The epidemiology of oral cancer

LAMP3 (CD208) Expression in Squamous Cell Carcinoma and Epithelial Dysplasia of the Oral Cavity and Clinicopathological Characteristics of Unfavorable Prognosis

Background

This study aimed to evaluate LAMP3 (CD208) gene expression in oral squamous cell carcinoma (OSCC) and dysplastic oral epithelium by quantitative real-time polymerase chain reaction (qPCR) and compare LAMP3 expression in different disease grades and stages.

Methods

In this study, 60 OSCC and dysplastic oral epithelium samples were obtained from the Mashhad University of Medical Sciences together with their demographic and clinicopathological documents. LAMP3 expression was measured by qPCR.

Results

LAMP3 expression was significantly greater in OSCC than in dysplasia samples (P=0.001), in grade III OSCC than in grades I and II, and also greater in advanced than in early OSCC disease stage (P=0.001).

Conclusion

The significantly greater LAMP3 expression in OSCC than in dysplastic epithelium indicates a role for LAMP3 in carcinogenesis in oral mucosa. Our results suggest LAMP3 may be useful as an anticancer target and/or to predict disease pathogenesis in OSCC patient's cells.

Epidemiology of human papillomavirus-related head and neck cancer

Human papillomavirus (HPV) is now recognized to cause a subset of head and neck squamous cell carcinomas (HNSCC). Although excessive tobacco and alcohol use continue to be important risk factors for HNSCC, epidemiologic studies suggest that more than 25% of HNSCC are now caused by HPV. The incidence of HPV-related HNSCC is increasing, highlighting the need to understand the oral HPV infections causing these cancers. This article reviews the evidence for a causal association between HPV and HNSCC, examines the changing epidemiologic trends of HNSCC, and discusses what is currently known about oral HPV infection, natural history, and transmission.

Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy

BACKGROUND

The management of advanced oral cavity and oropharyngeal cancers is problematic and has traditionally relied on surgery and radiotherapy, both of which are associated with substantial adverse effects. Radiotherapy has been in use since the 1950s and has traditionally been given as single daily doses. This method of dividing up the total dose, or fractionation, has been modified over the years and a variety of approaches have been developed with the aim of improving survival whilst maintaining acceptable toxicity.

OBJECTIVES

To determine which radiotherapy regimens for oral cavity and oropharyngeal cancers result in increased overall survival, disease free survival, progression free survival and locoregional control.

SEARCH STRATEGY

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 28 July 2010), CENTRAL (The Cochrane Library 2010, Issue 3), MEDLINE via OVID (1950 to 28 July 2010) and EMBASE via OVID (1980 to 28 July 2010). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

Randomised controlled trials where more than 50% of participants had primary tumours of the oral cavity or oropharynx, and which compared two or more radiotherapy regimens, radiotherapy versus other treatment modality, or the addition of radiotherapy to other treatment modalities.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of risk of bias was undertaken independently by two or more authors. Study authors were contacted for additional information as required. Adverse events data were collected from published trials.

MAIN RESULTS

30 trials involving 6535 participants were included. Seventeen trials compared some form of altered fractionation (hyperfractionation/accelerated) radiotherapy with conventional radiotherapy; three trials compared different altered fractionation regimens; one trial compared timing of radiotherapy, five trials evaluated neutron therapy and four trials evaluated the addition of pre-operative radiotherapy. Pooling trials of any altered fractionation radiotherapy compared to a conventional schedule showed a statistically significant reduction in total mortality (hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.76 to 0.98). In addition, a statistically significant difference in favour of the altered fractionation was shown for the outcome of locoregional control (HR 0.79, 95% CI 0.70 to 0.89). No statistically significant difference was shown for disease free survival.No statistically significant difference was shown for any other comparison.

AUTHORS' CONCLUSIONS

Altered fractionation radiotherapy is associated with an improvement in overall survival and locoregional control in patients with oral cavity and oropharyngeal cancers. More accurate methods of reporting adverse events are needed in order to truly assess the clinical performance of different radiotherapy regimens.

Oral cancer in Western Australia, 1982-2006: a retrospective epidemiological study

OBJECTIVE

To report differences and trends in oral cancer incidence by gender, age, indigenous status and area of residence and on mortality in Western Australia.

METHODS

Data were provided by Western Australian Cancer Registry. Oral cancer definition included ICD-O-3 codes C00C08. Age-specific, direct age-standardized rates and mortality:incidence ratios were computed with 95% confidence intervals.

RESULTS

The incidence and death rates of oral cancer accounted for 2.3% and 1.3% of all cancers respectively. Over 25 years, the male:female incidence ratio was 2.4:1. Eighty-eight percent of new cases were over the age of 40, peaking in the sixth decade of life. The incidence rates were 14.6 and 6.2 per 100,000 per annum in men and women respectively. Over 17 years, standardized mortality rates were less than 1 per 100,000 per year, with double the deaths in men. Mortality:incidence ratios for oral cancer were between 0.4 and 0.6 with the exception of lip.

CONCLUSIONS

Cancer registries are the only reliable source of data for epidemiologic surveillance of cancer incidence and mortality. Results from this study are comparable with studies on oral cancer in Australia and globally.

Factors Affecting the Referral of Potentially Malignant Lesions from Primary Dental Care: A Pilot Study in South Yorkshire

Aims

Early diagnosis of oral cancer is an essential element of prevention, yet many patients present late, suggesting that criteria used for referral miss the small or early-stage lesions. The aims of this study were to determine what cues are used by primary care dentists when making the decision to refer a suspicious lesion, and to investigate their recent referral behaviour.

Methods

A cross-sectional study using a postal questionnaire was undertaken in a major conurbation in South Yorkshire. The questionnaire was sent to all 95 practices in the area concerned. Primary care dentists were asked to score a range of cues on a five-point scale and list their top ten. Experience of referrals made in the last 12 months was also recorded.

Results

Forty-two questionnaires were returned (44.2%). The cues that primary care dentists ‘agreed’ or ‘strongly agreed’ would initiate a referral were: ‘fixed’, ‘smokes >20 cigarettes/day’, ‘indurated’, ‘ragged borders’ and ‘ulceration’. The most cited top-ten cues were ‘ulcerated’, ‘fixed to underlying tissues’, ‘smoking’ and ‘indurated’. The median number of lesions referred was 0.77 per 1000 adult patients. Twenty-six dentists recorded their experience of 29 lesions. Of these, 17% had been found by the patient whereas 80% had been found at a routine dental examination. Seventy-nine per cent had been present for more than six weeks. Reasons for referral included atypical appearance (38%), ulceration (21%) and location (21%). Fifty-four per cent of primary care dentists described their relationship with secondary care as either ‘good’ or ‘excellent’.

Conclusions

The most cited cues related to established or advanced disease, not to ‘red’ and ‘white’ lesions, which the National Institute for Health and Clinical Excellence (NICE) recommend for early referral. Even allowing for the relatively poor response rate, this suggests that some small lesions of oral cancer are being missed.

Current topics in the epidemiology of oral cavity and oropharyngeal cancers

Oral cancer incidence rates rose dramatically during the twentieth century in the United States and Europe, especially among individuals under the age of 60 years. Although influenced by age, sex, and country of origin, incidence trends were most strongly affected by elevated risk among individuals born after approximately 1915. This cohort effect was indicative of strong behavioral influences on oral cancer risk. In this article, associations between oral cancer risk and established behavioral risk factors including alcohol and tobacco use are reviewed. Additionally, possible associations between oral cancer risk and oral hygiene, diet, nutritional status, and sexual behavior as well as the influence of genetic factors on oral cancer risk are considered. Special emphasis is placed on evaluating possible risk differences in individuals above and below the age of 45 and in users and nonusers of alcohol and tobacco.

Interventions for the treatment of oral and oropharyngeal cancers: surgical treatment

BACKGROUND

Oral and oropharyngeal cancers can be managed by surgery alone or with any combination of radiotherapy, chemotherapy and immunotherapy/biotherapy. Opinions on the surgical treatment, the optimal combinational therapy and the sequence of treatments in combinational therapy varies enormously.

OBJECTIVES

To determine which surgical treatment modalities for oral and oropharyngeal cancers lead to the best outcomes compared with other surgical, radiotherapy, chemotherapy or immunotherapy/biotherapy combinations.

SEARCH STRATEGY

Electronic search of the Cochrane Oral Health Group Trials Register, CENTRAL, MEDLINE, OLDMEDLINE, EMBASE, AMED and the National Cancer Trials Database. Reference lists from relevant articles were searched and the authors of eligible trials were contacted. Date of the most recent searches: July 2007.

SELECTION CRITERIA

Randomised controlled trials of surgery alone or in combination with chemotherapy, radiotherapy or immunotherapy/biotherapy for the treatment of primary oral or oropharyngeal cancer or both.

DATA COLLECTION AND ANALYSIS

A minimum of two review authors conducted data extraction. Risk ratios were calculated for dichotomous outcomes at different time intervals, and hazard ratios were extracted or calculated for disease-free survival, total mortality, and disease-related mortality. Additional information from trial authors was sought. Data on adverse events were collected from the trial reports.

MAIN RESULTS

Thirty-one trials satisfied the inclusion criteria, only 13 of which were assessed as low risk of bias. Trials were grouped into 12 main comparisons. There were no trials that compared different surgical modalities of the primary tumour itself. However, there were a number of trials comparing different approaches to managing the cervical lymph nodes. The majority of treatment regimens under evaluation were surgery in combination with other modalities. As individual treatment regimens within each comparison varied, meta-analysis was inappropriate in most instances. Only two trials could be pooled, comparing concomitant radio/chemotherapy (with surgery) versus radiotherapy (with surgery). A statistically significant difference was shown for disease-free survival (hazard ratio 0.77, 95% confidence interval (CI): 0.64 to 0.92) and total mortality (hazard ratio 0.78, 95% CI: 0.64 to 0.95) in favour of the concomitant chemotherapy and radiotherapy (with surgery) arm. No other treatment regimens showed consistent statistically significant results across the outcomes measured.

AUTHORS' CONCLUSIONS

There is some evidence that concomitant radio/chemotherapy (with surgery) is more effective than radiotherapy (with surgery) and may benefit outcomes in patients with more advanced oral and oropharyngeal cancers. As these trials were based on head and neck studies, future studies should evaluate this treatment regimen specifically in oral and oropharyngeal cancers separately and also address tumour staging and its impact on outcomes. In general, future studies are encouraged to evaluate site-specific and stage-specific data for oral and oropharyngeal cancers. Future trials should include health-related quality of life assessment as an outcome measure. There is a need for a consolidated standardised approach to reporting adverse events.

Ethnic differences in the occurrence of oropharyngeal cancer in Taiwan

OBJECTIVE

The purpose of this study was to examine the oropharyngeal cancer pattern among different ethnic groups in Taiwan.

METHODS

The sample population was divided into three ethnic groups: the Fukkien, Hakka, and aboriginal communities. Age-standardized mortality rates (SMRs) and age-standardized incidence rates (SIRs) were estimated among these ethnic groups for the period 1979-1996/1997.

RESULTS

Our study found that the higher oropharyngeal cancer mortality and incidence rates in females of aboriginal groups are statistically significant, and higher than reference groups for both genders (SMR=3.76, SIR=2.18). However, in the lower areca quid chewing aboriginal groups, the higher pattern was not seen in females, and the lower pattern was even found in males. The incidence and mortality rate of oropharyngeal cancer in Hakkas was significantly lower than in the reference group.

CONCLUSIONS

The pattern of oropharyngeal cancer in Taiwan showed ethnic differences. The differences may be due to variation in exposure to different risk factors; however, in our study, we found that genetic differences might also be considered when explaining the different oropharyngeal cancer patterns among ethnic groups.

The process of symptom appraisal: cognitive and emotional responses to detecting potentially malignant oral symptoms

OBJECTIVE

Following the self-discovery of symptoms of oral cancer, approximately 30% of patients wait for more than 3 months before seeking attention from a health care professional. Although symptom appraisal is known to be an important stage in the decision to seek help, little is known about the process of symptom appraisal. The aims of the current study were to produce a theory-guided investigation of the specific cognitive interpretations and emotional reactions to the self-discovery of potentially malignant oral symptoms and to gain understanding as to why these may change prior to help seeking.

METHODS

In-depth semi-structured interviews were conducted with 57 consecutive patients who had been referred with potentially malignant oral symptoms. Participants were asked about symptom detection, initial and subsequent beliefs about symptoms, and emotional responses prior to their first visit to a health care professional. The tape-recorded interviews were transcribed verbatim and analyzed using "framework analysis."

RESULTS

Patients often attributed the symptoms to transient, minor conditions such as mouth ulcers, physical trauma, or dental problems and, in turn were unconcerned about their presence. Patients infrequently attributed their symptoms to cancer. Origins of specific interpretations included previous experiences, specific symptomatology, logical associations with the perceived cause, and information from medical literature. Stimuli for reinterpretation included receipt of new information, symptom development, and persistence of symptoms.

CONCLUSION

This study has documented the process of symptom appraisal and indicates that an individual's interpretation of potentially malignant oral symptoms is often misguided.

Analysis of Death Certification in Patients With Early Stage Oral Cavity Squamous Cell Carcinoma

PURPOSE

Although patients with T1 oral cavity carcinoma have a generally good prognosis, there is a significant burden of patients that have locoregional recurrence and mortality from early stage disease. The aim of this study was to investigate the specific cause of death in patients with T1N0M0 oral cavity squamous cell carcinoma (OCSCC) by analysis of death certification.

PATIENTS AND METHODS

Patients were identified with T1 OCSCC treated over a 15-year period between 1986 to 2001 from the Mayo Clinic Tumor Registry. All patients were treated by operation without neck dissection or postoperative neoadjuvant therapy as the initial method of treatment. On detailed examination of the death certificate the leading cause of death was identified along with other clinical predictors of death.

RESULTS

Two hundred fifty patients were identified and met inclusion criteria from the Mayo Clinic Tumor Registry. Of the study group, 8.5% and 16% developed local and regional recurrence, respectively, as the first recurrence. The majority of recurrences that were amenable to surgery were managed by radical resection and postoperative neoadjuvant therapy. Of 85 deaths in the study group, 40 death certificates were obtained and reviewed to ascertain a specific cause of death. Patients were grouped into death from oral cancer, other cancer, or medical disease. Primary cause of death from the death certificates available for review included uncontrolled locoregional disease (20%), metastatic oral cancer (15%), development of secondary nonoral malignancy (15%), and a variety of medical causes (50%). Patient age at the time of diagnosis older than 65 had a statistically significant increase in mortality. Interestingly, the presence of premorbid medical conditions, history, or persistent tobacco and alcohol use did not seem to be related to overall mortality.

CONCLUSION

Early stage OCSCC continues to portend a poor prognosis. Analysis of death certification provides useful information of the specific cause of death.

Serum concentration of AMDL DR-70 for the diagnosis and prognosis of carcinoma of the tongue

The aim of this study was to discover the clinical value of the tumour marker AMDL DR-70 in a group of patients with cancer of the tongue. Serum concentrations of AMDL DR-70 were estimated by enzyme linked immuno-sorbent assay in 52 patients with carcinoma of the tongue and compared with 40 controls and 42 patients with benign lesions in the tongue. Thirty-nine patients with carcinoma of the tongue had results above 6 mg/L (75%), compared with 3/40 (7%) in healthy controls and 4/42 (10%) in those with benign tumours. The concentration of AMDL DR-70 in serum correlated significantly with 3-year survival.

Head and neck squamous cell carcinoma in the young patient

PURPOSE OF THE REVIEW

Squamous cell carcinoma of the upper aerodigestive tract most commonly develops in the sixth or seventh decade of life, usually in patients who have significant risk factors from smoking or alcohol use. A subgroup of patients less than 45 years old, however, develops squamous cell carcinoma of the head and neck in whom the role of tobacco or alcohol use is less clear in the etiology of their cancer. Furthermore, there has been considerable debate regarding the tumor biology in this group of patients and its effects on prognosis and overall survival. This paper reviews the current literature and controversies on the etiology and management of squamous cell carcinoma of the head and neck in young patients.

RECENT FINDINGS

Young patients with head and neck squamous cell carcinoma do not have a poorer prognosis or disease-specific survival.

SUMMARY

Young patients with squamous cell carcinoma of the head and neck have a similar prognosis to older patients. There is a trend, however, towards a higher regional recurrence in young patients with head and neck squamous cell carcinoma, suggesting that prophylactic neck treatment should be considered. Further research is needed to determine whether a subgroup of patients (young nonsmoking women with tongue cancer) have a worse prognosis and warrant more aggressive treatment.

A systematic review of case-control studies of human papillomavirus infection in laryngeal squamous cell carcinoma

A role for human papillomavirus (HPV) has been suggested in laryngeal squamous cell carcinoma (LSCC). In order to quantitate the available evidence, we reviewed studies examining the risk of laryngeal cancer-associated HPV. PubMed was searched for case-control studies conducted worldwide and published in any language since 1966. Relevant papers were hand-searched and cross-referenced. Six studies met the inclusion criteria. The studies are heterogeneous in the methods used to harvest tissue samples and techniques for detecting the virus within the tissue. HPV-16 positivity among cases ranged from 2.7% to 46.9% and 0-5.7% among controls. Two studies showed a significantly increased risk of LSCC if HPV-16 was present (OR 18.5, 95% CI 2.2-154.8, OR 2.6, 95% CI 1.1-6.0). An increased risk was also observed for glottic versus supraglottic cancer in one study (OR 9.69, 95% CI 1.47-64.04). The direction of effect is towards an increase in risk of LSCC in people with evidence of HPV-16 infection. There is marked heterogeneity in the methods used to detect the virus and frequency with which it is detected. An adequately powered study using a reliable detection technique is required to confirm and quantify this risk and to examine effect modification.

An audit of the efficacy of the oral brush biopsy technique in a specialist Oral Medicine unit

The diagnosis of oral epithelial dysplasia has traditionally been based upon histopathological evaluation of a full thickness biopsy specimen from lesional tissue. It has recently been proposed that cytological examination of "brush biopsy" samples is a non-invasive method of determining the presence of cellular atypia, and hence the likelihood of oral epithelial dysplasia. The present audit determined, retrospectively the sensitivity, specificity and positive and negative predictive values of the oral brush biopsy technique in the diagnosis of potentially malignant disease in a group of 112 patients attending a specialist Oral Medicine unit. The sensitivity of detection of oral epithelial dysplasia or squamous cell carcinoma of the oral brush biopsy system was 71.4% while the specificity was 32%. The positive predictive value of an abnormal brush biopsy result (positive or atypical) was 44.1%, while the negative predictive value was 60%. It is concluded that not all potentially malignant disease is detected with this non-invasive investigative procedure.

Is the incidence of oral and pharyngeal cancer increasing in Finland? An epidemiological study of 17 383 cases in 1953-1999

OBJECTIVE

The aim of this study was to describe the occurrence of oral and pharyngeal cancer in Finland over the last half century.

MATERIALS AND METHODS

The study included all lip, oral and pharyngeal cancer cases diagnosed in Finland and reported to the nation-wide Finnish Cancer Registry between 1953 and 1999.

RESULTS

The study comprised 17,383 new cancer cases: 11,666 in males and 5717 in females. Of these, 83% were squamous cell carcinomas. By the end of the study, 1999, the mean age at diagnosis had increased to 63 years for males and 67 for females. The age-adjusted incidence of oral and pharyngeal cancer decreased in males from 12.5 per 10(5) to 8.4 per 10(5) while it increased in females from 3.0 per 10(5) to 3.9 per 10(5). This was because of a decrease in lip cancer incidence in males, while the incidence of tongue, mouth and salivary gland cancers increased in both genders. The annual number of new oral cancer cases increased, however, in both genders.

CONCLUSION

The incidence of lip cancer decreased in males, probably because of a decrease in smoking and in outdoor work. The incidence of intra-oral cancers increased in both genders, possibly because of increased alcohol consumption.

Prognostic value of facilitative glucose transporter Glut-1 in oral squamous cell carcinomas treated by surgical resection

Hypoxia in tumours of the oral cavity has not been extensively investigated with regard to clinical outcome and prognosis. The expression of the facilitative glucose transporter, Glut-1, has been shown to be related to hypoxia in tumours at other sites. The aim of the present study was to investigate the relationship between Glut-1 expression and clinical outcome in a series of oral squamous cell carcinomas. A retrospective series of 54 cases of oral squamous cell carcinomas with known clinical outcome and treated by one surgeon over a period of 6 years was used in the study. A representative section from each case was stained immunohistochemically with an antibody against Glut-1. The stained sections were then assessed independently by two observers using a semi-quantitative method. The relationship between these results and the clinical outcomes of local recurrence, regional lymph-node metastasis and disease-free survival were examined. Glut-1 staining was observed in most of the tissue specimens and all of the few sections with demonstrably necrotic areas histologically. Some showed more prominent staining in the epithelial islands of the tumour than others. However, the intensity of staining was variable. There was a significant relationship between those tumours which demonstrated intense staining and recurrence overall (chi(2)=6.18, P=0.032). This relationship was strongest in relation to regional lymph-node recurrence (chi(2)=10.19, P=0.005). A significant relationship between disease-related death and intense Glut-1 staining was also observed (chi(2)=11.67, P=0.002). In conclusion, the results of this study indicate a relationship between Glut-1 expression and disease progression of oral cancer and could indicate a need for neoadjuvant chemoradiotherapy for those tumours demonstrating intense Glut-1 expression.

Development of the Bowman-Birk inhibitor for oral cancer chemoprevention and analysis of Neu immunohistochemical staining intensity with Bowman-Birk inhibitor concentrate treatment

OBJECTIVES/HYPOTHESIS

Cancer chemoprevention is a rapidly evolving approach to reverse or inhibit carcinogenesis, and there is active interest in development of effective chemopreventive agents against head and neck cancers. The retinoids are archetypal chemopreventive agents for oral premalignant lesions. They have significant clinical effect, but widespread use is limited by significant clinical toxicity. The Bowman-Birk Inhibitor is one of several nontoxic compounds exhibiting both potent anticarcinogenic activity and minimal toxicity. The purposes of the study were to summarize the preclinical and clinical development of Bowman-Birk Inhibitor and a Bowman-Birk Inhibitor concentrate against oral premalignant lesions and to evaluate Neu immunohistochemical staining intensity for lesions and simultaneously obtained biopsy specimens of normal-appearing mucosa from the Phase IIa Bowman-Birk Inhibitor concentrate oral leukoplakia chemoprevention trial.

STUDY DESIGN

Part I is a selected literature review. Part II is a retrospective analysis of pathological specimens prospectively obtained from the Phase IIa clinical trial of Bowman-Birk Inhibitor concentrate.

METHODS

Thirty-two sets of biopsy specimens from lesions and uninvolved oral mucosa before and after treatment with Bowman-Birk Inhibitor concentrate in doses ranging from 200 to 1066 chymotrypsin inhibitory units were examined in blinded fashion for Neu immunohistochemical staining intensity using the 3B-5 monoclonal antibody. Staining intensity scores among the lesion and control biopsy specimens before and after Bowman-Birk Inhibitor concentrate treatment were analyzed and compared with previously obtained values for serum Neu, oral mucosal cell Neu, protease activity, and clinical response to treatment.

RESULTS

Mean Neu staining score was significantly higher in lesions compared with uninvolved mucosa (P <.001). Pretreatment staining scores for biopsy specimens of lesions and control biopsy specimens of normal-appearing tissues were correlated (Spearman correlation coefficient [r] = 0.375, P =.045), but no correlation between lesion and control biopsy specimen scores was evident after treatment. The change in Neu staining score with Bowman-Birk Inhibitor concentrate treatment in control site biopsy specimens demonstrated an inverse relationship of change in lesion area with Bowman-Birk Inhibitor concentrate treatment (Spearman r = -0.493, P <.007).

CONCLUSION

Bowman-Birk Inhibitor concentrate shows promise to become an effective nontoxic chemopreventive agent based on results of extensive preclinical studies, and Phase I and Phase IIa clinical trials. Bowman-Birk Inhibitor concentrate has dose-related clinical activity against oral leukoplakia and modulates levels of Neu and protease activity. The current investigation identified increased Neu staining intensity in hyperplastic lesions compared with simultaneously obtained biopsy specimens of normal-appearing mucosa both before and after Bowman-Birk Inhibitor concentrate treatment. This finding supports prior observations that increased Neu expression is present in a subset of oral premalignant lesions and head and neck cancers. The trend of increased Neu staining score in control biopsy tissues of subjects exhibiting decreased lesion area following Bowman-Birk Inhibitor concentrate treatment raises questions about the mechanisms of Bowman-Birk Inhibitor concentrate action. One possible explanation is that Bowman-Birk Inhibitor stabilizes the extracellular domain of Neu, thereby preventing receptor truncation and internalization. Further study of modulation of Neu and protease activity by Bowman-Birk Inhibitor concentrate treatment may provide insights into the role of proteases and protease inhibitors in oral premalignant lesions and the mechanisms underlying Bowman-Birk Inhibitor concentrate effects. A Phase IIb randomized, placebo-controlled clinical trial to determine the clinical effectiveness of Bowman-Birk Inhibitor concentrate and further evaluate these candidate biomarkers is under way.

Oral epithelial dysplasia: clinical characteristics of western European residents

To detail the clinical presentation of oral epithelial dysplasia in a large cohort of residents in western Europe. Descriptive statistical analysis of the data were calculated using chi-square and Fisher's exact tests. Oral epithelial dysplasia manifested typically as a white or mixed red and white lesion on the tongue, buccal mucosa or floor of mouth. The peak age of presentation of oral epithelial dysplasia was the 6th decade. Most clinically detected lesions had only mild oral epithelial dysplasia. Although uncommon, lesions with severe dysplasia were most likely to arise on the floor of mouth or lateral border of tongue. Oral epithelial dysplasia is likely to manifest as a solitary white patch, but it is not possible to accurately predict the likely degree of dysplasia from the clinical features of such lesions.

GDPs' self-perceived confidence and anxiety in their clinical and communication skills used when screening for oral cancer: UK variations

OBJECTIVE

To compare anxieties of general dental practitioners (GDPs) across the UK in communicating with patients about oral cancer and confidence in clinical skills required to perform soft tissue screening for oral cancer.

DESIGN

A questionnaire was sent to 2200 randomly selected GDPs from across the UK. Responses to the questionnaires were analysed using 95% confidence intervals.

SETTING

Dental practitioners in general practice within England, Northern Ireland, Scotland and Wales.

RESULTS

The response rate varied between 57% in England and 65% in Northern Ireland. A high percentage of dental practitioners across all UK regions reported performing soft tissue examinations (range 78% to 88%). The number of soft tissue examinations per month varied between 129 (95% CI 109, 148) and 162 (95% CI 154, 170) indicating criteria when selecting patients for screening. Using a nine-point rating scale (1 = not at all, 9 = extremely), confidence in the clinical skills required during oral cancer screening was generally good (ratings varying between 5.4 and 6.7). With the exception of reporting positive findings to patients (rating 4.5 to 5.2), anxiety in communication skills used during oral cancer screening was generally low (ratings varying between 1.8 and 3.9).

CONCLUSION

While concerns over generalizing the results exist, the situation with respect to the clinical and communication skills required by GDPs during oral cancer screening is generally encouraging. An area of concern is discussing positive findings with patients. This may be overcome by developing specialist courses on breaking bad news within undergraduate dental curricula and programmes of continuing professional development.

A new approach to pre-treatment assessment of the N0 neck in oral squamous cell carcinoma: the role of sentinel node biopsy and positron emission tomography

OBJECTIVES

Pre-operative staging of the clinically N(0) neck in patients with oral squamous cell carcinoma is hindered by the relatively high false negative/positive rates of conventional imaging techniques. The aim of this study is to evaluate the utility of (18)F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET) and sentinel lymph node (SLN) imaging and biopsy to determine the true disease status of the loco-regional lymphatics.

METHODS

Nineteen patients with biopsy proven disease without palpable or radiological evidence of neck metastases underwent pre-operative (18)F-FDG PET and SLN imaging. All patients underwent whole-body FDG PET and a single view of the head and neck. SLN technique was performed using four peri-tumoural injections of (99m)Tc labeled albumin colloid each of 10 MBq. Dynamic and static imaging followed in the antero-posterior and lateral projections. At operation 1 ml of 2.5% Patent Blue Dye and a hand held gamma probe (Neoprobe 1500) were used in combination to identify and remove the SLN. Surgery then continued along conventional lines including a neck dissection. Histology of the resultant specimen was correlated with that of the SLN and pre-operative imaging.

RESULTS

In all patients SLN harvesting was feasible. In 15/19 patients the SLN(s) and the residual neck dissection were -ve for tumour. In 3/19 patients the SLN(s) were +ve for tumour as were other neck nodes. In 1/19 patients the SLN was -ve but another single tumour +ve node was identified in the neck. This patient occurred early in our series with a SLN close to the primary tumour. (18)F-FDG PET failed to identify nodal disease in all four patients with histologically proven lymph node metastases. The size of these nodes ranged from 12 mm x 10 mm x 3 mm to 25 mm x 15 mm x 10 mm.

CONCLUSION

SLN imaging and biopsy with probe and Patent Blue Dye guided harvest is feasible in patients with oral squamous cell carcinoma and can predict cervical nodal status. (18)F-FDG PET may be less useful.

Opportunistic screening for oral cancer and precancer in general dental practice: results of a demonstration study

OBJECTIVES

To demonstrate the feasibility of opportunistic oral cancer and precancer screening in general dental practice and to determine the prevalence of relevant lesions and risk habits in a population of general dental practice attenders.

DESIGN

A prospective demonstration study, recruiting patients opportunistically.

SETTING

General dental practices.

METHODS

Eighteen general dental practitioners took part in this study. Each attended training sessions to be advised of the study protocol and the criteria of a positive and negative screen. Patients over the age of 35 years were prospectively and opportunistically recruited. Each patient was asked to complete a health questionnaire concerning age, gender, ethnicity, smoking and drinking habits. The dentist then examined the soft tissues and recorded the presence or absence of lesions independently on a second form. The forms were collated and data were analysed to determine prevalence of lesions and associations with risk habits.

RESULTS

Data on 2,265 patients were available for analysis. Oral lesions were detected in 319 patients (14.1%). Ninety-four patients (4.2%) had lesions considered to be either malignant or potentially malignant. There was a significant association between positive lesions and male gender(IRR 1.86, 95% CI 1.22-2.82), heavy smoking (males: IRR 3.68, 95% Cl2.10-6.43: female; IRR 3.58, 954b CI 1.35-9.50) and heavy alcohol use in males (IRR 2.98, 95%q CI 1.06-3.47).

CONCLUSIONS

The results suggest that patients attending general dental practices are representative of the general population both in terms of lesion prevalence and high risk habits such as smoking and drinking. This supports the view that opportunistic screening in a general dental practice setting may be a realistic alternative to population screening. Further research is needed to determine the cost effectiveness of this approach and to investigate the value of targeting high risk groups within this population. General dental practice is ideal for the evaluation of such systems prior to extending these studies to other healthcare settings.

A novel geranylated derivative, ethyl 3-(4'-geranyloxy-3'-methoxyphenyl)-2-propenoate, synthesized from ferulic acid suppresses carcinogenesis and inducible nitric oxide synthase in rat tongue

OBJECTIVES

We have previously observed the inhibitory effect of ferulic acid on rat tongue carcinogenesis. In this study, we investigated the modifying effects of a novel geranylated derivative, ethyl 3-(4'-geranyloxy-3'-methoxyphenyl)-2-propenoate (EGMP), synthesized from ferulic acid on tongue carcinogenesis initiated with 4-nitroquinoline 1-oxide (4-NQO).

METHODS

F344 male rats except those treated with EGMP alone and untreated rats were given 20 ppm 4-NQO in drinking water for 9 weeks to induce tongue neoplasms. Starting 1 week after the cessation of exposure to 4-NQO, the experimental groups given 4-NQO and a basal diet were fed the experimental diets containing EGMP (0.2% and 2%) for 20 weeks. The activities of glutathione S-transferase (GST) and quinone reductase (QR), the expression of proliferating cell nuclear antigen, polyamine content and ornithine decarboxylase activity in the tongue were examined for mechanistic analysis of modifying effects of EGMP on carcinogenesis. The expression of inducible nitric acid synthase (iNOS) was also assessed immunohistochemically.

RESULTS

At week 30, the incidence and multiplicity of tongue squamous cell carcinoma were significantly reduced by feeding of a 2% EGMP diet. EGMP feeding (2% in diet) elevated tongue GST activity and lowered QR activity in the tongue. Dietary EGMP decreased the expression of cell proliferation biomarker expression. Interestingly, EGMP feeding altered iNOS expression in the invasive parts of carcinoma.

CONCLUSIONS

These results suggest that EGMP, when given at the 2% dose level during the promotion phase, exerts a chemopreventive action against tongue tumorigenesis through modification of cell proliferation activity and/or detoxifying enzymatic activity.

Trends in the incidence of oral cancer in Nova Scotia from 1983 to 1997

OBJECTIVE

The purpose of the study was to characterize the total burden of oral cancer in Nova Scotia over the 15-year period from 1983 to 1997 and to identify any trends in the number of cases or incidence rates at specific anatomic sites or within specific age or sex groups over this time period.

STUDY DESIGN

All cases that had a diagnosis of invasive oral cancer (ICD-9 sites 140-146) during the study period were retrieved from the records of the Nova Scotia Cancer Registry, which theoretically includes all cancer cases in the province. Cases of in situ carcinoma, lymphoma, and leukemia were not included. All cases during the study period were categorized by tumor site and the age and sex of the patient. Tumors at ICD-9 sites 141 and 143-146 were analyzed separately as intraoral cancer. Trends were studied by grouping cases into three 5-year periods: period 1 (1983-1987), period 2 (1988-1992), and period 3 (1993-1997). Age-standardized incidence rates were calculated to the 1991 Canadian standard population.

RESULTS

A total of 1,155 cases of oral cancer were registered in Nova Scotia for this 15-year study period, accounting for 2.0% of all cancer cases. There was an average of 57 cases in men and 20 cases in women per year. Overall, the most common site was the lip (26% of cases), followed by the tongue (20%), other mouth (16%), tonsil/oropharynx (12%), salivary gland (12%), floor of mouth (10%), and gum (4%). About 5% of cases occurred in patients 40 years and younger, and 53% occurred in patients 65 years and older. Lip cancer in men decreased by 38%, and the age-standardized incidence rate fell from 5.6 to 3.0 per 100,000 from period 1 to period 3. Intraoral cancers in men increased by 23% and the age-standardized incidence rate increased by 10% from period 1 to period 3. Both measures peaked in period 2. Intraoral cancer in women increased steadily by 84%, and the age-standardized incidence rate increased by 48% from period 1 to 3. The male-to-female ratio for intraoral cancer cases decreased from 2.9 to 2.5 to 1.9 over the 3 periods.

CONCLUSION

Although there was a decreasing trend for lip cancer, the number of cases and the age-standardized incidence rate for intraoral cancer increased over the 15-year study period. Intraoral cancer increases in females were dramatic. Trends in the number of cases reflected changing risk and a growing, aging population. More oral cancers occurred each year than cancers of the uterine cervix, suggesting the need for more resource allocation in the areas of research, prevention, and early detection of oral cancer.

Upper airway diseases and airway management: a synopsis

This article summarizes some of the more important upper airway conditions likely to affect airway management. A number of upper airway conditions may present difficult challenges to the anesthesiologist. For instance, infected airway structures may lead to partial airway obstruction, stridor, or even complete airway obstruction. Partial airway obstruction may be mild, as in snoring or nasal congestion, or may be more severe, perhaps requiring the use of airway adjuncts, such as a nasopharyngeal airway. Complete airway obstruction is usually managed by prompt intubation, but surgical airways are sometimes needed as a last resort.

Need for appropriate written information for patients, with particular reference to head and neck cancer

Patients need and want written information. There is evidence that giving comprehensible information increases overall satisfaction with the care given by healthcare professionals. This paper provides a review of the literature on patients' need for appropriate information, with particular reference to head and neck cancer, based on searches of electronic databases. Head and neck cancers are among the least common cancers in the UK but these patients have very specific and great needs. Written information is a cost-effective intervention that complements verbal advice given by healthcare professionals. Evidence suggests that patient information leaflets are poor and are in language that is difficult for the public to understand. Considerable time, effort and user involvement are required to produce acceptable and appropriate information leaflets for patients.

The incidence of oropharyngeal cancer in Taiwan: an endemic betel quid chewing area

BACKGROUND

Oropharyngeal cancer is the one of the most common cancers in the world. The purpose of this study was to examine the trends in oropharyngeal cancer from 1979 to 1996 in Taiwan.

METHODS

Traditional cohort analysis was employed to show the birth-cohort effect of oropharyngeal cancer incidence. Age-period-cohort model analysis was used to examine the age, period and cohort effect between intraoral and pharyngeal cancer.

RESULT

A significant increasing trend in oropharyngeal cancer has been seen in males. The principal increases have been seen in tongue and mouth in males, and tongue in females. In males, an increasing trend was found in successive cohorts born after 1929. The increase in incidence of intraoral cancer of males was greater than the increase in incidence of pharyngeal cancer in the younger age group, more recent time periods and the younger cohorts.

CONCLUSION

The increasing incidence in oropharyngeal cancer in Taiwan is probably heavily influenced by the rising consumption of alcohol and use of betel quid. The effect of these etiologies on intraoral cancer was more significant in recent time periods, later cohorts and the younger group.

Risk factors for squamous cell carcinoma of the oral cavity in young people--a comprehensive literature review

There have been several reports of a rising incidence of oral cancer from many parts of the world. Although it is well known that oral cancer increases with age, recent trends for a rising incidence particularly relates to cancer of the tongue and mouth in young males. This review critically examines 46 publications devoted to oral cancer in the young adult. Most studies suggest that 4-6% of oral cancers now occur at ages younger than 40 years. Several studies examining risk factors for oral cancer in the young provide evidence that many younger patients have never smoked or consumed alcohol, which are recognised risk factors in older groups, or that duration of exposure may be too short for malignant transformation to occur. Information on many aspects of aetiology for this disease in the young implicating occupational, familial risk, immune deficits and virus infection are meagre. The spectrum of genetic abnormality disclosed is similar to older patients, there is paucity of specific studies involving younger cohorts, but predisposition to genetic instability has been hypothesised as a likely cause. Conflicting evidence is also reported on the sex distribution and outcome compared with older patients. Much work is required to understand the caveats related to global demography, risk factors and their diagnostic and prognostic markers for this disease which might be considered a disease distinct from that occurring in older patients.

Advances in dental public health

Dental public health has been defined as 'the science and art of preventing oral diseases, promoting oral health and improving the quality of life through the organised efforts of society'. Dental practitioners most often have the oral health of individual patients as their primary focus but the aim of public health is to benefit populations. Early developments in dental public health were concerned largely with demonstrating levels of disease and with treatment services. With greater appreciation of the nature of oral health and disease, and of their determinants has come recognition of the need for wider public health action if the effects of prevention and oral health promotion are to be maximized.

Expression of the alphavbeta6 integrin promotes migration and invasion in squamous carcinoma cells

The integrin alphavbeta6 is a fibronectin receptor whose expression is not detectable on normal oral epithelium but is increased significantly in healing and in oral epithelial dysplasia and oral squamous cell carcinoma, suggesting it may promote changes associated with tumor development. To study whether alphavbeta6 may drive invasive behavior we have used transfection and retroviral infection to create a panel of epithelial cell lines expressing various levels of alphavbeta6. We report that increased expression of alphavbeta6 in malignant keratinocytes promotes invasion and leads to an increased capacity for migration towards fibronectin. alphavbeta6 expression may have a significant role in contributing to the malignant behavior of epithelial cells.

AlphaVbeta6 integrin promotes invasion of squamous carcinoma cells through up-regulation of matrix metalloproteinase-9

The integrin alphaVbeta6 is a fibronectin receptor, which is not detectable on normal epithelium but is neo-expressed in oral epithelial dysplasia and oral squamous-cell carcinoma (SCC), suggesting a role in promoting malignant behaviour and tumour progression. We used transfection and retroviral infection to create a panel of SCC cell lines expressing various levels of alphaVbeta6 to examine this possibility. We found that increased expression of alphaVbeta6 in malignant keratinocytes up-regulates MMP-9 and MMP-2 expression and promotes invasion in an MMP-9-dependent manner. Our results suggest a possible mechanism for the involvement of alphaVbeta6 in squamous carcinoma in vivo.

Alcohol, tobacco and paan use and understanding of oral cancer risk among Asian males in Leicester

OBJECTIVES

To determine use of alcohol, tobacco and paan among males from the various Asian communities in Leicester; and assess their knowledge and attitudes towards oral cancer risk factors and prevention. Also, to determine any differences regarding habits and attitudes between first and second generation Asians.

DESIGN

Volunteers completed a confidential, bilingual questionnaire regarding alcohol, tobacco and paan use and also knowledge about oral cancer risk factors and preventive measures.

SETTING

Participants were recruited from sources that included GPs' surgeries, sixth form colleges and places of worship.

SUBJECTS

Asian males, i.e. those of Indian, Pakistani, Bangladeshi or Sri Lankan origin; over the age of 16 years and resident in Leicester.

MAIN OUTCOME MEASURES

Quantitative figures were obtained from the questionnaires as to the frequency of alcohol, tobacco and paan use and responses regarding oral cancer knowledge, risk factors and preventive measures.

RESULTS

The principal Asian community groups in Leicester were Hindu, Sikh, Muslim and Jain. Significant differences were found in males from these groups with regards to habits and oral cancer awareness. Muslim males use tobacco and paan more than the other groups but avoid alcohol. Sikh males drink more alcohol (especially spirits) than the other groups but their use of tobacco and paan is low. Habits of Hindu and Jain males are variable. However, approximately 10% of both 1st and 2nd generation Hindu males combine all three habits of alcohol, tobacco and paan; and are thus considered to be at high risk of developing oral cancer. Seven percent of 1st generation Hindu males were found to chew paans containing tobacco which are strongly associated with oral cancer. More 2nd generation Jains drank alcohol than the 1st generation, and a greater proportion of Hindu, Sikh and Jain 2nd generation males drink spirits than their older counterparts. Knowledge of oral cancer risk factors and preventive measures were variable, the lowest level of knowledge being among the 1st generation Sikh group. Few volunteers realised the risk of alcohol drinking in the aetiology of oral cancer.

CONCLUSION

The 'Asian' community in Leicester is not homogeneous, but consists of distinct community groups; each with their own cultural beliefs, habits and attitudes. Knowledge of these differences can be used to provide appropriate health education programmes suitably targeted to reduce the use of the known risk factors for oral cancer.

Oral cancer in young adults: report of three cases and review of the literature

Oral cancer in young adults is fortunately uncommon in the UK. However, since it is so rare, when cases present they are often misdiagnosed and inappropriately treated leading to delay in definitive treatment. This may, in turn, lead to a poorer prognosis for these patients. It is debatable if oral cancer in younger adults carries an inherently poor prognosis and presents with more aggressive tumours. Three cases of oral cancer in young adults, aged under 30 years are presented and the literature reviewed with respect to oral cancer in this group of patients.

The epidemiology of mouth cancer: a review of global incidence

Mouth cancer (143-145 ICD-9) is a major health problem in many parts of the world. While its incidence is relatively low in most western countries there are some important exceptions to this trend: on the Indian subcontinent and in other parts of Asia it remains one of the most common forms of cancer. This review article summarises the global incidence of mouth cancer using cancer maps. Data have been compiled from the latest edition of Cancer Incidence in Five Continents and recent studies from various locations around the world. Significant geographic variation is noted in the incidence of mouth cancer, with high rates reported for the Indian subcontinent and parts of Asia (male incidence rates in excess of 10 per 100,000 per annum). It is also noted that as with other forms of oral cancer, the majority of population-based data for mouth cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. Mouth cancer remains a serious health problem in many parts of the world with many regions reporting increasing incidence rates particularly in males. Ongoing research into the aetiologic risk factors associated with this disease must remain a very high priority if the causes of mouth cancer are to be established and disease control protocols introduced widely.

The epidemiology of tongue cancer: a review of global incidence

The tongue (141 ICD-9) is the most common intraoral site for cancer in most countries, however its global epidemiology shows significant geographic variation. This review paper summarises the global incidence of cancer of the tongue using cancer maps and references to recent studies from various locations. Tongue cancer remains a serious health problem in many countries including India (male incidence rates up to 6.5 per 100,000 per annum) and parts of Europe (male incidence rates in France up to 8.0 per 100,000 per annum). It is noted that as with other forms of oral cancer the majority of population-based data for tongue cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. The tongue remains the most common intraoral site for oral cancer worldwide and in a number of countries it is a serious public health problem with significant morbidity and mortality. While the incidence of tongue cancer appears to be stable or falling in some regions of the world, in other areas it is rising, particularly among younger people.

Immunoperoxidase detection of polycyclic aromatic hydrocarbon-DNA adducts in mouth floor and buccal mucosa cells of smokers and nonsmokers

Tobacco smoking is a major risk factor for oral cancer; mouth floor and buccal mucosa are among the most and least cancer-prone subsites, respectively, in the oral cavity. We investigated the applicability of immunohistochemistry of smoking-induced DNA adducts in oral cells for assessing the exposure to carcinogens, and estimating the risk for oral cancer. Polycyclic aromatic hydrocarbon (PAH)-DNA adducts were measured in mouth floor and buccal mucosa cells of smokers (n = 26) and nonsmokers (n = 22) by means of a semiquantitative immunoperoxidase assay. Smokers had elevated levels of PAH-DNA adducts compared to nonsmokers in their mouth floor cells (0.045 +/- 0.022 versus 0.022 +/- 0.016, P = 0.0008 arbitrary units of immunohistochemistry) as well as in their buccal mucosa cells (0.058 +/- 0.028 versus 0.028 +/- 0.012, P = 0.001). Also, there was a correlation between the levels of PAH-DNA adducts in mouth floor cells and those in buccal mucosa cells (r = 0.4, P = 0.01). Furthermore, PAH-DNA adduct levels in both mouth floor and buccal mucosa cells were significantly related to current smoking indices (amount of tar and number of cigarettes consumed per day). Expectedly, the levels of PAH-DNA adducts neither in mouth floor cells nor in buccal mucosa cells, both being short-lived cells, were related to smoking history index (pack years). The levels of PAH-DNA adducts, however, in mouth floor cells as the cancer prone cells were lower than those in buccal mucosa cells (0.037 +/- 0.023 versus 0.044 +/- 0.026, P = 0.04). We conclude that immunohistochemistry of PAH-DNA adducts in oral cells can be used for exposure assessment of tobacco-related carcinogens, however, it cannot be used for oral cancer risk estimation.

Chemopreventive effect of bovine lactoferrin on 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in male F344 rats

The modifying effects of dietary feeding of bovine lactoferrin (bLF) on tongue carcinogenesis initiated with 4-nitroquinoline 1-oxide (4-NQO) were investigated in male F344 rats. The activities of phase II detoxifying enzymes, glutathione S-transferase (GST) and quinone reductase (QR), polyamine content and ornithine decarboxylase (ODC) activity in the tongue were also examined for mechanistic analysis of possible modifying effects of bLF on carcinogenesis. At 7 weeks of age, all animals except those treated with bLF alone and untreated rats were given 20 ppm 4-NQO in drinking water for 8 weeks to induce tongue neoplasms. Starting 7 days before 4-NQO exposure, experimental groups were fed experimental diets containing bLF (0.2% and 2%) for 10 weeks ("initiation feeding"). Starting 1 week after the cessation of exposure to 4-NQO, the other experimental groups given 4-NQO and a basal diet were fed the experimental diets for 22 weeks ("postinitiation feeding"). At week 32, the incidence and multiplicity of tongue neoplasms in the "initiation feeding" groups of 0.2% and 2% bLF and the "post-initiation feeding" group of 0.2% bLF were lower than those of the 4-NQO alone group, but without statistical significance. However, "post-initiation feeding" of 2% bLF caused a significant reduction in the incidence (20% vs. 55%, P=0.02418) and multiplicity (0.25+/-0.54 vs. 0.70+/-0.71, P<0.05) of tongue squamous cell carcinoma (by 64%, P=0.02418). bLF treatment elevated liver and tongue GST activities and liver QR activity. The "post-initiation feeding" with 2% bLF significantly decreased QR activity, proliferating cell nulcear antigen-positive index and ODC activity in the tongue. In addition, feeding with bLF decreased tongue polyamine content. These results suggest that bLF, when given at the 2% dose level during the post-initiation phase, exerts chemopreventive action against tongue tumorigenesis through modification of cell proliferation activity and/or the activities of detoxifying enzymes.