Oral squamous cell carcinoma in a South African sample: Race/ethnicity, age, gender, and degree of histopathological differentiation

Research Progress of Metformin in the Treatment of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies and has a high mortality, posing a great threat to both human physical and mental health. With the advancement of scientific research, a variety of cancer therapies have been used for OSCC treatment. However, the prognosis of OSCC shows no significant improvement. Metformin has been recognized as the first-line drug for the treatment of diabetes, and recent studies have shown that metformin has a remarkable suppressive effect on tumor progression. Metformin can not only affect the energy metabolism of tumor cells but also play an antitumor role by modulating the tumor microenvironment and cancer stem cells. In this review, the molecular mechanism of metformin and its anticancer mechanism in OSCC are summarized. In addition, this article summarizes the side effects of metformin and the future prospects of its application in the treatment of OSCC.

Epidemiology and demographics of head and neck cancer in Africa: A scoping review

BACKGROUND

Low- to middle-income countries account for 70% of global cancer deaths. Evidence of the changing prevalence of head and neck cancer in Africa in terms of gender, race and epidemiology will inform future research and health planning.

AIM

To synthesise epidemiological literature for head and neck cancer in Africa from 2010 to 2020.

METHOD

A scoping review was completed. The Joanna Briggs Institute Population, context and concept framework confirmed the inclusion criteria. Studies from Africa that included participant demographics, the types, stages, signs and symptoms of head and neck cancer were selected. Five databases were used. Descriptive statistics was completed.

RESULTS

The Preferred Reporting Items for Systematic Reviews and MetaAnalysis guided the reporting of the findings. Of the 1891 articles downloaded, 66 were included in the final review. Nigeria produced the most studies and oral cancer at 74% was most prevalent. Substance abuse was the most prevalent cause. Diagnosis of head and neck cancers were in the late stage (stage IV) when signs and symptoms were severe. Males of lower socioeconomic status tended to have less health seeking behaviour.

CONCLUSION

Countries from North Africa produce the most research outputs on head and neck cancers. Gender differences were noted and may be linked to lifestyle choices. A range of head and neck cancers (HNCs) are prevalent however late diagnosis and severe symptomatology impact treatment options.Contribution: Earlier diagnosis and intervention to prevent late-stage diagnosis is necessary. Awareness campaigns linked to evidence on causes, habits and lifestyle choices, signs and symptoms are needed.

Tumour Genetic Heterogeneity in Relation to Oral Squamous Cell Carcinoma and Anti-Cancer Treatment

Oral squamous cell carcinoma (SCC) represents more than 90% of all oral cancers and is the most frequent SCC of the head and neck region. It may affect any oral mucosal subsite but most frequently the tongue, followed by the floor of the mouth. The use of tobacco and betel nut, either smoked or chewed, and abuse of alcohol are the main risk factors for oral SCC. Oral SCC is characterized by considerable genetic heterogeneity and diversity, which together have a significant impact on the biological behaviour, clinical course, and response to treatment and on the generally poor prognosis of this carcinoma. Characterization of spatial and temporal tumour-specific molecular profiles and of person-specific resource availability and environmental and biological selective pressures could assist in personalizing anti-cancer treatment for individual patients, with the aim of improving treatment outcomes. In this narrative review, we discuss some of the events in cancer evolution and the functional significance of driver-mutations in carcinoma-related genes in general and elaborate on mechanisms mediating resistance to anti-cancer treatment.

A Meta-analysis of Oral Squamous Cell Carcinoma in Young Adults with a Comparison to the Older Group Patients (2014-2019)

Background:

The oral squamous cell carcinoma (OSCC) often affects elderly aged adults, who had long-term tobacco exposure. In the recent past decade, there is an increasing incidence of OSCC in younger individuals, who had less tobacco association.

Aim:

The aim of this study is to examine the risk factors and to assess and compare the clinicopathological features and prognosis of OSCC in young patients with the older group patients.

Materials and Methods:

We included studies that addressed the OSCC involving young patients during the period between 2014 and 2019. Initially, we found 679 articles; after refined evaluation, 92 works had their titles matching to the present work. After extraction of case reports, reviews, and studies with un-matched objectives or inadequate data, we have chosen only 24 presentations matching to the abstract. The statistical analysis performed by Chi-square tests using SPSS 20.0 version for windows.

Results:

Of the total OSCC, 10% of patients belonged to the younger age group, and 90% were the older aged group. Both the groups showed male gender predominance and tongue as the predominant site of involvement. The younger patients tend to have significantly reduced tobacco exposure. The highly reported tumors were advanced staged and moderately differentiated tumors in both groups. There was a statistically evident high recurrence reported in the younger group. The overall survival seems to be similar for both groups.

Conclusion:

The identification of the potential risk factors, along with unique molecular mechanisms, and biological behavior of the disease is mandatory to control the incidence of OSCC in young adults.

Risk factors associated with the mortality rate of oral squamous cell carcinoma patients: A 10-year retrospective study

In Malaysia, oral cancer is very common and the reported 5-year survival of such patients is nearly 50% after treatment with surgery and radiotherapy, much lower than most of the developed countries. This study aimed to investigate the socio-demographic and clinicopathological parameters that influence the mortality rate of the patients suffering from oral squamous cell carcinoma (OSCC) in the Kelantanse population.In this retrospective study, data regarding socio-demographic, clinicopathological factors, and treatment outcome associated with OSCC were gathered from the archives of the medical records office of Hospital Universiti Sains Malaysia. For statistical analysis, simple and multiple logistic regression were performed. The significance level was set to P < .25.A total of 211 OSCC cases were registered in Hospital Universiti Sains Malaysia from January 1, 2000 to December 31, 2018. Majority of them were male (57.82%), non-smoker (54.97%), non-alcohol consumer (91.94%), and non-betel quid chewer (93.83%) Malay (60.66%) patients. The tongue was the most commonly involved part of the oral cavity (41.52%). Histologically, the majority of the cases had moderately-differentiated OSCC (52.82%). Most of the patients were diagnosed at stage IV at the time of diagnosis (61.61%). When this study was performed, the survival status of the majority of the patients was alive (68.24%).Within the analyzed socio-demographic and clinicopathological parameters, gender, alcohol consumption, T-classification, histological grading, and treatment status have been demonstrated as an independent risk factors for mortality rate in multivariate analysis. Hence, these parameters need to be taken into account for the individualized therapy management of OSCC patients.

Biological consequences of cancer radiotherapy in the context of oral squamous cell carcinoma

Approximately 50% of subjects with cancer have been treated with ionizing radiation (IR) either as a curative, adjuvant, neoadjuvant or as a palliative agent, at some point during the clinical course of their disease. IR kills cancer cells directly by injuring their DNA, and indirectly by inducing immunogenic cell killing mediated by cytotoxic T cells; but it can also induce harmful biological responses to non-irradiated neighbouring cells (bystander effect) and to more distant cells (abscopal effect) outside the primary tumour field of irradiation.Although IR can upregulate anti-tumour immune reactions, it can also promote an immunosuppressive tumour microenvironment. Consequently, radiotherapy by itself is seldom sufficient to generate an effective long lasting immune response that is capable to control growth of metastasis, recurrence of primary tumours and development of second primary cancers. Therefore, combining radiotherapy with the use of immunoadjuvants such as immune checkpoint inhibitors, can potentiate IR-mediated anti-tumour immune reactions, bringing about a synergic immunogenic cell killing effect.The purpose of this narrative review is to discuss some aspects of IR-induced biological responses, including factors that contributes to tumour radiosensitivity/radioresistance, immunogenic cell killing, and the abscopal effect.

Development of clinico-histopathological predictive model for the assessment of metastatic risk of oral squamous cell carcinoma

CONTEXT:

Oral cancer metastasis is the leading cause of death globally. The decision-making on the mode of surgical treatment in clinically negative lymph nodes is challenging.

AIM:

The aim of this study was to develop a predictive model using clinical and histopathologic parameters that may help in the assessment of the metastatic risk of oral squamous cell carcinoma (OSCC).

SETTINGS AND DESIGN:

Clinical data of histopathologically confirmed primary OSCC from 2014 to 2017 were retrieved from the archives. Histopathological parameters for metastasis that were considered for evaluation in the study were tumor buds, cytoplasmic pseudofragments, tumor grade, depth of invasion, invasive tumor front (ITF) pattern, and lymphovascular invasion (LVI).

METHODS:

Hematoxylin and eosin and pan-cytokeratin immunostained sections of metastatic and nonmetastatic OSCC were assessed for histopathological features and correlated with clinical parameters.

STATISTICAL ANALYSIS USED:

SPSS software (Statistical Package for Social Sciences for Windows, Version 22.0 (2013) (IBM Corp., Armonk, NY, USA)) was used for the statistical analysis. Pearson's Chi-square test was done to assess the grades of histopathological and clinical parameters between the study groups. Univariate analysis was performed to develop a clinicopathologic predictive model.

RESULTS:

The clinicopathologic model signifies that OSCC with clinical Stage IV, high grades of tumor buds and cytoplasmic pseudofragments, Type V ITF pattern, positive LVI, deeply invasive tumors, and poorly differentiated grades of OSCC have a high risk of developing nodal metastasis. These parameters may be used as early predictors for metastasis of OSCC both in incisional and excisional biopsy specimens.

CONCLUSIONS:

The proposed predictive model is simple, cost-effective, and user-friendly for the early assessment of nodal metastatic risk in clinically negative lymph nodes.

A retrospective pilot study of correlation of first maxillary premolar root trunk length with age and gender: a cone beam computed tomography study

BACKGROUND

Root trunk length (RTL) plays an important role in the diagnosis, prognosis and treatment of periodontitis. The aim of this retrospective pilot study was to evaluate the RTL of first maxillary premolar and to study the correlation with age and sex in this value.

METHODS

The sample included 110 cone beam computed tomography (CBCT) images comprising 220 maxillaries first premolars from systemically healthy patients aged between 18 and 70 years. The tooth length (TL), root length (RL) and RTL were measured (dependent variables). Age and sex were considered as independent variables.

RESULTS

No statistically significant correlation was found between the RTL and the TL. Longer RL and longer RTL were observed in younger patients than older subjects only in the left maxillary premolars. On the other hand, the sex of the patients had no effect on either of the dependent variables. The single rooted maxillary premolars were more frequent (relative to those with two roots) in woman and in elderly patients.

CONCLUSIONS

A correlation between the age and the RTL and RL has been found but only in left premolars. Sex seemed to have only a slight correlation on the frequency of single-rooted teeth of the right side of the mouth. Further studies should be addressed to clarify the significance of the asymmetries observed in the present study between the two sides of the mouth with the aim of deepening the knowledge and understanding of the different variables that could be correlated with the RTL.

Root and Root Canal Morphology Differences Between Genders: A Comprehensive in-vivo CBCT Study in a Saudi Population

OBJECTIVES

To comprehensively explore the differences of all maxillary and mandibular permanent teeth in relation to number of roots, number of root canals, and root canal configuration between both genders in a Saudi Arabian population.

METHODS

This retrospective radiographic study comprised 208 subjects (48% males and 52% females) with a mean age 28.74±9.56 years. The CBCT images of the recruited subjects were evaluated for all permanent teeth. A careful examination was obtained by optimal visualization using all the software features. The data were analyzed using SPSS software program. Cohen's Kappa test was used for reliability and the Chi-squared test of association was used for the differences between both genders in relation to the study variables. A P-value < 0.05 was considered significant.

RESULTS

A total of 5254 maxillary and mandibular permanent teeth were evaluated. In relation to number of roots, there were no significant differences between both genders for all maxillary and mandibular teeth together (P= 0.064) as well as for maxillary and mandibular teeth separately (P= 0.315 and P= 0.100, respectively). A significant difference was found between males and females in relation to the number of canals of maxillary teeth (P= 0.014). For mandibular teeth, the significant level of difference was at the cut-off point (P= 0.050). For all maxillary and mandibular teeth together, the distribution among both genders was not significant (P= 0.082). The difference between both genders with regard to canal configuration of maxillary roots was highly statistically significant (P< 0.001). For mandibular teeth, the difference between males and females in relation canal configuration of anterior and premolar teeth was significant (P= 0.016) while, the difference was not significant when related to mesial roots of 1st and 2nd molars (P= 0.205). However, the difference was highly significant when related to distal roots of 1st and 2nd molars (P< 0.001).

CONCLUSION

No significant differences between both genders in relation to number of roots were found. Regarding the number of canals, significant differences were found only in three groups out of 14 groups of teeth with females who had a smaller number of canals than males. For canal configuration, two groups of maxillary teeth and three groups of mandibular teeth showed statistically significant differences between both genders.

Micronuclei as a Predictor for Oral Carcinogenesis

Objectives:

The aim of the study was to provide a quantitative evaluation of oral mucosal micronuclei (MN) frequency as a biomarker for oral cancer susceptibility in carcinogenesis progression.

Methods:

60 patients were included in the study. 30 patients with biopsy proven epithelial dysplasia (ED, 15) and oral squamous cell carcinoma (OSCC, 15) comprised the study group and 30 patients with normal buccal mucosa, reporting for minor surgical procedures formed the controls. After informed consent, exfoliated cells were collected from the affected site using a premoistened wooden spatula and spread on precleaned slides, fixed, stained using modified rapid Papanicolaou method and subjected to microscopic examination. MN were identified and scored according to Tolbert et al. criteria.

Results:

Maximum patients with ED and OSCC were males and in age groups of 20–40 and 40–60 years, respectively. The most common site was the buccal mucosa. The maximum of MN count/500 cells in OSCC group was 11.93, 4.0 in ED and 1.46 in controls, with the mean and mean MN index ± SD distribution in the three groups showing high statistical significance (P = 0.000). A significant difference between mild and moderate ED and between moderately and well-differentiated OSCC was also observed.

Conclusion:

MN assays can help in early detection of premalignant and malignant lesions, thereby improving survival and reducing morbidity associated with treatment. MN index is thus a feasible and economical method for screening high-risk populations of oral cancer, to be able to timely identify genomic damage in order to prevent the cancer epidemic.

Ki-67 Prognostic Value in Different Histological Grades of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Introduction:

Abnormal cell proliferation appears to be a possible predictor of tumorigenesis, Ki-67 protein expression is closely related to the cell proliferation and could be used as a biomarker for the growth in the most of human tumors. The aim of the study: Investigating of Ki-67 expression in the pathological grades of oral epithelial dysplasia and oral squamous cell carcinomas.

Materials and Methods:

The sample consisted of 30 formalin-fixed, paraffin-embedded specimens of oral epithelial dysplasia (OED), 30 other of oral squamous cell carcinomas (OSCC), and 10 normal oral epithelium (NOE) were conventionally stained with hematoxylin and eosin and immunohistochemically stained with Ki-67 monoclonal antibody.

Results:

Expression of Ki-67 was restricted to the basal layers in the normal oral epithelium whereas Ki-67 positive cells in oral epithelial dysplasia (OED) were located in the basal, suprabasal and spinous layers, Ki-67 expression was increased in high-risk cases. Ki-67 positive cells in well-differentiated (OSCC) were located mainly in the periphery of the tumor nests, in moderately-differentiated (OSCC) were located in both peripheral and part of a center of the tumor nests whereas it was diffused in most of the Poorly-differentiated (OSCC). Statistical analysis indicated a significant difference between the expression in (OED) and (NOE), (OSCC) and (NOE), and no differences between (OED) and (OSCC).

Conclusion:

This study has concluded that Ki-67 antigen could be used as a marker for the histological grading of OED and OSCC, Expression of Ki 67 increased according to the severity of oral epithelial dysplasia.

High PD-L1 expression in the tumour cells did not correlate with poor prognosis of patients suffering for oral squamous cells carcinoma: A meta-analysis of the literature

OBJECTIVES

Oral cancer represents one of the most common malignancies in humans. Its prognosis is still poor, despite the most recent improvements in therapies. An increasing attention is placed on the role of programmed death ligand 1 (PD-L1) in the tumour immunity and its potential function as a marker for tumour prognosis. Whether PD-L1 expression is a prognostic factor for the poor outcomes in oral squamous cell carcinoma is still controversial. This study aimed to investigate, through a meta-analysis, a potential correlation between PD-L1 expression and the prognostic outcomes in patients with oral squamous cell carcinoma.

MATERIALS AND METHODS

The studies were identified by searching PubMed, SCOPUS, Web of Science and were assessed by two of the authors. After the selection process, 11 articles met eligibility criteria and were included in the meta-analysis. Quality assessment of studies was performed according to the REMARK guidelines, and the risk of biases across studies was investigated through Q and I² tests. Meta-analysis was performed to investigate the association between the PD-L1 expression either overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), gender and lymph node metastasis.

RESULTS

A total of 1060 patients were analysed in the 11 studies included in the meta-analysis. Pooled analysis revealed that the expression of PD-L1 did not correlate with poor OS (HR, 0.60; 95% CI: [0.33, 1.10]; P = 0.10), DFS (HR, 0.62; 95% CI: [0.21, 1.88]; P = 0.40), DSS (HR, 2.05; 95% CI: [0.53, 7.86]; P = 0.29 and lymph node metastasis (HR, 1.15; 95% CI: [0.74, 1.81]; P = 0.53). Furthermore, results of the meta-analysis showed that high expression of PD-L1 is two times more frequent in female patients (OR, 0.5; 95% CI: [0.36, 0.69]; P < 0.0001) compared to males. For all the three outcomes analysed, a high rate of heterogeneity was detected (I²  > 50%).

DISCUSSION

High PD-L1 expression did not correlate with poor prognosis of patients suffering for oral squamous cell carcinoma. Studies published on the topic showed a significant variation in results, limiting the use of PD-L1 expression by immunohistochemistry as prognostic biomarker in clinical practice.

Global incidence of oral and oropharynx cancer in patients younger than 45 years versus older patients: A systematic review

Head and neck squamous cell carcinoma (HNSCC) is typically regarded as a disease of elderly people. However, increasing numbers of patients worldwide with HNSCC at younger age (defined as <45 years old) have been reported in recent years. To assess geographical variations and trends worldwide in incidence of oral and oropharyngeal cancer in young patients, a systematic review was conducted in PubMed and Google scholar databases from 1975 to June 2016. Seventy-eight studies were selected for further study. Nineteen population-based studies on incidence rate were available from 13 countries, showing a prominent increase over time except for the Netherlands. A notable rise of oral (mobile) tongue cancer among white women and oropharyngeal cancer in white men was observed. Data suggest that cancer in young patients may be a distinct clinical entity and characterised by different aetiology and pathogenesis. Additionally, the relative proportion of oral and oropharyngeal cancer in young patients to total incidence revealed a significant difference between estimates from North America (5.5%) and both Africa (17.2%) and Middle East (14.5%). It is concluded that (i) a rising trend in oral and oropharynx cancers is observed in young patients worldwide; (ii) incidence studies should properly define outcomes in age cohorts and use a consensus cut-off for young patients; (iii) more population-based studies should be performed in non-Western regions to get accurate global measures of incidence for these cancers in young subpopulations and (iv) there is an urge to identify new aetiological factors in these young patients.