Epidemiology of oral cancer in South and South-East Asia: Incidence and mortality.

INTRODUCTION: This study provides an epidemiological description of cancer in the lip, oral cavity, and oropharynx in the South and South-East Asia region. METHODS: The number of new cases and deaths was extracted from the GLOBOCAN 2020 and the CI5 series. We present age-standardized incidence and mortality rates per 100,000 inhabitants. To assess temporal trends, we estimated the annual percent change. RESULTS: The incidence rates (ASR) for lip and oral cavity cancer in South and South-East Asia were highest in Taiwan (30.2), Sri Lanka (16.5), India (14.8), and Pakistan (13.2) among males. For oropharyngeal cancer, the highest rates were found in Taiwan (4.7), Bangladesh, Sri Lanka, and India (4.3, 2.9, and 2.6, respectively). Incidence rates were consistently higher in males compared to females. Overall, trends in lip and oral cavity cancer incidence were either stable or decreasing in most of the populations evaluated. In India, an increase in rates among males contrasted with a decline among females over the study period. CONCLUSION: Incidence and mortality rates of oral cavity cancer in South and South-East Asia are among the highest globally. Our results suggest an optimistic trend of reduction in oral cavity rates in the region, despite an increase in rates among Indian males.

Natural products and diet for the prevention of oral cancer: Research from south and southeast Asia.

Medicinal plants are of prime importance in the discovery of drugs. They are an inherent source of naturally available phytochemicals that can help in the prevention and treatment of several diseases including cancer. This article reviews the experimental and clinical evidence of phytochemicals available in natural dietary products that are used in everyday life across South Asia and South-East Asia for their perceived effectiveness in the management of Potentially Malignant Disorders and prevention of Oral Cancer. The review also highlights the active phytometabolites, their in vitro anti-proliferative properties and targeted signalling pathways, biological activities in in vivo models and translative potential for clinical trials in humans.

Prevalence of human papillomavirus in oral cancer in Asia: A systematic review and meta-analysis.

OBJECTIVE: To determine the prevalence of human papillomavirus (HPV) in oral squamous cell carcinoma (OSCC) across Asian countries, focusing on South and Southeast Asia. METHODS: A systematic search of four databases-MEDLINE/PubMed, EMBASE, Scopus, and ProQuest-was conducted to identify observational studies published between January 2013 and December 2023. The pooled prevalence of HPV was estimated using random-effects models, and subgroup analysis was performed to investigate the source of heterogeneity. RESULTS: A total of 77 studies were included, comprising 7289 OSCC cases from 11 countries. The pooled HPV prevalence in OSCC was 23.1% (95% CI 17.9-28.7, I2 = 96.7%). South Asia had the highest prevalence (27.1%), followed by East Asia (19.4%), and Southeast Asia (16.7%). Two subtypes were commonly reported: HPV-16 (9.1%) and HPV-18 (5.1%). Anatomical subsites, buccal mucosa (34.0%), and floor of the mouth (33.2%) had similar ranges of HPV prevalence. All studies exhibited a high degree of heterogeneity, with the OSCC location and risk of bias identified as potential sources of heterogeneity. CONCLUSIONS: Due to the high HPV prevalence in OSCC in Asia, HPV detection in routine pathology practice is recommended. Future studies should be conducted in multicentre settings using similar HPV detection methods and reporting detailed demographic and clinical information on oral sub-sites.

Malignant transformation of oral leukoplakia: Systematic review and comprehensive meta-analysis.

OBJECTIVES: To update the current evidence on the malignant transformation of oral leukoplakia (OL), including all studies published worldwide on the subject, selected with the maximum rigor regarding eligibility. MATERIALS AND METHODS: MEDLINE, Embase, Web of Science and Scopus were searched for studies published before June-2024, with no lower date limit. The risk of bias was analyzed using the Joanna Briggs Institute tool for meta-analyses of proportions. We carried out meta-analyses, explored heterogeneity across subgroups and identified risk factors with potential prognostic value. RESULTS: Fifty-five studies (41,231 with OL) were included. The pooled malignant transformation proportion for OL was 6.64% (95% CI = 5.21-8.21). The malignant transformation did not significantly vary by time periods (p = 0.75), 5.35% prior to 1978, 7.06% from 1979 to 2007 and 6.97% during more recent times. The risk factors that significantly had a higher impact on malignant transformation were the non-homogeneous leukoplakias (RR = 4.23, 95% CI = 3.31-5.39, p < 0.001), the larger size (RR = 2.08, 1.45-2.96, p < 0.001), leukoplakia located on the lateral border of tongue (malignant transformation = 12.71%; RR = 2.09, 95% CI = 1.48-2.95, p < 0.001), smoking (RR = 1.64, 95% CI = 1.25-2.15, p < 0.001), and the presence of epithelial dysplasia (RR = 2.75, 95% CI = 2.26-3.35, p < 0.001). CONCLUSIONS: OL presents a considerable malignant transformation probability that is especially increased in large non-homogeneous lesions in smokers, located on the lateral border of the tongue, with epithelial dysplasia.

Surgical protocols for oral leukoplakia and precancerous lesions across three different anatomic sites.

OBJECTIVE: This systematic review and meta-analysis aimed to compare the risk of recurrence and cancer progression after surgical treatment for oral potentially malignant disorders (OPMD) and precancerous lesions in different anatomical sites. MATERIALS AND METHODS: A comprehensive search was conducted in nine databases and grey literature. We included randomized controlled trials assessing surgical treatment efficacy for OPMD and precancerous lesions of cervical, vaginal, anal, and penile sites. Excision or ablation surgical treatments were considered. RESULTS: Overall, 12 studies met the eligibility criteria for oral leukoplakia (OL), proliferative verrucous leukoplakia, cervical intraepithelial neoplasia (CIN), vaginal intraepithelial neoplasia, and anal intraepithelial neoplasia (AIN). In qualitative analysis of surgical protocols, the lack of margin description impacts the clinical outcomes of OL and AIN, and the ablative protocols were heterogeneous in both OPMD and precancerous lesions. No significant difference in OL (risk ratio 0.82 [95% CI: 0.59-1.15]) and CIN (risk ratio 0.31 [95% CI: 0.09-1.09]) for recurrence was observed when cold-knife was compared with ablative protocols. OL exhibited higher recurrence and cancer progression rates compared to CIN and AIN. CONCLUSION: There is no difference in recurrence risk post-surgical treatment for OL and CIN. Surgical protocols for oral leukoplakia and CIN/AIN lack standardized approaches.

Barriers to early diagnosis and management of oral cancer in Latin America and the Caribbean.

OBJECTIVE: This study aimed to explore perceived barriers to early diagnosis and management of oral cancer, as well as potential pathways for improvement in Latin America and the Caribbean (LAC). METHODS: This cross-sectional study used a self-administered online questionnaire created via the Research Electronic Data Capture platform. The survey was distributed to health professionals trained in Oral Medicine, Oral Pathology, Oral and Maxillofacial Surgery, and Dentists with clinical and academic expertise in oral potentially malignant disorder (OPMD) and oral cancer. Data obtained were systematically organized and analyzed descriptively using Microsoft Excel. RESULTS: Twenty-three professionals from 21 LAC countries participated. Major barriers included the limited implementation of OPMD and oral cancer control plans (17.4%), low compulsory reporting for OPMD (8.7%) and oral cancer (34.8%), unclear referral pathways for OPMD (34.8%) and oral cancer (43.5%), and a shortage of trained professionals (8.7%). Participants endorsed the utility of online education (100%) and telemedicine (91.3%). CONCLUSION: The survey highlights major perceived barriers to early diagnosis and management of OPMD and oral cancer in LAC, as well as potential avenues for improvement.

Association between autoimmune rheumatic diseases and head and neck cancer: Systematic review and meta-analysis.

BACKGROUND: Personal history of autoimmune rheumatic diseases has been implicated in the development of malignant neoplasms. Our aim was to assess the risk of head and neck (H&N) cancers in patients with autoimmune rheumatic diseases. METHODS: The articles search included PubMed, EMBASE, LILACS, The Cochrane Library, CINAHL, Scopus, Web of Science, and Google Scholar with no language restrictions for studies published from inception of the databases to August 20, 2022, assessing the risk of H&N cancer in patients with autoimmune rheumatic diseases. Studies were included if they reported the standardized incidence ratio (SIR) with corresponding 95% confidence intervals (CIs). The primary outcome was risk of H&N cancers in patients with autoimmune rheumatic diseases compared with the general population. Pooled summary estimates were calculated using a random-effects model, and subgroup analyses were done to establish whether risk of H&N cancers varied according to study site. RESULTS: Our search identified 5378 records, of which 32 cohort studies were eligible for systematic review and 24 for meta-analysis (including 273 613 patients). A significant association was found between H&N cancer and autoimmune rheumatic diseases (SIR = 2.35; 95% CI: 1.57-3.50; p < 0.01, I2  = 94%). CONCLUSION: Our study suggests that patients with autoimmune rheumatic diseases had a significantly increased risk of H&N cancer compared with the general population, including thyroid, oral, and nasopharyngeal cancers. These findings have implications for the individualized screening of these patients and the planning of oncology units. The protocol is registered with PROSPERO, number CRD42020197827.

Machine learning for detection and classification of oral potentially malignant disorders: A conceptual review.

Oral potentially malignant disorders represent precursor lesions that may undergo malignant transformation to oral cancer. There are many known risk factors associated with the development of oral potentially malignant disorders, and contribute to the risk of malignant transformation. Although many advances have been reported to understand the biological behavior of oral potentially malignant disorders, their clinical features that indicate the characteristics of malignant transformation are not well established. Early diagnosis of malignancy is the most important factor to improve patients' prognosis. The integration of machine learning into routine diagnosis has recently emerged as an adjunct to aid clinical examination. Increased performances of artificial intelligence AI-assisted medical devices are claimed to exceed the human capability in the clinical detection of early cancer. Therefore, the aim of this narrative review is to introduce artificial intelligence terminology, concepts, and models currently used in oncology to familiarize oral medicine scientists with the language skills, best research practices, and knowledge for developing machine learning models applied to the clinical detection of oral potentially malignant disorders.

Oral epithelial dysplasia grading: Comparing the binary system to the traditional 3-tier system, an actuarial study with malignant transformation as outcome.

BACKGROUND: Establishing the risk of malignant transformation (MT) in oral leukoplakia is usually based on grading oral epithelial dysplasia (OED) on biopsy tissue, for which two systems are proposed: a 3-tier and a binary system. Only very few actuarial studies have tested the accuracy of such methods in predicting MT, especially for the binary system. This study aimed to assess the accuracy of the two grading systems in predicting MT in a cohort of oral leukoplakia (OL) from Brazil, with follow-up data. METHODS: The sample comprised 878 individuals diagnosed with OL from 2005 to 2018. Follow-up data were obtained both locally and from the regional cancer registry. All lesions were graded using both the 3-tier and the binary systems. Kaplan-Meier curves (Log-rank Mantel-Cox) were used to assess risk and kappa to assess interobserver agreement. RESULTS: Thirty-five individuals underwent MT (4%). Both systems demonstrated prognostic value, though the 3-tier system proved superior, with OR 9.23 (3.42-23.69), PPV 0.152, NPV 0.98, compared to binary OR 3.49 (1.79-6.79), PPV 0.079, NPV 0.976. Interobserver agreement was also superior in the 3-tier system (0.47, p < 0.05) compared to the binary system (0.139, p = 0.39). Combining the two systems enhanced prognostic values (OR 14.28, PPV 0.217, NPV 0.981). CONCLUSION: The 3-tier system presented superior prognostic value to the binary system. Combining both systems to double-grade intermediate lesions might enhance risk assessment.

The carcinogenicity of opium consumption: a systematic review and meta-analysis.

The carcinogenicity of opium consumption was recently evaluated by a Working Group convened by the International Agency for Research on Cancer (IARC). We supplement the recent IARC evaluation by conducting an extended systematic review as well as a quantitative meta-analytic assessment of the role of opium consumption and risk for selected cancers, evaluating in detail various aspects of study quality on meta-analytic findings. We searched the published literature to identify all relevant studies on opium consumption and risk of selected cancers in humans through 31 October, 2022. Meta-relative risks (mRRs) and associated 95% confidence intervals (CIs) were estimated using random-effects models for studies of cancer of the urinary bladder, larynx, lung, oesophagus, pancreas, and stomach. Heterogeneity among studies was assessed using the I2 statistic. We assessed study quality and conducted sensitivity analyses to evaluate the impact of potential reverse causation, protopathic bias, selection bias, information bias, and confounding. In total, 2 prospective cohort studies and 33 case-control studies were included. The overall pooled mRR estimated for 'ever or regular' versus 'never' use of opium ranged from 1.50 (95% CI 1.13-1.99, I2 = 0%, 6 studies) for oesophageal cancer to 7.97 (95% CI 4.79-13.3, I2 = 62%, 7 studies) for laryngeal cancer. Analyses of cumulative opium exposure suggested greater risk of cancer associated with higher opium consumption. Findings were robust in sensitivity analyses excluding studies prone to potential methodological sources of biases and confounding. Findings support an adverse association between opium consumption and cancers of the urinary bladder, larynx, lung, oesophagus, pancreas and stomach.