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

Chaperonin containing TCP1 subunit 6A may activate Notch and Wnt pathways to facilitate the malignant behaviors and cancer stemness in oral squamous cell carcinoma

Chaperonin containing TCP1 subunit 6A (CCT6A) was recently discovered to be involved in cancer pathogenesis and stemness; however, its role in oral squamous cell carcinoma (OSCC) has not been reported. The current study aimed to investigate the impact of CCT6A on OSCC cell malignant behaviors and stemness and to explore its potentially interreacted pathways. SCC-15 and HSC-3 cells were transfected with the plasmid loading control overexpression, CCT6A overexpression, control knockout, or CCT6A knockout. Wnt4 overexpression or Notch1 overexpression plasmids were transfected into CCT6A-knockout SCC-15 cells. Cell proliferation, apoptosis, invasion, stemness, Notch, and Wnt pathways were detected in both cell lines, whereas RNA sequencing was only performed in SCC-15 cells. CCT6A was upregulated in five OSCC cell lines, including SCC-15, HSC-3, SAT, SCC-9, and KON, compared to that in the control cell line. In SCC-15 and HSC-3 cells, CCT6A overexpression increased cell proliferation, invasion, sphere formation, CD133, and Sox2 expression, but decreased cell apoptosis; on the contrary, CCT6A knockout exhibited an opposite effect on the above indexes. RNA-sequencing data revealed that the Wnt and Notch pathways were involved in the CCT6A'effect on SCC-15 cell functions. CCT6A positively regulates the Wnt and Notch pathways in SCC-15 and HSC-3 cells. Importantly, it was shown that activation of the Wnt or Notch pathways attenuated the effect of CCT6A knockout on SCC-15 cell survival, invasion, and stemness. CCT6A may promote OSCC malignant behavior and stemness by activating the Wnt and Notch pathways.

Enhancing Oral Cancer Detection: A Systematic Review of the Diagnostic Accuracy and Future Integration of Optical Coherence Tomography with Artificial Intelligence

Introduction: Optical Coherence Tomography (OCT) has emerged as an important imaging modality in non-invasive diagnosis for oral cancer and can provide real-time visualisation of tissue morphology with the required high resolution. This systematic review aims to assess the diagnostic accuracy of OCT in the detection of oral cancers, and to explore the potential integration of OCT with artificial intelligence (AI) and other imaging techniques to enhance diagnostic precision and clinical outcomes in oral healthcare. Methods: A systematic literature search was conducted across PubMed, Embase, Scopus, Google Scholar, Cochrane Central Register, and Web of Science from inception until August 2024. Studies were included if they employed OCT for oral cancer detection, reported diagnostic outcomes, such as sensitivity and specificity, and were conducted on human subjects. Data extraction and quality assessment were performed independently by two reviewers. The synthesis highlights advancements in OCT technology, including AI-enhanced interpretations. Results: A total of 9 studies met the inclusion criteria, encompassing a total of 860 events (cancer detections). The studies spanned from 2008 to 2022 and utilised various OCT techniques, including clinician-based, algorithm-based, and AI-driven interpretations. The findings indicate OCT's high diagnostic accuracy, with sensitivity ranging from 75% to 100% and specificity from 71% to 100%. AI-augmented OCT interpretations demonstrated the highest accuracy, emphasising OCT's potential in early cancer detection and precision in guiding surgical interventions. Conclusions: OCT could play a very prominent role as a new diagnostic tool for oral cancer, with very high sensitivity and specificity. Future research pointed towards integrating OCT with other imaging methods and AI systems in providing better accuracy of diagnoses, plus more clinical usability. Further development and validation with large-scale multicentre trials is imperative for the realisation of this potential in changing the way we practice oral healthcare.

Initial negative resection margin versus revised negative resection margin in patients who underwent surgery without adjuvant therapy for early-stage oral tongue squamous cell carcinoma

BACKGROUND

In cases of positive resection margin (RM), re-resection is generally recommended. There has been controversy about the oncologic impact of revised negative RMs after re-resection. The aim of this study was to investigate the oncologic impact of revised negative RM in patients who underwent surgery without adjuvant therapy for early-stage (pT1-2/N0) oral tongue squamous cell carcinoma (OSCC).

METHODS

We retrospectively analyzed patients with pT1-2 N0 OSCC who did not receive adjuvant therapy (N=441). These patients were classified into an initial negative RM (R0, n = 380) group and a revised negative RM (R1-R0, n = 61) group. Demographic and clinical data (T stage, tumor length, depth of invasion [DOI], lymphovascular invasion [LVI], perineural invasion [PNI], and recurrence) were compared between the R0 and R1-R0 groups.

RESULTS

Age, sex, T stage, DOI, LVI, PNI, and SUVmax were not significantly different between the two groups. Local recurrence was more frequent (P=0.045) in the R1-R0 group (13.1 %) than in the R0 group (5.5 %). Local recurrence-free survival was better in the R0 group than in the R1-R0 group (P=0.046). There was no significant difference in overall recurrence or overall survival. On multivariate analysis, initial positive RM was the independent significant risk factor (hazard ratio, 2.249; 95 % confidence interval, 1.025-4.935; P=0.043) for local recurrence.

CONCLUSION

A revised clear RM after initial cut-through margin is a risk factor for local recurrence in early-stage OSCC. Cautious should be considered in early-stage OSCC patients with revised clear RM.

Rethinking Surgical Margins: A New Approach to Predict Outcomes in Oral Squamous Cell Carcinoma

OBJECTIVE

The traditional categorical division of surgical margins using a 5 mm cutoff in oral cavity squamous cell carcinoma (OCSCC) is controversial. The primary aim of this study was to investigate the presence of an optimal cutoff point or, alternatively, assess the potential improvement in predictive value by considering the surgical margins as a continuum.

METHODS

Retrospective analysis of OCSCC patients at a tertiary medical center in 1995-2020. Clinical, pathological, and surgical data were evaluated for effect on survivability by regression analyses.

RESULTS

The cohort included 266 patients (48.1% male, mean age 65.4 ± 17.7). Patient stratification by categorical margin status yielded no significant between-group differences in survival (p = 0.54). Significance was achieved when margin distance was reevaluated as a continuous variable (p = 0.0018). Similar results were shown in local control (categorical p = 0.59 vs. continuous p = 0.06). Multivariate model excluded possible confounders. A predictive model was created to provide a more accurate prediction of survival.

CONCLUSIONS

The continuum spectrum of margin distance better predicts survival outcomes and locoregional control in OCSCC.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Resection status and margin control in intraoperative frozen sectioning analysis of oral squamous cell carcinoma

PURPOSE

Intraoperative frozen section analysis (IFSA) is a well-established procedure for determining the intraoperative soft tissue resection status in patients with oral squamous cell carcinoma (OSCC). Margin status is a major predictor of the patient´s outcome, histologically free margins of ≥ 5 mm are demanded. This study evaluates the accuracy of IFSA, the impact of margin status and the impact of intraoperative margin revision on disease-free survival (DFS) and overall survival (OS).

METHODS

This retrospective study included 213 patients with OSCC. IFSA results were compared with definitive histopathological reports, Kaplan-Meier analysis was performed. Cut-off values were calculated for resection margins considering known risk factors.

RESULTS

IFSA showed positive margins in 8 cases (3.8%). Kaplan-Meier analysis revealed no significant differences for OS or DFS if R0-status was achieved by initial resection or immediate re-resection. Final histopathological evaluation revealed false-positive IFSA in 3/8 cases (37.5%) and false-negative IFSA in 1/205 cases (0.5%). Sensitivity was 83.3% and specificity was 98.6%. Analysis of optimal cut-off values showed no general need for larger resection margins in patients with risk factors. Cut-off values were slightly higher for patients with the risk factor alcohol consumption (7 mm for OS and DFS) or pN + ECS- disease (7 mm for DFS). Optimal cut-off values for tumour-margin-distance were around 6 mm.

CONCLUSION

IFSA provides a valuable assessment method for intraoperative soft tissue resection margins. Risk factors seemingly do not significantly influence the extent of tumour resection.

Discrimination of healthy oral tissue from oral cancer based on the mean grey value determined by optical coherence tomography

OBJECTIVE

This study aimed to identify a quantitative index for optical coherence tomography (OCT) images to discriminate tumours from surrounding tissues.

SUBJECTS AND METHODS

Based on OCT measurements, mean grey values were determined from 432 locations on fifty-four human tissue specimens (eighteen cancerous, para-cancerous, and normal tissues each). These results were histologically evaluated by hematoxylin and eosin staining (H&E).

RESULTS

The mean grey values of oral squamous cell carcinoma (OSCC) measurements were significantly different from those of the surrounding healthy tissue (p value < 0.0001), with the former being higher. The sensitivity and specificity of detecting tumourous tissue using this approach were 93 and 94%, respectively.

CONCLUSIONS

OCT as a non-invasive, real-time imaging method, correlates well with H&E pathological images. It can effectively distinguish squamous cell carcinoma from normal tissues with high sensitivity and specificity and is thus expected to assist and guide tumour margin evaluation.

CLINICAL RELEVANCE

This discovery highlights the potential of OCT in the objective evaluation of tumour margin during surgery.

A Prospective Double-Blinded Comparison of Reflectance Confocal Microscopy with Conventional Histopathology for In Vivo Assessment in Oral Cancer

PURPOSE

We investigated reflectance confocal microscopy (RCM) as a possible noninvasive approach for the diagnosis of cancer and real-time assessment of surgical margins.

EXPERIMENTAL DESIGN

In a phase I study on 20 patients, we established the RCM imaging morphologic features that distinguish oral squamous cell carcinoma (OSCC) from normal tissue with a newly developed intraoral RCM probe. Our subsequent phase II prospective double-blinded study in 60 patients tested the diagnostic accuracy of RCM against histopathology. Five RCM videos from the tumor and five from normal surrounding mucosa were collected on each patient, followed by a 3-mm punch biopsy of the imaged area. An experienced RCM reader, who was blinded to biopsy location and histologic diagnosis, examined the videos from both regions and classified each as "tumor" or "not tumor" based on RCM features established in phase I. Hematoxylin and eosin slides from the biopsies were read by a pathologist who was blinded to RCM results. Using histology as the gold standard, we calculated the sensitivity and specificity of RCM.

RESULTS

We report a high agreement between the blinded readers (95% for normal tissue and 81.7% for tumors), high specificity (98.3%) and negative predictive values (96.6%) for normal tissue identification, and high sensitivity (90%) and positive predictive values (88.2%) for tumor detection.

CONCLUSIONS

RCM imaging is a promising technology for noninvasive in vivo diagnosis of OSCC and for real-time intraoperative evaluation of mucosal surgical margins. Its inherent constraint, however, stems from the diminished capability to evaluate structures located at more substantial depths within the tissue.

Beneath the surface: A systematic review on intraoperative imaging techniques for deep margin assessment in oral squamous cell carcinoma

Resection margins of oral squamous cell carcinoma (SCC) are often inadequate. A systematic review on clinical intraoperative whole-specimen imaging techniques to obtain adequate deep resection margins in oral SCC is lacking. Such a review may render better alternatives for the current insufficient intraoperative techniques: palpation and frozen section analyses (FSA). This review resulted in ten publications investigating ultrasound (US), four investigating fluorescence, and three investigating MRI. Both US and fluorescence were able to image the tumor intraorally and perform ex-vivo imaging of the resection specimen. Fluorescence was also able to image residual tumor tissue in the wound bed. MRI could only be used on the ex-vivo specimen. The 95 % confidence intervals for sensitivity and specificity were large, due to the small sample sizes for all three techniques. The sensitivity and specificity of US for identifying < 5 mm margins ranged from 0 % to 100 % and 60 % to 100 %, respectively. For fluorescence, this ranged from 0 % to 100 % and 76 % to 100 %, respectively. For MRI, this ranged from 7 % to 100 % and 81 % to 100 %, respectively. US, MRI and fluorescence are the currently available imaging techniques that can potentially be used intraoperatively and which can image the entire tumor-free margin, although they have insufficient sensitivity for identifying < 5 mm margins. Further research on larger cohorts is needed to improve the sensitivity by determining cut-off points on imaging for inadequate margins. This improves the number of adequate resections of oral SCC's and pave the way for routine clinical implementation of these techniques.

Surgical margins in head and neck squamous cell carcinoma: A narrative review

Head and neck squamous cell carcinoma (HNSCC), a prevalent and frequently recurring malignancy, often necessitates surgical intervention. The surgical margin (SM) plays a pivotal role in determining the postoperative treatment strategy and prognostic evaluation of HNSCC. Nonetheless, the process of clinical appraisal and assessment of the SMs remains a complex and indeterminate endeavor, thereby leading to potential difficulties for surgeons in defining the extent of resection. In this regard, we undertake a comprehensive review of the suggested surgical distance in varying circumstances, diverse methods of margin evaluation, and the delicate balance that must be maintained between tissue resection and preservation in head and neck surgical procedures. This review is intended to provide surgeons with pragmatic guidance in selecting the most suitable resection techniques, and in improving patients' quality of life by achieving optimal functional and aesthetic restoration.

Variation of resection margins in oral cancer in dependence of tumor stage and subsite - a retrospective cohort study

OBJECTIVES

Surgical resection is a key component of the treatment of head and neck cancer and the achievement of free surgical margins are essential for the patients' outcome in terms of survival. While there is a general recommendation for a free resection range of 5 mm, up to date, there is a lack of investigations on the quality of tumor resection in dependence of affected subsite and tumor stage. In the presented study, predictors for the achieved resection margins in surgically treated oral squamous cell carcinomas were analyzed.

MATERIALS AND METHODS

A cohort of 567 patients was included in a retrospective analysis and resection status with exact margin ranges were analysed. Tumor stage, affected subsite and the results of the intraoperative frozen section analysis were assessed. Primary endpoint was the achieved resection margin in mm, secondary endpoints were overall and progression-free survival.

RESULTS

The observed mean values of minimal resection margins differed significantly between the investigated subsites (p = 0.042),pathological tumor stages (p < 0.001) and in tumors which demonstrated perineural infiltration (Pn1, p = 0.002). Furthermore, there was a significant impact of the results of the intraoperative frozen section analysis on progression-free and overall survival (p < 0.001).

CONCLUSIONS

Our data clearly indicate that resection status differs between tumors of different subsites and tumor stages.

CLINICAL RELEVANCE

Clinical procedures should be adapted in order to achieve similar certainty in all resections, and, thus to improve patients' outcome.

Tumor microenvironment-activatable nanocatalysts with chemodynamic therapy and enhanced autophagy for specific treatment of oral squamous cell carcinoma

Adjuvant therapy following surgery is imperative for enhancing the prognosis of patients with oral squamous cell carcinoma (OSCC) in the clinical setting. Nevertheless, challenges such as treatment resistance mediated by the tumor microenvironment (TME), systemic toxicity, and adverse side effects hinder the effectiveness of conventional adjuvant therapy. In this context, we introduce a novel nanocatalyst denoted as MnO2-x@HA-CCM (MnHA@CCM NC) designed specifically for treating OSCC. This nanocatalyst exerts targeted anti-tumor effects through TME-activatable chemodynamic therapy (CDT) and tumoricidal autophagy. The MnHA@CCM NCs exploit the biocompatibility of hyaluronic acid (HA) coating and the homologous targeting effect of cancer cell membrane (CCM) camouflage, ensuring safe in vivo delivery and specific accumulation at tumor sites. Following intracellular uptake, Fenton-like Mn2+ is generated by consuming glutathione (GSH) within the TME. Subsequently, Mn2+ catalyzes the overproduced H2O2 to generate reactive oxygen species (ROS), inducing cell apoptosis through mitochondrial damage. Additionally, phagocytized NCs and the resultant ROS accumulation in tumor cells elevate the autophagy flux, leading to autophagosome overload and consequent tumoricidal autophagy. Notably, normal cells without TME-catalytic CDT undergo mild protective autophagy to rebalance the stimulation of NCs. As a result, the TME-activatable MnHA@CCM NCs demonstrate a therapeutic efficacy in inhibiting cancer cell growth both in vitro and in vivo. This study presents a targeted treatment strategy for OSCC tumors while sparing normal cells, offering a potential alternative in the realm of adjuvant therapy.

5-Aminolevulinic Acid Fluorescence-Guided Surgery in Head and Neck Squamous Cell Carcinoma

OBJECTIVES

To determine the utility of 5-aminolevulinic acid (5-ALA) fluorescence for resection of head and neck carcinoma.

METHODS

In this prospective pilot trial, 5-ALA was administered as an oral suspension 3-5 h prior to induction of anesthesia for resection of head and neck squamous cell carcinoma (HNSCC). Following resection, 405 nm blue light was applied, and fluorescence of the tumor as well as the surgical bed was recorded. Specimen fluorescence intensity was graded categorically as none (score = 0), mild (1), moderate (2), or robust (3) by the operating surgeon intraoperatively and corroborated with final pathologic diagnosis.

RESULTS

Seven patients underwent resection with 5-ALA. Five (83%) were male with an age range of 33-82 years (mean = 60). Sites included nasal cavity (n = 3), oral cavity (n = 3), and the larynx (n = 1). All specimens demonstrated robust fluorescence when 5-ALA was administered 3-5 h preoperatively. 5-ALA fluorescence predicted the presence of perineural invasion, a positive margin, and metastatic lymphadenopathy. Two patients had acute photosensitivity reactions, and one patient had a temporary elevation of hepatic enzymes.

CONCLUSIONS

5-ALA induces robust intraoperative fluorescence of HNSCC, capable of demonstrating a positive margin, perineural invasion, and metastatic nodal disease. Although no conclusions are there about the safety of this drug in the head and neck cancer population, our study parallels the extensive safety data in the neurosurgical literature. Future applications may include intraoperative assessment of margin status, diagnostic accuracy, and impacts on survival.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:741-748, 2024.

Controversies in the treatment of early-stage oral squamous cell carcinoma

The treatment of early-stage oral squamous cell carcinoma (OSCC) is still a controversial issue. Thanks to the 8th edition of TNM by AJCC there is a better distinction between the stages of OSCC. However, Stages I and II still share the same treatment protocol, even if the prognosis is radically different. A retrospective study has been conducted including 70 previously untreated patients with Stage I or II OSCC, treated with tumorectomy and selective neck dissection. The study focuses on the link between pT1/2 and various other factors, particularly histological grading, vascular and perineural invasion, local and cervical recurrence, surgical margins and overall survival. These data reveal significant differences between pT1 and pT2 in histological grade, perineural invasion, cervical recurrence, surgical margins, and overall survival, emphasizing the necessity of different treatment protocols for T1 and T2 OSCC. Distinct strategies should be proposed to treat Stage I and II OSCC, with Stage II patients possibly benefitting from more aggressive treatments: following these data, a wait-and-see strategy should only be considered in Stage I, while certain treatments at the cervical level - such as prophylactic neck dissection and sentinel node biopsy - should always be considered for Stage II tumors.

Value and role of surgical margins in transoral laser microsurgery of the larynx, literature review and clinical considerations

PURPOSE

There is no agreement on the most appropriate post-operative pathway for the management of positive margins after laser cordectomy for early stage glottic tumours (T1-2N0M0). This literature review and meta-analysis aim to evaluate the post-operative treatment with the best oncological results among follow-up, radiotherapy (RT) and surgical second look. The parameters utilized were incidence of recurrence, overall (OS), disease-specific (DSS) and disease-free (DFS) survival and larynx preservation (LP).

METHODS

The articles were found through a string typed into PubMed from 2007 to 2022. The studies with detailed oncological results were selected according to inclusion criteria, and then the meta-analysis was carried out.

RESULTS

Sixteen studies met the inclusion criteria for 2808 patients. The positive margin was found in 748 patients (26.6%), of which 416 were referred to follow-up, 89 to RT and 242 to a surgical second look. A false positive margin was found in 58/104 patients (56%). The recurrence rate in patients with positive margins was significantly higher (p = 0.003). In OS, DSS, DFS and LP, the odds ratio (OR) value was always greater than 1, assessing the role of the positive margin as a risk factor.

CONCLUSIONS

Prospective studies will be necessary to establish the role of positive margin as a prognostic factor. A surgical second look in case of positive margin seems to be the best option for the patient in terms of lower risk of recurrence and better oncological results. Better collaboration between surgeon and pathologist would be desirable to limit the real and false positive margins.

Intraoperative Assessment of Resection Margin in Oral Cancer: The Potential Role of Spectroscopy

In parallel with the increasing number of oncological cases, the need for faster and more efficient diagnostic tools has also appeared. Different diagnostic approaches are available, such as radiological imaging or histological staining methods, but these do not provide adequate information regarding the resection margin, intraoperatively, or are time consuming. The purpose of this review is to summarize the current knowledge on spectrometric diagnostic modalities suitable for intraoperative use, with an emphasis on their relevance in the management of oral cancer. The literature agrees on the sensitivity, specificity, and accuracy of spectrometric diagnostic modalities, but further long-term prospective, multicentric clinical studies are needed, which may standardize the intraoperative assessment of the resection margin and the use of real-time spectroscopic approaches.

Development of a fibroblast activation protein-targeted PET/NIR dual-modality probe and its application in head and neck cancer

Purpose: The combination of near-infrared (NIR) and positron emission tomography (PET) imaging presents an opportunity to utilize the benefits of dual-modality imaging for tumor visualization. Based on the observation that fibroblast activation protein (FAP) is upregulated in cancer-associated fibroblasts (CAFs) infiltrating all solid tumors, including head and neck squamous cell carcinoma (HNSCC), we developed the novel PET/NIR probe [68Ga]Ga-FAP-2286-ICG. Preclinically, the specificity, biodistribution and diagnostic properties were evaluated. Methods: Cell uptake assays were completed with the U87MG cell to evaluate the specificity of the [68Ga]Ga-FAP-2286-ICG. The tumor-targeting efficiency, biodistribution and optimal imaging time window of the [68Ga]Ga-FAP-2286-ICG were studied in mice bearing U87MG xenografts. HNSCC tumor-bearing mice were used to evaluate the feasibility of [68Ga]Ga-FAP-2286-ICG for tumor localization and guided surgical resection of HNSCC tumors. Results: The in vitro experiments confirmed that [68Ga]Ga-FAP-2286-ICG showed good stability, specific targeting of the probe to FAP, and the durable retention effect in high-expressing FAP tumors U87MG cell. Good imaging properties such as good tumor uptake, high tumor-to-background ratios (5.44 ± 0.74) and specificity, and tumor contouring were confirmed in studies with mice bearing the U87MG xenograft. PET/CT imaging of the probe in head and neck cancer-bearing mice demonstrated specific uptake of the probe in the tumor with a clear background. Fluorescence imaging further validated the value of the probe in guiding surgical resection and achieving precise removal of the tumor and residual lesions. Conclusion: In a preclinical model, these attractive [68Ga]Ga-FAP-2286-ICG PET/NIR imaging acquired in head and neck cancer make it a promising FAP-targeted multimodal probe for clinical translation.

Systematic review of benefits and practical challenges for application of Mohs surgery for oral tumors

Mohs micrographic surgery (MMS) may be an effective treatment modality for oral cavity cancers (OCC) due to possibility of more effective visualization of tumor margins and greater preservation of benign tissue. The objective of this study is to review the existing literature on the use of MMS for the treatment of OCC and categorize its uses and limitations. A systematic review was performed in accordance with Assessing the Methodological Quality of Systematic Reviews (AMSTAR) guidelines. PubMed, Scopus, and Google Scholar from inception of databases to January 20, 2023 identified all published studies on the use of MMS for OCC. Nine studies met inclusion criteria. Seventy-seven patients were treated with MMS for OCC, 74 of which (96%) were treated for squamous cell carcinoma (SCC). The tongue was the most common site (n = 57). Six out of seven studies showed no recurrence of disease during the follow-up periods, which ranged from 8 to 42 months, and one study reported significantly lower loco-regional recurrence over a 2-years follow-up period (10.5% vs 25.7%). Mohs technique did not cause a statistically significant increase in operating time. Applicability of MMS is limited by operator comfort with surgical technique and pathological interpretation of specimens in the oral cavity. The main limitation was that various studies did not report specific patient characteristics. In conclusion, MMS may be an effective treatment for OCC, especially for squamous cell carcinomas, and tumors involving the tongue.

Prediction of postoperative hypokalemia in patients with oral cancer undergoing en bloc cancer resection: a retrospective cohort study

BACKGROUND

The factors associated with postoperative hypokalemia in patients with oral cancer remain unclear. We determined the preoperative factors associated with postoperative hypokalemia in patients with oral cancer following en bloc cancer resection and established a nomogram for postoperative hypokalemia prediction.

METHODS

Data from 381 patients with oral cancer who underwent en bloc cancer resection were retrospectively analyzed. Univariate and multivariate analyses were performed to identify the risk factors for postoperative hypokalemia. We used receiver operating characteristic (ROC) curves to quantify the factors' effectiveness. A nomogram was created to show each predictor's relative weight and the likelihood of postoperative hypokalemia development. The multinomial regression model's effectiveness was also evaluated.

RESULTS

Preoperative factors, including sex, preoperative serum potassium level, and preoperative platelet-to-lymphocyte ratio (PLR), were significantly associated with postoperative hypokalemia. Based on the ROC curve, the preoperative serum potassium and PLR cut-off levels were 3.98 mmol/L and 117, respectively. Further multivariate analysis indicated that female sex, preoperative serum potassium level < 3.98 mmol/L, and preoperative PLR ≥ 117 were independently associated with postoperative hypokalemia. We constructed a predictive nomogram with all these factors for the risk of postoperative hypokalemia with good discrimination and internal validation.

CONCLUSIONS

The predictive nomogram for postoperative hypokalemia risk constructed with these factors had good discrimination and internal validation. The developed nomogram will add value to these independent risk factors that can be identified at admission in order to predict postoperative hypokalemia.

Intraoperative assessment of resection margins by Raman spectroscopy to guide oral cancer surgery

Patients with oral cavity cancer are almost always treated with surgery. The goal is to remove the tumor with a margin of more than 5 mm of surrounding healthy tissue. Unfortunately, this is only achieved in about 15% to 26% of cases. Intraoperative assessment of tumor resection margins (IOARM) can dramatically improve surgical results. However, current methods are laborious, subjective, and logistically demanding. This hinders broad adoption of IOARM, to the detriment of patients. Here we present the development and validation of a high-wavenumber Raman spectroscopic technology, for quick and objective intraoperative measurement of resection margins on fresh specimens. It employs a thin fiber-optic needle probe, which is inserted into the tissue, to measure the distance between a resection surface and the tumor. A tissue classification model was developed to discriminate oral cavity squamous cell carcinoma (OCSCC) from healthy oral tissue, with a sensitivity of 0.85 and a specificity of 0.92. The tissue classification model was then used to develop a margin length prediction model, showing a mean difference between margin length predicted by Raman spectroscopy and histopathology of -0.17 mm.

Overexpression of CD73 is associated with recurrence and poor prognosis of gingivobuccal oral cancer as revealed by transcriptome and deep immune profiling of paired tumor and margin tissues

BACKGROUND

For various cancers, differences in response to treatment and subsequent survival period have been reported to be associated with variation in immune contextures.

AIM

We sought to identify whether such association exists in respect of gingivobuccal oral cancer.

MATERIALS AND METHODS

We performed deep immune profiling of tumor and margin tissues collected from 46 treatment naïve, Human Papillomavirus (HPV) negative, patients. Each patient was followed for 24 months and prognosis (recurrence/death) noted. Key findings were validated by comparing with TCGA-HNSC cohort data.

RESULTS

About 28% of patients showed poor post-treatment prognosis. These patients exhibited a high probability of recurrence even within 1 year and death within 2 years. There was restricted immune cell infiltration in tumor, but not in margin, among these patients. Reduced expression of eight immune-related genes (IRGs) (NT5E, THRA, RBP1, TLR4, ITGA6, BMPR1B, ITGAV, SSTR1) in tumor strongly predicted better quality of prognosis, both in our patient cohort and in TCGA-HNSC cohort. Tumors of patients with better prognosis were associated with (a) lower CD73+ cells with concomitant lower expression level of NT5E/CD73, (b) higher proportions of CD4+ and CD8+ T cells, B cells, NK cells, M1 macrophages, (c) higher %Granzyme+ cells, (d) higher TCR and BCR repertoire diversities. CD73 expression in tumor was associated with low CD8+ and CD4+ T cells, low immune repertoire diversity, and advanced cancer stage.

DISCUSSION AND CONCLUSION

High infiltration of anti-tumor immune cells in both tumors and margins results in good prognosis, while in patients with minimal infiltration in tumors in spite of high infiltration in margins results in poor prognosis. Targeted CD73 immune-checkpoint inhibition may improve clinical outcome.

Frozen Section Analysis in Head and Neck Surgical Pathology: A Narrative Review of the Past, Present, and Future of Intraoperative Pathologic Consultation

Frozen section has remained the diagnostic gold standard for intraoperative pathological evaluation of surgical margins for head and neck specimens. While achieving tumor-free margins is of utmost importance to all head and neck surgeons, in practice, there are numerous debates and a lack of standardization for the role and method of intraoperative pathologic consultation. This review serves as a summary guide to the historical and contemporary practice of frozen section analysis and margin mapping in head and neck cancer. In addition, this review discusses current challenges in head and neck surgical pathology, and introduces 3D scanning as a groundbreaking technology to bypass many of the pitfalls in the current frozen section workflow. The ultimate goal for all head and neck pathologists and surgeons should be to modernize practices and take advantage of new technology, such as virtual 3D specimen mapping techniques, that improves the workflow for intraoperative frozen section analysis.

Oral Cavity Squamous Cell Carcinoma: An Update of the Pharmacological Treatment

Oral cavity squamous cell carcinoma (OCSCC) represents a serious health and socio-economic problem in different geographical areas of the world. It is characterized by a high rate of mortality, recurrence and metastasis. Despite the therapeutic strategies implemented for its management and resolution, currently the survival estimate for locally advanced disease is about 50%. The available therapeutic options comprise surgery and pharmacological treatment. Recently, an increased emphasis has been placed on the drugs that might be of benefit in this life-threatening disease. Therefore, the aim of this present review was to offer a general survey of the current available pharmacological treatment for OCSCC. The PubMed database was used to retrieve the papers using "OCSCC" as the search terms. We limited our search to the last 5 years to give a more updated and recent picture of the state of the art, including preclinical and clinical investigations. We found that 77 out of 201 papers were on the surgical treatment of OCSCC, 43 out of 201 focused on the radiotherapy and 81 out of 201 underwent evaluation for the aim of our review. We excluded the case reports, editorial letters, observational studies and papers written in languages other than English. A total of 12 articles were included in the final review. Our results showed that nanotechnologies use to enhance the efficacy of anticancer drugs such as: cisplatin, paclitaxel, cetuximab, EGFR antagonists, MEK1/2 and immune check inhibitors combination could have promising anti-cancer activity. However, the paucity of available data on drugs suggests the urgent need to improve the pharmacological armamentarium for OCSCC treatment.

Prognostic relevance of pre-treatment inflammatory biomarkers along with other clinicopathological and treatment factors in oral cavity cancers

Background

Inflammation has traditionally been considered to be one of the hallmarks of cancer, and systemic inflammatory responses have a prognostic value in many solid cancers. The use of inflammation-based prognostic markers along with traditional clinicopathological prognostic markers in oral cavity cancers has not been studied well.

Materials and Methods

This is a retrospective study from a prospectively maintained database of patients with oral cancers who were managed in a regional cancer center in south India. The study included patients with squamous cell carcinoma of the oral cavity who were treated with curative intent from January to December 2016.

Results and Discussion

Three hundred sixty-one patients met the eligibility criteria and were included in the study. The median age of our patient cohort was 45 years; the male-to-female ratio was 3.7:1. All of the patients underwent curative treatments after a multi-disciplinary board concurrence. Advanced T stage, patients with buccal mucosal cancers and patients who received upfront non-surgical treatments have poorer survival outcomes. The clinicopathological variables that predicted a poorer overall survival in the cohort of patients treated with upfront surgery were advanced T Stage, higher grade, presence of perineural invasion, a higher inflammatory maker, and combination of platelet and neutrophil lymphocyte ratio (COP-NLR).

Conclusion

Our unique study of oral cavity cancer patients with a primary aim of exploring the prognostic significance of the pre-treatment inflammatory markers gave very interesting results. The prognostic significance of COP-NLR and other inflammatory markers in oral cancers need to be further explored. More importantly, our study has clearly reiterated that meaningful long-term survival outcomes in oral cavity cancers can only be achieved with the incorporation of upfront surgery.

Variance in 3D anatomic localization of surgical margins based on conventional margin labeling in head and neck squamous cell carcinoma

OBJECTIVE

In head and neck cancer (HNC), positive margins are strongly predictive of treatment failure. We sought to measure the accuracy of localization of margin sampling sites based on conventional anatomic labels using a digital 3D-model.

METHODS

Preoperative CT scans for 9 patients with HNC treated operatively at our institution were imported into a multiplanar radiology software, which was used to render a digital 3D model of each tumor intended to represent the resection specimen. Surgical margin labels recorded during the operative case were collected from pathology records. Margin labels (N = 64) were presented to participating physicians.Participants were asked to mark the anatomic location of each surgical margin using the 3D-model and corresponding radiographic planes for reference.For each individual margin, the 3D coordinates of each participant's marker were used to calculate a mean localization point called the geometric centroid. Mean distance from individual markers to the centroid was compared between participantsand margin types.

RESULTS

Amongst 7 surgeons, markers were placed a mean distance of 12.6 mm ([SD] = 7.5) from the centroid.Deep margins were marked with a greater mean distance than mucosal/skin margins (19.6 [24.8] mm vs. 15.3 [14.9] mm, p = 0.034). When asked to relocate a margin following re-resection, surgeons marked a point an average of 20.6 [12.4] mm from their first marker with a range of 3.9- 45.1 mm.

CONCLUSIONS

Retrospective localization of conventionally labeled margins is an imprecise process with variability across the care team. Future interventions targeting margin documentation and communication may improve sampling precision.

Rational Design of a Self-Assembling High Performance Organic Nanofluorophore for Intraoperative NIR-II Image-Guided Tumor Resection of Oral Cancer

The first line of treatment for most solid tumors is surgical resection of the primary tumor with adequate negative margins. Incomplete tumor resections with positive margins account for over 75% of local recurrences and the development of distant metastases. In cases of oral cavity squamous cell carcinoma (OSCC), the rate of successful tumor removal with adequate margins is just 50-75%. Advanced real-time imaging methods that improve the detection of tumor margins can help improve success rates,overall safety, and reduce the cost. Fluorescence imaging in the second near-infrared (NIR-II) window has the potential to revolutionize the field due to its high spatial resolution, low background signal, and deep tissue penetration properties, but NIR-II dyes with adequate in vivo performance and safety profiles are scarce. A novel NIR-II fluorophore, XW-03-66, with a fluorescence quantum yield (QY) of 6.0% in aqueous media is reported. XW-03-66 self-assembles into nanoparticles (≈80 nm) and has a systemic circulation half-life (t_1/2 ) of 11.3 h. In mouse models of human papillomavirus (HPV)+ and HPV- OSCC, XW-03-66 outperformed indocyanine green (ICG), a clinically available NIR dye, and enabled intraoperative NIR-II image-guided resection of the tumor and adjacent draining lymph node with negative margins. In vitro and in vivo toxicity assessments revealed minimal safety concerns for in vivo applications.

Ultrasound-guided resection for squamous cell carcinoma of the buccal mucosa: A feasibility study

BACKGROUND

Image-guided surgery could help obtain clear (≥5.0 mm) resection margins. This feasibility study investigated ultrasound-guided resection accuracy of buccal mucosa squamous cell carcinoma (BMSCC).

METHODS

MRI and ultrasound measurements of tumor thickness were compared to histology in 13 BMSCC-patients. Ultrasound measured margins (at five locations) on the specimen were compared to the corresponding histological margins.

RESULTS

Accuracy of in- and ex-vivo ultrasound (mean deviation from histology: 1.6 mm) for measuring tumor thickness was comparable to MRI (mean deviation from histology: 2.6 mm). The sensitivity to detect clear margins using ex-vivo ultrasound was low (48%). If an ex-vivo ultrasound cutoff of ≥7.5 mm would be used, the sensitivity would increase to 86%.

CONCLUSIONS

Ultrasound-guided resection of BMSCC's is feasible. In- and ex-vivo ultrasound measure tumor thickness in BMSCC accurately. We recommend ≥7.5 mm resection margins on ex-vivo ultrasound to obtain histological clear margins. Additional research is required to establish the effect of 7.5 mm ultrasound cutoff.

The computer-aided design margin: Ex vivo 3D specimen mapping to improve communication between surgeons and pathologists

BACKGROUND

Numerous challenges exist in determining surgical margin status. Communication between surgeons and pathologists is crucial for specimen orientation and accurate margin assessment.

METHODS

A prospective study to determine feasibility of incorporating three-dimensional (3D) scanning into surgical pathology workflow was performed. A structured-light 3D scanner captured the photorealistic surface topography of fresh surgical specimens. Computer-aided design (CAD) software was used to document sites of margin sampling and sectioning. Surveys were distributed among faculty and staff stakeholders to assess feasibility.

RESULTS

A series of 40 cases were 3D-scanned. Median image acquisition time was 8 min. The majority of respondents agreed that the experimental 3D system helped achieve clearer communication. 3D specimen maps assisted in the communication of a focally positive or close margin in 4 of 17 cases.

CONCLUSIONS

Routine 3D scanning and specimen mapping is feasible and represents an innovative approach to intraoperative and final pathology documentation, margin analysis, and surgeon-pathologist communication.

Utilizing 3D head and neck specimen scanning for intraoperative margin discussions: Proof of concept of our novel approach

BACKGROUND

The current standard of documenting and communicating frozen section margin results is inefficient. We present a novel method of generating 3D digital models of gross tumor specimens to more clearly visualize histopathological margin results.

METHODS

Fifty-five head and neck specimens were scanned and virtually "inked" using 3D software. These 3D specimen maps were displayed in the operating room to provide the surgeon with a real-time specimen-to-defect relationship by which further resections could be guided.

RESULTS

Margin results were reported within an average of 34 min using the proposed workflow. The scanner rendered accurate models of specimens that exceeded 3.0 × 3.0 × 3.0 cm. Critical specimen features to consider were size, color, textural complexity, and the presence of discernible anatomic landmarks.

CONCLUSIONS

Optical 3D scanning technology can improve the quality of head and neck margin documentation and the efficiency with which results are communicated between the pathologist and surgeon.

Applicability of autofluorescence and fluorescent probes in the trans-surgical of oral carcinomas: A systematic review

Oral cancer represents an important health problem, as it is the sixth most common type of cancer in the world and is associated with high rates of morbidity and mortality. The treatment considered the gold standard for this type of tumor is surgical resection with negative margins, with a distance of at least 5 mm from the tumor. This procedure is strongly associated with local control and disease-specific survival, however, in many cases, large amounts of healthy tissue are removed, resulting in surgical defects, compromising various functions and directly affecting the individual's quality of life. From this perspective, this systematic review aimed to evaluate the use of autofluorescence and fluorescent probes as potential adjuvant techniques to facilitate the delineation of surgical margins for oral cancers. A comprehensive search was performed in Pubmed, Scopus, Web of Science, LIVIVO, Embase, ProQuest Open Access Dissertations & Theses, Open Access Theses and Dissertations, and DART Europe databases, where 1948 articles were found. After the different stages of critical evaluation, 15 articles were selected, eligible for the inclusion criteria. Of these, 7 articles used autofluorescence, 7 used fluorescent probes and 1 article used both methods. As for autofluorescence, the most used device was the VELScope, and indocyanine green was the most used probe. Compared to histopathology, autofluorescence did not obtain significant and/or superiors results. In contrast to fluorescent probes that, most articles showed a good performance of margins during surgical resection, making them a promising alternative. However, it is still necessary to carry out the analysis of more articles, with more significant samples and sensitivity and specificity data to qualify the results.

Surgical Extent for Oral Cancer: Emphasis on a Cut-Off Value for the Resection Margin Status: A Narrative Literature Review

The optimal cut-off point of the resection margin was recently debated in oral cancer. To evaluate the current evidence of the dynamic criteria of the resection margin, a review of the available literature was performed. Studies were sourced from PubMed and EMBASE by searching for the keywords "mouth neoplasm", "oral cancer", "oral cavity cancer", "oral squamous cell carcinoma", "tongue cancer", "margins of excision", "surgical margin" and "resection margin". We found approximately 998 articles on PubMed and 2227 articles on EMBASE. A total of 3225 articles was identified, and 2763 of those were left after removing the duplicates. By applying advanced filters about the relevance of the subjects, these were narrowed down to 111 articles. After the final exclusion, 42 full-text articles were reviewed. The universal cut-off criteria of 5 mm used for determining the resection margin status has been debated due to recent studies evaluating the impact of different margin criteria on patient prognosis. Of note, the degree of the microscopic extension from the gross tumor border correlates with tumor dimensions. Therefore, a relatively narrow safety margin can be justified in early-stage oral cancer without the additional risk of recurrence, while a wide safety margin might be required for advanced-stage oral cancer. This review suggests a surgical strategy to adjust the criteria for risk grouping and adjuvant treatments, according to individual tumor dimensions or characteristics. In the future, it might be possible to establish individual tumor-specific surgical margins and risk stratification during or after surgery. However, the results should be interpreted with caution because there is no strong evidence (e.g., prospective randomized controlled studies) yet to support the conclusions. Our study is meaningful in suggesting future research directions and discussions.

Impact of histological tumor grade on the behavior and prognosis of squamous cell carcinoma of the oral cavity

INTRODUCTION

Unlike other types of cancers, the prognostic value of histological tumor grade is not well determined for oral squamous cell carcinoma (OSCC). This study therefore aimed to evaluate the impact of tumor differentiation on prognosis and overall survival of patients affected by squamous cell carcinoma of the oral cavity.

MATERIALS AND METHOD

A retrospective analysis was conducted using the records of patients diagnosed with squamous cell carcinoma of the oral cavity between 2010 and 2015. The study included 162 patients treated with a tumorectomy and selective neck dissection. The influence of histological tumor grade on several prognostic factors such as T-Stage, N-stage, recurrence rate, perineural invasion, vascular invasion, surgical margins, and overall survival was analyzed.

RESULTS

Histological grade strongly correlated with N-stage, recurrence rate, perineural invasion, vascular invasion, surgical margins, and overall survival. Overall survival was 71.6% in patients with well-differentiated tumors and 43.2% in those with moderately and poorly differentiated tumors.

CONCLUSIONS

Histological grade represents an important prognostic factor for OSCC. Therefore, various treatment strategies based on this histological parameter could improve the overall survival rate of patients affected by oral squamous cell carcinoma.

Impact of preanalytical freezing delay time on the stability of metabolites in oral squamous cell carcinoma tissue samples

INTRODUCTION

Metabolite stability is critical for tissue metabolomics. However, changes in metabolites in tissues over time from the operating room to the laboratory remain underexplored.

OBJECTIVES

In this study, we evaluated the effect of postoperative freezing delay time on the stability of metabolites in normal and oral squamous cell carcinoma (OSCC) tissues.

METHODS

Tumor and paired normal tissues from five OSCC patients were collected after surgical resection, and samples was sequentially quenched in liquid nitrogen at 30, 40, 50, 60, 70, 80, 90 and 120 min (80 samples). Untargeted metabolic analysis by liquid chromatography-mass spectrometry/mass spectrometry in positive and negative ion modes was used to identify metabolic changes associated with delayed freezing time. The trends of metabolite changes at 30-120 and 30-60 min of delayed freezing were analyzed.

RESULTS

190 metabolites in 36 chemical classes were detected. After delayed freezing for 120 min, approximately 20% of the metabolites changed significantly in normal and tumor tissues, and differences in the metabolites were found in normal and tumor tissues. After a delay of 60 min, 29 metabolites had changed significantly in normal tissues, and 84 metabolites had changed significantly in tumor tissues. In addition, we constructed three tissue freezing schemes based on the observed variation trends in the metabolites.

CONCLUSION

Delayed freezing of tissue samples has a certain impact on the stability of metabolites. For metabolites with significant changes, we suggest that the freezing time of tissues be reasonably selected according to the freezing schemes and the actual clinical situation.

Surgical margins of the oral cavity: is 5 mm really necessary?

Background

Squamous cell carcinoma is the most common malignancy of the oral cavity. Primary treatment involves surgical resection of the tumour with a surrounding margin. Historically, the most commonly accepted margin clearance is 5 mm. This distance is controversial, with recent publications suggesting closer margins do not impact local recurrence and survival. The objective of this study is to determine the closest surgical margin that does not impact local recurrence and overall survival.

Methods

A retrospective review of the London Health Sciences Centre Head and Neck Multidisciplinary Clinic between 2010 and 2018 was performed. Demographic data, subsite, tumour staging, treatment modality, margins, and survival outcomes were analyzed. The primary endpoint was local recurrence free survival. Secondary endpoints included recurrence-free survival and overall survival. Descriptive statistics, as well as univariable and multivariable Cox proportional hazards regression modelling were performed for all patients.

Results

Four-hundred and twelve patients were included in the study, with a median follow-up of 3.3 years. On univariable analysis, positive margins and margins < 1 mm were associated with significantly worse local recurrence-free survival, recurrence-free survival, and overall survival (p < 0.05), compared to margins > 5 mm. Patients with surgical margins > 1 mm experienced similar outcomes to those with margins > 5 mm. Multivariable analysis identified age of diagnosis, alcohol consumption, pathological tumour and nodal category as predictors of local recurrence free survival.

Conclusions

Although historical margins for head and neck surgery are 5 mm, similar outcomes were observed for margins greater than 1 mm in our cohort. These findings require validation through multi-institutional collaborative efforts.

Graphical abstract

Fluorescent Molecular Imaging Can Improve Intraoperative Sentinel Margin Detection in Oral Squamous Cell Carcinoma

In head and neck cancer, a major limitation of current intraoperative margin analysis is the ability to detect areas most likely to be positive based on specimen palpation, especially for larger specimens where sampling error limits detection of positive margins. This study aims to prospectively examine the clinical value of fluorescent molecular imaging to accurately identify "the sentinel margin," the point on a specimen at which the tumor lies closest to the resected edge in real-time during frozen section analysis. Methods: Eighteen patients with oral squamous cell carcinoma were enrolled into a prospective clinical trial and infused intravenously with 50 mg of panitumumab-IRDye800CW 1-5 d before surgery. Resected specimens were imaged in a closed-field near-infrared optical imaging system in near real-time, and custom-designed software was used to identify locations of highest fluorescence on deep and peripheral margins. The surgeon identified the sentinel margin masked to optical specimen mapping, and then the regions of highest fluorescence were identified and marked for frozen analysis. Final pathology based on specimen reconstruction was used as reference standard. Results: Resected specimens were imaged in the operating room, and fluorescence had a higher interobserver agreement with pathology (Cohen κ value 0.96) than the surgeon (Cohen κ value of 0.82) for the location of the closest margin. Plotting margin distance at the predicted sentinel margin location of each observer versus the actual closest margin distance at pathology demonstrated best correlation between fluorescence and pathology (R² = 0.98) with surgeon (R² = 0.75). Conclusion: Fluorescence imaging can improve identification of the sentinel margin in head and neck cancer resections, holding promise for rapid identification of positive margins and improved oncologic outcomes.

Folic acid-modified disulfiram/Zn-IRMOF3 nanoparticles for oral cancer therapy by inhibiting ALDH1A1+ cancer stem cells

The repurposing of old drugs can reduce the cost of drug development and speed up the availability of drugs for clinical use. Disulfiram (DSF) is an approved drug for alcohol abuse. In recent years, it has been established that DSF exerts an antitumor effect via targeted inhibition of ALDH1+ cancer stem cells (CSCs). However, due to its metal ion dependence, easy hydrolysis and low availability, the clinical application of DSF is limited. Previous studies have also shown that Zn²⁺ can inhibit CSCs. Accordingly, we developed a novel metal organic framework (IRMOF3)-Zn²⁺, and DSF was incorporated in the IRMOF3. Folic acid (FA) was subsequently loaded on the surface yielding IRMOF3 (IRMOF3-DSF-FA) for targeted therapy of tumors. The nanoscale IRMOF3-DSF-FA exhibited a high loading capacity, good biocompatibility and strong cell uptake capacity, which could provide metal ions, target tumor tissues and inhibit ALDH1+ CSCs. In vivo experiments showed that IRMOF3-DSF-FA could significantly inhibit the growth of CSCs and tumors, with no significant vital organ damage during treatment. Accordingly, IRMOF3-DSF-FA has great prospects for application as a DSF carrier, opening new horizons for targeted therapy of oral cancer.

Prognostic significance of a 4-lncRNA glycolysis-related signature in oral squamous cell carcinoma

BACKGROUND/PURPOSE

Oral squamous cell carcinoma (OSCC) is a highly malignant tumor, and the overall survival (OS) time of patients with OSCC varies considerably. This study aimed to identify reliable biomarkers for OSCC and construct a new prognostic signature, which may guide personalized precision treatment.

MATERIALS AND METHODS

Transcriptome array data of 317 patients with OSCC from The Cancer Genome Atlas Project (TCGA) cohort were retrospectively analyzed. Single-sample gene set enrichment analysis (ssGSEA) and univariate Cox regression were performed to identify the prognostic significance of the hallmarks of each tumor in OSCC. Subsequently, lncRNAs related to glycolysis were identified through co-expression analysis. A glycolysis-related prognostic signature was constructed by combining univariate Cox regression, least absolute shrinkage and selection operator (Lasso) regression, and multivariate Cox regression analyses. Additionally, the infiltration of immune cells in OSCC was evaluated based on data from ssGSEA and TIMER databases.

RESULTS

Glycolysis was identified as the main risk factor for OS in a variety of cancer hallmarks. The 4-lncRNA glycolysis prognostic signature could distinguish high and low-risk patients. This risk signature was found to be an independent prognostic risk factor for OSCC, showing good predictive power compared with other clinicopathological indicators. Immune correlation analysis showed that patients in the low-risk group exhibited higher levels of immune cell infiltration.

CONCLUSION

The novel 4-lncRNA prognostic signature can predict the clinical outcome of patients with OSCC well, and it is expected to become a promising prognostic biomarker as well as a potential therapeutic target in the future.

Trends in Positive Surgical Margins in cT1-T2 Oral Cavity Squamous Cell Carcinoma

OBJECTIVES/HYPOTHESIS

To evaluate trends in contemporary positive surgical margin incidence in cT1-T2 oral cavity squamous cell carcinoma and to evaluate factors associated with surgical margin status.

STUDY DESIGN

Retrospective analysis of large dataset.

METHODS

Retrospective analysis of the National Cancer Database.

RESULTS

Between 2004 and 2016, 39,818 patients with cT1 or cT2 oral cavity squamous cell carcinoma received primary curative-intent surgery. Positive surgical margins were present in 7.95% of patients, and univariable adjusted probability of positive surgical margins over the study period declined by 1% per year (odds ratio [OR], 0.99; 95% confidence interval [CI], 0.98-1.0; P = .049). Multivariable regression revealed the annual rate of positive surgical margins declined significantly (OR, 0.95 per year; 95% CI, 0.92-0.97; P < .001). Factors associated with increased odds of positive surgical margins included cT2 disease, subsite, understaged disease, lymphovascular invasion, tumor grade, and positive lymph nodes. Race and socioeconomic status were not associated with surgical margin status. Treatment at an academic center was associated with increased time to definitive surgery (median 35 days IQR 22-50 vs. median 27 days IQR 14-42; P < .001) and a 20% reduction in positive surgical margin rate (OR, 0.80; 95% CI, 0.71-0.90; P < .001). Treatment at high-volume centers was less likely to be associated with positive surgical margins (OR, 0.85; 95% CI, 0.74-0.98; P = .02).

CONCLUSION

Surgical subsite, clinical T and N category, presence of lymphovascular invasion, and histologic grade were independent predictors of positive surgical margins. Patients are increasingly being treated at high-volume and academic centers. Overall, the rate of positive surgical margins in cT1-T2 oral cavity squamous cell carcinoma is decreasing.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Review:Surgical Tumour Margins and their Significance in Oral Squamous Cell Carcinoma

There are many prognostic indicators used to predict tumour recurrence and overall prognosis in oral squamous cell carcinoma (OSCC). Most of these biological factors cannot be directly influenced by clinicians managing these heterogeneous group of tumours. Excision margins can potentially be increased at the time of surgery by including more normal tissue than the commonly accepted 1cm resection distance from the macroscopic tumour edge. However, this can lead to poorer quality of life for patients and does not necessarily address microscopic extensions or dicohesive patterns of tumour growth. Surgical margins can be affected by tissue shrinkage immediately following resection, and the choice of instrument used for surgery. Currently most regard a clear resection margin as being >5mm, a close margin as more than 1mm but less than 5mm, and an involved margin less than 1mm. In this article we provide a brief overview of tumour margins in OSCC, including several recently published large meta-analyses. Based upon these and other studies, there is still conflicting data in the literature about the ideal margin for OSCC. There is a growing body of evidence which suggests a clearance of 1mm might be adequate for some cancers. However, adequacy of resection should be considered along with the many other prognostic indicators of OSCC when the multi-disciplinary team considers further treatment for these patients.

Multiple Free Flap Reconstruction of a Complex Intraoral Defect after Squamous Cell Carcinoma Excision: A Case Report

Background: Squamous cell carcinoma is the most frequent malignant cancer of the oral cavity. Metastasis involvement is one of the most relevant prognostic factors in terms of survival probability. Patients with oral cancers often undergo extensive en bloc resective surgery of the mandible and maxilla, with or without cervical nodal dissection, based on the presence or occult risk of regional metastases. Several factors affect the choice of flap, to recover aesthetics and function. Case Presentation: The case of a 60-year-old man who underwent maxillectomy with neck dissection as well as a reconstruction with a combination of multiple vascularized free flaps is presented. Conclusions: The excellent integration of the free flaps and the total absence of complications led to a high-quality aesthetic and functional performance of the reconstruction obtained through two different flaps. More specifically, the fibular free flap for bone reconstruction allows a two-team approach and maintains an excellent vascularization, even in case of several osteotomies for the maxillary reconstruction as reported. In addition, the use of free radial forearm flap for soft tissue reconstruction permits to obtain long caliber vessels, thus facilitating surgery without repositioning of the patient during surgery and therefore, consequently reducing surgery times.

An overview of the current clinical status of optical imaging in head and neck cancer with a focus on Narrow Band imaging and fluorescence optical imaging

Early and accurate identification of head and neck squamous cell carcinoma (HNSCC) is important to improve treatment outcomes and prognosis. New optical imaging techniques may assist in both the diagnostic process as well as in the operative setting by real-time visualization and delineation of tumor. Narrow Band Imaging (NBI) is an endoscopic technique that uses blue and green light to enhance mucosal and submucosal blood vessels, leading to better detection of (pre)malignant lesions showing aberrant blood vessel patterns. Fluorescence optical imaging makes use of near-infrared fluorescent agents to visualize and delineate HNSCC, resulting in fewer positive surgical margins. Targeted fluorescent agents, such as fluorophores conjugated to antibodies, show the most promising results. The aim of this review is: (1) to provide the clinical head and neck surgeon an overview of the current clinical status of various optical imaging techniques in head and neck cancer; (2) to provide an in-depth review of NBI and fluorescence optical imaging, as these techniques have the highest potential for clinical implementation; and (3) to describe future improvements and developments within the field of these two techniques.

Evaluation of autofluorescence visualization system in the delineation of oral squamous cell carcinoma surgical margins

INTRODUCTION

Delineating the margins of Oral squamous cell carcinoma (OSCC) is a critical step for optimaltumor resection. The aim of this study was to evaluate the accuracy of lesion surgical margin identification using autofluorescence visualization.

MATERIALS AND METHODS

Thirty patients with OSCC were included in this study. For each lesion, the fluorescence loss boundary was determined using VELscope before ablative surgical resection (with a 1.5-2cm safety margin) was performed. A total of 126 samples were obtained from 30 surgical specimens, each containing the tissue from the fluorescence loss boundary to surgical margin. The status of each sample was determined by oral pathologists and the staining intensities of Ki-67, E-cadherin, and Vimentin at the fluorescence loss boundary and surgical margin were evaluated by immunohistochemistry.

RESULTS

Fluorescence loss regions were identified in all patients. Of the 126 samples collected, HE staining identified 77 normal epithelia (61.1%), 26 mild dysplasia (20.6%), 17 severe dysplasia (13.4%) and 6 carcinomas in situ (4.9%). A significant correlation was found between the differentiation grade of tumor cells and the pathological status of the surgical marginal specimens (P<0.05). Forty-two of the 126 samples were randomly selected for further immunohistochemical staining. No significant differences were seen in Ki-67, E-cadherin, or Vimentin expression at the fluorescence loss boundary or surgical margin, however, the proteins' expression level was positively correlated with the degree of dysplasia (P<0.01).

CONCLUSION

Autofluorescence visualization has potential as a simple surgical margin setting device for OSCC and may help delineate the superficial area of OSCC with acceptable accuracy. However, when considering the inherent limitations of this system, we suggest that the approach should only be applied under certain conditions, such as when dealing with superficial, well-differentiated lesions.

In situ DESI-MSI lipidomic profiles of mucosal margin of oral squamous cell carcinoma

Background

Although there is consensus that the optimal safe margin is ≥ 5mm, obtaining clear margins (≥5 mm) intraoperatively seems to be the major challenge. We applied a molecular diagnostic method at the lipidomic level to determine the safe surgical resection margin of OSCC by desorption electrospray ionisation mass spectrometry imaging (DESI-MSI).

Methods

By overlaying mass spectrometry images with hematoxylin-eosin staining (H&E) from 18 recruited OSCC participants, the mass spectra of all pixels across the diagnosed tumour and continuous mucosal margin regions were extracted to serve as the training and validation datasets. A Lasso regression model was used to evaluate the test performance.

Findings

By leave-one-out validation, the Lasso model achieved 88.6% accuracy in distinguishing between tumour and normal regions. To determine the safe surgical resection distance and margin status of OSCC, a set of 14 lipid ions that gradually decreased from tumour to normal tissue was assigned higher weight coefficients in the Lasso model. The safe surgical resection distance of OSCC was measured using the developed 14 lipid ion molecular diagnostic model for clinical reference. The overall accuracy of predicting tumours, positive margins, and negative margins was 92.6%.

Interpretation

The spatial segmentation results based on our diagnostic model not only clearly delineated the tumour and normal tissue, but also distinguished the different status of surgical margins. Meanwhile, the safe surgical resection margin of OSCC on frozen sections can also be accurately measured using the developed diagnostic model.

Funding

This study was supported by Nanjing Municipal Key Medical Laboratory Constructional Project Funding (since 2016) and the Centre of Nanjing Clinical Medicine Tumour (since 2014).

Salvage surgery for patients with residual/persistent diseases after improper or insufficient treatment of oral squamous cell carcinoma: can we rectify these mistakes?

BACKGROUND

Patterns of failure after treatment of oral and squamous cell carcinomas (OSCC) are diversified, with recurrences being one of the common causes. A special group of patients are sometimes encountered in the outpatient clinic for improper or insufficient initial treatment with reports of positive margins, implying residual/persistent diseases. The question of whether these patients can be surgically salvaged remain unanswered.

METHODS

A retrospective study was performed between January 2013 and December 2017 for patients with residual or rapid recurrent (within 3 months) OSCCs, who received salvage surgeries in our institution. The patients with residual/persistent OSCCs were those with microscopic or macroscopic positive surgical margins, while those with rapid recurrent OSCCs were those with close or negative margins, but unabated painful symptoms right after treatment. Both clinicopathological and prognostic variables were analyzed. The focus was also directed towards lessons for possible initial mistakes, resulting in these residual/persistent diseases.

RESULTS

Of 103 patients, 68 (66%) were men, with mean age of 56.3 years. The overall survival reached 60.2%. Regarding the primary OSCC status, most of our patients (n = 75, 72.8%) were diagnosed with ycT2-3 stages. Besides, most patients were found with macroscopic residual diseases (52.4%) before our salvage surgery. The sizes of the residual/persistent OSCCs were generally under 4 cm (87.3%) with minimally residual in 21 (20.4%). Among all the variables, primary T stage (p = 0.003), and residual lesion size (p < 0.001) were significantly associated with the prognosis in multivariate analysis. Though the causes for the initial surgical failure were multifactorial, most were stemmed from poor planning and unstandardized execution.

CONCLUSIONS

Cases with residual/persistent OSCCs were mostly due to mistakes which could have been avoided under well-round treatment plans and careful surgical practice. Salvage surgery for cases with smaller residual/persistent OSCCs is still feasible with acceptable outcomes.

Specimen oriented intraoperative margin assessment in oral cavity and oropharyngeal squamous cell carcinoma

OBJECTIVE

Evaluate the oncologic outcomes and cost analysis of transitioning to a specimen oriented intraoperative margin assessment protocol from a tumour bed sampling protocol in oral cavity (OCSCC) and oropharyngeal squamous cell carcinoma (OPSCC).

STUDY DESIGN

Retrospective case series and subsequent prospective cohort study SETTING: Tertiary care academic teaching hospital SUBJECTS AND METHODS: Retrospective case series of all institutional T1-T2 OCSCC or OPSCC treated with primary surgery between January 1st 2009 - December 31st 2014. Kaplan-Meier survival estimates with log rank tests were used to compare patients based on final margin status. Cost analysis was performed for escalation of therapy due to positive final margins. Following introduction of a specimen derived margin protocol, successive prospective cohort study of T1-T4 OCSCC or OPSCC treated with primary surgery from January 1st 2017 - December 31st 2018. Analysis and comparison of both protocols included review of intraoperative margins, final pathology and treatment cost.

RESULTS

Analysis of our intra-operative tumour bed frozen section protocol revealed 15 of 116 (12.9%) patients had positive final pathology margins, resulting in post-operative escalation of therapy for 14/15 patients in the form of re-resection (7/14), radiation therapy (6/14) and chemoradiotherapy (1/14). One other patient with positive final margins received escalated therapy for additional negative prognostic factors. Recurrence free survival at 3 years was 88.4 and 50.7% for negative and positive final margins respectively (p = 0.048). Implementation of a specimen oriented frozen section protocol resulted in 1 of 111 patients (0.9%) having positive final pathology margins, a statistically significant decrease (p < 0.001). Utilizing our specimen oriented protocol, there was an absolute risk reduction for having a final positive margin of 12.0% and relative risk reduction of 93.0%. Estimated cost avoidance applying the specimen oriented protocol to our previous cohort was $412,052.812017 CAD.

CONCLUSION

Implementation of a specimen oriented intraoperative margin protocol provides a statistically significant decrease in final positive margins. This change in protocol leads to decreased patient morbidity by avoiding therapy escalation attributable only to positive margins, and avoids the economic costs of these treatments.

Can Radiographic Tumor Volume of Oral Squamous Cell Carcinoma Help Predict Clinical and Pathological Tumor Features?

PURPOSE

Radiographic tumor volume (RTV) of oral squamous cell carcinoma (SCC) is seldom measured in practice. Aims of the study are to estimate RTV of SCC and to investigate its relationship with clinical and pathological stage, tumor margin status, recurrence, and need for chemo/radiation.

METHODS

The Design is a retrospective cohort study. The predictor variable is SCC RTV. The primary outcome variables are clinical and pathological tumor size. The secondary outcomes are margin status and postoperative chemo/radiation. Tumor dimensions were measured on preoperative maxillofacial or neck computer tomography images with contrast. Information on patient and tumor characteristics was obtained. Pearson correlation, t test, ANOVA and log rank test were used for statistical analysis. The significance level was set at .05.

RESULTS

Thirty-Six subjects aged 36 to 86 were included in the study. Positive association was found between clinical T stage and RTV (P = .0003) and between pathologic T stage and RTV (P = .002). Mean value of RTV was significantly higher in group with positive margins (P = .0004). RTV was significantly higher in cancers requiring adjuvant chemo/radiation (P = .033). Mean RTV for patients with recurrence was 1.86 cm³ as compared to 1.29 cm³ for patients with no recurrence. Higher tumor volumes were more likely to be associated with recurrence.

CONCLUSIONS

RTV is a variable that is readily available to head and neck surgeons. RTV is associated with clinical and pathological tumor sizes, margin status, need for adjuvant chemo/radiation and tumor recurrence.

MCU That Is Transcriptionally Regulated by Nrf2 Augments Malignant Biological Behaviors in Oral Squamous Cell Carcinoma Cells

OBJECTIVE

To clarify the role and molecular mechanism of mitochondrial calcium uniporter (MCU) in the malignant biological behaviors of oral squamous cell carcinoma (OSCC) cells through clinical and cellular experiments.

METHODS

Immunohistochemistry and qRT-PCR techniques were used to observe the expression of MCU, nuclear factor erythroid 2-related factor 2 (Nrf2), mitochondrial calcium uptake 1 (MICU1), and MICU2 in OSCC and normal tissues. After treatment with si-MCU, spermine, and/or sh-Nrf2, malignant biological behaviors of OSCC cells including proliferation, migration, and apoptosis were detected by clone formation, migration, and mitochondrial membrane potential (MMP) assays. Furthermore, MCU, MICU1, MICU2, Nrf2, and other proteins related to malignant biological behaviors were examined using western blot, immunohistochemistry, and immunofluorescence assays.

RESULTS

MCU, Nrf2, and MICU1 were strongly expressed in OSCC as compared to normal tissues, while MICU2 was relatively weakly expressed in OSCC tissues. Knockdown of MCU distinctly weakened proliferation and migration and lowered MMP level in CAL 27 cells. Conversely, its activation reinforced migrated capacity and increased MMP level in CAL 27 cells, which was reversed after cotransfection with sh-Nrf2. After treatment with si-MCU or spermine, Nrf2 expression was not affected in CAL 27 cells. However, MCU expression was distinctly suppressed in CAL 27 cells transfected with sh-Nrf2. Furthermore, knockdown of Nrf2 significantly reversed the increase in expression of MICU1 and MICU2 induced by MCU activation in CAL 27 cells.

CONCLUSION

MCU, as a novel oncogene of OSCC, augments malignant biological behaviors of OSCC cells, which could be transcriptionally regulated by Nrf2.

The impact of intraoperative frozen section analysis on final resection margin status, recurrence, and patient outcome with oral squamous cell carcinoma

Background

The objective of this study was to evaluate the diagnostic value of intraoperative frozen section analysis (IFSA) of tumor bed margins in patients with oral squamous cell carcinoma (OSCC).

Methods

This retrospective study includes 194 primary OSCC cases. The impact of intraoperative information by IFSA on final margin status, local recurrence, and disease-specific survival were analyzed.

Results

IFSA revealed a 50% sensitivity and a 100% specificity, with a positive and negative predictive value of 100% and 89.1%, respectively. In 19 cases, margins were rated positive by IFSA and remained positive in eight cases (42.1%), despite immediate re-resection. This constellation led to higher recurrence and lower survival rates than in cases with consecutive R0 status (each p = 0.046). Positive margins in IFSA were associated with closer final margins (p = 0.022) and early recurrences (p = 0.050).

Conclusions

Achieving instant R0 status has a crucial impact on disease recurrence and patient survival. IFSA falls short to ensure secure definite surgical margins. Thus, improved intraoperative diagnostic information on the location and extent of OSCC could support patient treatment.

Clinical relevance

Considering that patient survival has not improved despite progress in surgical and adjuvant therapy, the process and outcome of IFSA was scrutinized as one part of the treatment concept.

Novel imaging techniques for intraoperative margin assessment in surgical oncology: A systematic review

Inadequate margins continue to occur frequently in patients who undergo surgical resection of a tumor, suggesting that current intraoperative methods are not sufficiently reliable in determining the margin status. This clinical demand has inspired the development of many novel imaging techniques that could help surgeons with intraoperative margin assessment. This systematic review provides an overview of novel imaging techniques for intraoperative margin assessment in surgical oncology, and reports on their technical properties, feasibility in clinical practice and diagnostic accuracy. PubMed, Embase, Web of Science and the Cochrane library were systematically searched (2013‐2018) for studies reporting on imaging techniques for intraoperative margin assessment. Patient and study characteristics, technical properties, feasibility characteristics and diagnostic accuracy were extracted. This systematic review identified 134 studies that investigated and developed 16 groups of techniques for intraoperative margin assessment: fluorescence, advanced microscopy, ultrasound, specimen radiography, optical coherence tomography, magnetic resonance imaging, elastic scattering spectroscopy, bio‐impedance, X‐ray computed tomography, mass spectrometry, Raman spectroscopy, nuclear medicine imaging, terahertz imaging, photoacoustic imaging, hyperspectral imaging and pH measurement. Most studies were in early developmental stages (IDEAL 1 or 2a, n = 98); high‐quality stage 2b and 3 studies were rare. None of the techniques was found to be clearly superior in demonstrating high feasibility as well as high diagnostic accuracy. In conclusion, the field of imaging techniques for intraoperative margin assessment is highly evolving. This review provides a unique overview of the opportunities and limitations of the currently available imaging techniques.

What's new?

While surgical resection is critical in the treatment of primary solid tumors, resection at tumor margins remains problematic, with inadequately resected margins facilitating tumor recurrence. In this systematic review, the authors collected information on novel imaging techniques applied to the intraoperative assessment of tumor margins across cancer types. A total of 16 groups of techniques were identified, with many in early stages of clinical application. Following comparison, no single technique was clearly superior in clinical feasibility or diagnostic accuracy. The review highlights the evolving nature of imaging techniques for intraoperative margin assessment and identifies opportunities and limitations in the field.

Assessment of the deep resection margin during oral cancer surgery: A systematic review

The main challenge for radical resection in oral cancer surgery is to obtain adequate resection margins. Especially the deep margin, which can only be estimated based on palpation during surgery, is often reported inadequate. To increase the percentage of radical resections, there is a need for a quick, easy, minimal invasive method, which assesses the deep resection margin without interrupting or prolonging surgery. This systematic review provides an overview of technologies that are currently being studied with the aim of fulfilling this demand. A literature search was conducted through the databases Medline, Embase and the Cochrane Library. A total of 62 studies were included. The results were categorized according to the type of technique: 'Frozen Section Analysis', 'Fluorescence', 'Optical Imaging', 'Conventional imaging techniques', and 'Cytological assessment'. This systematic review gives for each technique an overview of the reported performance (accuracy, sensitivity, specificity, positive predictive value, negative predictive value, or a different outcome measure), acquisition time, and sampling depth. At the moment, the most prevailing technique remains frozen section analysis. In the search for other assessment methods to evaluate the deep resection margin, some technologies are very promising for future use when effectiveness has been shown in larger trials, e.g., fluorescence (real-time, sampling depth up to 6 mm) or optical techniques such as hyperspectral imaging (real-time, sampling depth few mm) for microscopic margin assessment and ultrasound (less than 10 min, sampling depth several cm) for assessment on a macroscopic scale.

Performance of Intraoperative Assessment of Resection Margins in Oral Cancer Surgery: A Review of Literature

Introduction

Achieving adequate resection margins during oral cancer surgery is important to improve patient prognosis. Surgeons have the delicate task of achieving an adequate resection and safeguarding satisfactory remaining function and acceptable physical appearance, while relying on visual inspection, palpation, and preoperative imaging. Intraoperative assessment of resection margins (IOARM) is a multidisciplinary effort, which can guide towards adequate resections. Different forms of IOARM are currently used, but it is unknown how accurate these methods are in predicting margin status. Therefore, this review aims to investigate: 1) the IOARM methods currently used during oral cancer surgery, 2) their performance, and 3) their clinical relevance.

Methods

A literature search was performed in the following databases: Embase, Medline, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and Google Scholar (from inception to January 23, 2020). IOARM performance was assessed in terms of accuracy, sensitivity, and specificity in predicting margin status, and the reduction of inadequate margins. Clinical relevance (i.e., overall survival, local recurrence, regional recurrence, local recurrence-free survival, disease-specific survival, adjuvant therapy) was recorded if available.

Results

Eighteen studies were included in the review, of which 10 for soft tissue and 8 for bone. For soft tissue, defect-driven IOARM-studies showed the average accuracy, sensitivity, and specificity of 90.9%, 47.6%, and 84.4%, and specimen-driven IOARM-studies showed, 91.5%, 68.4%, and 96.7%, respectively. For bone, specimen-driven IOARM-studies performed better than defect-driven, with an average accuracy, sensitivity, and specificity of 96.6%, 81.8%, and 98%, respectively. For both, soft tissue and bone, IOARM positively impacts patient outcome.

Conclusion

IOARM improves margin-status, especially the specimen-driven IOARM has higher performance compared to defect-driven IOARM. However, this conclusion is limited by the low number of studies reporting performance results for defect-driven IOARM. The current methods suffer from inherent disadvantages, namely their subjective character and the fact that only a small part of the resection surface can be assessed in a short time span, causing sampling errors. Therefore, a solution should be sought in the field of objective techniques that can rapidly assess the whole resection surface.