Trends in the relative frequency of histologically diagnosed epithelial dysplasia and intra-oral carcinoma in Northern Ireland, 1975-1989

Long-term follow-up of oral epithelial dysplasia: A hospital based cross-sectional study

Background/purpose

Oral epithelial dysplasia (OED) is characterized histopathologically by cellular and morphological changes that remain the single most important factor predicting risk for subsequent development of invasive neoplasia. Hence the aims of the present study were to determine the rate of malignant change of OED in a group of patients followed-up for a number of years, and hence determine factors likely to influence this malignant change, and to describe the clinical characteristics of patients who developed recurrence of OED and second dysplastic lesions.

Materials and methods

This is hospital based cross-sectional study of all biopsy reports with histologically confirmed OED between 2012 and 2018 were retrospectivelly reviewed.

Results

A total of 359 patients with histologically confirmed OED were reviewed, twenty (5.5%) of the 359 patients developed an invasive squamous cell carcinoma (SCC) of the oral mucosa over a period of 2 to 274 months with mean transformation time of 3.3 years.

Conclusion

The high risk of malignant transformation of OED seems to be related to patients older than 50 years when lesions were on the floor of mouth with severe dysplastic changes.

Conceiving a national head and neck cancer screening programme

BACKGROUND

This study was undertaken to determine the optimum approach to screening for head and neck cancer based on international experiences.

OBJECTIVE

To determine whether or not head and neck cancer is suitable for screening, and, if so, what the ideal approach should be.

METHODS

An electronic search of online databases up to and including May 2014 was conducted. Key search terms included 'head and neck', 'cancer', 'screening', 'larynx', 'oropharynx' and 'oral'.

RESULTS

Subset analysis of high-risk cohorts showed statistically significant improvements in early detection of head and neck cancer via screening.

CONCLUSION

Current levels of public awareness regarding head and neck cancers are suboptimal, despite increased incidence and mortality. Scheduled and opportunistic screening, coupled with efforts to enhance education and health behaviour modification, are highly recommended for pre-defined, high-risk, targeted populations. This can enable early detection and therefore improve morbidity and mortality.

Feasibility of recruitment to an oral dysplasia trial in the United Kingdom

Background

Oral epithelial dysplasia (OED) has a malignant potential. Therapeutic options for OED remain both limited and without good evidence. Despite surgery being the most common method of treating OED, recurrence and potentially significant morbidity remain problematic. Consequently, there has been much interest in non-surgical treatments for OED. Cyclo-oxygenase (COX) up-regulation is known to occur in the dysplasia-carcinoma sequence and evidence now exists that COX-2 is a prognostic marker of malignant transformation in OED. COX-inhibitors are therefore considered a potential therapeutic strategy for treating this condition. We aimed to provide both proof of principal evidence supporting the effect of topical COX inhibition, and determine the feasibility of recruitment to an OED chemoprevention trial in the UK.

Methods

Recruitment of 40 patients with oral leukoplakia to 4 study arms was planned. The total daily dose of Aspirin would increase in each group and be used in the period between initial diagnostic and follow-up biopsies.

Results

During the 15-month recruitment period, 15/50 screened patients were eligible for recruitment, and 13 (87%) consented. Only 1 had OED diagnosed on biopsy. 16 patients were intolerant of, or already taking Aspirin and 16 patients required no biopsy. Initial recruitment was slow, as detection relied on clinicians identifying potentially eligible patients. Pre-screening new patient letters and directly contacting patients listed for biopsies improved screening of potentially eligible patients. However, as the incidence of OED was so low, it had little impact on trial recruitment. The trial was terminated, as recruitment was unlikely to be achieved in a single centre.

Conclusion

This feasibility trial has demonstrated the low incidence of OED in the UK and the difficulties in conducting a study because of this. With an incidence of around 1.5/100,000/year and a high proportion of those patients already taking or intolerant of Aspirin, a large multi-centred trial would be required to fulfil the recruitment for this study. The ability of topical non-steroidal anti-inflammatory drugs to modify COX and prostaglandin expression remains an important but unanswered question. Collaboration with centres in other parts of the world with higher incidences of the disease may be required to ensure adequate recruitment.

ISRCTN

31503555.

Potentially malignant oral lesions in Northern Ireland: size (extent) matters

OBJECTIVES

We examined clinical parameters of patients from Northern Ireland with potentially malignant lesions (PML) to determine association with development of intraoral squamous cell carcinoma (SCC).

DESIGN

retrospective, cross-sectional, population-based, clinically validated, laboratory-verified.

SUBJECTS AND METHODS

All patients who had more than one incisional oral mucosal biopsy diagnosed from 1975-1991 were abstracted from a database of all PML and SCC and their clinical records and biopsies reviewed. Patients were excluded if there was priorlsynchronous SCC or radiotherapy, frictional keratosis or lichen planus, missing clinical records/biopsy material or follow-up of <24 months. From the 50 suitable patients, gender, age, smoking status, site, clinical appearance and extent of lesion(s), treatment and year of diagnosis were recorded. Patients who developed SCC from PML were compared with those who did not.

RESULTS

Squamous cell carcinoma occurred significantly more often in patients with single rather than multiple PML, those with 'non-homogenous' PML and in patients diagnosed prior to 1980. In Cox's survival analysis, only the clinical extent was predictive of SCC.

CONCLUSIONS

Of all the features considered in our series, size (extent) was the most important clinical factor in determining the risk of future SCC in PML, particularly when several adjacent anatomical sites were affected.

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.

Bcl-2 expression in sequential biopsies of potentially malignant oral mucosal lesions assessed by immunocytochemistry

OBJECTIVE

To examine, for the first time Bcl-2 expression in sequential (autogenous) oral mucosal biopsies taken from the same sites in a gender, risk-factor matched, Caucasoid sample, over a 21-year period.

DESIGN

Retrospective immunocytochemical longitudinal study of archival serial biopsies.

MATERIALS AND METHODS

Computer records were used to identify biopsy specimens derived from 12 patients. These were divided into four groups: (1) Histologically innocuous lesions which remained histologically innocuous. (2) Dysplastic lesions which remained dysplastic. (3) Histologically innocuous lesions which later progressed to squamous cell carcinoma (SCC). (4) Dysplastic lesions which later progressed to SCC. This represented 65 biopsies in total. Bcl-2 expression was studied using mouse antihuman BCL-2 oncoprotein clone 124 (Dako, Denmark).

RESULTS

Generally, there was a lack of Bcl-2 immunoreactivity in the epithelium, with one exception in dysplastic epithelium from a group (3) patient.

CONCLUSION

These findings suggest that in our series, Bcl-2 is not expressed early in oral premalignant lesions and appears to contradict previous reports. Possible explanations for this disparity are considered.

Antioxidant status of oral mucosal tissue and plasma levels in smokers and non-smokers

The antioxidant status of an individual is thought to be important in the development of potentially malignant oral lesions (PMOL) and oral squamous cell carcinoma (OSCC). To date, little detailed information on mucosal antioxidant status is available in a United Kingdom population and neither has the relationship between smoking and mucosal antioxidant status been established. Furthermore, it has been implied that serum levels of antioxidants and tissue levels in the oral mucosa should be equivalent, but that is unproven. To address these deficiencies in our knowledge we studied 60 individuals, all of whom had an oral mucosal biopsy and simultaneous venous blood sampling. Antioxidant levels were measured using high performance liquid chromatography. Smokers (n= 19) were found to have significantly lower levels of plasma beta-carotene (P<0.05) and significantly lower levels of tissue alpha-carotene (P<0.05) than non-smokers (n=41). Tissue alpha-carotene correlated with plasma levels, but this was not the case with alpha-tocopherol, retinol, lycopene or beta-carotene. This is the first data on oral mucosal antioxidant levels and provides baseline data from which to study patients with potentially malignant oral lesions and oral squamous cell carcinoma.

A comparison of the management of potentially malignant oral mucosal lesions by oral medicine practitioners and oral & maxillofacial surgeons in the UK

This study describes the results of a survey undertaken to assess the management of potentially malignant oral mucosal lesions by oral medicine practitioners and compares their approach with that of oral & maxillofacial surgeons that we have previously described. Significant differences were noted between the two groups in the use of photography to document the lesions and in the use of certain special investigations, which included measurement of serum iron, serum ferritin, serum Vit B12, red cell folate and candidal isolation. The groups also varied in the perceived importance of the age of the patient and anatomical site of the lesion when deciding on the need for further biopsy. There was also significant variation in the use of certain treatment modalities, including excising non-dysplastic and severely dysplastic/carcinoma in-situ lesions and eliminating trauma when treating mild/moderately dysplastic and severely dysplastic/carcinoma in-situ lesions. Significant differences in the frequency and duration of follow-up were noted for non-dysplastic lesions. Finally, the two groups differed significantly when asked to rank the perceived importance of certain factors (the histopathology of the most recent biopsy and the anatomical site of the lesion) when deciding the need to follow-up. Possible reasons for the variation are discussed.

Oral cancer in the UK: to screen or not to screen

Although oral squamous cell carcinoma accounts for only a small proportion of malignant neoplasms in the UK, oral cancer incidence and mortality rates have been rising in recent years. The natural history of oral cancer is not adequately understood at present and there is very little information about the epidemiology of precancerous lesions in the UK. There are also insufficient data to provide firm evidence that the percentage of cases arising de novo is greater in the UK and the Western world as compared to the Indian subcontinent. Screening for oral cancer by visual examination is simple, inexpensive and causes little discomfort; however, there is no evidence for the effectiveness of screening for oral cancer either in reducing mortality from the disease or in reducing the incidence of invasive disease by detection and treatment of precancerous lesions. There is currently insufficient evidence to recommend population screening for oral cancer in the UK. Measures aimed at primary prevention of the disease may be a more feasible method of disease control at present.

Paraffin-embedded tissue as a source of RNA for gene expression analysis in oral malignancy

OBJECTIVE

To assess the feasibility of using archival oral mucosal tissue to examine gene expression at the ribonucleic acid (RNA) level.

MATERIALS AND METHODS

We describe the isolation of RNA from 8 microns sections of formalin-fixed paraffin-embedded oral mucosal tissue. RNA was reverse transcribed and three candidate genes amplified by polymerase chain reaction (PCR). The ribosomal protein S14 gene is a housekeeping gene which has been used as an internal standard in several quantitative PCR protocols. The thymidine kinase (TK) gene is expressed at low levels in most tissues and, with a well-documented genomic organisation, is a useful tool for discrimination between genomic DNA and cDNA. The RI alpha gene is reported to be overexpressed in many cancer cell lines, in malignant tissue and in vitro transformed cells.

RESULTS

The S14 gene, the TK gene and the RI alpha gene of the cAMP-dependent protein kinase (PKA) were amplified successfully from formalin-fixed paraffin-embedded tissue sections. The TK primer pair is a useful additional tool in the unambiguous identification of RNA-derived species.

CONCLUSION

RNA suitable for reverse transcribed (RT)-PCR was extracted from archival oral mucosal tissue. This should permit rapid sequence analysis of transcribed tumor suppressor genes and oncogenes in this material. Furthermore, the RT-PCR approach described may allow quantification of gene expression in oral mucosal archival material processed in a standard fashion.