Screening programmes for the early detection and prevention of oral cancer

Liquid biopsy: an examination of platelet RNA obtained from head and neck squamous cell carcinoma patients for predictive molecular tumor markers

Aim

Recently, a tumor cell-platelet interaction was identified in different tumor entities, resulting in a transfer of tumor-derived RNA into platelets, named further "tumor-educated platelets (TEP)". The present pilot study aims to investigate whether such a tumor-platelet transfer of RNA occurs also in patients suffering from head and neck squamous cell carcinoma (HNSCC).

Methods

Sequencing analysis of RNA derived from platelets of tumor patients (TPs) and healthy donors (HDs) were performed. Subsequently, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used for verification of differentially expressed genes in platelets from TPs and HDs in a second cohort of patients and HDs. Data were analyzed by applying bioinformatic tools.

Results

Sequencing of RNA derived from the tumor as well as from platelets of TPs and HDs revealed 426 significantly differentially existing RNA, at which 406 RNA were more and 20 RNA less abundant in platelets from TPs in comparison to that of HDs. In TPs' platelets, abundantly existing RNA coding for 49 genes were detected, characteristically expressed in epithelial cells and RNA, the products of which are involved in tumor progression. Applying bioinformatic tools and verification on a second TP/HD cohort, collagen type I alpha 1 chain (COL1A1) and zinc finger protein 750 (ZNF750) were identified as the strongest potentially platelet-RNA-sequencing (RNA-seq)-based biomarkers for HNSCC.

Conclusions

These results indicate a transfer of tumor-derived messenger RNA (mRNA) into platelets of HNSCC patients. Therefore, analyses of a patient's platelet RNA could be an efficient option for liquid biopsy in order to diagnose HNSCC or to monitor tumorigenesis as well as therapeutic responses at any time and in real time.

Challenges in the Early Diagnosis of Oral Cancer, Evidence Gaps and Strategies for Improvement: A Scoping Review of Systematic Reviews

Oral cancer is a growing problem, accounting for 377,713 worldwide new cases per year, and 177,757 deaths annually and representing a 5-year mortality rate close to 50%, which is a considerable mortality that has not decreased substantially in the last 40 years. The main cause of this high mortality is related to the diagnosis of a high percentage of oral cancers in advanced stages (stages III and IV) in which treatment is complex, mutilating or disabling, and ineffective. The essential cause of a cancer diagnosis at a late stage is the delay in diagnosis, therefore, the achievement of the objective of improving the prognosis of oral cancer involves reducing the delay in its diagnosis. The reasons for the delay in the diagnosis of oral cancer are complex and involve several actors and circumstances-patients, health care providers, and health services. In this paper, we present the results of a scoping review of systematic reviews on the diagnostic delay in oral cancer with the aim to better understand, based on the evidence, and discuss in depth, the reasons for this fact, and to identify evidence gaps and formulate strategies for improvement.

Opportunistic Screening of Oral Potentially Malignant Disorders: A Public Health Need for India

PURPOSE

Oral cancer (OC) is the leading cancer in 25% of Indian cancer registries, and 80% of OCs are diagnosed in advanced stages. OC screening is a topic of debate. Studies from other countries have used a variety of study designs as OC screening strategies. There are not many studies from India on strategic screening, and there is a need to review the literature to provide insights and knowledge about screening programs. The purpose of this narrative review is to present broad epidemiologic evidence on the OC burden in India, to discuss and summarize the currently available evidence for OC screening strategies, and to highlight a feasible opportunistic screening strategy for addressing OC burden in India.

METHODS

Medline and EMBASE were used to identify articles. Data from GLOBOCAN and government reports were obtained from websites. As many key concepts and divergent views cannot be addressed with a single research question, a narrative review was considered appropriate, but to ensure a comprehensive literature search, a systematic review search strategy was used.

RESULTS

OC rates are rising more rapidly in India than projected. Wide variations in OC incidence within India reflect regional diversity of risk factors. Studies abroad have demonstrated the feasibility of opportunistic screening of oral potentially malignant disorders by dentists; however, although recommendations exist in India, no studies of opportunistic screening by dentists have been reported.

CONCLUSION

The projected major increases in the OC burden necessitate an OC screening program; opportunistic screening of high-risk groups by dentists using oral visual examination is recommended as a cost-effective strategy. As a way forward, a pilot project to assess the feasibility of regional opportunistic screening is in progress.

Early Detection of Oral Cancer- Dentists’ Knowledge and Practices in the United Arab Emirates

Objectives: The aim of this study was to evaluate the knowledge, opinions and practices of dentists regarding early detection of oral cancer in the United Arab Emirates (UAE). Method: A cross-sectional study was conducted using a simple random sampling technique with a self-reported questionnaire applied to 298 dentists, working in private and public sectors in three cities (Abu Dhabi, Dubai and Sharjah) in the UAE. Dentists’ knowledge about risk factors and diagnostic concepts of oral cancer, current practices and opinions as well as interest in continuing education programs were assessed. Results: The dentists, aged 23-65 years, were generally aware of the major risk factors most likely associated with oral cancer. Thirty percent of the participants identified the tongue as the most common site on which oral cancer develops. The best known clinical presentation of oral cancer identified by the respondents was a persistent ulcer (87.6 %). Only thirty dentists (9.9%) were comfortable in performing a biopsy in their clinic. Less than half (48.0%) had attended a continuing education course on oral cancer within the past 5 years. The majority of the participants (84.9%) felt that they needed further training on oral cancer detection. Conclusion: The findings of the present study identified several deficiencies in the knowledge of dentists working in the UAE with regard to early detection of oral cancer. Some changes to dental educational and training could be made to improve the confidence and ability of dentists in this regard.

Lugol Chromoscopy in the Follow-up of Head and Neck Carcinoma

Introduction:

Lugol is helpful in identifying early second primary tumors (SPTs) during oroscopy and pharyngoscopy, but this technique has not been assessed during follow-up visits with these patients.

Aim:

The aim of this study is to describe the use of Lugol (a low-cost method) to diagnose SPTs in the oral cavity and oropharynx.

Methods:

Patients treated for squamous cell carcinoma of the head and neck were randomly assigned to two groups. Group A was examined with routine oroscopy and pharyngoscopy without Lugol, and Group B was examined with routine oroscopy and pharyngoscopy without stain and with Lugol. A total of 211 patients were included during 4 years.

Results:

Six oral and oropharynx carcinomas were detected in Group A. Eighteen oral and oropharynx carcinomas were detected in Group B, twelve of which were not seen without chromoscopy but were detected with Lugol.

Conclusion:

Lugol increases the detection of malignant lesions compared to routine examination alone.

Investigating Patient and Physician Delays in the Diagnosis of Head and Neck Cancers: a Canadian Perspective

Diagnostic delays for head and neck cancer (HNC) patients are common. Patients often disregard symptoms for long periods before seeking help, and some family physicians may not be alert to the warning symptoms and signs of HNCs. This study evaluated the factors associated with length of delays in the diagnosis of HNCs in a Canadian population. This was a mixed-method study consisting of patient interviews and surveys in an academic health center. A questionnaire requesting demographic and disease information was completed by HNC patients followed by a 30 min semi-structured interview in a private setting. Interviews were audio recorded, transcribed, anonymized, and descriptively coded for emergent themes. Twenty-eight head and neck cancer patients participated in the study. More patients experienced physician delay (71 %) than patient delay (36 %). The median physician delay and patient delay were 108 and 31 days, respectively. Two main themes regarding these delays were (1) physician lack of knowledge and (2) lack of patient awareness. Results indicate that physician delay needs to be focused on compared to patient delay, as it is more common and has longer delays. More comprehensive training in head and neck clinical examination skills during undergraduate and residency training is recommended to reduce physician delay. Patient delay could be targeted by public education programs via both physicians and dentists.

Screening programmes for the early detection and prevention of oral cancer

BACKGROUND

Oral cancer is an important global healthcare problem, its incidence is increasing and late-stage presentation is common. Screening programmes have been introduced for a number of major cancers and have proved effective in their early detection. Given the high morbidity and mortality rates associated with oral cancer, there is a need to determine the effectiveness of a screening programme for this disease, either as a targeted, opportunistic or population-based measure. Evidence exists from modelled data that a visual oral examination of high-risk individuals may be a cost-effective screening strategy and the development and use of adjunctive aids and biomarkers is becoming increasingly common.

OBJECTIVES

To assess the effectiveness of current screening methods in decreasing oral cancer mortality.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 22 July 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 6), MEDLINE via OVID (1946 to 22 July 2013), EMBASE via OVID (1980 to 22 July 2013) and CANCERLIT via PubMed (1950 to 22 July 2013). There were no restrictions on language in the search of the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of screening for oral cancer or potentially malignant disorders using visual examination, toluidine blue, fluorescence imaging or brush biopsy.

DATA COLLECTION AND ANALYSIS

Two review authors screened the results of the searches against inclusion criteria, extracted data and assessed risk of bias independently and in duplicate. We used mean differences (MDs) and 95% confidence intervals (CIs) for continuous data and risk ratios (RRs) with 95% CIs for dichotomous data. Meta-analyses would have been undertaken using a random-effects model if the number of studies had exceeded a minimum of three. Study authors were contacted where possible and where deemed necessary for missing information.

MAIN RESULTS

A total of 3239 citations were identified through the searches. Only one RCT, with 15-year follow-up met the inclusion criteria (n = 13 clusters: 191,873 participants). There was no statistically significant difference in the oral cancer mortality rates for the screened group (15.4/100,000 person-years) and the control group (17.1/100,000 person-years), with a RR of 0.88 (95% CI 0.69 to 1.12). A 24% reduction in mortality was reported between the screening group (30/100,000 person-years) and the control group (39.0/100,000) for high-risk individuals who used tobacco or alcohol or both, which was statistically significant (RR 0.76; 95% CI 0.60 to 0.97). No statistically significant differences were found for incidence rates. A statistically significant reduction in the number of individuals diagnosed with stage III or worse oral cancer was found for those in the screening group (RR 0.81; 95% CI 0.70 to 0.93). No harms were reported. The study was assessed as at high risk of bias.

AUTHORS' CONCLUSIONS

There is evidence that a visual examination as part of a population-based screening programme reduces the mortality rate of oral cancer in high-risk individuals. In addition, there is a stage shift and improvement in survival rates across the population as a whole. However, the evidence is limited to one study, which has a high risk of bias and did not account for the effect of cluster randomisation in the analysis. There was no evidence to support the use of adjunctive technologies like toluidine blue, brush biopsy or fluorescence imaging as a screening tool to reduce oral cancer mortality. Further RCTs are recommended to assess the efficacy and cost-effectiveness of a visual examination as part of a population-based screening programme in low, middle and high-income countries.

Screening programmes for the early detection and prevention of oral cancer

BACKGROUND

Oral cancer is an important global healthcare problem, its incidence is increasing and late-stage presentation is common. Screening programmes have been introduced for a number of major cancers and have proved effective in their early detection. Given the high morbidity and mortality rates associated with oral cancer, there is a need to determine the effectiveness of a screening programme for this disease, either as a targeted, opportunistic or population based measure. Evidence exists from modelled data that a visual oral examination of high-risk individuals may be a cost-effective screening strategy and the development and use of adjunctive aids and biomarkers is becoming increasingly common.

OBJECTIVES

To assess the effectiveness of current screening methods in decreasing oral cancer mortality.

SEARCH STRATEGY

The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 20 May 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), MEDLINE via OVID (1950 to 20 May 2010), EMBASE via OVID (1980 to 20 May 2010) and CANCERLIT via PubMed (1950 to 20 May 2010). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of screening for oral cancer or potentially malignant disorders using visual examination, toluidine blue, fluorescence imaging or brush biopsy.

DATA COLLECTION AND ANALYSIS

The original review identified 1389 citations and this update identified an additional 330 studies, highlighting 1719 studies for consideration. Only one study met the inclusion criteria and validity assessment, data extraction and statistics evaluation were undertaken by six independent review authors.

MAIN RESULTS

One 9-year RCT has been included (n = 13 clusters: 191,873 participants). There was no statistically significant difference in the age-standardised oral cancer mortality rates for the screened group (16.4/100,000 person-years) and the control group (20.7/100,000 person-years). A 43% reduction in mortality was reported between the intervention cohort (29.9/100,000 person-years) and the control arm (45.4/100,000) for high-risk individuals who used tobacco or alcohol or both, which was statistically significant. However, this study had a number of methodological weaknesses and the associated risk of bias was high.

AUTHORS' CONCLUSIONS

Although there is evidence that a visual examination as part of a population based screening programme reduced the mortality rate of oral cancer in high-risk individuals, whilst producing a stage shift and improvement in survival rates across the population as a whole, the evidence is limited to one study and is associated with a high risk of bias. This was compounded by the fact that the effect of cluster randomisation was not accounted for in the analysis. Furthermore, no robust evidence was identified to support the use of other adjunctive technologies like toluidine blue, brush biopsy or fluorescence imaging within a primary care environment. Further randomised controlled trials are recommended to assess the efficacy, effectiveness and cost-effectiveness of a visual examination as part of a population based screening programme.

Exploring the reasons for delay in treatment of oral cancer

BACKGROUND

Oral cancer continues to be diagnosed and treated at a late stage, which has a negative effect on outcomes. This study identified and quantified delays in diagnosis and treatment.

METHODS

The authors conducted a study that included all new patients seen in the Department of Oral and Maxillofacial Surgery, University of California, San Francisco, between 2003 and 2007 who had a diagnosis of squamous cell carcinoma of the oral cavity. They identified the time intervals for six stages, beginning with the time at which patients first became aware of symptoms and ending with the time at which definitive treatment began.

RESULTS

The total time from patients' first sign or symptoms to commencement of treatment was a mean of 205.9 days (range, 52-786 days). The longest delay was from the time symptoms first appeared to the initial visit to a health care professional (mean time, 104.7 days; range, 0-730 days).

CONCLUSIONS

Health care professionals need to place greater emphasis on patient education to encourage early self-referrals.

CLINICAL IMPLICATIONS

Patients should be encouraged to visit a health care professional when signs or symptoms of oral cancer first develop.

Critical evaluation of diagnostic aids for the detection of oral cancer

Historically, the screening of patients for signs of oral cancer and precancerous lesions has relied upon the conventional oral examination. A variety of commercial diagnostic aids and adjunctive techniques are available to potentially assist in the screening of healthy patients for evidence of otherwise occult cancerous change or to assess the biologic potential of clinically abnormal mucosal lesions. This manuscript systematically and critically examines the literature associated with current oral cancer screening and case-finding aids or adjuncts such as toluidine blue, brush cytology, tissue reflectance and autofluorescence. The characteristics of an ideal screening test are outlined and the authors pose several questions for clinicians and scientists to consider in the evaluation of current and future studies of oral cancer detection and diagnosis. Although the increased public awareness of oral cancer made possible by the marketing of recently-introduced screening adjuncts is commendable, the tantalizing implication that such technologies may improve detection of oral cancers and precancers beyond conventional oral examination alone has yet to be rigorously confirmed.

Oral cancer: experiences and diagnostic abilities elicited by dentists in North-western Spain

BACKGROUND

Opinions, knowledge, behaviours and attitudes of general dental practitioners on oral cancer prevention and detection have been reported from many countries. However, experiences and skills of oral cancer detection have not been evaluated systematically.

OBJECTIVE

To obtain information on behaviours of screening and ability to correctly detect oral cancer and precancer among general dentists (GDP) in North-western Spain.

SUBJECTS AND METHODS

Thirty-two randomly selected GDPs completed questionnaires and then classified 50 projected images of clinical lesions, into cancer, precancer or benign lesions.

RESULTS

87.5% reported conducting routine oral examinations, 84.4% provided routine advice to their subjects for risk modifications and 84.4% claimed to biopsy a suspected oral mucosal lesion that they detected in practice. In a quasi research setting using clinical slides, the sensitivity of visual diagnosis of a cancerous lesion was 61.4% and precancer 59.5%. The diagnostic accuracy reported here is lower than what is already reported by evaluation of published screening programmes by dentists.

CONCLUSIONS

Our data from Spain suggest a need for improving the diagnostic ability of GDPs in the visual detection of oral cancer/precancer by strengthening continuing professional education.

Economics methods in Cochrane systematic reviews of health promotion and public health related interventions

BACKGROUND

Provision of evidence on costs alongside evidence on the effects of interventions can enhance the relevance of systematic reviews to decision-making. However, patterns of use of economics methods alongside systematic review remain unclear. Reviews of evidence on the effects of interventions are published by both the Cochrane and Campbell Collaborations. Although it is not a requirement that Cochrane or Campbell Reviews should consider economic aspects of interventions, many do. This study aims to explore and describe approaches to incorporating economics methods in a selection of Cochrane systematic reviews in the area of health promotion and public health, to help inform development of methodological guidance on economics for reviewers.

METHODS

The Cochrane Database of Systematic Reviews was searched using a search strategy for potential economic evaluation studies. We included current Cochrane reviews and review protocols retrieved using the search that are also identified as relevant to health promotion or public health topics. A reviewer extracted data which describe the economics components of included reviews. Extracted data were summarised in tables and analysed qualitatively.

RESULTS

Twenty-one completed Cochrane reviews and seven review protocols met inclusion criteria. None incorporate formal economic evaluation methods. Ten completed reviews explicitly aim to incorporate economics studies and data. There is a lack of transparent reporting of methods underpinning the incorporation of economics studies and data. Some reviews are likely to exclude useful economics studies and data due to a failure to incorporate search strategies tailored to the retrieval of such data or use of key specialist databases, and application of inclusion criteria designed for effectiveness studies.

CONCLUSION

There is a need for consistency and transparency in the reporting and conduct of the economics components of Cochrane reviews, as well as regular dialogue between Cochrane reviewers and economists to develop increased capacity for economic analyses alongside such reviews. Use of applicable economics methods in Cochrane reviews can help provide the international context within which economics data can be interpreted and assessed as a preliminary to full economic evaluation.

The efficacy of oral lumenoscopy (ViziLite) in visualizing oral mucosal lesions

Early diagnosis of oral mucosal lesions has been advocated as a means of improving outcomes of cancer therapy. Improved visualization of mucosal lesions may aid in diagnosis by guiding tissue sampling or referral. This multicenter study reports the effect of chemiluminescent light (ViziLite) upon visualization of mucosal lesions. The chemiluminescent light did not appear to improve visualization of red lesions, but white lesions and lesions that were both red and white showed enhanced brightness and sharpness.

Screening programmes for the early detection and prevention of oral cancer

BACKGROUND

Screening programmes for major cancers, such as breast and cervical cancer have effectively decreased the mortality rate and helped to reduce the incidence of these cancers. Although oral cancer is a global health problem with increasing incidence and mortality rates, no national population-based screening programmes for oral cancer have been implemented. To date there is debate on whether to employ screening methods for oral cancer in the daily routine work of health providers.

OBJECTIVES

To assess the effectiveness of current screening methods in decreasing oral cancer mortality.

SEARCH STRATEGY

Electronic databases (MEDLINE, CANCERLIT, EMBASE, the Cochrane Central Register of Controlled Trials; 1966 to July 2005, The Cochrane Library - Issue 3, 2005), bibliographies, handsearching of specific journals and contact authors were used to identify published and unpublished data.

SELECTION CRITERIA

Randomised controlled trials of screening for oral cancer or precursor oral lesions using visual examination, toluidine blue, fluorescence imaging or brush biopsy.

DATA COLLECTION AND ANALYSIS

The search found 112 citations and these have been reviewed. One randomised controlled trial of screening strategies for oral cancer was identified as meeting the review's inclusion criteria. Validity assessment, data extraction and statistics evaluation were undertaken by two independent review authors.

MAIN RESULTS

One 10-year randomised controlled trial has been included (n = 13 clusters: 191,873 participants). There was no difference in the age-standardised oral cancer mortality rates for the screened group (16.4/100,000 person-years) and the control group (20.7/100,000 person-years). Interestingly, a significant 34% reduction in mortality was recorded in high-risk subjects between the intervention cohort (29.9/100,000 person-years) and the control arm (45.4/100,000). However, this study has some methodological weaknesses. Additionally, the study did not provide any information related to costs, quality of life or even harms of screening from false-positive or false-negative findings.

AUTHORS' CONCLUSIONS

Given the limitation of evidence (only one included randomised controlled trial) and the potential methodological weakness of the included study, it is valid to say that there is insufficient evidence to support or refute the use of a visual examination as a method of screening for oral cancer using a visual examination in the general population. Furthermore, no robust evidence exists to suggest that other methods of screening, toluidine blue, fluorescence imaging or brush biopsy, are either beneficial or harmful. Future high quality studies to assess the efficacy, effectiveness and costs of screening are required for the best use of public health resources. In addition, studies to elucidate the natural history of oral cancer, prevention methods and the effectiveness of opportunistic screening in high risk groups are needed. Future studies on improved treatment modalities for oral cancer and precancer are also required.

Preventing and detecting oral cancer

BACKGROUND

The authors conducted a study to examine oral cancer prevention and early detection practice patterns in a population-based random sample of practicing oral health care professionals in New York state.

METHODS

The authors surveyed a population-based, self-weighting, stratified random sample of dentists (n = 1,025) and dental hygienists (n = 1,025) in New York state. They assessed the subjects' readiness to offer tobacco-use cessation and alcohol-abuse counseling and oral cancer examinations.

RESULTS

The effective response rates were 55 and 66 percent for dentists and dental hygienists, respectively. In terms of readiness to perform oral cancer examinations for patients aged 40 years and older, the large majority (82 percent of dentists and 72 percent of dental hygienists) were in the maintenance stage of behavior, indicating that oral cancer examinations were a routine part of their practice. In terms of readiness to offer tobacco-use cessation counseling, only 12 percent of dentists and 21 percent of dental hygienists were in the maintenance stage, and only 2 percent of dentists and 4 percent of dental hygienists were in the maintenance stage of offering alcohol-abuse counseling.

CONCLUSIONS

Oral cancer examinations seem to have been adopted as a standard of practice by most oral health care providers in New York state, but cancer prevention services, such as counseling regarding cessation of tobacco use and alcohol abuse, are lacking.

CLINICAL IMPLICATIONS

Oral health care providers should be trained in oral cancer prevention services such as tobacco-use cessation and alcohol-abuse counseling and encouraged to include these services, along with continued provision of oral cancer examinations, as a standard aspect of care.

Profiling early head and neck cancer

Head and neck squamous-cell carcinoma (HNSCC) is the sixth most common cancer worldwide and, disappointingly, survival rates are not improving. Moreover, HNSCC has a severe impact on the quality of life of patients and survivors, and the significant morbidity subsequent to treatment often mandates long-term multidisciplinary care, which places significant financial pressures on the treating institution. Therefore, prevention and early diagnosis of high-risk pre-malignant lesions are high priorities for reducing deaths due to head and neck cancer. Recent advances have begun to elucidate the different aetiologies of HNSCCs in relation to previous pre-malignancies and to identify which pre-malignant lesions are likely to progress to malignancy.