Clinicopathological prognostic implicators of oral squamous cell carcinoma: need to understand and revise

Exotic Keratin Pearl Degradation Mechanism by Giant Cells in Oral Squamous Cell Carcinoma and its Plausible Hypothesis

Introduction

Oral squamous cell carcinoma (OSCC) is a formidable malignancy in the Indian subcontinent, characterized by high morbidity and mortality, with a dismal 5-year survival rate of 40-50%. The tumor's histopathological heterogeneity is well documented, particularly in its differentiation status, which ranges from well-differentiated lesions with prominent keratin pearls to poorly differentiated forms lacking such structures.

Objectives

Existing literature has elucidated the role of neutrophils and macrophages in the degradation of keratin pearls, the involvement of multinucleated giant cells (MNGCs) in this process remains cryptic.

Case report

This study reports a novel case of a 49-year-old male with moderately differentiated OSCC, characterized by ulcerative growth in the left buccal mucosa. Histopathological analysis revealed neoplastic cell infiltration, keratinization, and abnormal mitoses, alongside the degradation of keratin pearls by large foreign body and Langhans MNGCs. This intricate keratin pearl degradation by MNGCs in OSCC highlights tumor heterogeneity and aggressiveness, offering profound insights into surgical, radiotherapy, and chemotherapy strategies. Surgeons must meticulously consider this process as a marker of aggressive behavior, warranting precise surgical planning and a multidisciplinary approach for optimal outcomes.

Conclusion

This case emphasizes the critical role of foreign body and Langhans MNGCs in the degradation of keratin pearls within OSCC, revealing a hitherto unrecognized facet of tumor biology. This discovery holds profound implications for understanding OSCC progression, prognosis, and therapeutic responsiveness, warranting further investigation into the molecular mechanisms underpinning this process.

Development and validation of accelerated failure time model for cause-specific survival and prognostication of oral squamous cell carcinoma: SEER data analysis

BACKGROUND

Oral Squamous Cell Carcinoma is the most prevalent malignancies affecting the oral cavity. Despite progress in studies and treatment options its outlook remains grim with survival prospects greatly affected by demographic and clinical factors. Precisely predicting survival rates and prognosis plays a role in making treatment choices for the best achievable overall health outcomes.

OBJECTIVE

To develop and validate an accelerated failure time model as a predictive model for cause-specific survival and prognosis of Oral Squamous Cell Carcinoma patients and compare its results to the traditional Cox proportional hazard model.

METHOD

We screened Oral cancer patients diagnosed with Squamous Cell Carcinoma from the Surveillance Epidemiology and End Results (SEER) database between 2010 and 2020. An accelerated failure time model using the Type I generalized half logistic distribution was used to determine independent prognostic factors affecting the survival time of patients with oral squamous carcinoma. In addition, accelerated factors were estimated to assess how some variables influence the survival times of the patients. We used the Akaike Information Criterion, Bayesian Information Criterion to evaluate the model fit, the area under the curve for discriminability, Concordance Index (C-index) and Root Mean Square Error and calibration curve for predictability, to compare the type I generalized half logistic survival model to other common classical survival models. All tests are conducted at a 0.05 level of significance.

RESULTS

The accelerated failure time models demonstrated superior effectiveness in modeling (fit and predictive accuracy) the cause-specific survival (CSS) of oral squamous cell carcinoma compared to the Cox model. Among the accelerated failure time models considered, the Type I generalized half logistic distribution exhibited the most robust model fit, as evidenced by the lowest Akaike Information Criterion (AIC = 27370) and Bayesian Information Criterion (BIC = 27415) values. This outperformed other parametric models and the Cox Model (AIC = 47019, BIC = 47177). The TIGHLD displayed an AUC of 0.642 for discrimination, surpassing the Cox model (AUC = 0.544). In terms of predictive accuracy, the model achieved the highest concordance index (C-index = 0.780) and the lowest root mean square error (RMSE = 1.209), a notable performance over the Cox model (C-index = 0.336, RMSE = 6.482). All variables under consideration in this study demonstrated significance at the 0.05 level for CSS, except for race and the time span from diagnosis to treatment, in the TIGHLD AFT model. However, differences emerged regarding the significant variations in survival times among subgroups. Finally, the results derived from the model revealed that all significant variables except chemotherapy, all TNM stages and patients with Grade II and III tumor presentations contributed to the deceleration of time to cause-specific deaths.

CONCLUSIONS

The accelerated failure time model provides a relatively accurate method to predict the prognosis of oral squamous cell carcinoma patients and is recommended over the Cox PH model for its superior predictive capabilities. This study also underscores the importance of using advanced statistical models to improve survival predictions and outcomes for cancer patients.

Association of Cellular Cannibalism with Immunohistochemical Expression of CD31, CD68 and BCL2 in Oral Squamous Cell Carcinoma: An Observational Study

Objective

Cellular cannibalism (CC) is a prime metabolic event to determine the aggressive potential of oral squamous cell carcinoma (OSCC). However, the etiology and mechanism behind this degradation are still ambiguous. The aim of the study was to explore the etiopathogenetic mechanism behind CC, along with its association with degree of differentiation, angiogenic, phagocytic and antiapoptotic activity in OSCC.

Design

Seventy-three tissue sections of various histological grades of OSCC were retrieved from departmental archives and scanned for cannibalistic cells. Immunohistochemical analysis using CD31, CD68, and BCL2 was performed. The data obtained were analyzed using Chi-square, Spearman's correlation test and multiple regression analysis (p < 0.05).

Results

CCs were present significantly in various grades of OSCC (p < 0.00). Immunohistochemical analysis revealed a significant difference in CD68, BCL2 (p < 0.05 in both), and CD31 (p < 0.001) expression with CC. The internalized cells showed positivity for CD68 and negativity for BCL2. Regression analysis revealed that tumor grade, CD31 and BCL2 immunoreactivity were significant predictors of frequency of CC.

Conclusion

The association of CC with degree of differentiation, CD31, CD68, and BCL2 expression could predict the biological behavior of OSCC and might serve as a promising histopathological parameter in future.

Recurrence of oral squamous cell carcinoma in surgically treated patients at Khartoum Teaching Dental Hospital retrospective cross-sectional study

BACKGROUND

In terms of survival rate, recurrent oral squamous cell carcinoma (OSCC) after primary surgery is considered as a poor prognostic indicator.

OBJECTIVE

This study aims to determine the incidence of OSCC recurrence among patients treated at Khartoum Teaching Dental Hospital (KTDH) and possible risk factors associated with it.

METHODS

Records of 303 patients with a history of radical surgery were retrieved from the hospital's archives, and the histopathological records were retrieved from the archival specimens of Professor Ahmed Suleiman Oral Pathology Laboratory, Faculty of Dentistry, and University of Khartoum.

RESULTS

Advanced stages of OSCC (III, IV) were associated with higher recurrence rates, and the poorly differentiated OSCC was the commonest recurrent type.

CONCLUSION

The condition of the surgical margin is a significant predictor of OSCC recurrence and tumor stage. The tumor site, the type of surgical resection, and the tumor differentiation were also identified as significant factors influencing the recurrence of OSCC.

Impact of histopathological parameters in prognosis of oral squamous cell carcinoma

OBJECTIVE

Squamous cell carcinomas comprise approximately 90% of all oral malignancies. There is a wide geographical variation in the incidence of oral cancer, with South and South East Asia (SSEA) accounting for almost two third of new cases. The prognosis of oral cancer is influenced by a vast array of factors including demographic, clinical, histopathological and molecular factors. The objective this review is to analyse the impact of histopathological features assessed in hematoxylin and eosin stained sections on the prognosis of OSCC.

MATERIALS AND METHODS

Medline and Scopus data base search was performed in order to identify related articles on histopathological parameters in predicting prognosis of oral squamous cell carcinoma. The primary emphasis is on the studies conducted in SSEA, with an accompanying comparison of their findings with those from research conducted in other parts of the world.

RESULTS

It has been shown that the number of studies conducted in SSEA is not proportionate to the high prevalence of Oral Cancer in the region. There is no significant difference between the findings from SSEA compared to the rest of the world. It is clearly shown that most histopathological parameters can be accurately used to predict nodal metastasis and prognosis.

CONCLUSIONS

Histopathological parameters can be used reliably in planning treatment of Oral cancer. Clinicians should combine clinical and histopathological parameters in drawing treatment plan for Oral Cancer.

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.

A comprehensive analysis of LINC00958 as a prognostic biomarker for head and neck squamous cell carcinoma

This work focused on exploring whether the long intergenic non-protein coding RNA LINC00958 is associated with the prognosis of head and neck squamous cell carcinoma (HNSCC). Associations of the LINC00958 expression level with clinicopathological features of HNSCC were investigated by logistic regression and Wilcoxon signed-rank test. The Kaplan-Meier method was applied to evaluate patient survival. Clinical data and expression profiles were obtained from The Cancer Genome Atlas (TCGA). Associations of patient clinical characteristics with overall survival (OS), progression-free interval (PFI), and disease-specific survival (DSS) were assessed by univariate and multivariate analysis using the Cox proportional hazard model. Immune cell infiltration analysis and gene set enrichment analysis (GSEA) were applied to determine any significant effects of LINC00958. High LINC00958 expression was related to early pT stage (P < 0.01), primary therapy outcome (P < 0.01), HPV status (P < 0.001), lymphovascular invasion (P < 0.001), and perineural invasion (P < 0.01). The receiver operating characteristic curve showed strong prognostic power for LINC00958 (area under curve = 0.886). High LINC00958 expression predicted poor OS (P = 0.007), DSS (P = 0.036), and PFI (P = 0.040). LINC00958 was related to signalling pathways and the infiltration of certain immune cells. miR-27b-5p was significantly associated with LINC00958, and downstream NT5E predicted poor survival in HNSCC cases. LINC00958 may affect the prognosis by regulating NT5E via miR-27b-5p, and could serve as a possible factor to predict the prognosis of HNSCC, especially oral squamous cell carcinoma.

Impact of LINC00312 gene polymorphism coupled with habitual risks on buccal mucosa cancer

Oral squamous cell carcinoma (OSCC) is a prevalent and lethal malignancy with a diverse etiology. LINC00312 is a long intergenic non-coding RNA that functions as a signal hub to regulate the progression and treatment of head and neck cancer. The aim of this study was to evaluate the effect of LINC00312 single nucleotide polymorphisms (SNPs) on the development of oral cancer. Two LINC00312 SNPs, namely rs12497104 and rs164966, were investigated among 469 male patients with cancer of buccal mucosa and 1194 gender- and age-matched controls. No significant correlation was observed between these two SNPs and the occurrence of OSCC in the case and control groups. While assessing the clinicopathological features, carriers of at least one minor allele of rs164966 (GA and GG) were less prone to develop lymph node metastasis (adjusted odds ratio [AOR], 0.666; 95% confidence interval [CI], 0.447-0.991; p=0.045) in comparison with homozygous carriers of the major allele (AA). Subsequent stratifying surveys revealed that this genetic association with nodal spread was seen only in cases who habitually chewed betel quid (AOR, 0.616; 95% CI, 0.386-0.985; p=0.042) or smoked cigarettes (AOR, 0.612; 95% CI, 0.393-0.953; p=0.029), but undetected in cases free of these main behavioral risks. Our results indicate an interactivity of LINC00312 rs164966 with lifestyle-related risks on modulating OSCC progression.

Role of Lymphovascular Invasion in Oral Cavity Squamous Cell Carcinoma Regional Metastasis and Prognosis

OBJECTIVE

The overall 5-year survival for oral squamous cell carcinoma (OSCC) has not changed in the last 20 years despite advances in treatment. Lymphovascular invasion (LVI) has been shown to be a negative prognostic factor in other cancers, however its role in the prognosis of OSCC remains unclear. This study aims to determine if LVI is a predictor of cervical lymph node metastasis and/or recurrence in OSCC.

METHODS

We conducted a retrospective cohort review of patients from our institutional cancer registry who were treated for OSCC between 2004 and 2018. Patient demographics, surgical pathology results, and clinical outcome data were collected. A multivariable logistic regression analysis was performed to determine if LVI was an independent predictor of cervical lymph node metastasis and/or recurrence.

RESULTS

442 patients were included, 32.8% were female and median age at time of diagnosis was 61.2 years. LVI was present in 32.8% of patients. When controlled for age, sex, t-classification, perineural invasion, depth of invasion (DOI), and margin status, LVI was a significant predictor of the presence of cervical node metastasis (OR: 3.42, CI: 2.17-5.39, P < .001). There was no significant association found between LVI and local recurrence (OR: 1.03, CI: 0.57-1.84, P = .92), regional recurrence (OR: 1.10, CI: 0.57-2.11, P = .78), or distant recurrence (OR: 1.59, CI: 0.87-2.94, P = .13).

CONCLUSION

The results of this study suggest that LVI is a significant predictor of the presence of cervical lymph node metastasis at presentation independent of other known prognostic factors. LVI, however, was not found to be a significant independent predictor of locoregional or distant recurrence.Level of Evidence: Level III.

Transverse Cervical Artery Based Free Flap in Reconstruction of a Tongue Defect: A Case Report

In the era of reconstructive surgery, new and revolutionary options are being explored in oro-facial defect reconstruction. As free flaps are presently front runners for reconstruction of defects resulting from resection of benign and malignant lesions, there is a need for devising newer options to serve the need of covering defects following oncological resection. The availability of promising pedicles in the supraclavicular region makes it a potential donor site for harvesting regional flaps, and going forward, free flaps. Transverse cervical artery flap has been a useful regional flap for head and neck reconstruction but there are limited literature pertaining to transverse cervical artery free flap. We report a case of successful reconstruction of tongue defect with transverse cervical artery free flap.

Interactive effects of CDKN2B-AS1 gene polymorphism and habitual risk factors on oral cancer

Oral squamous cell carcinoma (OSCC) is a common malignant disease associated with a high mortality rate and heterogeneous disease aetiology. Cyclin dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1), is a long noncoding RNA that has been shown to act as a scaffold, sponge, or signal hub to promote carcinogenesis. Here, we attempted to assess the effect of CDKN2B-AS1 single-nucleotide polymorphisms (SNPs) on the susceptibility to OSCC. Five CDKN2B-AS1 SNPs, including rs564398, rs1333048, rs1537373, rs2151280 and rs8181047, were analysed in 1060 OSCC cases and 1183 cancer-free controls. No significant association of these five SNPs with the risk of developing OSCC was detected between the case and control group. However, while examining the clinical characteristics, patients bearing at least one minor allele of rs1333048 (CA and CC) were more inclined to develop late-stage (stage III/IV, adjusted OR, 1.480; 95% CI, 1.129-1.940; p = 0.005) and large-size (greater than 2 cm in the greatest dimension, adjusted OR, 1.347; 95% CI, 1.028-1.765; p = 0.031) tumours, as compared with those homologous for the major allele (AA). Further stratification analyses demonstrated that this genetic correlation with the advanced stage of disease was observed only in habitual betel quid chewers (adjusted OR, 1.480; 95% CI, 1.076-2.035; p = 0.016) or cigarette smokers (adjusted OR, 1.531; 95% CI, 1.136-2.063; p = 0.005) but not in patients who were not exposed to these major habitual risks. These data reveal an interactive effect of CDKN2B-AS1 rs1333048 with habitual exposure to behavioural risks on the progression of oral cancer.

PTP4A1 promotes oral squamous cell carcinoma (OSCC) metastasis through altered mitochondrial metabolic reprogramming

PTP4A1 (Protein tyrosine phosphatase 4A1) is a protein tyrosine phosphatase that regulates a range of pro-oncogenic signaling pathways. Here, we report a novel role for PTP4A1 in oral squamous cell carcinoma (OSCC) growth and development. We show that PTP4A1 is frequently overexpressed in OSCC cells and tissues compared to adjacent non-tumor tissue. In OSCC, the overexpression of PTP4A1 increased cell growth and invasion in vitro, and enhanced tumor progression in vivo. At the molecular level, PTP4A1 was found to regulate mitochondrial metabolic reprogramming to enhance the invasive capacity of OSCC cells. Mechanistically, these effects were mediated through binding to pyruvate kinase isoenzyme M2 (PKM2) to promote its expression and aconitase 2 (ACO2) to enhance its degradation. Together, these data reveal PTP4A1 as a viable target for OSCC therapeutics.

Oral Cavity Cancer Tissues Differ in Isotopic Composition Depending on Location and Staging

The aim of this paper was to characterise the isotopic composition of oral squamous cell carcinoma (OSCC) specimens of different areas of the oral cavity. Secondly, we assessed whether there was a correlation between clinical stages of OSCC and isotopic abundance. The IRMS procedure was performed on 124 samples derived from 31 patients with OSCC of 15 N and 13 C to assess the isotopic composition. From each individual, four samples from the tumour, two from the margins, and two samples of healthy oral mucous membranes were derived. The two samples from the tumour and two samples from the margin were additionally subjected to histopathological assessment. Then, statistical analysis was conducted. Tumour infiltration tissues of the lower lip were characterised by higher mean δ13C values compared to samples derived from cancers of the other oral cavity regions (-23.82 ± 1.21 vs. -22.67 ± 1.35); (p = 0.04). The mean percentage of nitrogen content in tumour tissues was statistically higher in patients with the most advanced cancers (11.89 ± 0.03%) versus the group of patients with II and III stage cancers (11.12 ± 0.02%); (p = 0.04). In patients at stage IV, the mean δ13C value in the cancer samples equalled -22.69 ± 1.42 and was lower than that in patients at less severe clinical stages (p = 0.04). Lower lip cancer tissues differed in the isotopic abundance of carbon in comparison with tissues derived from the group of combined samples from other locations. Values of δ13C observed in specimens derived from lower lip cancers were similar to those observed in healthy oral mucous membranes. Cancer tissues obtained from patients in the last stage of OSCC had a different isotopic composition in comparison with those obtained from earlier stages. To confirm these observations, further research on larger groups of patients is needed.

Lymph Node Ratio as a Prognostic Factor for Oral Tongue Squamous Cell Carcinoma: A Retrospective Study

Background Oral squamous cell carcinoma (OSCC) incidence and its mortality have increased recently. The oral part of the tongue is one of the commonest sites for OSCC. Apart from Tumour-Node-Metastasis (TNM) staging, lymph node ratio (LNR) has been implicated as one of the useful predictors for the better clinical outcome of the disease. The aim of the present study was to assess the LNR as a prognostic factor for patients having oral tongue squamous cell carcinoma (OTSCC). Materials and methods It is a retrospective study of 122 patients with OTSCC who were managed primarily by surgery with curative intent from January 2014 to December 2016. The mean lymph node ratio was measured and compared with various parameters of clinical outcome such as five-year overall survival (OS), five-year disease-free survival (DFS), locoregional failure (LRF) within three years, and distant metastasis (DM) within five years using Kruskal-Wallis Test followed by Mann-Whitney Post Hoc Test. The association of LNR with other tumor characteristic features like perineural invasion, extra-nodal extension (ENE), and histopathological grading was also elicited. Results The study population's mean age was 50.5 ± 11.77 years. Among them, 85 were males and 37 were females. On comparing the mean LNR value with patient status after primary treatment, the patients with minimal LNR value had statistically significant five-year OS and five-year DFS (p< 0.001). High mean LNR values were associated with other adverse features like perineural invasion and ENE, which were statistically significant (p<0.001). Receiver operator characteristics (ROC) curve analysis for the LNR parameter for determining the cut-off (0.02) between OS and DFS had 86% sensitivity and 40% specificity. Conclusion The LNR could be an important prognosis factor for OTSCC that helps in determining better clinical outcomes.

Applicable Strains, Processing Techniques and Health Benefits of Fermented Oat Beverages: A Review

Based on the high nutrients of oat and the demand of health-conscious consumers for value-added and functional foods, fermented oat beverages have great market prospects. This review summarizes the applicable strains, processing techniques and health benefits of fermented oat beverages. Firstly, the fermentation characteristics and conditions of the applicable strains are systematically described. Secondly, the advantages of pre-treatment processes such as enzymatic hydrolysis, germination, milling and drying are summarized. Furthermore, fermented oat beverages can increase the nutrient content and reduce the content of anti-nutritional factors, thereby reducing some risk factors related to many diseases such as diabetes, high cholesterol and high blood pressure. This paper discusses the current research status of fermented oat beverages, which has academic significance for researchers interested in the application potential of oat. Future studies on fermenting oat beverages can focus on the development of special compound fermentation agents and the richness of their taste.

Detection of micro-metastasis using cytokeratins (AE1/AE3) in haematoxylin & eosin-stained N0 lymph nodes of oral squamous cell carcinoma

Background & objectives

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies affecting the head-and-neck region, regional lymph nodes being an important prognostication factor dictating the survival rate. Despite an array of modalities used, clinically, radiographically and routine histopathologically, the detection of micro-metastasis (2-3 mm tumour cell deposits) in the lymph nodes often escapes identification. The presence of few of these tumour epithelial cells in the lymph nodes drastically increases mortality and alters treatment plan. Hence, the identification of these cells is of major prognostic significance for a patient. Thus, the present study was aimed to evaluate and detect the efficacy of the immunohistochemical (IHC) marker [cytokeratin (CK) AE1/AE3] over routine Hematoxylin & eosin (H & E) staining in detecting micro-metastasis in the lymph nodes of OSCC cases.

Methods

Hundred H & E-stained N0 lymph nodes of OSCC cases treated with radical neck dissection were subjected to IHC with marker AE1/AE3 antibody cocktail for detecting micro-metastasis.

Results

The IHC marker CK cocktail (AE1/AE3) did not demonstrate any positive reactivity for the target antigen in all the 100 H & E stained lymph node sections evaluated in the present study.

Interpretation & conclusions

This study was undertaken to check the efficacy of IHC (CK cocktail AE1/AE3) in the detection of micro-metastasis in lymph nodes that are found to be negative in routine H&E stained sections. The findings of this study suggest that the IHC marker AE1/AE3 did not prove to be useful to detect micro-metastasis in this study population.

Role of E2F transcription factor in Oral cancer: Recent Insight and Advancements

The family of mammalian E2F transcription factors (E2Fs) comprise of 8 members (E2F1-E2F8) classified as activators (E2F1-E2F3) and repressors (E2F4-E2F8) primarily regulating the expression of several genes related to cell proliferation, apoptosis and differentiation, mainly in a cell cycle-dependent manner. E2F activity is frequently controlled via the retinoblastoma protein (pRb), cyclins, p53 and the ubiquitin-proteasome pathway. Additionally, genetic or epigenetic changes result in the deregulation of E2F family genes expression altering S phase entry and apoptosis, an important hallmark for the onset and development of cancer. Although studies reveal E2Fs to be involved in several human malignancies, the mechanisms underlying the role of E2Fs in oral cancer lies nascent and needs further investigations. This review focuses on the role of E2Fs in oral cancer and the etiological factors regulating E2Fs activity, which in turn transcriptionally control the expression of their target genes, thus contributing to cell proliferation, metastasis, and drug/therapy resistance. Further, we will discuss therapeutic strategies for E2Fs, which may prevent oral tumor growth, metastasis, and drug resistance.

Characterization of Cornulin as a Molecular Biomarker for the Progression of Oral Squamous Cell Carcinoma

Introduction It has been shown that the expression of the epidermal differentiation marker, Cornulin, declines with the progression of squamous cell carcinomas of several tissue types. Objectives This study aims to examine Cornulin expression at the cellular level in various cell lines representative of the successive progression steps of oral squamous cell carcinoma (OSCC), a major type of head and neck cancer. This can pave the way for the utilization of this novel biomarker as a diagnostic and prognostic indicator for oral cancer and help guide treatment options. Study design Western blotting was performed to measure Cornulin expression levels using standardized cell lysates from four different cell lines representing the successive steps of OSCC progression. Specifically, primary gingival keratinocytes, dysplastic oral keratinocytes (DOK), squamous cell carcinoma 25 (SCC25) cells, and Detroit 562 cells were used to represent normal oral keratinocytes, DOKs, locally invasive OSCC cells, and metastatic OSCC cells, respectively. Results Cornulin expression was found to be downregulated with the progression from normal to premalignant to malignant cells. Quantitative analysis revealed that Cornulin is significantly downregulated by 3.4 folds in DOK cells, by 23.7 folds in SCC25 cells, and by 5.2 folds in Detroit 562 cells compared to normal gingival keratinocytes. Interestingly, Cornulin was upregulated by 4.5 folds in the metastatic Detroit 562 cell line compared to the locally invasive SCC25 cells. Conclusion Altogether, Cornulin proved to be differentially expressed at the cellular level in cell lines representative of the successive steps of OSCC progression. Specifically, we documented a gradual decrease in Cornulin expression with the progression from normal to premalignant to malignant cells. Notably, there is a significant increase in the expression of Cornulin in the metastatic cell line Detroit 562 compared to the locally invasive cell line SCC25, suggesting a possible correlation with the biological behavior and unique characteristics of these two different phenotypes.

Prognosis of tongue squamous cell carcinoma associated with individual surgical margin and pathological features

The specific muscular structure of the tongue greatly affects margin shrinkage and tumor invasion, making the optimal surgical margin controversial. This study investigated surgical margin correlated prognosis of TSCC (tongue squamous cell carcinoma) according to margin location and its value, and the histopathologic factors which are suggestive of tumor invasion. And we would like to propose defining of the surgical margin for TSCC via prognosis according to location and margin values. We reviewed 45 patients diagnosed with TSCC who visited Seoul National University Dental Hospital (SNUDH) (Seoul, Republic of Korea) from 2010 to 2019, who were managed by a single surgical team. Patient clinical and pathological data of patients were retrospectively reviewed, and in 36 out of 45 patients, the pathologic parameters including the worst pattern of invasion (WPOI) and tumor budding were investigated via diagnostic histopathology slide reading. When standardized with as 0.25 cm anterior margins, as 0.35 cm deep margin, there was no significant difference in disease specific survival (DSS) or loco-regional recurrence-free survival (LRFS). Additionally, there was a non-significant difference in DSS and LRFS at the nearest margin of 0.35 cm (PDSS=0.276, PLRFS=0.162). Aggressive WPOI and high tumor budding showed lower survival and recurrence-free survival, and there were significant differences in close margin and involved margin frequencies. In TSCC, the value and location of the surgical margin did not have a significant relationship with prognosis, but WPOI and tumor budding suggesting the pattern of muscle invasion affected survival and recurrence-free survival. WPOI and tumor budding should be considered when setting an optimal surgical margin.

Assessment of Knowledge, Attitude, and Practice Regarding Oral Cancer among Dental Graduates-A Web-Based Survey

The present study was conducted to assess the knowledge, attitude, and practice among new dental graduates across India. A web-based questionnaire was generated as a link through Google Drive which was sent to approximately 250 dental graduates using Whatsapp messenger. A total of 205 complete responses were received and analyzed. Frequency analysis was done using SPSS software version 21. Oral squamous cell carcinoma (OSCC) was identified as most common cancer by 48% of the subjects while the stage of oral cancer in which it is most often diagnosed was only responded correctly by 15.5% as advanced stage. Approximately one fourth (25.4%) of the participants performed dental examination to detect cancer routinely in all patients. Half of the study subjects were confident in detecting oral cancer, still majority (70.6%) of the subjects were interested in attending continuing education course on oral cancer in the future. This study revealed that the majority of the new dental clinicians were not having legitimate knowledge regarding oral cancer. Thus, this lacuna in knowledge and skills can be eliminated by conducting workshops and continuing education programs. This may subsequently aid to improve patient care.

Non-Coding RNAs and Oral Cancer: Small Molecules With Big Functions

Oral cancer remains a major public concern with considerable socioeconomic impact in the world. Despite substantial advancements have been made in treating oral cancer, the five-year survival rate for oral cancer remained undesirable, and the molecular mechanisms underlying OSCC carcinogenesis have not been fully understood. Noncoding RNAs (ncRNAs) include transfer RNAs (tRNAs), as well as small RNAs such as microRNAs, and the long ncRNAs such as HOTAIR are a large segment of the transcriptome that do not have apparent protein-coding roles, but they have been verified to play important roles in diverse biological processes, including cancer cell development. Cell death, such as apoptosis, necrosis, and autophagy, plays a vital role in the progression of cancer. A better understanding of the regulatory relationships between ncRNAs and these various types of cancer cell death is therefore urgently required. The occurrence and development of oral cancer can be controlled by increasing or decreasing the expression of ncRNAs, a method which confers broad prospects for oral cancer treatment. Therefore, it is urgent for us to understand the influence of ncRNAs on the development of different modes of oral tumor death, and to evaluate whether ncRNAs have the potential to be used as biological targets for inducing cell death and recurrence of chemotherapy. The purpose of this review is to describe the impact of ncRNAs on cell apoptosis and autophagy in oral cancer in order to explore potential targets for oral cancer therapy.

Prognostic value of pretreatment lymphocyte-to-monocyte ratio in patients with advanced oral cavity cancer

Introduction

Lymphocyte-to-monocyte ratio (LMR) has been reported as a prognostic factor in many cancers but the data are to date limited for its use in oral cavity cancer. The purpose of this study was to evaluate the prognostic value of LMR in advanced-stage oral cavity cancer.

Methods

Data from 211 advanced-stage oral cancer patients treated with curative intent between January 2009 and December 2015 were obtained from the hospital information system. Pretreatment LMR and other hematologic parameters were recorded and an LMR cutoff value was calculated. Overall survival between the groups above (high LMR) and below (low LMR) the cutoff was compared and hazard ratios from univariate and multivariate analyses using a Cox proportional hazards model calculated.

Results

Overall survival and disease-specific survival were better in the high LMR group. The 5-year overall survival rates were 31.6% and 15% in the high LMR and low LMR groups, respectively. Multivariate analysis using a Cox proportional hazards model showed that treatment modality and LMR were the only factors associated with overall survival.

Conclusion

Low LMR was associated with poor survival outcome in patients with advanced-stage oral cavity cancer.

Level of Evidence

2b.

Emerging histopathologic markers in early-stage oral tongue cancer: A systematic review and meta-analysis

Although there are many histopathologic prognosticators, grading of early oral tongue squamous cell carcinoma (OTSCC) is still based on morphological cell differentiation which has low prognostic value. Here we summarize the emerging histopathological markers showing powerful prognostic value, but are not included in pathology reports. Using PubMed, Scopus, Ovid Medline, and Web of Science databases, a systematic literature search was preformed to identify early OTSCC studies that investigated the prognostic significance of hematoxylin–eosin‐based histopathologic markers. Our meta‐analysis showed that tumor budding was associated with overall survival (hazard ratio [HR] 2.32; 95% CI 1.40–3.84; p < 0.01) and disease‐specific survival (DSS) (1.89; 95% CI 1.13–3.15; p = 0.02). Worst pattern of invasion was associated with disease‐free survival (DFS) (1.95; 95% CI 1.04–3.64; p = 0.04). Tumor–stroma ratio was also associated with DFS (1.75, 95% CI 1.24–2.48; p < 0.01) and DSS (1.69; 95% CI 1.19–2.42; p < 0.01). Tumor budding, worst pattern of invasion, and tumor–stroma ratio have a promising prognostic value in early OTSCC. The evaluation and reporting of these markers is cost‐effective and can be incorporated in daily practice.

Early-onset oral cancer as a clinical entity: aetiology and pathogenesis

Oral squamous cell carcinoma (OSCC) is one of the most important medical and socio-economic problems in many of the developed countries worldwide, due to the high mortality. The incidence of OSCC among individuals under 45 years of age is growing every year; however, the aetiological factors and pathogenetic mechanisms are poorly understood. This review summarizes the available information regarding clinicopathological features, extrinsic and intrinsic aetiological factors, and the molecular and immune landscape of early-onset OSCC. This cancer shows high recurrence rates and is not associated with the aetiological factors specific to adult-onset OSCC. Young adults with OSCC are not infected with human papillomavirus and rarely consume alcohol or tobacco, but more frequently use smokeless tobacco. Data from single studies indicate the hereditary nature of early-onset OSCC: the KIR2DL1⁺-HLA-C2⁺ genotype and MMP-1 2 G allele are frequently detected in young patients. Early-onset OSCC shows specific genetic, epigenetic, transcriptomic, and proteomic changes. The tumour microenvironment in early-onset OSCC is tolerogenic rather than immunogenic. All of the data suggest that OSCC in young patients is a separate clinical entity with a specific aetiology and pathogenesis. Further studies are needed to reveal the causes and molecular targets of early-onset OSCC for the development of preventive and therapeutic strategies.

Association Between Mean Platelet Volume, Platelet Count, and Distribution Width With Depth of Invasion in Oral Cancers

INTRODUCTION

To examine the potential predictive roles of the preoperative mean platelet volume (MPV), platelet count (PC), and platelet distribution width (PDW) in patients with oral cancer and their association with the depth of invasion (DOI).

METHODS

This retrospective study included 122 patients (66 males, 56 females) diagnosed with oral cancer between January 2009 and January 2015 by our Otolaryngology Department. At diagnosis, the mean age was 64.6 ± 13.9 years. The average follow-up period was 39.2 ± 23.9 months.

RESULTS

We found significant differences in all parameters (PDW, MPV, PC) based on the positivity of the lymph node and the tumor stage. The mean PDW, MPV, and PC were significantly higher in the exitus group than in the survivor group (P = .010, .036, and .047, respectively). In patients with high PDW, we observed a lower progression-free survival. We observed that PDW had a significant impact on the recurrence of the disease. Platelet distribution width, MPV, and PC were significant prognostic factors. A high PDW increased fatality 4.1 times, and a high MPV increased fatality 4.7 times (P = .040 and .032, respectively). We found in a univariate analysis that tumor grade, PDW, MPV, and PC were predictive factors for fatality. On multivariate analysis, we found that MPV, PC, and predictors were independent of tumor grade. We observed an association between MPV and DOI.

CONCLUSION

High PC, MPV, and PDW could be meaningful prognostic predictors for low survival rates. Mean platelet volume appears to be a more effective marker because it is associated with the DOI and prognosis. However, further research is required to confirm our findings.

Prognostic Impact of Pattern of Mandibular Involvement in Gingivo-Buccal Complex Squamous Cell Carcinomas: Marrow and Mandibular Canal Staging System

Purpose

To study the pattern of mandibular involvement and its impact on oncologic outcomes in patients with gingivo-buccal complex squamous cell carcinoma (GBC-SCC) and propose a staging system based on the pattern of bone involvement (MMC: Marrow and mandibular canal staging system) and compare its performance with the 8th edition of the American Joint Committee on Cancer (AJCC8).

Methods

This retrospective observational study included treatment-naïve GBC-SCC patients who underwent preoperative computed tomography (CT) imaging between January 1, 2012, and March 31, 2016, at a tertiary care cancer center. Patients with T4b disease with high infratemporal fossa involvement, maxillary erosion, and follow-up of less than a year were excluded. The chi-square or Fisher’s exact test was used for descriptive analysis. Kaplan–Meier estimate and log-rank test were performed for survival analysis. Multivariate analysis was done using Cox regression analysis after making adjustments for other prognostic factors. p-Value <0.05 was considered as significant. Based upon the survival analysis with different patterns of bone invasion, a new staging system was proposed “MMC: Marrow and mandibular canal staging system”. “Akaike information criterion” (AIC) was used to study the relative fitted model of the various staging (TNM staging—AJCC8) with respect to survival parameters.

Results

A total of 1,200 patients were screened; 303 patients were included in the study. On radiology review, mandibular bone was involved in 62% of patients. The pattern of bone involvement was as follows: deep cortical bone erosion (DCBE) in 23%, marrow in 34%, and marrow with the mandibular canal in 43% of patients. Patients with DCBE and no bone involvement (including superficial cortical) had similar survival [disease-free survival (DFS) and locoregional recurrence-free survival (LRRFS)], and this was significantly better than those with marrow with or without mandibular canal involvement (for both DFS and LRRFS). Patients with DCBE were staged using the MMC, and when compared with the AJCC8, the MMC system was better for the prediction of survival outcomes, as AIC values were lower compared with those of the AJCC8. There was a significant association (p = 0.013) between the type of bone involvement and the pattern of recurrence.

Conclusions

For GBC-SCC, only marrow with or without mandibular canal involvement is associated with poorer survival outcomes. As compared with the AJCC8, the proposed Mahajan et al. MMC staging system downstages DCBE correlates better with survival outcomes.

SNHG1/miR-194-5p/MTFR1 Axis Promotes TGFβ1-Induced EMT, Migration and Invasion of Tongue Squamous Cell Carcinoma Cells

Tongue squamous cell carcinoma (TSCC) is a common malignancy with aggressive biological behaviors. Mitochondrial fission regulator 1 (MTFR1), is aberrantly expressed in head and neck squamous cell carcinoma (HNSC), but its role in TSCC remains unclear. We aimed to explore the role of MTFR1 in TSCC. The expression of long non-coding RNA small nucleolar RNA host gene 1 (SNHG1), microRNA-194-5p and MTFR1 in TSCC cells was measured by RT-qPCR. Luciferase reporter assay and RNA pull down assay were applied to confirm the binding capacity between miR-194-5p and SNHG1 (or MTFR1). TSCC cell invasion and migration were accessed by Transwell assays. The protein levels of MTFR1 and epithelial-mesenchymal transition (EMT) markers were examined by western blot. MTFR1 had high expression level in TSCC. MTFR1 knockdown inhibited transforming growth factor β1 (TGFβ1)-induced EMT, migration and invasion of TSCC cells in vitro. MiR-194-5p targeted MTFR1 and negatively regulated its expression. In addition, SNHG1 upregulated the expression of MTFR1 by binding with miR-194-5p. Importantly, SNHG1 promoted EMT, invasion and migration of TSCC cells by upregulating MTFR1. SNHG1/miR-194-5p/MTFR1 axis promotes TGFβ1-induced EMT, migration and invasion of cells in TSCC, which could be potential targets for treating TSCC patients.

Machine Learning Algorithms as a Computer-Assisted Decision Tool for Oral Cancer Prognosis and Management Decisions: A Systematic Review

INTRODUCTION

Despite multiple prognostic indicators described for oral cavity squamous cell carcinoma (OCSCC), its management still continues to be a matter of debate. Machine learning is a subset of artificial intelligence that enables computers to learn from historical data, gather insights, and make predictions about new data using the model learned. Therefore, it can be a potential tool in the field of head and neck cancer.

METHODS

We conducted a systematic review.

RESULTS

A total of 81 manuscripts were revised, and 46 studies met the inclusion criteria. Of these, 38 were excluded for the following reasons: use of a classical statistical method (N = 16), nonspecific for OCSCC (N = 15), and not being related to OCSCC survival (N = 7). In total, 8 studies were included in the final analysis.

CONCLUSIONS

ML has the potential to significantly advance research in the field of OCSCC. Advantages are related to the use and training of ML models because of their capability to continue training continuously when more data become available. Future ML research will allow us to improve and democratize the application of algorithms to improve the prediction of cancer prognosis and its management worldwide.

CD44-positive cancer stem cells from oral squamous cell carcinoma exhibit reduced proliferation and stemness gene expression upon adipogenic induction

We proposed to assess adipogenic differentiation and its effect on the proliferation and stemness markers in CD44 + OSCC CSCs. D44 + CSCs were sorted by magnetic sorting from the single-cell suspension of the OSCC tumor. Adipogenic differentiation was induced by an adipogenic induction medium. Lipid droplet formation was confirmed by oil red O staining. The expression of the cell surface marker was analyzed by flow cytometry. Real-time qPCR was performed to examine the gene expression activity. CD44 + OSCC CSCs can differentiate into adipocytes and adipogenesis in these cells decrease their proliferation and stemness gene expression. Adipogenic induction can make the cancer stem cells from OSCC tumors lose their stemness potential. Oral cancer, especially OSCC, is a huge burden worldwide. Similar to other stem cells, cancer stem cells can differentiate into other lineage cells. Our study shows that the proliferation and stemness gene expression in the CSCs from OSCC tumors can be thwarted by inducing them to differentiate into adipocytes, which could be advantageous to find out new clinical approaches in the treatment of cancers, like OSCC.

Body Mass Index and Diabetes Mellitus May Predict Poorer Overall Survival of Oral Squamous Cell Carcinoma Patients: A Retrospective Cohort From a Tertiary-Care Centre of a Resource-Limited Country

Introduction:

Oral squamous cell carcinoma (OSCC) is one of the highest-ranking cancers among both genders in Pakistan. Obesity is linked to a much higher risk for developing multiple cancer types. Individuals with Diabetes mellitus (DM) face an increased risk for developing oral cancer. Hence, the objective of this study was to identify the effect of obesity and DM on the prognosis of OSCC patients.

Methods:

This retrospective cohort analysis was conducted on 386 patients diagnosed and treated for OSCC at The Aga Khan University Hospital, Karachi, Pakistan. Patient information was obtained from hospital medical records. Obesity was defined as having a body mass index (BMI) of ⩾25 kg/m² according to the WHO Asian cut-offs for BMI. Patient BMI was correlated with diabetes status, clinicopathological features and overall survival. Kaplan-Meier survival analysis was performed, along with univariate and multivariate cox regression analysis to test the effect of obesity and diabetes on overall survival.

Results:

In a set of 386 patients, there were 296 males (76.7%) and 90 females (23.3%). The mean BMI was 24.4 (SD ± 5.25) and 42.7% of patients were found to be obese (⩾25 BMI). 64 patients (16.6%) were diabetic. The risk of death was significantly higher in underweight patients (P = .035) compared with normal weight individuals. Diabetics had a higher mean BMI compared with non-diabetics. However, DM was not a statistically valid predictor of survival.

Conclusion:

Underweight OSCC patients were at a higher risk of death compared with normal weight OSCC patients.

Diagnostic Accuracy of Confocal Laser Endomicroscopy for the Diagnosis of Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Background: Advances in treatment approaches for patients with oral squamous cell carcinoma (OSCC) have been unsuccessful in preventing frequent recurrences and distant metastases, leading to a poor prognosis. Early detection and prevention enable an improved 5-year survival and better prognosis. Confocal Laser Endomicroscopy (CLE) is a non-invasive imaging instrument that could enable an earlier diagnosis and possibly help in reducing unnecessary invasive surgical procedures. Objective: To present an up to date systematic review and meta-analysis assessing the diagnostic accuracy of CLE in diagnosing OSCC. Materials and Methods. PubMed, Scopus, and Web of Science databases were explored up to 30 June 2021, to collect articles concerning the diagnosis of OSCC through CLE. Screening: data extraction and appraisal was done by two reviewers. The quality of the methodology followed by the studies included in this review was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. A random effects model was used for the meta-analysis. Results: Six studies were included, leading to a total number of 361 lesions in 213 patients. The pooled sensitivity and specificity were 95% (95% CI, 92–97%; I² = 77.5%) and 93% (95% CI, 90–95%; I² = 68.6%); the pooled positive likelihood ratios and negative likelihood ratios were 10.85 (95% CI, 5.4–21.7; I² = 55.9%) and 0.08 (95% CI, 0.03–0.2; I² = 83.5%); and the pooled diagnostic odds ratio was 174.45 (95% CI, 34.51–881.69; I² = 73.6%). Although risk of bias and heterogeneity is observed, this study validates that CLE may have a noteworthy clinical influence on the diagnosis of OSCC, through its high sensitivity and specificity. Conclusions: This review indicates an exceptionally high sensitivity and specificity of CLE for diagnosing OSCC. Whilst it is a promising diagnostic instrument, the limited number of existing studies and potential risk of bias of included studies does not allow us to draw firm conclusions. A conclusive inference can be drawn when more studies, possibly with homogeneous methodological approach, are performed.

Prognostic Matrisomal Gene Panel and Its Association with Immune Cell Infiltration in Head and Neck Carcinomas

Simple Summary

Squamous cell carcinoma of the head and neck (SCCHN) is a heterogeneous group of tumors arising from squamous cells lining different anatomic sites. This type of malignancy has been mainly investigated by focusing primarily on tumor cells, but recent evidence highlighted the importance of the tumor microenvironment (TME) in cancer growth, progression and metastasis. Hence, we hypothesized that dysregulated matrisomal components could have a common association with patient survival, irrespective of the subsite of origin of the SCCHN. Using bioinformatic methods and public datasets, we successfully identified a gene panel with prognostic value in HPV-negative and non-metastatic node-negative tumors and demonstrated its association with immune cell infiltration.

Abstract

Squamous cell carcinoma of the head and neck (SCCHN) is common worldwide and related to several risk factors including smoking, alcohol consumption, poor dentition and human papillomavirus (HPV) infection. Different etiological factors may influence the tumor microenvironment and play a role in dictating response to therapeutics. Here, we sought to investigate whether an early-stage SCCHN-specific prognostic matrisome-derived gene signature could be identified for HPV-negative SCCHN patients (n = 168), by applying a bioinformatics pipeline to the publicly available SCCHN-TCGA dataset. We identified six matrisome-derived genes with high association with prognostic outcomes in SCCHN. A six-gene risk score, the SCCHN TMI (SCCHN-tumor matrisome index: composed of MASP1, EGFL6, SFRP5, SPP1, MMP8 and P4HA1) was constructed and used to stratify patients into risk groups. Using machine learning-based deconvolution methods, we found that the risk groups were characterized by a differing abundance of infiltrating immune cells. This work highlights the key role of immune infiltration cells in the overall survival of patients affected by HPV-negative SCCHN. The identified SCCHN TMI represents a genomic tool that could potentially aid patient stratification and selection for therapy in these patients.

Somatic mutations in oral squamous cell carcinomas in 98 Japanese patients and their clinical implications

INTRODUCTION

The somatic mutational profile of oral squamous cell carcinoma (OSCC) among Japanese patients has been less investigated, partly because of the rarity of the tumor. Moreover, previous studies have either used formalin-fixed paraffin-embedded samples or lacked paired normal tissues. We aimed to determine somatic mutations in the exomes of 76 genes, including 50 driver genes of solid cancers and NOTCH-related genes, some of which are previously reported as frequently mutated in head and neck squamous cell carcinoma or OSCC.

MATERIALS AND METHODS

We used fresh-frozen tumor/normal-paired samples from 98 treatment-naïve Japanese patients with OSCC and analyzed their correlations with clinicopathological characteristics and survival.

RESULTS

We identified 136 exonic mutations, including 78 non-synonymous mutations, 13 synonymous mutations, 22 nonsense mutations, 2 non-frameshift deletions, 11 frameshift deletion, and 5 each of splice-site and frameshift insertions. The most frequently mutated genes were TP53 (36.7%), FAT1 (9.2%), NOTCH1 (8.2%), CDKN2A (7.1%), ZFHX4 (5.1%), CASP8 (4.1%), EP300 (4.1%), and KMT2D (4.1%). We followed up 90 of the 98 patients for 3 years. Among them, TP53 mutation was associated with significantly shorter 3-year disease-free survival. Most of the identified TP53 mutations occurred in the DNA-binding domain and were functionally deleterious.

DISCUSSION

Our findings and the mutation spectra can contribute to the development of a therapeutic strategy for Japanese patients with OSCC.

Identification of specific clinical risk factors associated with the malignant transformation of oral epithelial dysplasia

BACKGROUND

Factors that increase the risk of malignant transformation of oral epithelial dysplasia (OED) are not completely elucidated.

METHODS

A retrospective chart review was performed assessing risk factors for transformation of OED, and cancer staging for transformed cases at Sunnybrook Health Sciences Centre.

RESULTS

Two-hundred four patients were diagnosed with OED, and 16.7% (34) underwent malignant transformation. Risk factors associated with transformation included: heavy tobacco smoking, excessive EtOH consumption, non-homogenous leukoplakia, size >200 mm² , moderate dysplasia or greater than moderate, progression of dysplasia grades, and immunosuppression. Transformed cases followed for a dysplastic lesion were associated with a stage-I cancer diagnosis, and cancer cases with no prior biopsy were associated with a stage-IV diagnosis.

CONCLUSIONS

In addition to commonly cited risk factors, immunosuppression was associated with malignant transformation, including the use of topical steroids. Analyzing risk factors can help clinicians define risk of progression in patients with OED.

Development and Assessment of a Machine Learning Model to Help Predict Survival Among Patients With Oral Squamous Cell Carcinoma

Importance

Predicting survival of oral squamous cell carcinoma through the use of prediction modeling has been underused, and the development of prediction models would augment clinicians' ability to provide absolute risk estimates for individual patients.

Objectives

To develop a prediction model using machine learning for 5-year overall survival among patients with oral squamous cell carcinoma and compare this model with a prediction model created from the TNM (Tumor, Node, Metastasis) clinical and pathologic stage.

Design, Setting, and Participants

A retrospective cohort study was conducted of 33 065 patients with oral squamous cell carcinoma from the National Cancer Data Base between January 1, 2004, and December 31, 2011. Patients were excluded if the treatment was considered palliative, staging demonstrated T0 or Tis, or survival or staging data were missing. Patient, tumor, treatment, and outcome information were obtained from the National Cancer Data Base. The data were split into a distribution of 80% for training and 20% for testing. The model was created using 2-class decision forest architecture. Permutation feature importance scores were used to determine the variables that were used in the model's prediction and their order of significance. Statistical analysis was conducted from August 1, 2018, to January 10, 2019.

Main Outcomes and Measures

Ability to predict 5-year overall survival assessed through area under the curve, accuracy, precision, and recall.

Results

Among the 33 065 patients in the study, the mean (SD) age was 64.6 (14.0) years, 19 791 were men (59.9%), 13 274 were women (40.1%), and 29 783 (90.1%) were white. At 60 months, there were 16 745 deaths (50.6%). The median time of follow-up was 56.8 months (range, 0-155.6 months). Age, pathologic T stage, positive margins at the time of surgery, lymph node size, and institutional identification were identified among the most significant variables. The calculated area under the curve for this machine learning model was 0.80 (95% CI, 0.79-0.81), accuracy was 71%, precision was 71%, and recall was 68%. In comparison, the calculated area under the curve of the TNM staging system was 0.68 (95% CI, 0.67-0.70), accuracy was 65%, precision was 69%, and recall was 52%.

Conclusions and Relevance

Using machine learning algorithms, a prediction model was created based on patient social, demographic, clinical, and pathologic features. The developed prediction model proved to be better than a prediction model that exclusively used TNM pathologic and clinical stage according to all performance metrics. This study highlights the role that machine learning may play in individual patient risk estimation in the era of big data.

Socioeconomic Influences on Short-term Postoperative Outcomes in Patients With Oral Cavity Cancer Undergoing Free Flap Reconstruction

OBJECTIVE

To evaluate the associations between median household income (MHI) and area deprivation index (ADI) on postoperative outcomes in oral cavity cancer.

STUDY DESIGN

Retrospective review (2000-2019).

SETTING

Single-institution tertiary medical center.

METHODS

MHI and ADI were matched from home zip codes. Main postoperative outcomes of interest were length of tracheostomy use, length of hospital stay, return to oral intake, discharge disposition, and 60-day readmissions. Linear and logistic regression controlled for age, sex, race, body mass index, tobacco and alcohol use history, primary tumor location, disease staging at presentation, and length of surgery. A secondary outcome was clinical disease staging (I-IV) at time of presentation.

RESULTS

The cohort (N = 681) was 91.3% White and 38.0% female, and 51.7% presented with stage IV disease. The median age at the time of surgery was 62 years (interquartile range [IQR], 53-71). The median MHI was $47,659 (IQR, $39,324-$58,917), and the median ADI was 67 (IQR, 48-79). ADI and MHI were independently associated with time to return of oral intake (β = 0.130, P = .022; β = -0.092, P = .045, respectively). Neither was associated with length of tracheostomy, hospital stay, discharge disposition, or readmissions. MHI quartiles were associated with a lower risk of presenting with more advanced disease (Q3 vs Q1: adjusted odds ratio, 0.56 [95% CI, 0.32-0.97]).

CONCLUSION

MHI is associated with oral cavity cancer staging at the time of presentation. MHI and ADI are independently associated with postoperative return to oral intake following intraoral tumor resection and free flap reconstruction.

Association of LINC00673 Genetic Variants with Progression of Oral Cancer

Oral squamous cell carcinoma (OSCC) is a multifactorial malignancy, and its high incidence and mortality rate remain a global public health burden. Polymorphisms in the long intergenic noncoding RNA 673 (LINC00673) have been currently connected to the predisposition to various cancer types. The present study attempted to explore the impact of LINC00673 gene polymorphisms on the risk and progression of OSCC. Three LINC00673 single-nucleotide polymorphisms (SNPs), including rs11655237, rs9914618, and rs6501551, were evaluated in 1231 OSCCC cases and 1194 cancer-free controls. We did not observe any significant association of three individual SNPs with the risk of OSCC between the case and control group. However, while assessing the clinicopathological parameters, patients carrying at least one minor allele of rs9914618 (GA and AA; OR, 1.286; 95% CI, 1.008–1.642; p = 0.043) were found to develop lymph node metastasis more often compared to those who are homozygous for the major allele. Further stratification analyses revealed that this genetic correlation with increased risk of lymphatic spread was further fortified in habitual betel quid chewers (OR, 1.534; 95% CI, 1.160–2.028; p = 0.003) or smokers (OR, 1.320; 95% CI, 1.013–1.721; p = 0.040). Moreover, through analyzing the dataset from The Cancer Genome Atlas (TCGA), we found that elevated LINC00673 levels were associated with the development of large tumors in patients with head and neck squamous cell carcinoma and the risk of lymphatic spread in smokers. These data demonstrate a joint effect of LINC00673 rs9914618 with betel nut chewing or smoking on the progression of oral cancer.

Overexpression of miRNA-9 enhances galectin-3 levels in oral cavity cancers

Oral cavity cancer (OCC) is the predominant subtype of head and neck cancer (HNC) and has up to 50% mortality. Genome-wide microRNA (miR) sequencing data indicates overexpression of miR-9-5p in HNC tumours, however, the biological role of miR-9-5p in OCC is complex; it can either act as a tumour suppressor or an oncomir, regulating many target genes at the post-transcriptional level. We have investigated the overexpression of miR-9-5p in three OCC cell lines. We have evaluated its expression levels and Galectin-3 as potential biomarkers in saliva samples collected from controls and OCC patients. We found that over expression of miR-9-5p in OCC cell lines resulted in a significant reduction in cell proliferation and migration, and an increase in apoptosis, which was paralleled by an increase in Galectin-3 secretion and export of Galectin-3 protein. Our data are consistent with miR-9-5p being a modulator of Galectin-3 via the AKT/γ-catenin pathway. In addition, the positive correlation between the levels of miR-9-5p expression and secreted Galectin-3 in saliva reflects a similar relationship in vivo, and supports the utility of their integrative evaluation in OCC. Our findings indicate that both miR-9-5p and Galectin-3 are critical biomolecules in the progression of OCC.

Application of the Interaction between Tissue Immunohistochemistry Staining and Clinicopathological Factors for Evaluating the Risk of Oral Cancer Progression by Hierarchical Clustering Analysis: A Case-Control Study in a Taiwanese Population

The aim of this single-center case-control study is to investigate the feasibility and accuracy of oral cancer protein risk stratification (OCPRS) to analyze the risk of cancer progression. All patients diagnosed with oral cancer in Taiwan, between 2012 and 2014, and who underwent surgical intervention were selected for the study. The tissue was further processed for immunohistochemistry (IHC) for 21 target proteins. Analyses were performed using the results of IHC staining, clinicopathological characteristics, and survival outcomes. Novel stratifications with a hierarchical clustering approach and combinations were applied using the Cox proportional hazard regression model. Of the 163 participants recruited, 102 patients were analyzed, and OCPRS successfully identified patients with different progression-free survival (PFS) profiles in high-risk (53 subjects) versus low-risk (49 subjects) groups (p = 0.012). OCPRS was composed of cytoplasmic PLK1, phosphoMet, and SGK2 IHC staining. After controlling for the influence of clinicopathological features, high-risk patients were 2.33 times more likely to experience cancer progression than low-risk patients (p = 0.020). In the multivariate model, patients with extranodal extension (HR = 2.66, p = 0.045) demonstrated a significantly increased risk for disease progression. Risk stratification with OCPRS provided distinct PFS groups for patients with oral cancer after surgical intervention. OCPRS appears suitable for routine clinical use for progression and prognosis estimation.

Quantitative evaluation and comparison of two prodrug-activating suicide gene therapies on oral squamous cell carcinoma

Prodrug-activating suicide gene therapy (PA suicide gene therapy for short) for cancer is to introduce cancer cells with suicide genes. The enzyme encoded by suicide gene is not toxic but is able to kill cancer cells by converting a non-toxic prodrug into a toxic compound. This approach is a promising cancer gene therapy that could reduce non-specific toxicity to normal tissue. However, there is no quantitative method to evaluate efficacy of suicide gene therapy in preclinical study. The aim of this study is to develop a new method to quantitatively evaluate and compare prodrug-activating suicide gene therapies. This study was carried out on an oral squamous cell carcinoma (OSCC) cell line CAL-27. Suicide genes were integrated into ROSA26 locus of CAL-27 by CRISPR-Cas9. CAL-27 cell lines stably expressing herpes simplex virus-thymidine kinase (TK) or yeast cytosine deaminase (CD) were used to evaluate and compare PA suicide gene therapies. The efficacies of PA suicide gene therapies were quantitatively evaluated from three aspects: effective prodrug concentration, prodrug treatment time, and bystander effect. This method also could be used for different types of suicide gene therapies and different types of cancer. When the prodrug concentration, treatment time, and rate of suicide gene-positive cells (related to bystander effect) are fixed, anti-cancer effects could be quantitatively measured. This information is important for suicide gene therapy preclinical development.

MicroRNA-363-3p inhibits tumor cell proliferation and invasion in oral squamous cell carcinoma cell lines by targeting SSFA2

The aim of the present study was to evaluate the expression levels of microRNA (miR)-363-3p and its underlying physiological function in oral squamous cell carcinoma (OSCC). miR-363-3p expression levels were measured in OSCC cell lines using reverse transcription-quantitative PCR. The role of miR-363-3p in OSCC cells was examined using gain-of-function assays in vitro. Cell proliferation was assessed using Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine assays and flow cytometry. Cell migration and invasion were evaluated in wound-healing and Transwell Matrigel assays. In addition, bioinformatics analysis predicted binding sites of miR-363-3p on sperm-specific antigen 2 (SSFA2). Luciferase reporter and RNA pull-down assays were conducted to test whether miR-363-3p interacted with SSFA2. miR-363-3p expression was downregulated in OSCC cell lines compared with that in the normal epithelial cell line (NHOK). Additionally, miR-363-3p overexpression suppressed OSCC cell proliferation, migration and invasion in vitro. SSFA2 was verified as a direct target of miR-363-3p, and SSFA2 overexpression partially counteracted the inhibitory effects of miR-363-3p on cell proliferation, migration and invasion in OSCC cell lines. Thus, miR-363-3p may serve as a tumor suppressor via targeting SSFA2 and may represent a potential therapeutic target for OSCC.

Major Molecular Signaling Pathways in Oral Cancer Associated With Therapeutic Resistance

Oral cancer is a sub-category of head and neck cancers that primarily initiates in the oral cavity. The primary treatment option for oral cancer remains surgery but it is associated with massive disfigurement, inability to carry out normal oral functions, psycho-social stress and exhaustive rehabilitation. Other treatment options such as chemotherapy and radiotherapy have their own limitations in terms of toxicity, intolerance and therapeutic resistance. Immunological treatments to enhance the body's ability to recognize cancer tissue as a foreign entity are also being used but they are new and underdeveloped. Although substantial progress has been made in the treatment of oral cancer, its complex heterogeneous nature still needs to be explored, to elucidate the molecular basis for developing resistance to therapeutic agents and how to overcome it, with the aim of improving the chances of patients' survival and their quality of life. This review provides an overview of up-to-date information on the complex role of the major molecules and associated signaling, epigenetic changes, DNA damage repair systems, cancer stem cells and micro RNAs in the development of therapeutic resistance and treatment failure in oral cancer. We have also summarized the current strategies being developed to overcome these therapeutic challenges. This review will help not only researchers but also oral oncologists in the management of the disease and in developing new therapeutic modalities.

Extracellular matrix metalloproteinase inducer expression in histological grades of oral squamous cell carcinoma - An immunohistochemical study

Background:

Oral squamous cell carcinoma (OSCC) is the most common type of head-and-neck cancer. It is a complex and relentless malignancy prone to local invasion and dissemination. An insight into the molecular alterations associated with metastasis will provide critical insights into the fundamental mechanisms underlying its progression and further contribute to improvements in the clinical management of H and N cancer patients. Hence, identifying specific biomarkers would pave the way for early detection and prognosis of OSCC. Extracellular matrix metalloproteinase inducer (EMMPRIN) is a membrane-bound glycoprotein found on the surface of tumor cells. It plays a central role in the promotion of tumor invasion, progression and metastasis as it upregulates matrix metalloproteinases secreted from adjacent fibroblasts. There is a paucity of studies on the expression of EMMPRIN in OSCC.

Objectives:

The aim is to assess the immunohistochemical expression of EMMPRIN in OSCC and to compare it with the clinicopathological parameters and histological grades of OSCC.

Materials and Methods:

Thirty histopathologically diagnosed cases of OSCC were included in the study. The slides were immunohistochemically analyzed for EMMPRIN expression and correlated with the clinicopathological parameters and histological grades of OSCC.

Results:

EMMPRIN expression was noted in all 30 cases of OSCC. Strong EMMPRIN expression was noted in the advanced clinical stages of OSCC. Higher histological grades of OSCC exhibited strong EMMPRIN expression.

Conclusion:

EMMPRIN overexpression indicates that this protein could be used as an important biological prognostic marker to identify high-risk OSCC patients.

Expression of p53 at invasive front of oral squamous cell carcinoma and negative histopathological surgical margins to establish correlation at 3-year survival

Background:

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity. The histologic features of OSCC differ from area to area within same tumor, and most prognostic information can be revealed from the invasive front of tumor. The most accepted line of treatment is radical neck dissection. The boundaries of a resected specimen are the surgical margins (SMs), which are excised by the surgeon. The survival outcome is based on the status of these resected SMs. To avoid local recurrence and improve overall survival, it is necessary to attain negative SM. Apart from routine histopathology, the molecular assessment of resected margins has recently gained value which has a promising role for margin surveillance. The value of the use of molecular markers in the routine examination of resection specimens of OSCC has not yet established. It is crucial to identify the percentage of altered cells in SMs which go undetectable in the routine histopathology. It is essential to assess their role in recurrence and survival.

Materials and Methods:

The study was divided into two groups, i.e., Group I (control group): ten cases of normal oral mucosa and Group II consisted of thirty cases, in which biopsy samples of invasive tumor front and histopathologically negative SM of OSCC were included. Both the groups were subjected to p53 immunohistochemical staining

Results:

There was overexpression of p53 at the deep tumor invasive front of OSCC associated with different histologic grades of malignancy.

Conclusion:

The overexpression of p53 at the invading tumor front with clear SMs is associated with poor survival. p53 expression at the tumor front can be a prognostic marker for OSCC.

Tumor-associated macrophages: Harbingers of aggressiveness in oral squamous cell carcinoma

BACKGROUND

The significance of the tumor microenvironment (TME) as a modulator of tumor behavior was acknowledged by Hanahan and Weinberg in 2011 as the emerging hallmarks and enabling characteristics of the hallmarks of cancer. Subsequently, the role of inflammation, in conferring aggressiveness to a tumor, was regarded as a fundamental process in the evolution of the TME. Tumor-associated macrophages (TAMs) are distinctly polarized inflammatory cells and key shapers of a protumorigenic microenvironment.

AIMS

The aim of the study was to evaluate the distribution of TAMs and the expression of CD-163 as a marker to evince tumor aggressiveness, in oral squamous cell carcinoma (OSCC).

SETTINGS AND DESIGN

A retrospective institutional study was approved by the institutional ethics committee, and random sampling was carried out. Cases fulfilling the inclusion criteria were subjected to S(site), T(tumor), N( node), M( metastasis), P(pathology) STNMP staging along with immunohistochemical evaluation of CD-163.

METHODS

Samples for this study included 58 archival cases of OSCC. Demographic details were recorded, and the STNMP stage ascertained, following which, each case was reevaluated histopathologically for the invasive front. Cases with sufficient stroma and demonstrating the invasive front were further subjected to immunohistochemical evaluation of CD-163 for TAMs. The density of CD-163-positive cells was assessed by three pathologists, independently, in a double-blinded evaluation using Image-J©.

STATISTICAL ANALYSIS

Descriptive data were evaluated and analyzed statistically using Spearman's/Pearson's correlation tests based on the distribution of data.

RESULTS

The density of TAMs was noted to be directly proportional to the STNMP stage. In addition, a strong positive, statistically significant correlation was noted between the density of TAMs and tumor size, nodal status and STNMP stage.

CONCLUSION

The crucial role of the tumor microenvironment must be considered when evaluating OSCC. TAMs prove to be a reliable marker for assessing tumor aggressiveness and could aid in improved prognostication of OSCC, while also being potential targets for therapy.

SAHA Overcomes 5-FU Resistance in IFIT2-Depleted Oral Squamous Cell Carcinoma Cells

Simple Summary

IFIT2 depletion is associated with increased epithelial-mesenchymal transition and metastasis. The main aim of our study was to understand the link between drug resistance and IFIT2 depletion. In this study, we confirmed resistance to multiple common therapeutic drugs, particularly 5-FU, which showed especially high resistance in IFIT2-depleted cells. Interestingly, combination of SAHA and 5-FU overcame 5-FU resistance in IFIT2-depleted cells. Hence, our findings suggest that IFIT2 expression may be used as a biomarker to decide whether to undergo 5-FU treatment, but also the SAHA and 5-FU combination may be a potential new treatment regimen to augment 5-FU therapy in patients with thymidylate synthase-mediated drug-resistant oral squamous cell carcinoma.

Abstract

Interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) is a member of the interferon-stimulated gene family that contains tetratricopeptide repeats (TPRs), which mediate protein–protein interactions in various biological systems. We previously showed the depletion of IFIT2 enhanced cell migration and metastatic activity in oral squamous cell carcinoma (OSCC) cells via the activation of atypical PKC signaling. In this study, we found that IFIT2-knockdown cells displayed higher resistance to 5-fluorouracil (5-FU) than control cells. The comet assay and annexin V analysis showed decreased DNA damage and cell death in IFIT2-knockdown cells compared to control cells treated with 5-FU. Cell cycle progression was also perturbed by 5-FU treatment, with the accumulation of IFIT2-depleted cells in S phase in a time-dependent manner. We further observed the overexpression of thymidylate synthase (TS) and thymidine kinase (TK) in IFIT2-knockdown cells. Inhibition of TS alone or double inhibition of TS and TK1 using the siRNA technique increased susceptibility to 5-FU in IFIT2-knockdown cells. We further identified that suberanilohydroxamic acid (SAHA) treatment decreased the expression of TS in IFIT2-knockdown cells and demonstrated that pretreatment with SAHA sensitized IFIT2-knockdown cells to 5-FU in vitro and in vivo. In conclusion, IFIT2 knockdown enhances TS expression, which mediates 5-FU resistance, and SAHA pretreatment suppresses TS expression and hence sensitizes cells to 5-FU. SAHA will be an effective strategy for the treatment of OSCC patients with 5-FU resistance.

Evaluation of lymphocyte apoptosis in patients with oral cancer

Objectives

To evaluate apoptotic levels of peripheral blood mononuclear cells (PBMCs) and apoptotic regulatory proteins (Bax and Bcl-2) in lymphocyte subsets of oral cancer (OC) patients and healthy controls (HC).

Methodology

The percentage of apoptotic cells and lymphocyte counts were measured in the first cohort using PBMCs obtained from 23 OC patients and 6 HC. In the second cohort, (OC, 33; HC, 13), the mean fluorescence intensity (MFI) of Bax and Bcl-2 in CD19⁺ B, CD4⁺ T, CD8⁺ T, and CD16⁺56⁺ natural killer (NK) cells was determined via flow cytometry.

Results

The percentage of apoptotic cells was higher in the PBMCs of OC patients than in HC patients, particularly in patients with stage IV cancer (p<0.05). However, lymphocyte counts were significantly lower in stage IV patients (p<0.05). NK CD19⁺ B and CD16⁺56⁺ cell counts were significantly lower in OC patients compared with HC patients (p<0.001 and p<0.01, respectively), but CD4⁺ T cells were interestingly significantly higher in OC patients (p<0.001). While Bax MFI was slightly higher, Bcl-2 MFI was significantly lower for all four lymphocyte subsets in OC samples, particularly in stage IV patients, when compared with HC. Consequently, Bax/Bcl-2 ratios showed an upward trend from HC to OC patients, particularly those in stage IV. We found similar trends in Bax and Bcl-2 MFI for tumor stage, tumor size, and lymph node involvement.

Conclusions

The increased lymphocyte apoptosis in stage IV OC patients may be related to higher Bax levels and lower Bcl-2 levels. The Bax/Bcl-2 ratio in lymphocytes may be useful to determine the prognosis of OC patients, and could be considered a mean for supportive treatment in the future.

Interaction of human oral cancer and the expression of virulence genes of dental pathogenic bacteria

Oral squamous cell carcinoma (OSCC) are one of the major causes of cancer morbidity and mortality worldwide. Dental microbiome has been considered as inducing agents in oral carcinogenesis. Therefore, the objective of this study was to investigate the interaction of the gene expression of the dental microbiome and OSCC patients. A cross-sectional study was designed by recruiting confirmed OSCC patients attending the University hospital during October 2018 and July 2019. The dental bacteria were isolated and confirmed by PCR technique. The expression of host and bacterial virulence genes was determined using qPCR. This study shows that 54% of T. forsythia found to be the most predominant organisms in 30 positive cases, followed by 34% of Campylobacter rectus and 29% of Prevotella intermedia. The expression of mRNA levels of bspA, csxA, fadA and interpain A in the OSCC- bacteria positive cases was significantly higher than the control group (P < 0.001). It was further found that interpainA, csxA, fadA, and bspA genes have the potential effects on the cellular gene expression in OSCC patients. A significant correlation was seen between expression patterns of CXCL10, DIAPH1, NCLN and MMP9 genes with interpain A, fadA, and bspA involved in OSCC cases The results indicate that the species specific bacteria may play a role in triggering chronic inflammation in OSCC patients. Therefore, alteration in the gene expression through the dental microbiome could be used as an alternative target in the clinical practice to detect OSCC.

Optimum surgical margins in squamous cell carcinoma of the oral tongue: Is the current definition adequate?

OBJECTIVES

To evaluate the impact of progressively increasing margin distances on locoregional recurrence-free survival (LFRS) and determine an optimum margin distance for tongue cancers.

METHODS

We retrospectively reviewed the records of patients with squamous carcinoma of oral tongue, surgically treated between January 2012 and December 2013. The patients were divided based on ROC derived optimal distance and differences in LRFS per millimeter: margin distances with no significant difference in LRFS starting from 0 mm onwards (Group-I), from upper limit of Group-I to ROC cut-off (Group-II), and all values above it (Group-III). Group-II and III were matched for clinicopathologic factors and type of adjuvant therapy received.

RESULTS

451 patients had a median LRFS of 29.4 months that included 32.1% of Stage I/II and 51.7% of Stage III/IV. Group-I consisted of 0--2.0 mm (2.0-2.1 mm (p-0.029)), Group-II form 2.1 to 7.5 (7.5-7.6 mm (p-0.042)) and Group-III were ≥ 7.6 mm. In the matched group, each millimeter increase in margin provided a 3.67 months survival advantage from 2.1 mm to 7.5 mm while a substantial advantage of 15 months was seen from 7.5 to 7.6 mm. No significant advantage was gained in LRFS when the margin was increased by a millimeter from the cut-off value (p-0.602). Among the patients that were not prescribed any adjuvant therapy, a significantly better LRFS was observed in Group III than Group II (HR-3.01, p-value = 0.002).

CONCLUSION

Based on these results, adequacy of surgical margins should be re-considered for oral tongue cancers.