findings reveal a key role in EBV-associated NPC for SSTR2 in infection, imaging, targeted therapy and survival.

Proliferating trichilemmal tumour: diagnostic challenge on core biopsy.

A 70-year-old woman presented with a 10-month history of an irregular mass in the left lateral nape of her neck which had recently increased in size rapidly. Ultrasound-guided core needle biopsy was obtained, and the tumour was diagnosed as a well-differentiated squamous cell carcinoma. Further imaging studies failed to demonstrate additional malignant characteristics. In view of these findings, a wide local excision of the tumour was performed. Histopathological assessment of the resected tumour revealed a proliferating trichilemmal tumour with well-differentiated features and smooth invasion front. This article serves as an important reminder of the challenges associated with pathological evaluation of core needle biopsies of adnexal tumours. It emphasises the importance of clinical-radiological-pathological correlation preferably in a multidisciplinary team setting prior to agreeing on a definitive management plan.

Frequent HPV-independent p16/INK4A overexpression in head and neck cancer.

OBJECTIVES: p16INK4A (p16) is the most widely used clinical biomarker for Human Papillomavirus (HPV) in head and neck squamous cell cancer (HNSCC). HPV is a favourable prognostic marker in HNSCC and is used for patient stratification. While p16 is a relatively accurate marker for HPV within the oropharynx, recent reports suggest it may be unsuitable for use in other HNSCC subsites, where a smaller proportion of tumors are HPV-driven. MATERIALS AND METHODS: We integrated reverse phase protein array (RPPA) data for p16 with HPV status based on detection of viral transcripts by RNA-seq in a set of 210 HNSCCs profiled by The Cancer Genome Atlas project. Samples were queried for alterations in CDKN2A, and other pathway genes to investigate possible drivers of p16 expression. RESULTS: While p16 levels as measured by RPPA were significantly different by HPV status, there were multiple HPV (-) samples with similar expression levels of p16 to HPV (+) samples, particularly at non-oropharyngeal subsites. In many cases, p16 overexpression in HPV (-) tumors could not be explained by mutation or amplification of CDKN2A or by RB1 mutation. Instead, we observed enrichment for inactivating mutations in the histone H3 lysine 36 methyltransferase, NSD1 in HPV (-)/p16-high tumors. CONCLUSIONS: RPPA data suggest high p16 protein expression in many HPV (-) non-oropharyngeal HNSCCs, limiting its potential utility as an HPV biomarker outside of the oropharynx. HPV-independent overexpression of wild-type p16 in non-oropharyngeal HNSCC may be linked to global deregulation of chromatin state by inactivating mutations in NSD1.

Head and neck sarcomas: A single institute series.

BACKGROUND: Sarcomas are tumours of mesenchymal origin, accounting for 1% of all malignancies. METHODS: This is a retrospective analysis of 107 head and neck sarcoma cases, treated over a period of thirteen years. RESULTS: Fifty-four patients had with craniofacial bone sarcomas (BSs) (male: 33; female: 21) with high grade osteosarcoma being the most predominant type. The soft tissue sarcomas (STS) (53 patients; male: 28, female: 25) were histologically diverse with rhabdomyosarcomas and myxofibrosarcomas being the predominant types. The majority of BSs were managed with neoadjuvant chemotherapy followed by surgery, whereas in STSs treatment included predominantly surgery followed by radiotherapy. Overall survival estimates were 79% at 2years and 64% at 5years (mean follow-up period was 48months). CONCLUSIONS: The mesenchymal origin of sarcomas, the pattern of disease spread and the different extent of cancellous bone infiltration in contrast to epithelial tumours, dictate distinct principles for surgical clearance.

Optical coherence tomography in the assessment of oral squamous cell carcinoma resection margins.

BACKGROUND: Incomplete surgical removal of cancer is believed to be the main cause of local recurrence and high mortality. This study assessed the use of optical technology (namely optical coherence tomography [OCT]) in examining oral squamous cell carcinoma (OSCC) resection margins to assess if this modality could guide the surgeon during surgical resections. MATERIALS AND METHODS: Twenty-eight T1-T2 N0M0 oral squamous cell carcinoma patients participated in this study. Nineteen patients were males and nine were females. The majority of lesions were in the ventro-lateral tongue, floor of mouth, retromolar trigone and the buccal mucosa. Following tumour resection, the specimen resection margins were optically scanned in the immediate ex vivo phase. Two independent assessors commented on the four resection margins of each specimen. The findings were then compared to the corresponding gold standard histopathology. The average epithelial thickness for both tumor-free and tumor-involved margins was also calculated. RESULTS: The pathology reports of the 112 margins revealed 90 tumor-free margins and 22 tumor-involved margins. Examining the data from both senior operating surgeons (assessors), the overall sensitivity and specificity was found to be 81.5% and 87%, respectively. Whilst the positive predictive value was 61.5% and the negative predictive value was 95%. OCT accuracy for the first assessor was 88% and for the second assessor 84%. The assessors' inter-observer agreement was "very good" for superior, inferior and medial margins; while agreement on the lateral surgical margin status was "good". Using OCT, the mean epithelial thickness at the tumor-free resection margins was 360 µm; while, it was 567 µm for the tumour-involved margins. CONCLUSION: OCT is a valuable tool in the assessment of surgical margins. Tumour-involved margins can be identified by architectural changes and increase in epithelial layer thickness on the OCT image. Further studies are required to assess tumour margins in vivo.

Multicentric human papillomavirus-associated head and neck squamous cell carcinoma.

BACKGROUND: The purpose of this study was to present the clinicopathological features of a series of patients with human papillomavirus (HPV)-associated head and neck second primary tumors. METHODS: Patients with HPV-associated head and neck second primary tumors from 3 centers were identified. HPV infection was evaluated using p16 by immunohistochemistry (IHC), high-risk HPV DNA by in situ hybridization (ISH), and HPV genotyping by DNA polymerase chain reaction (PCR) enzyme immunoassay (EIA). RESULTS: Eleven patients were identified: 5 with synchronous and 6 with metachronous HPV-positive second primary tumors, the latter demonstrating a mean time interval of 5 years. There were 13 second primary tumors: 11 oropharyngeal, 1 nasopharyngeal, and 1 floor of the mouth. Nine of 10 genotyped patients harbored HPV-16, and 1 patient had HPV-33 in 3 synchronous tumors. CONCLUSION: HPV-associated second primary tumors may present as synchronous and/or metachronous lesions and can arise outside the oropharynx after prolonged intervals. Further work is necessary to identify patients at risk and to elucidate the mechanisms of HPV-associated head and neck second primary tumors.

Is [F-18]-fluorodeoxy-D-glucose positron emission tomography of value in the management of patients with craniofacial bone sarcomas undergoing neo-adjuvant treatment?

BACKGROUND: We evaluated the role of 18FDG PET/CT used to assess response to preoperative chemotherapy in patients with primary craniofacial bone sarcomas. METHODS: Fourteen patients with craniofacial bone sarcomas (13 osteosarcoma, 1 spindle cell sarcoma) were retrospectively evaluated. All patients received up to 6 cycles of preoperative chemotherapy followed by resection of the primary tumour. Response to treatment was assessed using MRI (RECIST criteria) and 18FDG PET/CT (EORTC guidelines), performed at least at baseline, after 2-4 cycles and pre-operatively. RESULTS: The median baseline 18FDG PET/CT SUV was 10.2 (range 0-41); in 2 patients no uptake was detected. The preoperative 18FDG PET/CT, compared with the baseline, demonstrated a partial metabolic response in 7 patients (59%), complete metabolic response in 2 (16%) and stable metabolic disease in 3 (25%). In contrast, only two patients achieved a RECIST response on MRI: 10 (83%) had stable disease. One patient underwent early resection due to clinical progression after an initial response to treatment. This was confirmed by PET (SUV from 21 to 42) but not on MRI. Twelve of 14 patients (86%) had <90% histological necrosis in the resected tumour. At a median follow-up 23 months, 11 patients (79%) remain disease free, two had metastatic progression (14%) and 1 a local relapse (7%). The median DFS was 17 months. For those patients who achieved a response to preoperative 18FDG PET/CT the median DFS was 19 months (range: 1-66) compared with 3 months (range: 3-13) in those who did not (p = 0.01). In contrast, the median disease free survival (DFS) did not differ according to histological response (19 versus 17 months, >90% versus <90% necrosis, p = 0.45) or resection margins (19 months for R0 versus 18 months for R1, p = 0.2). CONCLUSION: 18FDG PET/CT is more reliable than standard imaging in evaluating response to neo-adjuvant chemotherapy in craniofacial bone sarcomas, changed management in one patient, and in this small series, correlated better with patient outcome than histological response and resection margins. These results warrant prospective validation in a larger cohort of patients.

Integrated virus-host methylome analysis in head and neck squamous cell carcinoma.

One in six cancers worldwide is caused by infection and human papillomavirus (HPV) is one of the main culprits. To better understand the dynamics of HPV integration and its effect on both the viral and host methylomes, we conducted whole-genome DNA methylation analysis using MeDIP-seq of HPV+ and HPV- head and neck squamous cell carcinoma (HNSCC). We determined the viral subtype to be HPV-16 in all cases and show that HPV-16 integrates into the host genome at multiple random sites and that this process predominantly involves the transcriptional repressor gene (E2) in the viral genome. Comparative analysis identified 453 (FDR ≤ 0.01) differentially methylated regions (DMRs) in the HPV+ host methylome. Bioinformatics characterization of these DMRs confirmed the previously reported cadherin genes to be affected but also revealed new targets for HPV-mediated methylation changes at regions not covered by array-based platforms, including the recently identified super-enhancers.

Targeted next-generation sequencing of head and neck squamous cell carcinoma identifies novel genetic alterations in HPV+ and HPV- tumors.

BACKGROUND: Human papillomavirus positive (HPV+) head and neck squamous cell carcinoma (HNSCC) is an emerging disease, representing a distinct clinical and epidemiological entity. Understanding the genetic basis of this specific subtype of cancer could allow therapeutic targeting of affected pathways for a stratified medicine approach. METHODS: Twenty HPV+ and 20 HPV- laser-capture microdissected oropharyngeal carcinomas were used for paired-end sequencing of hybrid-captured DNA, targeting 3,230 exons in 182 genes often mutated in cancer. Copy number alteration (CNA) profiling, Sequenom MassArray sequencing and immunohistochemistry were used to further validate findings. RESULTS: HPV+ and HPV- oropharyngeal carcinomas cluster into two distinct subgroups. TP53 mutations are detected in 100% of HPV negative cases and abrogation of the G1/S checkpoint by CDKN2A/B deletion and/or CCND1 amplification occurs in the majority of HPV- tumors. CONCLUSION: These findings strongly support a causal role for HPV, acting via p53 and RB pathway inhibition, in the pathogenesis of a subset of oropharyngeal cancers and suggest that studies of CDK inhibitors in HPV- disease may be warranted. Mutation and copy number alteration of PI3 kinase (PI3K) pathway components appears particularly prevalent in HPV+ tumors and assessment of these alterations may aid in the interpretation of current clinical trials of PI3K, AKT, and mTOR inhibitors in HNSCC.

Optical coherence tomography in the assessment of suspicious oral lesions: an immediate ex vivo study.

BACKGROUND: Optical coherence tomography (OCT) is an evolving optical technology that is capable of delivering real-time, high-resolution signatures of tissue. OBJECTIVES: The purpose of this immediate ex vivo prospective clinical study was: (1) to assess the sensitivity and specificity of OCT on biopsy material in identifying potentially malignant and malignant oral lesions, (2) to determine the inter-observer agreement in the analysis of specific image parameters, and (3) to find out the oral epithelial thickness for different pathology groups. MATERIALS AND METHODS: This prospective study involved 125 suspicious oral lesions from 125 patients. The lesions were surgically biopsied and subjected to OCT in the immediate ex vivo phase. Two independent readers (surgeon and pathologist) examined the OCT images and assessed several cellular features including keratin layer, epithelial layer, basement membrane and lamina propria, and recorded their findings using special OCT reading score. The sensitivity, specificity and accuracy of OCT to predict "the future need for surgical biopsy in case of any similar lesion" were calculated. The epithelial thickness was also measured. The degree of agreement between the two readers was recorded. RESULTS: The pathological diagnosis revealed that the majority of lesions demonstrated microinvasive carcinomas (n=43). Forty-one had different degree of dysplasia. Benign oral lesions were less common and included 22 keratosis, 11 non-specific lesions, 6 mucocels and 2 papillomas. Optical coherence tomography achieved a sensitivity of 85% and a specificity of 78% in the assessment of oral potentially malignant and malignant disorders. The positive and negative predictive values were 86.5% and 77.5%, respectively. The accuracy was 82% and the kappa coefficient of inter-observer agreement was 0.72 on "the need for biopsy". OCT imaging of oral lesions provided valuable information on the oral epithelial thickness. CONCLUSION: This study proposes that OCT can accurately identify wide spectrum of oral tissue pathologies. Further studies can assess the role of OCT in evaluating and guiding surgical biopsies and monitoring disease.

Identification and functional validation of HPV-mediated hypermethylation in head and neck squamous cell carcinoma.

BACKGROUND: Human papillomavirus-positive (HPV+) head and neck squamous cell carcinoma (HNSCC) represents a distinct clinical and epidemiological condition compared with HPV-negative (HPV-) HNSCC. To test the possible involvement of epigenetic modulation by HPV in HNSCC, we conducted a genome-wide DNA-methylation analysis. METHODS: Using laser-capture microdissection of 42 formalin-fixed paraffin wax-embedded (FFPE) HNSCCs, we generated DNA-methylation profiles of 18 HPV+ and 14 HPV- samples, using Infinium 450 k BeadArray technology. Methylation data were validated in two sets of independent HPV+/HPV- HNSCC samples (fresh-frozen samples and cell lines) using two independent methods (Infinium 450 k and whole-genome methylated DNA immunoprecipitation sequencing (MeDIP-seq)). For the functional analysis, an HPV- HNSCC cell line was transduced with lentiviral constructs containing the two HPV oncogenes (E6 and E7), and effects on methylation were assayed using the Infinium 450 k technology. RESULTS AND DISCUSSION: Unsupervised clustering over the methylation variable positions (MVPs) with greatest variation showed that samples segregated in accordance with HPV status, but also that HPV+ tumors are heterogeneous. MVPs were significantly enriched at transcriptional start sites, leading to the identification of a candidate CpG island methylator phenotype in a sub-group of the HPV+ tumors. Supervised analysis identified a strong preponderance (87%) of MVPs towards hypermethylation in HPV+ HNSCC. Meta-analysis of our HNSCC and publicly available methylation data in cervical and lung cancers confirmed the observed DNA-methylation signature to be HPV-specific and tissue-independent. Grouping of MVPs into functionally more significant differentially methylated regions identified 43 hypermethylated promoter DMRs, including for three cadherins of the Polycomb group target genes. Integration with independent expression data showed strong negative correlation, especially for the cadherin gene-family members. Combinatorial ectopic expression of the two HPV oncogenes (E6 and E7) in an HPV- HNSCC cell line partially phenocopied the hypermethylation signature seen in HPV+ HNSCC tumors, and established E6 as the main viral effector gene. CONCLUSIONS: Our data establish that archival FFPE tissue is very suitable for this type of methylome analysis, and suggest that HPV modulates the HNSCC epigenome through hypermethylation of Polycomb repressive complex 2 target genes such as cadherins, which are implicated in tumor progression and metastasis.

Structural validation of oral mucosal tissue using optical coherence tomography.

BACKGROUND: Optical coherence tomography (OCT) is a non-invasive optical technology using near-infrared light to produce cross-sectional tissue images with lateral resolution. OBJECTIVES: The overall aims of this study was to generate a bank of normative and pathological OCT data of the oral tissues to allow identification of cellular structures of normal and pathological processes with the aim to create a diagnostic algorithm which can be used in the early detection of oral disorders. MATERIAL AND METHODS: Seventy-three patients with 78 suspicious oral lesions were referred for further management to the UCLH Head and Neck Centre, London. The entire cohort had their lesions surgically biopsied (incisional or excisional). The immediate ex vivo phase involved scanning the specimens using optical coherence tomography. The specimens were then processed by a histopathologist. Five tissue structures were evaluated as part of this study, including: keratin cell layer, epithelial layer, basement membrane, lamina propria and other microanatomical structures. Two independent assessors (clinician and pathologist trained to use OCT) assessed the OCT images and were asked to comment on the cellular structures and changes involving the five tissue structures in non-blind fashion. RESULTS: Correct identification of the keratin cell layer and its structural changes was achieved in 87% of the cohort; for the epithelial layer it reached 93.5%, and 94% for the basement membrane. Microanatomical structures identification was 64% for blood vessels, 58% for salivary gland ducts and 89% for rete pegs. The agreement was "good" between the clinician and the pathologist. OCT was able to differential normal from pathological tissue and pathological tissue of different entities in this immediate ex vivo study. Unfortunately, OCT provided inadequate cellular and subcellular information to enable the grading of oral premalignant disorders. CONCLUSION: This study enabled the creation of OCT bank of normal and pathological oral tissues. The pathological changes identified using OCT enabled differentiation between normal and pathological tissues, and identification of different tissue pathologies. Further studies are required to assess the accuracy of OCT in identification of various pathological processes involving the oral tissues.

Carcinoma cuniculatum arising in the tongue.

Carcinoma cuniculatum (CC) is a rare, distinct clinico-pathological variant of squamous cell carcinoma (SCC) that is defined histologically by the characteristic infiltrative pattern of a deep, broad, and complex proliferation of stratified squamous epithelium with keratin cores and keratin-filled crypts. Herein, we present a case report of CC of the oral tongue and discuss its diagnosis, management, and outcome, as well as briefly review the world literature. To our knowledge, this is the first documented case of CC of the tongue to be reported in the English literature. We draw attention to its clinico-pathological features and highlight that awareness of this entity as a distinct variant of SCC facilitates its correct management.

Clinicopathological parameters, recurrence, locoregional and distant metastasis in 115 T1-T2 oral squamous cell carcinoma patients.

The incidence of oral squamous cell carcinoma remains high. Oral and oro-pharyngeal carcinomas are the sixth most common cancer in the world. Several clinicopathological parameters have been implicated in prognosis, recurrence and survival, following oral squamous cell carcinoma. In this retrospective analysis, clinicopathological parameters of 115 T1/T2 OSCC were studied and compared to recurrence and death from tumour-related causes. The study protocol was approved by the Joint UCL/UCLH committees of the ethics for human research. The patients' data was entered onto proformas, which were validated and checked by interval sampling. The fields included a range of clinical, operative and histopathological variables related to the status of the surgical margins. Data collection also included recurrence, cause of death, date of death and last clinic review. Causes of death were collated in 4 categories (1) death from locoregional spread, (2) death from distant metastasis, (3) death from bronchopulmonary pneumonia, and (4) death from any non-tumour event that lead to cardiorespiratory failure. The patients' population comprised 65 males and 50 females. Their mean age at the 1st diagnosis of OSCC was 61.7 years. Two-thirds of the patients were Caucasians. Primary sites were mainly identified in the tongue, floor of mouth (FOM), buccal mucosa and alveolus. Most of the identified OSCCs were low-risk (T1N0 and T2N0). All patients underwent primary resection +/- neck dissection and reconstruction when necessary. Twenty-two patients needed adjuvant radiotherapy. Pathological analysis revealed that half of the patients had moderately differentiated OSCC. pTNM slightly differed from the cTNM and showed that 70.4% of the patients had low-risk OSCC. Tumour clearance was ultimately achieved in 107 patients. Follow-up resulted in a 3-year survival of 74.8% and a 5-year survival of 72.2%. Recurrence was identified in 23 males and 20 females. The mean age of 1st diagnosis of the recurrence group was 59.53 years. Most common oral sites included the lateral border of tongue and floor of mouth. Recurrence was associated with clinical N-stage disease. The surgical margins in this group was evaluated and found that 17 had non-cohesive invasion, 30 had dysplasia at margin, 21 had vascular invasion, 9 had nerve invasion and 3 had bony invasion. Severe dysplasia was present in 37 patients. Tumour clearance was achieved in only 8 patients. The mean depth of tumour invasion in the recurrence group was 7.6 mm.An interesting finding was that 5/11 patients who died of distant metastasis had their primary disease in the tongue. Nodal disease comparison showed that 8/10 patients who died of locoregional metastasis and 8/11 patients who died from distant metastasis had clinical nodal involvement. Comparing this to pathological nodal disease (pTNM) showed that 10/10 patients and 10/11 patients who died from locoregional and distant metastasis, respectively, had nodal disease. All patients who died from locoregional and distant metastasis were shown to have recurrence after the primary tumour resection. Squamous cell carcinoma of the oral cavity has a poor overall prognosis with a high tendency to recur at the primary site and extend to involve the cervical lymph nodes. Several clinicopathological parameters can be employed to assess outcome, recurrence and overall survival.

In vitro examination of suspicious oral lesions using optical coherence tomography.

We compared findings of optical coherence tomography (OCT) with histopathological results of suspicious oral lesions to assess the feasibility of using OCT to identify malignant tissue. Thirty-four oral lesions from 27 patients had swept-source frequency-domain OCT. Four variables were assessed (changes in keratin, epithelial, and sub-epithelial layers, and identification of the basement membrane) and from this we calculated whether or not there were architectural changes. These data were then compared with histopathological results. Two clinicians, who were unaware of the clinical and histopathological diagnoses, decided whether biopsy was necessary. The basement membrane was recognised in only 15 oral lesions. OCT could identify diseased areas but could not provide a diagnosis or differentiate between lesions. The two clinicians, who recommended biopsy agreed in all cases. This pilot study confirms the feasibility of using OCT to identify architectural changes in malignant tissues.