Narrow Band Imaging-guided resection of oral cavity cancer decreases local recurrence and increases survival

Impact of intraoperative NBI on complete resections and recurrence in oral and oropharyngeal cancer

PURPOSE

The aim of this study was to assess the number of complete resections and recurrence rates in oral and oropharyngeal squamous cell carcinoma treated with intraoperative narrow-band-imaging.

MATERIALS AND METHODS

In this observational study, superficial resection margins of oral and oropharyngeal squamous cell carcinoma were intraoperatively defined using narrow-band-imaging. The number of complete resections was assessed. Patients were followed up for at least 5 years: disease free survival and the cumulative incidence of local recurrence were recorded.

RESULTS

93 squamous cell carcinoma were considered. Surgical resection was complete in 84.9 % of cases. The 5-years disease free survival was 76.2 % (95%CI: 67.1 %-84.4 %). Cumulative incidence of local recurrence was 9.7 % (95%CI: 4.7 %-16.7 %), lower compared to previous literature: it was higher in patients over 68 years (14.3 %, 95%CI: 6.2 %-25.6 % vs 4.5 %, 95%CI: 0.8 %-13.8 %) although without statistically significance.

CONCLUSIONS

In oral and oropharyngeal squamous cell carcinoma surgery, narrow-band imaging is a valuable tool for accurately identifying the true superficial extent of the tumor, facilitating complete resection and potentially reducing local recurrence.

New IPCL Classification Using NBI for Early Detection of OPMDs Malignant Transformation

OBJECTIVES

Introduce a new intrapapillary capillary loop (IPCL) classification using narrow-band imaging (NBI) to diagnose early malignant transformation in oral potentially malignant disorders (OPMDs).

METHODS

In the exploratory phase, NBI images from 241 patients with OPMDs and oral squamous cell carcinoma (OSCC) were assessed for three basic IPCL features-dilation, unevenness, and tortuosity-to identify patterns associated with OPMDs malignant transformation. Chi-square analysis and logistic regression differentiated these patterns between low-risk (no/mild dysplasia) and high-risk (moderate/severe dysplasia, invasive carcinoma) lesions, establishing a new classification system. In the validation phase, the system was applied to 90 patients with histopathological results confirming diagnostic accuracy.

RESULTS

Four distinct IPCL types were identified: normal, dilated, irregular, and chaotic, with increasing odds ratios for high-risk lesions. The ROC curve had an AUC of 0.913, with irregular and chaotic types providing the best diagnostic performance, achieving sensitivities and specificities of 84.2% and 88.4%, respectively. In the validation phase, the new classification achieved an overall diagnostic accuracy of 84.4% and substantial inter-observer consistency (κ = 0.694).

CONCLUSION

The new IPCL classification effectively identifies high-risk oral lesions, enhancing the diagnostic utility of NBI for early detection of OPMDs malignant transformations.

Recent advances of photodiagnosis and treatment for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) are the most common type of head and neck tumor that severely threatens human health due to its highly aggressive nature and susceptibility to distant metastasis. The diagnosis of HNSCC currently relies on biopsy and histopathological examination of suspicious lesions. However, the early mucosal changes are subtle and difficult to detect by conventional oral examination. As for treatment, surgery is still the primary treatment modality. Due to the complex anatomy and the lack of intraoperative modalities to accurately determine the incision margins, surgeons are in a dilemma between extensive tumor removal and improving the quality of patient survival. As more knowledge is gained about HNSCC, the increasing recognition of the value of optical imaging has been emphasized. Optical technology offers distinctive possibilities for early preoperative diagnosis, intraoperative real-time visualization of tumor margins, sentinel lymph node biopsies, phototherapy. Fluorescence imaging, narrow-band imaging, Raman spectroscopy, optical coherence tomography, hyperspectral imaging, and photoacoustic imaging have been reported for imaging HNSCC. This article provides a comprehensive overview of the fundamental principles and clinical applications of optical imaging in the diagnosis and treatment of HNSCC, focusing on identifying its strengths and limitations to facilitate advancements in this field.

PSMA2 promotes chemo- and radioresistance of oral squamous cell carcinoma by modulating mitophagy pathway

Oral cavity squamous cell carcinoma (OSCC) represents the most prevalent malignancy among head and neck squamous cell carcinomas (HNSCCs). Standard treatment modalities include surgical resection combined with radiation and chemotherapy. However, locoregional failure remains a critical issue affecting the prognosis of OSCC patients, largely due to tumor resistance against radiation or chemotherapy. In this study, we established a gene database related to OSCC recurrence and identified PSMA2 as a novel molecule influencing prognosis in OSCC patients. An independent Taiwanese cohort confirmed that elevated PSMA2 transcript levels were associated with poorer prognosis and contributed to the chemo- and radioresistance phenotype in OSCC. Furthermore, we confirmed that PSMA2 regulates cell cycle, mitochondrial dysfunction, and mitophagy, thereby contributing to carcinogenesis and resistance. Notably, mitophagy inducer exhibit antitumor effects in PSMA2-overexpressing OSCC xenograft mouse model. Collectively, our results provide a mechanistic understanding of the atypical function of PSMA2 in promoting OSCC recurrence.

Narrow band imaging in oral cancer did not improve visualisation of the tumour borders: a prospective cohort study

BACKGROUND

In oral cancers, tumour borders are typically defined by white light (WL). Narrow-band imaging (NBI) is an optical endoscopic technique commonly used for the larynx and for cancers of unknown primary. However, evidence for using NBI in oral cancers is insufficient.

AIMS/OBJECTIVES

We investigated whether NBI is a better predictor of the true mucosal tumour borders than WL in oral cancers. Additionally, we examined the agreement between NBI-based Takano intrapapillary capillary loop classifications and pathology reports.

MATERIALS AND METHODS

In this prospective study, the tumour borders were assessed by both NBI and WL at the time of surgical resection and then compared. Pathology reports of the examined areas were used as gold standard.

RESULTS

Forty-nine participants were included. After exclusion of 15 patients due to missing data, 34 were included in analyses. In 26.5% of the assessments, the tumour borders defined by NBI were outside the borders defined by WL. However, 55.5% of these were false-positives.

CONCLUSIONS AND SIGNIFICANCE

The delineation of mucosal tumour borders in oral cancers by NBI was not better than that by WL in this study. Several methodological challenges may have influenced the findings of this study, similar to the limitations reported in previous studies.

What's behind Margin Status in Oral Cancer?

In the 2nd century AD, Galen argued that the failure to remove any single 'root' of a malignant tumor could result in a local relapse. After nearly 2 millennia, this problem appears to be even more challenging due to our increased understanding of the complexity of tumor formation and spread. Pathological analysis of tumor margins under a microscope remains the primary and only accepted method for confirming the complete tumor removal. However, this method is not an all-or-nothing test, and it can be compromised by various intrinsic and extrinsic limitations. Among the intrinsic limitations of pathological analysis we recall the pathologist handling, tissue shrinkage, the detection of minimal residual disease and the persistence of a precancerous field. Extrinsic limitations relate to surgical tools and their thermal damage, the different kinds of surgical resections and frozen sections collection. Surgeons, as well as oncologists and radiotherapists, should be well aware of and deeply understand these limitations to avoid misinterpretation of margin status, which can have serious consequences. Meanwhile, new technologies such as Narrow band imaging have shown promising results in assisting with the achievement of clear superficial resection margins. More recently, emerging techniques like Raman spectroscopy and near-infrared fluorescence have shown potential as real-time guides for surgical resection. The aim of this narrative review is to provide valuable insights into the complex process of margin analysis and underscore the importance of interdisciplinary collaboration between pathologists, surgeons, oncologists, and radiotherapists to optimize patient outcomes in oral cancer surgery.

Narrow-band imaging features of oral lichenoid conditions: A multicentre retrospective study

OBJECTIVE

Narrow-band imaging (NBI), which highlights epithelial intrapapillary capillary loops (IPCLs) classified into five patterns (0 toIV) with increasing correlation to malignancy, has demonstrated effectiveness for detection of oral squamous cell carcinoma (OSCC). Lack of standardised procedures limits its use for routine inspection of oral lichenoid lesions including oral lichen planus (OLP), oral lichenoid lesion (OLL) and oral lichenoid reaction (OLR). The aim of this study was to analyse IPCL patterns of such lesions, assessing correlations with histopathological outcomes.

MATERIALS AND METHODS

A multicentre, retrospective study was performed on 84 patients who underwent NBI and subsequent biopsy for suspected OLP/OLL/OLR. Patients were examined with Evis Exera III NBI system. Recorded NBI video endoscopies were evaluated to assess IPCL patterns and correlated with histopathological outcomes.

RESULTS

No significant differences were detected among OLP/OLL/OLR on NBI inspection. All lichenoid lesions were significantly related to low-grade (0-II) IPCL patterns, clearly distinguishable from OSCC, showing pattern IV (p < 0.05).

CONCLUSIONS

NBI cannot discern among OLP/OLL/OLR lesions. Interpretation should be modulated when assessing lichenoid lesions. NBI has potential to discern malignant transformation occurring in lichenoid lesions undergoing long-term follow-up, as IPCL pattern IV may be used as a clinical marker of malignancy arising in chronic inflammatory lesions.

Comparison of narrow band and fluorescence molecular imaging to improve intraoperative tumour margin assessment in oral cancer surgery

OBJECTIVE

New techniques have emerged to aid in preventing inadequate margins in oral squamous cell carcinoma (OSCC) surgery, but studies comparing different techniques are lacking. Here, we compared narrow band imaging (NBI) with fluorescence molecular imaging (FMI), to study which intraoperative technique best assesses the mucosal tumour margins.

MATERIALS AND METHODS

NBI was performed in vivo and borders were marked with three sutures. For FMI, patients received 75 mg of unlabelled cetuximab followed by 15 mg cetuximab-800CW intravenously-two days prior to surgery. The FMI borders were defined on the excised specimen. The NBI borders were correlated with the FMI outline and histopathology.

RESULTS

Sixteen patients were included, resulting in 31 NBI and 30 FMI measurements. The mucosal border was delineated within 1 mm of the tumour border in 4/31 (13 %) of NBI and in 16/30 (53 %) FMI cases (p = 0.0008), and within 5 mm in 23/31 (74 %) of NBI and in 29/30 (97 %) of FMI cases (p = 0.0048). The median distance between the tumour border and the imaging border was significantly greater for NBI (3.2 mm, range -6.1 to 12.8 mm) than for FMI (0.9 mm, range -3.0 to 7.4 mm; p = 0.028). Submucosal extension and previous irradiation reduced NBI accuracy.

CONCLUSION

Ex vivo FMI performed more accurately than in vivo NBI in mucosal margin assessment, mainly because NBI cannot detect submucosal extension. NBI adequately identified the mucosal margin especially in early-stage and not previously irradiated tumours, and may therefore be preferable in these tumours for practical and cost-related reasons.

Transcriptomic Biomarker Signatures for Discrimination of Oral Cancer Surgical Margins

Relapse after surgery for oral squamous cell carcinoma (OSCC) contributes significantly to morbidity, mortality and poor outcomes. The current histopathological diagnostic techniques are insufficiently sensitive for the detection of oral cancer and minimal residual disease in surgical margins. We used whole-transcriptome gene expression and small noncoding RNA profiles from tumour, close margin and distant margin biopsies from 18 patients undergoing surgical resection for OSCC. By applying multivariate regression algorithms (sPLS-DA) suitable for higher dimension data, we objectively identified biomarker signatures for tumour and marginal tissue zones. We were able to define molecular signatures that discriminated tumours from the marginal zones and between the close and distant margins. These signatures included genes not previously associated with OSCC, such as MAMDC2, SYNPO2 and ARMH4. For discrimination of the normal and tumour sampling zones, we were able to derive an effective gene-based classifying model for molecular abnormality based on a panel of eight genes (MMP1, MMP12, MYO1B, TNFRSF12A, WDR66, LAMC2, SLC16A1 and PLAU). We demonstrated the classification performance of these gene signatures in an independent validation dataset of OSCC tumour and marginal gene expression profiles. These biomarker signatures may contribute to the earlier detection of tumour cells and complement existing surgical and histopathological techniques used to determine clear surgical margins.

A Systematic Review of Oral Biopsies, Sample Types, and Detection Techniques Applied in Relation to Oral Cancer Detection

Background: Early identification of the stage of oral cancer development can lead to better treatment outcomes and avoid malignant transformation. Therefore, this review aims to provide a comprehensive overview that describes the development of standardized procedures for oral sample collection, characterization, and molecular risk assessment. This can help investigators to choose the appropriate sampling method and downstream analyses for different purposes. Methods: This systematic review was conducted according to the PRISMA guidelines. Using both PubMed and Web of Science databases, four independent authors conducted a literature search between 15 and 21 June 2021. We used key search terms to broaden the search for studies. Non-conforming articles were removed using an EndNote-based and manual approach. Reviewers used a designed form to extract data. Results: This review included a total of 3574 records, after eliminating duplicate articles and excluding papers that did not meet the inclusion criteria. Finally, 202 articles were included in this review. We summarized the sampling methods, biopsy samples, and downstream analysis. The biopsy techniques were classified into tissue and liquid biopsy. The common sequential analysis of tissue biopsy includes histopathological examination such as H&E or IHC to identify various pathogenic features. Meanwhile, liquid samples such as saliva, blood, and urine are analyzed for the purpose of screening to detect mutations in cancer. Commonly used technologies are PCR, RT-PCR, high-throughput sequencing, and metabolomic analysis. Conclusions: Currently, tissue biopsies provide increased diagnostic value compared to liquid biopsy. However, the minimal invasiveness and convenience of liquid biopsy make it a suitable method for mass screening and eventual clinical adoption. The analysis of samples includes histological and molecular analysis. Metabolite analysis is rising but remains scarce.

Techniques, Tricks, and Stratagems of Oral Cavity Computed Tomography and Magnetic Resonance Imaging

The oral cavity constitutes a complex anatomical area that can be affected by many developmental, inflammatory, and tumoural diseases. MultiSlice Computed Tomography (MSCT) and Magnetic Resonance Imaging (MRI) currently represent the essential and complementary imaging techniques for detecting oral cavity abnormalities. Advanced MRI with diffusion-weighted imaging (DWI) and dynamic contrast-enhanced perfusion-weighted imaging (DCE-PWI) has recently increased the ability to characterise oral lesions and distinguish disease recurrences from post therapy changes. The analysis of the oral cavity area via imaging techniques is also complicated both by mutual close appositions of different mucosal surfaces and metal artifacts from dental materials. Nevertheless, an exact identification of oral lesions is made possible thanks to dynamic manoeuvres and specific stratagems applicable on MSCT and MRI acquisitions. This study summarises the currently available imaging techniques for oral diseases, with particular attention to the role of DWI, DCE-PWI, and dynamic manoeuvres. We also propose MSCT and MRI acquisition protocols for an accurate study of the oral cavity area.

SNHG15 facilitated malignant behaviors of oral squamous cell carcinoma through targeting miR-188-5p/DAAM1

BACKGROUND

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 15 (SNHG15) has been discovered and demonstrated to have significant function in multiple cancers. Nevertheless, how it participates in the progression of oral squamous cell carcinoma (OSCC) and its potential regulatory system are still unclear.

METHODS

RT-qPCR detected the expression of SNHG15, miR-188-5p, and DAAM1. RNA pull down, RT-qPCR, and bioinformatics were used for finding and selecting downstream targets of SNHG15.

RESULTS

SNHG15 presented a high expression in OSCC cells. Moreover, inhibition of SNHG15 exhibited repressive influence on proliferative, migrated, and invasive abilities but induce apoptosis of OSCC cells. Through the search of bioinformatics and RNA pull down assays, we confirmed that miR-188-5p was one target of SNHG15 in OSCC cells. Additionally, miR-188-5p could hamper the growth of OSCC cells. Moreover, it was manifested that DAAM1 was down-regulated by miR-188-5p. DAAM1 was up-regulated in OSCC cells. Furthermore, it exerted oncogenic function in the course of OSCC. Eventually, overexpression of DAAM1 offsets the effects of down-regulation of SNHG15 on the development of OSCC.

CONCLUSION

To summarize, our study certified that SNHG15 contributed to the process of OSCC via sponging miR-188-5p to elevate DAAM1 expression. SNHG15 might offer novel sight to improve the results of treatment for OSCC.

Endoscopic-Assisted Oropharyngectomy for Early Oropharyngeal Cancer in Trismus Patients

Objective: Management of the early-stage oropharyngeal carcinoma in trismus patients underlying with multiple head and neck cancer history is a clinical challenge because minimal invasive surgery such as transoral robotic surgery or transoral laser microsurgery is contraindicated, while open surgery or concurrent chemoradiation (CCRT) wound cause long-term adverse effect. Therefore, we developed a novel endoscopic surgical approach for these patients. Methods: Four patients were enrolled for endoscopic-assisted oropharyngectomy. The oropharyngeal tumor was resected with an adequate margin via a one-surgeon bimanual approach with the aid of a high-resolution videoendoscopic system, scope holder, and designed surgical instruments. The postoperative surgical margin status, trismus status, perioperative complication, average hospital stay, and follow-up period were recorded. Results: The endoscopic-assisted oropharyngectomy was successfully applied in all 4 patients with en bloc tumor excision and adequate free margin status. The mean hospital stay was 6.5 days, and all patients could tolerate oral diet within 2 weeks. There was no perioperative complication noted. No tumor recurrence was identified in patients followed up 2 years after surgery. Conclusion: Endoscopic-assisted oropharyngectomy for patients with trismus and multiple head and neck cancer history is a safe, minimal invasive, and effective treatment choice other than open surgery or CCRT. It provides a safe option for patients with limited mouth opening.

Narrow-Band Imaging in oncologic otorhinolaryngology: State of the art

OBJECTIVES

To describe the diagnostic performance of Narrow Band Imaging (NBI) combined with White Light Imaging (WLI) in the diagnosis of mucosal lesions at each location of the upper aerodigestive tract, for detection of primary tumor in case of carcinoma of unknown primary, for determination of intraoperative resection margins, and to describe its main diagnostic pitfalls.

MATERIAL AND METHODS

A PubMed search was carried out according to the PRISMA method.

RESULTS

Four hundred and seventy-seven articles published between 2007 and 2020 were identified, 133 of which met the study inclusion criteria and were assessed.

CONCLUSION

The current literature seems to support the use of NBI in diagnosis and/or follow-up of (pre-)malignant head & neck tumors, and in the determination of intraoperative resection margins.

Evaluating Laryngopharyngeal Tumor Extension Using Narrow Band Imaging Versus Conventional White Light Imaging

OBJECTIVE/HYPOTHESIS

Comparing detection and extension of malignant tumors by flexible laryngoscopy in the outpatient setting with laryngoscopy under general anesthesia using both White Light Imaging (WLI) and Narrow Band Imaging (NBI).

STUDY DESIGN

Prospective study.

METHODS

Two hundred and thirty-three patients with laryngeal and pharyngeal lesions underwent flexible and rigid laryngoscopy, with both WLI and NBI. Extension of malignant lesions (n = 132) was compared between both techniques in detail.

RESULTS

Sensitivity of NBI during flexible endoscopy (92%), was comparable with that of WLI during rigid endoscopy (91%). The correlation of tumor extension between flexible and rigid laryngoscopy was high (r_s  = 0.852-0.893). The observed tumor extension was significantly larger when using NBI in both settings. The use of NBI during flexible laryngoscopy leads to upstaging (12%) and downstaging (2%) of the T classification.

CONCLUSIONS

NBI during flexible laryngoscopy could be an alternative to WLI rigid endoscopy. NBI improves visualization of tumor extension and accuracy of T staging.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E2222-E2231, 2021.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

Is Lugol necessary for endoscopic resection of esophageal squamous cell neoplasia?

Background and study aims  Recent evidence suggests that lugol chromoendoscopy (LCE) and narrow-band imaging (NBI) have comparable sensitivity for detection of superficial esophageal squamous cell carcinoma (SCC). However, LCE is time-consuming and associated with side effects. The aim of this study was to compare the effectiveness of NBI and LCE in defining resection margins of esophageal SCC. Patients and methods  This was a retrospective observational cohort study of patients with esophageal SCC and dysplasia who underwent en-bloc resection between 1999 and 2017 at the Cliniques universitaires Saint-Luc, Brussels. Two groups were defined: 1) inspection with NBI only; and 2) inspection with LCE (with or without NBI). The primary endpoint was complete lateral resection rate. Multivariate regression was used to adjust for potential confounders. Results  A total of 102 patients with 132 lesions were included. Lesions were inspected with LCE in 52 % (n = 68) and with NBI only in 48 % (n = 64). Lesions 0-IIa were more frequent in the NBI group (37 %) and 0-IIb (60 %) in LCE. Lesion location, size, and histology and resection technique (endoscopic submucosal dissection in 122/132 cases, 92 %) were similar between the groups. The rate of complete lateral resection for invasive carcinoma was 90 % in LCE group and 94 % in NBI group ( P  = 0.498) and 65 % and 67 % ( P  = 0.813), respectively, for dysplasia complete lateral resection. These results remained non-significant after adjusting for potential confounders. Conclusions  Mucosal inspection and delineation of tumors with lugol chromoendoscopy before endoscopic resection of esophageal squamous cell lesions was not associated with increased complete lateral resection rate when compared to NBI.

CD147 promotes proliferation and migration of oral cancer cells by inhibiting junctions between E-cadherin and β-catenin

BACKGROUND

Although association between oral squamous cell carcinoma (OSCC) with epithelial-mesenchymal transition (EMT) has been demonstrated, we found CD147, one transmembrane protein we previously studied in oral submucous fibrosis, was correlated with E-cadherin, one marker of EMT. Here, we investigated CD147 expression in the different stages of OSCC and assessed its association with epithelial-mesenchymal transition (EMT).

MATERIALS AND METHODS

CD147 and E-cadherin expression in tissue microarrays containing 48 OSCC specimens and matched adjacent tissues was analysed using immunohistochemistry. CD147 was overexpressed or knocked down using exogenous cloning vector and RNA interference, respectively, in OSCC cell lines. Cell proliferation and migration were measured using the CCK8 assay and scratch test, respectively. The expression and localization of EMT-associated proteins was analysed by Western blotting and immunofluorescence.

RESULTS

CD147 expression in OSCC tissues was significantly higher than that in adjacent tissues and was markedly higher in cancer tissues with metastasis (P < .05). CD147 expression showed significant negative correlation with E-cadherin expression. CD147 overexpression downregulated E-cadherin and inhibited its complex with β-catenin and then upregulated N-cadherin and vimentin. Additionally, alterations in CD147 protein expression affected proliferation and migration ability in OSCC cells and were related to β-catenin nuclear translocation.

CONCLUSION

CD147 plays an important role in tumorigenesis and metastasis by promoting EMT progression in OSCC. It may be considered as a novel potential diagnostic and therapeutic target for OSCC.

Gene expression analysis of autofluorescence margins in leukoplakia and oral carcinoma: A pilot study

OBJECTIVES

Autofluorescence is considered a useful technique in the early detection of oral mucosal alterations. However, its efficacy to discriminate tumor margins is still under debate. The purpose of this pilot study was to confirm the existence of molecular divergence from the center of a lesion compared to white light and autofluorescence (VELscope^TM ) visualized margins in leukoplakia and oral carcinoma.

MATERIALS AND METHODS

Molecular divergence from the center of the lesion to white light and VELscope^TM defined margins was compared in patients with leukoplakia (n = 3) and oral carcinoma (n = 4). Expression profiling of 45 selected genes was performed through custom-made TaqMan arrays. Gene Ontology was used for biological pathway analysis.

RESULTS

Irrespective of pathology, the greatest molecular divergence existed between the center of the lesion and both white light and VELscope^TM margins. VELscope^TM and white light margins were also molecularly distinct in oral carcinoma samples. Indeed, the white light margin retained molecular abnormalities observed in the center of the lesion thus suggesting the existence of a "partially transformed" cell population.

CONCLUSION

Despite the limited low number of patients, our data confirm the benefit of combining autofluorescence with conventional oral examination in identifying surgical margins during biopsy procedures for leukoplakia and oral carcinoma.

Hyperspectral Imaging of Head and Neck Squamous Cell Carcinoma for Cancer Margin Detection in Surgical Specimens from 102 Patients Using Deep Learning

Surgical resection of head and neck (H and N) squamous cell carcinoma (SCC) may yield inadequate surgical cancer margins in 10 to 20% of cases. This study investigates the performance of label-free, reflectance-based hyperspectral imaging (HSI) and autofluorescence imaging for SCC detection at the cancer margin in excised tissue specimens from 102 patients and uses fluorescent dyes for comparison. Fresh surgical specimens (n = 293) were collected during H and N SCC resections (n = 102). The tissue specimens were imaged with reflectance-based HSI and autofluorescence imaging and afterwards with two fluorescent dyes for comparison. A histopathological ground truth was made. Deep learning tools were developed to detect SCC with new patient samples (inter-patient) and machine learning for intra-patient tissue samples. Area under the curve (AUC) of the receiver-operator characteristic was used as the main evaluation metric. Additionally, the performance was estimated in mm increments circumferentially from the tumor-normal margin. In intra-patient experiments, HSI classified conventional SCC with an AUC of 0.82 up to 3 mm from the cancer margin, which was more accurate than proflavin dye and autofluorescence (both p < 0.05). Intra-patient autofluorescence imaging detected human papilloma virus positive (HPV+) SCC with an AUC of 0.99 at 3 mm and greater accuracy than proflavin dye (p < 0.05). The inter-patient results showed that reflectance-based HSI and autofluorescence imaging outperformed proflavin dye and standard red, green, and blue (RGB) images (p < 0.05). In new patients, HSI detected conventional SCC in the larynx, oropharynx, and nasal cavity with 0.85-0.95 AUC score, and autofluorescence imaging detected HPV+ SCC in tonsillar tissue with 0.91 AUC score. This study demonstrates that label-free, reflectance-based HSI and autofluorescence imaging methods can accurately detect the cancer margin in ex-vivo specimens within minutes. This non-ionizing optical imaging modality could aid surgeons and reduce inadequate surgical margins during SCC resections.

Hyperspectral imaging for head and neck cancer detection: specular glare and variance of the tumor margin in surgical specimens

Head and neck squamous cell carcinoma (SCC) is primarily managed by surgical cancer resection. Recurrence rates after surgery can be as high as 55%, if residual cancer is present. Hyperspectral imaging (HSI) is evaluated for detection of SCC in ex-vivo surgical specimens. Several machine learning methods are investigated, including convolutional neural networks (CNNs) and a spectral-spatial classification framework based on support vector machines. Quantitative results demonstrate that additional data preprocessing and unsupervised segmentation can improve CNN results to achieve optimal performance. The methods are trained in two paradigms, with and without specular glare. Classifying regions that include specular glare degrade the overall results, but the combination of the CNN probability maps and unsupervised segmentation using a majority voting method produces an area under the curve value of 0.81 [0.80, 0.83]. As the wavelengths of light used in HSI can penetrate different depths into biological tissue, cancer margins may change with depth and create uncertainty in the ground truth. Through serial histological sectioning, the variance in the cancer margin with depth is investigated and paired with qualitative classification heat maps using the methods proposed for the testing group of SCC patients. The results determined that the validity of the top section alone as the ground truth may be limited to 1 to 2 mm. The study of specular glare and margin variation provided better understanding of the potential of HSI for the use in the operating room.

The economic burden of oral squamous cell carcinoma in Australia

OBJECTIVES

The financial burden of treatment for oral squamous cell carcinoma in Australia has never been reported, and there is a paucity of international data. Here, we report the direct costs of treatment of surgically resectable oral cancer in a tertiary public hospital in Australia over a 15-year period.

MATERIALS AND METHODS

Pathology department records, records of hospital attendance and hospital finance department records were interrogated to determine the direct costs of inpatient and outpatient treatment. Costs were adjusted using the total health price index so that all costs were equivalent to costings for the 2016/2017 financial year.

RESULTS

A total of 113 cases were identified as suitable for inclusion. Complete inpatient and outpatient hospital attendance and costing data for treatment and subsequent 2-year follow-up was available for 29 cases. The average total cost over the 2-year period was $92 958AUD (median $102 722, range $11 662-$181 512). On average, 92.8% of costs were incurred in the first year post-diagnosis. Inpatient costs, outpatient costs and total costs increased with increasing pathological cancer stage. Both 1- and 2-year post-diagnosis overall cost for patients with Stage 4 oral cavity cancer were more than two times greater than for patients with Stage 1 oral cancer.

CONCLUSION

It is well documented that patients diagnosed at an earlier stage will have better survival outcomes, and it is assumed that the economic burden of their treatment will be less. We have shown that there is a direct correlation between cancer stage and cancer treatment cost. The findings provide clear economic support for oral cancer screening initiatives to detect earlier stage cancers, and the need to investigate novel techniques and technologies to detect oral squamous cell carcinoma early and reduce recurrence and mortality rates.

Surgical margins in oral squamous cell cancer: intraoperative evaluation and prognostic impact

PURPOSE OF REVIEW

To summarize recent findings regarding surgical management of oral squamous cell cancer (OSCC) through analysis of different intraoperative techniques for assessment of margins, evaluate the pros and cons of each, and ensuing prognostic impact.

RECENT FINDINGS

'En bloc' OSCC resection and histopathologic evaluation of margins on the formalin-fixed specimen remain the 'gold standard' for oral oncologic surgery, whereas assessment of intraoperative surgical margins and its overall clinical value are still questioned and debated in the literature. The commonly applied evaluation of frozen sections still raises concerns regarding its efficacy and reproducibility; therefore, several ancillary diagnostic methods have entered the field of head and neck oncology in the last decades, aiming to support the surgeon in achieving tumor-free margins during ablative procedures.

SUMMARY

Poor prognosis of OSCC is strongly associated with residual tumor after surgery. Negative surgical margins are one of the strongest prognosticators for disease-free survival and locoregional control, but their intraoperative determination seems still to be suboptimal and needs better refinement. The most studied techniques to assess intraoperative margins include fluorescence, Raman spectroscopy, narrow band imaging, optical coherence tomography, and cytological bone margins analysis; each has its unique characteristics that are described in detail herein.

Oral lichen planus and other confounding factors in narrow band imaging (NBI) during routine inspection of oral cavity for early detection of oral squamous cell carcinoma: a retrospective pilot study

Background

Narrow Band Imaging is a noninvasive optical diagnostic tool. It allows the visualization of sub-mucosal vasculature; four patterns of shapes of submucosal capillaries can be recognized, increasingly associated with neoplastic transformation. With such characteristics, it has showed high effectiveness for detection of Oral Squamous Cell Carcinoma. Still, scientific literature highlights several bias/confounding factors, such as Oral Lichen Planus. We performed a retrospective observational study on patients routinely examined with Narrow Band Imaging, investigating for bias, confounding factors and conditions that may limit its applicability.

Methods

Age, sex, smoking, use of dentures, history of head & neck radiotherapy, history of Oral Squamous Cell Carcinoma, site of the lesion and thickness of the epithelium of origin were statistically evaluated as possible bias/confounding factors. Pearson’s Chi-squared test, multivariate logistic regression, Positive Predictive Value, Negative Predictive Value, Sensitivity, Specificity, Positive Likelihood Ratio, Negative Likelihood Ratio and accuracy were calculated, normalizing the cohort with/without patients affected by Oral Lichen Planus, to acknowledge its role as bias/confounding factor.

Results

Five hundred fifty-six inspections were performed on 106 oral cavity lesions from 98 patients. Age, sex, smoking, use of dentures and anamnesis of Oral Squamous Cell Carcinoma were not found to influence Narrow Band Imaging. History of head & neck radiotherapy was not assessed due to insufficient sample. Epithelium thickness does not seem to interfere with feasibility. Presence of Oral Lichen Planus patients in the cohort led to false positives but not to false negatives. Among capillary patterns, number IV was the most significantly associated to Oral Squamous Cell Carcinoma (p < 0.001), not impaired by the presence of Oral Lichen Planus patients in the cohort (accuracy: 94.3, 95% confidence interval: 88.1–97.9%; odds ratio: 261.7, 95% confidence interval: 37.7–1815.5).

Conclusion

Narrow Band Imaging showed high reliability in detection of Oral Squamous Cell Carcinoma in a cohort of patients with oral cavity lesions not normalized for bias/confounding factors. Still, Oral Lichen Planus may lead to false positives. Narrow Band Imaging could help in the follow-up of patients with multiple lesions through detection of capillary pattern IV, which seems to be the most significantly associated to neoplastic epithelium.

Surgical margins in oral cavity squamous cell carcinoma: Current practices and future directions

OBJECTIVE

To discuss the current available techniques for intraoperative margin assessment in the surgical treatment of oral squamous cell carcinoma (OSCC) through a review of the available literature.

METHODS

A systematic review was undertaken of the available English literature between 2008 through 2018 regarding surgical margins in OCSS. A total of 893 relevant articles were returned; 144 met criteria for review; and 64 articles were included.

RESULTS

In this review, we discuss the data surrounding the use of frozen section in OCSS. Additionally, alternative techniques for margin assessment are discussed, including Mohs, molecular analysis, nonfluorescent dyes, fluorescent dyes, autofluorescent imaging, narrow-band imaging, optical coherence tomography, confocal microscopy, high-resolution microendoscopy, and spectroscopy. For each technique, particular emphasis is placed on the local recurrence, disease-free survival, and overall survival rates when available.

CONCLUSION

This review provides support for the practice of specimen-driven margin assessment when using frozen section analysis to improve the utility of the results. Finally, several alternatives for intraoperative margin assessment currently under investigation, including pathologic, wide-field imaging and narrow-field imaging techniques, are presented. We aim to fuel further investigation into methods for margin assessment that will improve survival for patients with OSCC through a critical analysis of the available techniques.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:128-138, 2020.