The prevalence of oral cancers (OC) is high in Asian countries, especially in South and Southeast Asia. Asian distinct cultural practices such as betel-quid chewing, and varying patterns of tobacco and alcohol use are important risk factors that predispose to cancer of the oral cavity. The aim of this review is to provide an update on epidemiology of OC between 2000 and 2012. A literature search for this review was conducted on Medline for articles on OC from Asian countries. Some of the articles were also hand searched using Google. High incidence rates were reported from developing nations like India, Pakistan, Bangladesh, Taiwan and Sri Lanka. While an increasing trend has been observed in Pakistan, Taiwan and Thailand, a decreasing trend is seen in Philippines and Sri Lanka. The mean age of occurrence of cancer in different parts of oral cavity is usually between 51-55 years in most countries. The tongue is the leading site among oral cancers in India. The next most common sites in Asian countries include the buccal mucosa and gingiva. The 5 year survival rate has been low for OC, despite improvements in diagnosis and treatment. Tobacco chewing, smoking and alcohol are the main reasons for the increasing incidence rates. Low socioeconomic status and diet low in nutritional value lacking vegetables and fruits contribute towards the risk. In addition, viral infections, such as HPV and poor oral hygiene, are other important risk factors. Hence, it is important to control OC by screening for early diagnosis and controlling tobacco and alcohol use. It is also necessary to have cancer surveillance at the national-level to collect and utilise data for cancer prevention and control programs.

https://www.koreascience.or.kr:443/article/JAKO201305981337596.pdf

Epidemiology of Oral Cancer in Asia in the Past Decade- An Update (2000-2012)

Background
Oral squamous cell carcinoma is the most common form of malignancy of the lip and oral cavity, often being proceeded by potentially malignant disorders (PMD). Early detection can reduce the malignant transformation of PMD and can improve the survival rate for oral cancer. The current standard of scalpel biopsy with histology is painful for patients and involves a delay whilst histology is completed; other tests are available that are unobtrusive and provide immediate results.

Objectives
Primary objective: To estimate the diagnostic accuracy of index tests for the detection of oral cancer and PMD of the lip and oral cavity, in people presenting with clinically evident lesions.

Secondary objective: To estimate the relative accuracy of the different index tests.

Search methods
The electronic databases were searched on 30 April 2013. We searched MEDLINE (OVID) (1946 to April 2013) and four other electronic databases (the Cochrane Diagnostic Test Accuracy Studies Register, the Cochrane Oral Health Group's Trials Register, EMBASE (OVID) and MEDION (Ovid)). There were no restrictions on language in the searches of the electronic databases. We conducted citation searches and screened reference lists of included studies for additional references.

Selection criteria
We selected studies that reported the diagnostic test accuracy of the following index tests when used as an adjunct to conventional oral examination in detecting PMD or oral squamous cell carcinoma of the lip or oral cavity: vital staining, oral cytology, light-based detection and oral spectroscopy, blood or saliva analysis (which test for the presence of biomarkers in blood or saliva).

Data collection and analysis
Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction and quality assessment were carried out by at least two authors, independently and in duplicate. Studies were assessed for methodological quality using QUADAS-2. Meta-analysis was used to combine the results of studies for each index test using the bivariate approach to estimate the expected values of sensitivity and specificity.

Main results
We included 41 studies, recruiting 4002 participants, in this review. These studies evaluated the diagnostic accuracy of conventional oral examination with: vital staining (14 studies), oral cytology (13 studies), light-based detection or oral spectroscopy (13 studies). Six studies assessed two combined index tests. There were no eligible diagnostic accuracy studies evaluating blood or salivary sample analysis.

The summary estimates for vital staining obtained from the meta-analysis were sensitivity of 0.84 (95% CI 0.74 to 0.90) with specificity of 0.70 (0.59 to 0.79), with 14 studies were included in the meta-analysis. For cytology, sensitivity was 0.91 (0.81 to 0.96) and specificity was 0.91 (0.81 to 0.95) with 12 studies included in the meta-analysis. For light-based detection, sensitivity was 0.91 (0.77 to 0.97) and specificity was 0.58 (0.22 to 0.87) with 11 studies included in the meta-analysis. The relative test accuracy was assessed by adding covariates to the bivariate analysis, no difference in model fit was observed.

Authors' conclusions
The overall quality of the included studies was poor. None of the adjunctive tests can be recommended as a replacement for the currently used standard of a scalpel biopsy and histological assessment. Given the relatively high values of the summary estimates of sensitivity and specificity for cytology, this would appear to offer the most potential. Combined adjunctive tests involving cytology warrant further investigation.

/pdf/diagnostic-tests-for-oral-cancer-and-potentially-malignant-grpev4192f.pdf

Diagnostic tests for oral cancer and potentially malignant disorders in patients presenting with clinically evident lesions

Background: Increasing incidence of head and neck cancer (HNC) in young adults has been reported. We aimed to compare the role of major risk factors and family history of cancer in HNC in young adults and older patients.

Methods: We pooled data from 25 case-control studies and conducted separate analyses for adults ≤45 years old (‘young adults’, 2010 cases and 4042 controls) and >45 years old (‘older adults’, 17 700 cases and 22 704 controls). Using logistic regression with studies treated as random effects, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

Results: The young group of cases had a higher proportion of oral tongue cancer (16.0% in women; 11.0% in men) and unspecified oral cavity / oropharynx cancer (16.2%; 11.1%) and a lower proportion of larynx cancer (12.1%; 16.6%) than older adult cases. The proportions of never smokers or never drinkers among female cases were higher than among male cases in both age groups. Positive associations with HNC and duration or pack-years of smoking and drinking were similar across age groups. However, the attributable fractions (AFs) for smoking and drinking were lower in young when compared with older adults (AFs for smoking in young women, older women, young men and older men, respectively, = 19.9% (95% CI = 9.8%, 27.9%), 48.9% (46.6%, 50.8%), 46.2% (38.5%, 52.5%), 64.3% (62.2%, 66.4%); AFs for drinking = 5.3% (−11.2%, 18.0%), 20.0% (14.5%, 25.0%), 21.5% (5.0%, 34.9%) and 50.4% (46.1%, 54.3%). A family history of early-onset cancer was associated with HNC risk in the young [OR = 2.27 (95% CI = 1.26, 4.10)], but not in the older adults [OR = 1.10 (0.91, 1.31)]. The attributable fraction for family history of early-onset cancer was 23.2% (8.60% to 31.4%) in young compared with 2.20% (−2.41%, 5.80%) in older adults.

Conclusions: Differences in HNC aetiology according to age group may exist. The lower AF of cigarette smoking and alcohol drinking in young adults may be due to the reduced length of exposure due to the lower age. Other characteristics, such as those that are inherited, may play a more important role in HNC in young adults compared with older adults.

Risk factors for head and neck cancer in young adults: a pooled analysis in the INHANCE consortium

Background An expert panel convened by the American Dental Association (ADA) Council on Scientific Affairs and the Center for Evidence-Based Dentistry conducted a systematic review and formulated clinical recommendations to inform primary care clinicians about the potential use of adjuncts as triage tools for the evaluation of lesions, including potentially malignant disorders (PMDs), in the oral cavity. Types of Studies Reviewed This is an update of the ADA's 2010 recommendations on the early diagnosis of PMDs and oral squamous cell carcinoma. The authors conducted a systematic search of the literature in MEDLINE and Embase via Ovid and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials and diagnostic test accuracy studies. The authors used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the certainty in the evidence and to move from the evidence to the decisions. Results The panel formulated 1 good practice statement and 6 clinical recommendations that concluded that no available adjuncts demonstrated sufficient diagnostic test accuracy to support their routine use as triage tools during the evaluation of lesions in the oral cavity. For patients seeking care for suspicious lesions, immediate performance of a biopsy or referral to a specialist remains the single most important recommendation for clinical practice. In exceptional cases, when patients decline a biopsy or live in rural areas with limited access to care, the panel suggested that cytologic testing may be used to initiate the diagnostic process until a biopsy can be performed (conditional recommendation, low-quality evidence). Conclusions and Practical Implications The authors urge clinicians to remain alert and take diligent action when they identify a PMD. The authors emphasize the need for counseling because patients may delay diagnosis because of anxiety and denial.

Evidence-based clinical practice guideline for the evaluation of potentially malignant disorders in the oral cavity: A report of the American Dental Association.

Objective The aim of this study was to assess the relevance of clinical and histopathologic parameters on survival of oral squamous cell carcinoma (OSCC) patients in Sri Lanka. Study Design A cohort of 193 previously diagnosed OSCC patients were followed for up to 5 years. Clinical and histopathologic parameters were analyzed regarding local recurrence and 5-year survival after treatment. Results Site, stage, local recurrence, degree of differentiation, degree of keratinization, pattern of invasion, and status of the excision margins showed a significant association with the 5-year survival ( P P Conclusions Stage, pattern of invasion, and status of the excision margins are superior prognostic indicators of OSCC compared with other parameters.

Clinical and histopathologic parameters in survival of oral squamous cell carcinoma

Demographic, aetiological and survival differences of oral squamous cell carcinoma in the young and the old in Sri Lanka.

Background: To screen for oral cancer or not is being debated, but for high-risk populations with minimal access to regular dental care systematic oral examinations could provide some benefit.

Methods:  We undertook oral mucosal examinations of labourers employed in tea estate plantations in Sri Lanka. In a two-stage screening procedure, first by estate medical officers and then by visiting specialists, we examined 12 716 persons at their workplaces achieving a coverage of one-sixth of the total workforce.

Results:  Fourteen oral cancers and 848 subjects with oral pre-cancer (6.7%) were detected giving population prevalences of 46.1 per 1000 for leukoplakia and 16.4 per 1000 for oral submucous fibrosis. Among subjects with any oral mucosal disorder (n = 1159) proportions of current users of betel quid, smokers and alcohol use was recorded at 92%, 31% and 61% respectively. The synergistic effect of these three risk habits on the development of oral leukoplakia was evident in mixed habit groups.

Conclusions:  The prevalence of oral pre-cancer in tea estate labourers was higher than estimates reported in previous studies. In the absence of state-sponsored preventive activities, it is necessary to improve the capacity of individual health practitioners and small medical centres to participate in oral health promotion and oral cancer/pre-cancer screening.

Prevalence of oral cancer and pre-cancer and associated risk factors among tea estate workers in the central Sri Lanka.

Background: Oral squamous cell carcinoma (OSCC) most commonly occurs in the middle-aged and older individuals. The purpose of the present study was to evaluate the histopathological and immunohistochemical differences of the younger (<40 years) and the older (more than 50 years) groups.



Methods:  The histopathological parameters of 112 patients (younger 56 and older 56) were compared according to three grading systems (Broder JAMA 1920; 74: 656, Anneroth et al. Scand J Dent Res 1987; 95: 229, Bryne et al. J Pathol 1992; 166: 375) and as individual histopathological parameters. Further, the expression of p53 and Proliferative Cell Nuclear Antigen (PCNA) index was also compared.



Results:  Although there was no significant difference between two groups regarding the three grading systems, a significantly higher number of nuclear aberrations was found in younger group (P < 0.001). Interestingly, higher number of mitoses (P < 0.05) and lymph node metastasis (P < 0.05) were observed in the older group (P < 0.05). Furthermore, significantly a higher PCNA index was found in the older group (P < 0.005).



Conclusions:  Although tumours of the young patients showed more nuclear aberrations, OSCC of the older patients is proliferative and showed higher metastatic rate.

Analysis of histopathological and immunohistochemical differences of oral squamous cell carcinoma in young and old patients in Sri Lanka.

Background
The use of oral cytology to diagnose malignant and premalignant lesions at an early stage is considered crucial. The aim of this study was to evaluate the diagnoses of the spatula and the cytobrush techniques compared with the gold standard histopathological findings, analysed according to different diagnostic criteria.

Methods
Cytological smears were obtained from 76 suspicious oral malignant lesions and 116 oral leukoplakia lesions using two techniques: cytobrush plus cell collector and metal spatula. Subsequently, a surgical biopsy was performed on each lesion to achieve a histopathological diagnosis. Evaluation was conducted with respect to three different diagnostic criteria.

Results
The sensitivity for diagnosing carcinoma in clinically malignant cases was 89.58% and 60.42% for cytobrush and spatula techniques, respectively. Inclusion of severe dysplastic cases for ‘high-risk’ lesions increased the sensitivity up to 96.36% and 78.18% for two techniques, respectively. In leukoplakia lesions, malignant and severely dysplastic cells were diagnosed at a sensitivity of 88.89% in the cytobrush and 55.56% in the spatula techniques. Extending the criteria by defining malignant or any dysplastic findings as positive, sensitivity was increased to 98.02% and 89.11% for the spatula and the cytobrush techniques, respectively. Specificity for both techniques increased to 100%. The difference between the diagnoses of histopathology and the spatula cytology was statistically significant (P 0.1).

Conclusion
The cytobrush, unlike the spatula, is a useful screening instrument for early diagnosis of suspicious oral lesions and could therefore contribute to improved oral cancer prognosis.

Comparison of spatula and cytobrush cytological techniques in early detection of oral malignant and premalignant lesions: a prospective and blinded study

E. A. P. D. Amaratunga

Papers

Demographic, aetiological and survival differences of oral squamous cell carcinoma in the young and the old in Sri Lanka.

Prevalence of oral cancer and pre-cancer and associated risk factors among tea estate workers in the central Sri Lanka.

Analysis of histopathological and immunohistochemical differences of oral squamous cell carcinoma in young and old patients in Sri Lanka.

Comparison of spatula and cytobrush cytological techniques in early detection of oral malignant and premalignant lesions: a prospective and blinded study