Oral Potentially Malignant Disorders and Squamous Cell Carcinoma at the Tongue: Clinicopathological Analysis in a Thai Population

The Discovery of Oral Cancer Prognostic Factor Ranking Using Association Rule Mining

OBJECTIVE

 A 5-year survival rate is a predictor for the assessment of oral cancer prognosis. The purpose of this study is to analyze oral cancer data to discover and rank the prognostic factors associated with oral cancer 5-year survival using the association rule mining (ARM) technique.

MATERIALS AND METHODS

 This study is a retrospective analysis of 897 oral cancer patients from a regional cancer center between 2011 and 2017. The 5-year survival rate was assessed. The multivariable Cox proportional hazards analysis was performed to determine prognostic factors. ARM was applied to clinicopathologic and treatment modalities data to identify and rank the prognostic factors associated with oral cancer 5-year survival.

RESULTS

 The 5-year overall survival rate was 35.1%. Multivariable Cox proportional hazards analysis showed that tumor (T) stage, lymph node metastasis, surgical margin, extranodal extension, recurrence, and distant metastasis of tumor were significantly associated with overall survival rate (p < 0.05). The top associated death within 5 years rule was positive extranodal extension, followed by positive perineural and lymphovascular invasion, with confidence levels of 0.808, 0.808, and 0.804, respectively.

CONCLUSION

 This study has shown that extranodal extension, and perineural and lymphovascular invasion were the top ranking and major deadly prognostic factors affecting the 5-year survival of oral cancer.

Description of clinicopathological characteristics of oral potentially malignant disorders with special focus on two histopathologic grading systems and subepithelial inflammatory infiltrate

OBJECTIVE

This study was conducted to evaluate the clinicopathological features of oral potentially malignant disorders (OPMDs) with a focus on two histologic grading systems and subepithelial inflammatory infiltrates.

MATERIALS AND METHODS

This cross-sectional and multicenter study was conducted from April 2016 to September 2021 and comprised patients diagnosed with OPMDs. Hematoxylin and eosin-stained slides of 127 cases were assessed based on the World Health Organization (WHO) 2005 classification system, namely, epithelial precursor lesions and binary system of oral epithelial dysplasia (OED). Chi-square test and Fisher's exact test were used to compare different categorical variables related to OPMDs.

RESULTS

The mean age of OPMD cases at presentation was 54.72 13.30 (P < 0.01) with a male to female ratio of 1.6:1. Oral leukoplakia (52.8%) was the most commonly diagnosed form of OPMD. Most OPMDs were classified as oral epithelial hyperplasia (59.1%) and the remaining (40.9%) as OED (P < 0.01). Of the 52 OPMDs with OED, all cases of mild dysplasia (36.5%) and carcinoma in situ (9.6%) were categorized as low-risk and high-risk lesions, respectively. Chronic inflammatory infiltrate (79.5%) was the most common subepithelial inflammatory alteration observed among OPMDs.

CONCLUSIONS

Early detection of OPMDs is vital due to increased risk of developing into oral cancer. Timely clinicopathological risk assessment of OPMD is desirable for improving the prognosis and preventing the malignant transformation in oral premalignancy. Besides the epithelial precursor lesions' classification by the WHO, binary system of grading OED use can be encouraged. Also, subepithelial inflammatory infiltrate can be of importance in future research regarding OPMDs.

Evaluating the Clinicopathologic Parameters of Tongue Squamous Cell Carcinoma based on its Local Distribution

Background

Oral squamous cell carcinoma (OSCC) is one of the most common oral lesions and the tongue is one of the most common areas involved. The aim of this study was to evaluate the clinicopathologic feature of tongue SCCs based on its local distribution.

Materials and Methods

In this cross-sectional study, clinical data such as age, gender, location, and clinical appearance were extracted from the archives of the Oral Pathology Department, Isfahan Dental School, registered with a definitive diagnosis of tongue SCC during 2005-2019. Then, 34 specimens were selected for histopathological evaluation in a simple random way. The histopathologic slides were examined to determine the grade of tumor malignancy. The data were entered into SPSS23 software and analyzed by Chi-square, Fisher exact, One-way ANOVA, and Non-parametric tests. P value <0.05 was considered significant.

Results

Of the 275 OSCCs, 68 samples were tongue SCC. The mean age of patients was 61.7 ± 15 and 61.8% were women. The most common clinical manifestations were exophytic lesions (42.6%) and the most common site was the lateral border of the tongue (36.8%). The results did not show a significant relationship between the clinicopathologic feature including mean age (p = 0.766), gender (p = 0.338), clinical presentation (p = 0.434), grade of malignancy (p = 0.763) and location. But, among the histopathological parameters, the pattern of invasion (p = 0.047) was significantly associated with the local distribution.

Conclusion

Given that most OSCCs had moderate differentiation of malignancy, identification of clinical features is needed. Attention to the pattern of invasion and location on the tongue can be effective in determining the therapeutic approach.

Histopathological and risk factor analyses of oral potentially malignant disorders and oral cancer in a proactive screening in northeastern Thailand

BACKGROUND

Lip and oral cavity cancer has been reported as the 10th most common cancer in Thailand. Recently, a screening program for oral potentially malignant disorders (OPMDs) and oral cancer was conducted in the northeastern Thailand which took into consideration a total of 371,911 people who resided in the provinces of Buriram, Chaiyaphum, Nakhon Ratchasima, and Surin.

METHODS

A total of 330,914 subjects were consecutively screened for risk factors of oral cancer by village health volunteers (VHVs) using a questionnaire (S1). Then, 186,710 subjects with one or more risk factors for oral cancer were referred for oral screening by dental auxiliaries or dentists at sub-district level hospitals (S2) where 86,941 subjects were subsequently screened. Afterwards, 1576 subjects with suspicious oral lesions for OPMDs or oral cancer attended local hospitals for further investigation and treatment. Oral medicine specialists, oral surgeons, and local dentists at the district level hospitals performed biopsies and the samples were sent for histopathological analysis. The objectives of the study were to report the histopathology findings from the biopsies obtained from these subjects and the associated risk factors.

RESULTS

Out of 427 subjects who received biopsies, complete diagnostic results were obtained from 409 patients (462 specimens). The 5 most common histopathological results from these specimens were mild epithelial dysplasia (27.3%), fibroepithelial hyperplasia (14.5%), oral lichen planus/oral lichenoid reactions (11.5%), moderate epithelial dysplasia (8%), and acanthosis with or without hyperkeratosis (5%). Oral squamous cell carcinoma was detected in 14 subjects and 11 other forms of oral cancer were revealed. Among the analyzed risk factors, habitual betel quid chewing was established as a statistically significant risk factor associated with OPMDs and oral cancer.

CONCLUSION

The most frequently observed histopathological results of clinically suspected oral cancer and OPMDs included mild epithelial dysplasia, fibroepithelial hyperplasia, oral lichen planus/oral lichenoid reactions, moderate epithelial dysplasia, and acanthosis with or without hyperkeratosis. Betel quid chewing habit was found to be associated with OPMDs and oral cancer.

The Expression of Methyltransferase-Like 3 in Oral Precancerous Lesions and Oral Squamous Cell Carcinoma

OBJECTIVE

 N6-methyladenosine is the most frequent mRNA modification in eukaryotic cells. It is catalyzed by the methyltransferase complex, methyltransferase-like 3 (METTL3). Previous studies have revealed that METTL3 plays a role in various cancers. However, there is limited information about the roles of METTL3 in oral epithelial dysplasia (OED). This study determined METTL3 expression in normal oral mucosa (NOM), OED, and oral squamous cell carcinoma (OSCC) by immunohistochemistry.

MATERIALS AND METHODS

 Twenty formalin-fixed paraffin embedded specimens each of NOM, OED, and OSCC were included. The expression pattern, the number of positive cells, the staining intensity, and the histochemical score (H-score) of METTL3 were investigated.

STATISTICAL ANALYSIS

 The data were analyzed by using one-way analysis of variance, chi-squared test, and a Kruskal-Wallis test. A p-value < 0.05 indicated statistically significant.

RESULTS

 The METTL3 expression in NOM was observed in the basal, parabasal, and lower layers of epithelium. In low-grade OED, METTL3 was expressed in the lower epithelial layers and partially presented in the spinous layer. However, in high-grade OED, METTL3 expression was observed in the lower layers, spinous layers, and upper layers of dysplastic epithelium. For OSCC, METTL3 immunostaining was presented in both the peripheral and central cells of the tumor islands. All NOM samples showed weak-to-moderate METTL3 staining intensity, while the moderate-to-strong METTL3 staining intensity was observed in 95% of both OED and OSCC specimens (p < 0.05). The percentage of METTL3 positive cells and H-score was highest in OSCC, followed by OED and NOM, respectively (p < 0.05). Interestingly, H-score was greater in high-grade OED (209.8 ± 18.61) when compared with low-grade OED (162.1 ± 38.93) (p < 0.05).

CONCLUSION

 METTL3 expression in OED and OSCC was more outstanding than in NOM, suggesting possible roles for OED and OSCC pathogenesis. Additionally, METTL3 expression may be an indicator for OED progression to OSCC.

Multiple approaches to oral epithelial dysplasia degree analyses: a pilot study

BACKGROUND

Oral epithelial dysplasia (OED) is the presence of cells of an abnormal type within a tissue, which may signify a stage preceding the development of cancer. Our aim was to determine the interrelation between the expression of multiple molecular markers and the histological features of oral dysplasia.

METHODS

Fifteen samples of OED (five for each severity degree) were analyzed through software assisted image cytometry nuclear morphology. p53 (wild-type and mutated form), Bax and Bcl2 expression was immunohistochemically determined, and the gene expression of MMP1, MMP2, MMP9 and hTERT was determined by RT-PCR. The mean, standard deviation, ANOVA and Fisher's Exact Test (P<0.05) were performed.

RESULTS

Our analysis indicated congruence between the software-assisted measurement of nuclear morphology and severity degree. Only five samples were positive to p53-mutated form; and Bax was more expressed than Bcl-2. hTERT expression was significantly expressed in relation to severity, and MMP1 was predominantly expressed, followed by MMP9 and MMP2.

CONCLUSIONS

Our results reinforce that software-assisted measurement is an alternative to severity degree determination. MMP1 is an important marker for severity dysplasia degree; however, the predominant expression of Bax over Bcl-2 suggests that this pro-apoptotic state could be used to minorize the progression, perhaps, as a future therapeutic target.

The Relationship of Tobacco, Alcohol, and Betel Quid with the Formation of Oral Potentially Malignant Disorders: A Community-Based Study from Northeastern Thailand

This study's objective was to describe the relationship between the main risk factors for oral cancer, including tobacco (in the form of cigarettes, smokeless tobacco (SLT), secondhand smoking (SS)), alcohol, and betel quid (BQ), and the occurrence of oral potentially malignant disorders (OPMDs). A community-based case-control study was conducted with a population of 1448 adults aged 40 years or above in northeastern Thailand. Patients aged 60 years or above (OR 1.79, p < 0.001) and female patients (OR 2.17, p < 0.001) had a significant chance of having OPMDs. Our multivariate analysis showed that the most potent risk factor for OPMDs occurrence was betel quid (BQ) (adjusted OR 4.65, p < 0.001), followed by alcohol (OR 3.40, p < 0.001). Even former users were at risk of developing OPMDs. The synergistic effect between these main risk factors was significantly shown in the group exposed to SLT, SS, BQ, and alcohol. The most potent synergistic effect was found in the group exposed to SLT, BQ and alcohol with the OR = 20.96.

Profiling risk factors of micro-invasive carcinoma within oral potentially malignant disorders: a cross-sectional study

OBJECTIVES

To investigate the clinicopathological profile and risk factors of micro-invasive carcinoma within oral potentially malignant disorders (OPMD).

METHODS

Micro-invasive carcinomas were identified in a large prospective series of OPMD patients (n = 810) from eastern China. Logistic regression was applied to evaluate odds ratios (OR) with 95% confidence interval (CI) for indicative of malignant risk in general OPMD.

RESULTS

Leukoplakia (41.4%), lichen planus (28.0%), and lichenoid lesion (23.7%) were the most 3 clinical subtypes of OPMD. A total of 62 (7.7%) micro-invasive carcinomas within OPMD were identified, and 96.8% of micro-invasive carcinoma was found within leukoplakia and erythroplakia. Multivariate regression analysis revealed that the risk of malignant change within OPMD located on lateral/ventral tongue (OR, 15.1; 95% CI, 1.85-122.8; P = 0.011) was higher than other sites. The risk of malignant change within non-homogenous type (OR, 103.3; 95% CI, 13.39-796.7; P < 0.001) was strikingly higher than other subtypes of OPMD, respectively. Intriguingly, the risk of micro-invasive carcinoma diagnosed in current smoker (OR, 3.96; 95% CI, 1.31-12.02; P = 0.015) was higher than non-smoker.

CONCLUSION

This large-scale cross-sectional study elucidated the clinical factors and risk assessment of micro-invasive carcinoma within OPMD.

CLINICAL RELEVANCE

Non-homogenous lesions located on lateral/ventral tongue might be monitored at closer intervals, and the need for rigorous management to detect malignant changes.

DNA aneuploidy with image cytometry for detecting dysplasia and carcinoma in oral potentially malignant disorders: A prospective diagnostic study

BACKGROUND

Current evidence on diagnostic value of aneuploidy with DNA image cytometry (ICM) using brushings for oral potentially malignant disorders (OPMD) is limited by sample size and inconsistent classification criteria of aneuploidy. This study aimed to explore the optimal cut-off values of DNA content and evaluate the diagnostic accuracy of DNA-ICM for detecting dysplasia and/or carcinoma in OPMD.

MATERIALS AND METHODS

A total of 401 consecutive patients with OPMD were enrolled in this prospective diagnostic study. Brushing and biopsy sample form each patient was processed by DNA-ICM and histological examination respectively.

RESULTS

When the optimal cut-off of at least one aneuploid cell with DNA index (DI) ≥2.3, the area under the curves (AUC) was 0.735 and positive predictive value was 92.7% for detecting dysplasia within OPMD. When the optimal cut-off of at least one aneuploid cell with DI ≥ 3.5, the AUC was 0.851 and negative predictive values was 96.8% for detecting carcinoma within OPMD. Importantly, multivariate analysis revealed that aneuploidy with DI ≥ 2.3 in OPMD was significantly associated with dysplasia risk (adjusted OR, 5.52; 95%CI, 2.90-10.51; P < .001), and aneuploidy with DI ≥ 3.5 in OPMD was strongly associated with malignant risk (adjusted OR, 21.05; 95%CI, 9.34-47.41; P < .001).

CONCLUSIONS

This largest-scale diagnostic study optimized the criteria of aneuploidy cytology for noninvasive detection of oral dysplasia and carcinoma within OPMD. DNA aneuploidy in OPMD was an independent marker that strongly associated with oral dysplasia/carcinoma. Our findings suggest that DNA-ICM may serve as a useful noninvasive adjunctive tool for oral cancer and OPMD screening.

A Multicenter Study of Tongue Lesions from Thailand

OBJECTIVE

Tongue lesions constitute a considerable proportion of the oral lesions. Previous studies on tongue lesions were based on clinical studies. There has been a scarcity of the studies which are based on histopathological examination. This study aimed to determine the prevalence, demographic, and pathologic features of tongue lesions from Thailand.

MATERIALS AND METHODS

 Biopsy records of the participating institutions were reviewed for lesions on the tongue diagnosed during 1998 to 2017. Demographic data were collected from the biopsy records. Locations were arbitrarily classified as dorsal, lateral, and ventral surfaces, tip of the tongue, and the combination of sites. Lesions of the tongue were classified as reactive/inflammatory, developmental, immune-mediated, cystic, benign, premalignant, malignant, infectious, and miscellaneous categories.

STATISTICAL ANALYSIS

 Data were analyzed by descriptive statistics using SPSS version 20.0.

RESULTS

 Of the 44,188 accessioned cases, 2,153 cases (4.87%) were diagnosed from the tongue. The age of the patients ranged from 3 to 93 years with the mean ± standard deviation = 45.26 ± 20.48 years. The female-to-male ratio was 1.49:1. The majority of the tongue lesions were encountered at the lateral border of the tongue (47.66%). Most of the tongue lesions in the present study (53.74%) fell into the reactive/inflammatory category. Irritation fibroma was the most prevalent lesion (18.99%) followed by squamous cell carcinoma (16.91%), and mucus extravasation phenomenon (14.26%), respectively.

CONCLUSIONS

 This study offers new perspective into the study of tongue lesions apart from the clinically based studies. It also demonstrates the difference between the pediatric and the elderly patients. This study provides invaluable database for clinicians when formulating the clinical diagnosis of tongue lesions.