Oral cancer associated with chronic mechanical irritation of the oral mucosa

Increased prevalence of oral potentially malignant lesions among Croatian War invalids, a cross-sectional study

Background

The main objective of this study was to investigate the frequency and type of oral pathological changes, oral subjective symptoms and the knowledge about oral cancer in the population of Croatian military invalids from the Homeland War.

Material and Methods

A total of 102 Croatian military invalids from the Homeland War participated in the study. Data were collected on the presence of subjective symptoms in the oral cavity, and a detailed clinical examination of the oral mucosa was performed.

Results

Almost half of the participants, 46 (45.1%), reported being smokers, and 64 (62.7%) consumed alcohol daily. Subjective symptoms in the oral cavity were reported by 25 (24.5%) of them. Pathological changes were found in 35 (34.3%) participants, of whom 14 (13.7%) had potentially malignant changes. Pathohistological findings confirmed the diagnosis of a potentially malignant lesion in 10 subjects and indicated the presence of moderate dysplasia in two, carcinoma in situ in one, and invasive carcinoma in one.

Conclusions

Participants didn't show adequate knowledge of risk factors. Forty-one changes in the oral cavity were found in 35 subjects, and as many as 14 were potentially malignant. According to the participants, most dentists and family physicians don't thoroughly and regularly examine their patients' oral mucosa. Key words:Oral cancer, oral lichen planus, leukoplakia, erythroplakia, actinic cheilitis, Croatian Homeland War invalids.

Hamular bursitis as a cause of orofacial pain. A case report

Pterygoid hamular bursitis is an infrequent cause of orofacial pain due to a hypertrophic pterygoid hamulus. The pain is often referred to the pharynx, temporomandibular region and facial zone, and requires a differential diagnosis with other craniofacial entities. This paper describes a patient with pterygoid hamular bursitis that presented pain of neuropathic characteristics in the left retromolar region, associated with odynophagia and temporomandibular joint disorders. Based on the clinical and radiological findings, a surgical resection of the pterygoid hamulus was decided. After the surgical procedure the patient still reported symptoms so additional specific treatments such as peripheral nerve block and infiltration were performed. Four months later, the patient developed a squamous cell carcinoma on the left margin of the tongue, which was surgically treated. At present (thirty months follow-up), the patient has no pain or signs of tumor relapse. Key words:Pterygoid hamular bursitis, orofacial pain, oral carcinoma, temporomandibular joint disorders, radiofrequency, neuropathic pain.

Oral squamous cell carcinoma arising from chronic traumatic ulcers

BACKGROUND

A proportion of oral squamous cell carcinoma (OSCC) is preceded by oral potentially malignant disorders (OPMD), and the rest might not be associated with any well-established OPMD. Chronic traumatic ulcer (CTU) has been suggested as a lesion with potential for malignant transformation, but the evidence is inconclusive.

OBJECTIVE

The aim of this study was to describe clinicopathological features of non-healing CTU (NHCTU) that later developed to OSCC.

MATERIALS AND METHODS

A retrospective cohort study was performed of patients attending the Facultad de Odontología Universidad Nacional de Córdoba (2013-2019). The study included patients with a provisional diagnosis of CTU. CTUs without complete healing after removal of traumatic factors-non healing CTU (NHCTU)-were investigated by biopsy. A detailed description of cases where a malignancy was diagnosed is presented.

RESULTS

A total of 107 CTU were included. Of these, 32 CTUs were considered NHCTU and two cases showed histological features of OSCC in the background of NHCTU. In both cases, lesions were found on the lateral tongue. Both were non smoking, non alcohol drinking individuals. Absence of any well-known OPMD was also registered.

CONCLUSIONS

The possibility of malignant transformation in a subset of tongue NHCTU should not be underestimated.

CLINICAL RELEVANCE

In a subgroup of patients, NHCTU could be considered an OPMD. Although the potential malignant transformation rate is low, these conditions should be always followed up.

Chronic mechanical irritation enhances the effect of tobacco and alcohol on the risk of oral squamous cell carcinoma: a case-control study in Argentina

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is a multifactorial disease. The individual effect of each risk factor for OSCC may be conditioned by the frequency of other factors. The objective of this study was to identify the association between chronic mechanical irritation (CMI) and OSCC and to analyse the influence of CMI on other important risk factors for OSCC.

MATERIALS AND METHODS

A prospective and age/sex-matched case-control study was performed in two institutions from Argentina between 2009 and 2019, with consecutive and newly diagnosed OSCC. The frequencies of tobacco, alcohol, and CMI were analysed using conditional logistic regression. Cumulative tobacco consumption and the presence of CMI were analysed using the Mann-Whitney test.

RESULTS

CMI and OSCC were associated with an OR of 7.02 (95% CI 3.57-13.78, p < 0.001). The combination of CMI and alcohol demonstrated the highest risk of OSCC (OR 53.83, CI 95% 8.04-360, p < 0.0001), followed by the combination of CMI, tobacco, and alcohol (OR 48.06, CI 95% 8.47-272, p < 0.0001). The combination of CMI and tobacco was also significant (OR 5.61, CI 95% 1.07-29.54, p = 0.042). Patients with CMI developed OSCC with less cumulative tobacco use compared with those without CMI.

CONCLUSION

CMI is an independent risk factor for OSCC, and it could act as a risk modifier among tobacco and alcohol users having an enhancing effect.

CLINICAL RELEVANCE

Elimination of CMI could decrease the risk of OSCC.

Molecular Research on Oral Diseases and Related Biomaterials: A Journey from Oral Cell Models to Advanced Regenerative Perspectives

Oral diseases such as gingivitis, periodontitis, and oral cancer affect millions of people worldwide. Much research has been conducted to understand the pathogenetic mechanisms of these diseases and translate this knowledge into therapeutics. This review aims to take the reader on a journey from the initial molecular discoveries to complex regenerative issues in oral medicine. For this, a semi-systematic literature search was carried out in Medline and Web of Science databases to retrieve the primary literature describing oral cell models and biomaterial applications in oral regenerative medicine. First, an in vitro cell model of gingival keratinocytes is discussed, which illustrates patho- and physiologic principles in the context of oral epithelial homeostasis and carcinogenesis and represents a cellular tool to understand biomaterial-based approaches for periodontal tissue regeneration. Consequently, a layered gradient nonwoven (LGN) is described, which demonstrates that the key features of biomaterials serve as candidates for oral tissue regeneration. LGN supports proper tissue formation and obeys the important principles for molecular mechanotransduction. Furthermore, current biomaterial-based tissue regeneration trends, including polymer modifications, cell-based treatments, antimicrobial peptides and optogenetics, are introduced to represent the full spectrum of current approaches to oral disease mitigation and prevention. Altogether, this review is a foray through established and new concepts in oral regenerative medicine and illustrates the process of knowledge translation from basic molecular and cell biological research to future clinical applications.

Squamous cell carcinoma around a subperiosteal implant in the maxilla and the association of chronic mechanical irritation and peri-implantitis: a case report

Background

As carcinogenic risk factors, environmental factors can be classified into physical, biological, and chemical factors. Subperiosteal implants (SIs) are associated with complications, such as framework exposure, infection, and fistula formation. A current hypothesis suggests that chronic mechanical irritation could be a co-factor in carcinogenesis, while peri-implantitis might be an initiating or promoting agent in the development of oral mucosal cancer. Herein, we report a case of squamous cell carcinoma (SCC) around a maxillary SI associated with chronic mechanical irritation and peri-implantitis as physical and biological factors, respectively.

Case presentation

A 74-year-old male patient presented with severe mobility of the SI and an undermined ulcer with induration, accompanied by a palatal fistula and the exposure of the metal framework. The SI had been placed on the maxilla for the occlusal reconstruction of the molar area 20 years ago. An incisional biopsy of the ulcer revealed SCC (cT4aN2cM0). Neoadjuvant chemotherapy was initiated, followed by bilateral neck dissection and partial resection of the maxilla with SI removal. Energy-dispersive X-ray analysis suggested that the SI was fabricated using pure titanium, and titanium was absent in the specimen. Scanning electron microscopy of the SI in contact with the SCC showed a few microcracks, suggesting pitting corrosion.

Discussion

Chronic mechanical irritation due to the mobility of an improperly designed SI can be a physical factor, and prolonged peri-implantitis without regular maintenance can be a biological factor in carcinogenesis. Improperly designed main struts and a large masticatory force in the molar area resulted in deterioration of the retention and mobility of the SI. The screw and framework frequently moved on mastication and came in direct contact with the ulcer as chronic mechanical irritation. Bacterial invasion into the subperiosteal space expanded by the mobility of the metal framework led to peri-implantitis. The influence of chemical factors was considered relatively small in this case since the patient had no history of smoking or drinking, and titanium was absent in the specimen. Therefore, it is conceivable that SCC can arise owing to persistent inflammation caused by chronic mechanical irritation and peri-implantitis as physical and biological factors, respectively.

Evaluation of YouTube videos as a source of information about oral self-examination to detect oral cancer and precancerous lesions

Objectives:

The aim of this study was to investigate quality, reliability, and comprehensiveness of YouTube videos about oral self-examination to detect oral cancer and precancerous lesions and to assess whether the source, duration, quality, reliability, and/or comprehensiveness of videos influence their visibility and popularity.

Materials and Methods:

Videos on YouTube were searched using eight keywords similar to oral self-examination. The first 100 videos for each search term were included. Strict inclusion and exclusion criteria were adhered to, and videos were assessed for quality, reliability, and comprehensiveness. Upload date, views, likes, dislikes, duration, and source of the videos were noted. Viewing rate and interaction index were calculated for each video.

Results:

A total of 800 videos were analyzed, 24 of which met the inclusion criteria. Majority of videos (87%) were uploaded by the healthcare group. The visibility, quality, reliability, and comprehensiveness were higher in videos uploaded by the healthcare group when compared with the non-healthcare group, but not at a level of statistical significance. The mean interaction index score of the non-healthcare group was found to be higher than the healthcare group, with statistically significant difference. Duration of videos showed an impact on the comprehensiveness of the videos.

Conclusion:

There are relatively few videos on oral self-examination on YouTube, and most do not have satisfactory quality, reliability, and comprehensiveness. There is a potential to increase public awareness about oral self-examination by utilizing this tool. Videos with complete and accurate information regarding oral self-examination must be uploaded to YouTube, which is currently an important source of information for the general public.

Malignant transformation of oral leukoplakia: Systematic review and meta-analysis of the last 5 years

OBJECTIVE

Oral leukoplakia (OL) is the most frequently encountered oral potentially malignant disorder. The aims of this systematic review are to estimate the overall malignant transformation of OL and to assess the risk factors associated with malignant transformation of OL published in the last 5 years (2015-2020).

MATERIALS AND METHODS

We performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and Cochrane databases with keywords "oral leukoplakia", "oral cancer", "oral carcinoma" and "oral squamous cell carcinoma". Meta-analysis was conducted using a random-effects model.

RESULTS

Twenty-four studies were selected, that reported a total of 16,604 patients. Malignant transformation proportion varied between 1.1% and 40.8%. Female gender, non-homogeneous clinical type, and presence of epithelial dysplasia were significantly related to MT. Other risk factors previously suggested did not show significant results.

CONCLUSIONS

The pooled proportion of malignant transformation MT was 9.8% (95% CI: 7.9-11.7). It is necessary to continue to conduct well-designed prospective clinicopathological studies on OL, using a uniform definition for OL to reduce the risk of bias for evaluating various factors associated with the MT.

Cytogenetic analysis of genetic damage in young individuals exposed to chronic mechanical irritation in the lateral border of the tongue due to sharp teeth - a novel study

Background

Chronic inflammation is estimated to contribute to approximately 25% of human cancers. Inflammation can be induced by chronic mechanical irritation which can lead to oral pre-cancer and oral cancer. Though many studies have been conducted to identify the genetic damage in oral cancer or dysplastic stages, no study has been conducted so far on early detection of genetic damage in healthy individuals presenting with sharp teeth in contact with the lateral border of the tongue.

Objective

The study is aimed at analyzing the genetic damage (micronuclei) in healthy individuals with sharp teeth in contact with the lateral border of the tongue causing chronic mechanical irritation.

Methods

The study group included 75 clinically healthy individuals with sharp teeth in contact with the lateral border of the tongue and 25 clinically healthy individuals with normal teeth in contact with the lateral border of the tongue as a control group. Brush samples of epithelial cells were collected, then spread over clean glass slide and fixed in 100% alcohol, stained with rapid PAP and analyzed under the light microscope. The exfoliated cells were examined to detect micronuclei.

Results

Micronuclei frequency was found to be increased in the study group where sharp teeth were in contact with the lateral border of the tongue of healthy individuals without deleterious habits such as usage of tobacco in smoking/smokeless form, areca nut chewing or alcohol consumption.

Conclusions

Cytogenetic analysis is a simple and scantly invasive technique allowing clinicians the early detection of DNA damage in patients with sharp teeth and subsequently preventing carcinogenesis by proper treatment and follow-up.

Autophagy-A Hidden but Important Actor on Oral Cancer Scene

The duration of denture use, oral hygiene, smoking and male sex were identified as risk factors for oral mucosal lesions. As it is well known, all the oral mucosal lesions associated with risk factors have an important degree of malignity. Chronic mechanical irritation can be another cause of oral cancer and it is produced by the constant action of a deleterious agent from the oral cavity. Autophagy represents a complex evolutionary conserved catabolic process in which cells self-digest intracellular organelles in order to regulate their normal turnover and remove the damaged ones with compromised function to further maintain homeostasis. Autophagy is modulated by mTOR kinase and indirectly by PI3K/AKT survival pathway. Due to its dual capacity to either induce cell death or promote cell survival, important evidence pointed that autophagy has a two-faced role in response to chemotherapy in cancer. In conclusion, understanding how to overcome cytoprotective autophagy and how to take advantage of autophagic cell death is critical in order to enhance the cancer cells sensitivity to particular therapeutic agents.

Clinical and Immunohistochemical epithelial profile of non-healing chronic traumatic ulcers

Background

Chronic wounds were previously related to cancer. Chronic Traumatic Ulcers (CTU) are lesions caused by chronic mechanical irritation (CMI) frequently diagnosed in Oral Medicine. Although these conditions may reflect a benign nature, some authors have proposed its relationship with malignant transformation. Currently, there are scarce investigations that evaluate biomarkers within CTU. The aim of this study was to evaluate cell differentiation and proliferation biomarkers patterns of CTU and OSCC through recognized markers such as cytokeratin 19 and Ki67 and correlate it with clinical features of both groups of patients.

Material and Methods

A Cross-sectional study of adult patients (n=79), both sexes, attended at Oral Medicine Department, Facultad de Odontología, Universidad Nacional de Córdoba. The patients were classified into two groups: CTU (n=41), and OSCC (n=38). A subset of specimens were immunolabeled with Ki67 and Ck19.

Results

The population consisted of 51.9% male and 48.1% female, with an average of 57.0 ± 13.9. years (OSCC group) and 60.9 ± 14.9 years (CTU group). OSCC group presented higher scores for both biomarkers (Ki67 and Ck19), but only there were differences statistically significant for Ki67 (p=0.032). 25% of non-healing CTU were positive with medium scores of Ck19 and showed an immunohistochemical profile similar to OSCC. The lateral tongue was the most frequent site in both groups.

Conclusions

The altered immunohistochemical pattern found in many specimens of CTU was also observed in OSCC. The tongue border presents physiological conditions that could offer a suitable environment for the development of neoplastic events associated with CMI. Further studies are needed to understand the underlying mechanisms that could link oral non-healing ulcers with early malignant changes.

Key words:Ck19, Ki67, Oral Cancer, Chronic Traumatic Ulcer, Chronic Mechanical Irritation.

The inflammatory potential of Argentinian diet and oral squamous cell carcinoma

Introduction

Introduction: the goal of this study was to evaluate whether an association exists between dietary components related to inflammation and oral squamous cell carcinoma (OSCC) in Argentina. Methods: a case-control study was carried out with 3 controls for each case and participants of both genders who were between 24 and 85 years of age, who were recruited at the outpatient clinic, Odontology School, Universidad Nacional de Córdoba, between 2012 and 2015. Dietary information was collected using a semi-quantitative food frequency questionnaire from which energy-adjusted Dietary Inflammatory Index (E-DIITM) scores were computed. Logistic regression models were fit to assess the association between E-DII and OSCC. Results: significantly higher intakes of macronutrients such as fat, protein and cholesterol, and of micronutrients such as iron, riboflavin, monounsaturated, polyunsaturated, omega-6 and omega-3 fatty acids, and vitamin B6 were observed in cases as compared to controls (all p < 0.05). We also observed a significant 69% increase in OSCC for each point on the E-DII scale (OR 1.69, 95% CI [1.18-2.43]) after adjusting for alcohol and tobacco consumption. Conclusion: we found an association between diet-associated inflammation, as represented by the E-DII, and risk of OSCC. Future research should be directed at deepening our understanding of this association in other populations, and should include studies utilizing prospective designs.

YAP1 is a potent driver of the onset and progression of oral squamous cell carcinoma

Head-and-neck squamous cell carcinoma (HNSCC) is the sixth most common group of cancers in the world, and patients have a poor prognosis. Here, we present data indicating that YAP1 may be a strong driver of the onset and progression of oral SCC (OSCC), a major subtype of HNSCC. Mice with tongue-specific deletion of Mob1a/b and thus endogenous YAP1 hyperactivation underwent surprisingly rapid and highly reproducible tumorigenesis, developing tongue carcinoma in situ within 2 weeks and invasive SCC within 4 weeks. In humans, precancerous tongue dysplasia displays YAP1 activation correlating with reduced patient survival. Combinations of molecules mutated in OSCC may increase and sustain YAP1 activation to the point of oncogenicity. Strikingly, siRNA or pharmacological inhibition of YAP1 blocks murine OSCC onset in vitro and in vivo. Our work justifies targeting YAP1 as therapy for OSCC and perhaps HNSCC, and our mouse model represents a powerful tool for evaluating these agents.

Analysis of Mortality from Carcinomas Primary Localized in Region of Lip, Oral Cavity and Pharynx in Central Serbia, 1999-2015

BACKGROUND

Lip, oral cavity, and pharyngeal cancers have been globally estimated to account for about 3.8% of all cancer cases and 3.6% of cancer deaths. Mortality of these cancers is generally higher in developing than in developed countries. Overall cancer mortality rate in Serbia is one of the highest in the world. The aim of this study was to determine the mortality rate trends and the most common localization of lip, oral and pharyngeal cancers in Serbia.

METHODS

The study was conducted in 2018 as descriptive epidemiological study and included years from 1999 to 2015. The differences in standardized mortality rates and number of deaths were analyzed with regard to age, gender, and tumor localization. Linear trend and regression were used to determine mortality rate trend.

RESULTS

There was statistically significant difference in the number of deaths between men and women in the ages of 40 and over (P < 0.01); male/female cancer mortality ratio was 4.56:1. Generally, the most common localization of this carcinoma was hypopharynx. There was no statistically significant increase of mortality rates from these cancers for both genders (males: y = 4.77 + 0.42x, P = 0.069 % change = +20.35; females: y = 1.03 + 0.01x, P = 0.40 % change = +4) during 17-year period.

CONCLUSION

Promotion of healthy habits, life-styles and regular inspection of mouth by patients and health professionals should be better prioritized especially in developing countries where implementing and improving national health prevention programs are essential.