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Keywords:

  • Oral cancer;
  • squamous cell carcinoma;
  • dental attendance

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Background:  Dentists have recently seen the introduction of devices which aim to facilitate early oral cancer detection, sparking interest in opportunistic oral cancer screening. However, concerns have been raised about the lack of regular dental attendance amongst high risk individuals. The purpose of this study was to obtain information pertaining to dental attendance of oral and oropharyngeal cancer patients.

Methods:  All records of patients referred to the Oral Medicine Clinic at the Oral Health Centre of Western Australia, between January 2005 and December 2009, from one major teaching hospital were examined. Information extracted included age, gender, smoking status, referral date, tumour type, tumour site, disease stage (TNM classification), and information on dental attendance. Outcomes measured included time (months) since the patient’s last dental visit and information concerning regularity of dental attendance.

Results:  No association was found between dental attendance and gender, smoking, disease stage or age at diagnosis. Most patients had not visited a dentist in the preceding 12 months. The mean date of last dental visit was 5.6 years prior.

Conclusions:  More should be done in Australia to encourage patients at high risk of oral cancer to attend the dentist and undergo annual oral soft tissue examination.


Abbreviations and acronyms:
ADA

Australian Dental Association Inc.

OHCWA

Oral Health Centre of Western Australia

SCC

squamous cell carcinoma

Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Squamous cell carcinoma (SCC) is the most common form of oral and oropharyngeal cancer1 with over 2000 new cases (International Statistical Classification of Diseases and Related Health Problems (ICD10) codes: C00-C06 and C090-C10) diagnosed annually in Australia, and the incidence is increasing.2,3

Treatment modalities for oral SCC include surgery, radiation and chemotherapy. Treatment failures include locoregional recurrences, metastatic disease and second primaries.4 It is generally accepted that individual patient’s prognosis is determined by a number of factors including tumour site, size, nodal involvement and grade.4,5 In recent years, tumour thickness of 4 mm or more and presence of lymphovascular invasion have emerged as particularly important risk factors adversely affecting prognosis.6,7 The presence of lymph node metastasis is the single most important predictor of survival in oral and oropharyngeal SCC patients, reducing survival rates to below 50%.8 Despite advances in treatment of oral SCC, survival still remains poor.9 Early detection, diagnosis and treatment appear paramount in efforts to improve survival.10 This very point is also highlighted in the 2020 World Health Organization’s goals for oral health.11 Unfortunately, international research indicates that most oral and oropharyngeal cancers are diagnosed at an advanced stage, contributing to the poor five-year survival of this patient group.12 Australian dental practitioners have been shown to refer more oral cancer patients than their medical colleagues and at earlier disease stage, highlighting the important role of dentists in disease detection.13

The Australian Dental Association Inc. (ADA), in an effort to facilitate early oral cancer detection, recommends at least annual, comprehensive oral soft tissue examination.14 This oral cancer screening, leading to early cancer detection, in the dental office setting may be effective but requires that high risk individuals – who need the screening – attend for regular examinations. While the data in this area are conflicting, on the whole it does appear to suggest that high risk patients do not visit the dentist regularly.15–17

Netuveli and colleagues15 in a large survey based British study (n = 13 784) looked at the relationship between dental attendance and recognized oral cancer risk factors (age, gender, alcohol, smoking, consumption of fruit and vegetables). Authors found that, as the number of risk factors increased, the probability of seeing a dentist regularly decreased, with the odds ratio for regular dental attendance for individuals with all five risk factors being only 0.28.

Another survey based longitudinal British study (n = 5547) by Mohd Yusof et al.16 examined patterns of attendance for dental check-ups for a period of 10 years. Authors found that males, aged over 40 years, less educated manual workers and smokers were significantly less likely to attend for dental check-ups than females and younger, higher educated, higher socio-economic class non-smokers (p <0.05). In fact, individuals at high risk for oral SCC would only visit the dentist every 5 to 10 years.

Rubright et al.18 in a US study examined risk factors for advanced stage oral SCC. Authors interviewed 53 patients and found that only 34% attended the dental office within 12 months before discovery of their tumour, with the average date of last dental visit being 8.2 years prior. A significant inverse relationship was found between the time since the last visit to the dentist and disease stage. The lowest risk for advanced stage disease was among patients who had a dental visit within the last year before discovery of their tumour.

Interestingly, Jullien et al.19 in another British study evaluating a screening test for early detection of oral cancer and precancer (n = 2027), failed to demonstrate a significant relationship between the presence or absence of a cancerous or precancerous lesion at examination and self-reported time since last dental check (≤12/12 to ≥12/12).19

The overall purpose of this study was to obtain information pertaining to dental attendance of recently diagnosed oral and oropharyngeal cancer patients. At present, no such data are available for Australian populations. This information may form the basis for public and professional education about oral cancer and oral cancer screening.

The specific aims were to: (1) determine the date of the last dental visit and/or information pertaining to the regularity of attending dental appointments of oral and oropharyngeal (ICD10 codes: C00-C06 and C090-C10) SCC patients referred to the Oral Medicine Clinic from one major teaching hospital between January 2005 and December 2009, prior to commencing radiation therapy to the head and neck region; and (2) describe basic characteristics of this patient group including age, gender, smoking status, date of referral, tumour type, tumour site and disease stage (based on TNM classification).

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

This study was a retrospective, observational study using data from patients’ existing records. Approval for the study was obtained from the Human Research Ethics Committee of the University of Western Australia.

All records of oral and oropharyngeal (ICD10 codes: C00-C06 and C090-C10) SCC patients referred to the Oral Medicine Clinic at the Oral Health Centre of Western Australia (OHCWA) from one major teaching hospital in Western Australia, between January 2005 and December 2009, were used in the study. Only oral and oropharyngeal SCC patients were included in this study as these sites are easily examined by a general dentist and conventional oral soft tissue examination should form part of every patient’s dental visit. Patients with other head and neck cancers (e.g. laryngeal cancers) were therefore excluded for the purpose of this study.

It is standard practice at our hospital for all newly diagnosed head and neck cancer patients to undergo a comprehensive dental work-up prior to commencing radiation therapy to the head and neck region. The aim of the dental work-up is to: minimize risks of osteoradionecrosis; ensure that a patient is free of dental disease; ensure the patient understands the implications of radiation therapy to the head and region from a dental point of view; and in cases where dentition is retained, ensure the patient understands what prophylactic measures and lifestyle changes are required to maintain residual dentition and optimal oral health for life.

Information extracted from the records included age, gender, smoking status, date of referral, tumour type, tumour site, disease stage (based on TNM classification) and date of the patient’s last dental visit and/or best available information pertaining to the regularity of attending dental appointments. The outcomes measured in this study included time (months) since the patient’s last dental visit and information pertaining to the regularity of attending dental appointments.

Data from records were entered in a Microsoft Excel spreadsheet and converted to a Stata 11 (StataCorp. 2009, Stata Statistical Software: Release 11, College Station, StataCorp LP, TX, USA) dataset for analysis using Stat Transfer Version 9.3. The presence of associations were investigated using Fisher’s Exact Test (appropriate for small cell numbers).

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Between January 2005 and December 2009, 163 head and neck cancer patients were referred to the Oral Medicine Clinic at OHCWA. One hundred and twenty-seven of these patients were oral and oropharyngeal SCC patients (ICD10 codes: C00-C06 and C090-C10). Site distributions with respective disease stages are presented in Table 1. The majority of these patients were male, smokers and presented with advanced disease (Stage III and IV). Most patients required combined modality treatment (Table 2). The relative gender, smoking status and overall disease stage distributions of oral and oropharyngeal SCC patients are illustrated in Table 3.

Table 1.   Distribution of oral and oropharyngeal SCC per site and disease stage
Site of squamous cell carcinomaFrequency
Lip
n = 3 (2%) 
 Stage I0 (0%)
 Stage II0 (0%)
 Stage III0 (0%)
 Stage IV2 (67%)
 Stage unknown1 (33%)
Buccal mucosa
n = 3 (2%)
 Stage I0 (0%)
 Stage II1 (33%)
 Stage III2 (67%)
 Stage IV0 (0%)
 Stage unknown0 (0%)
Floor of mouth
n = 20 (16%)
 Stage I7 (35%)
 Stage II5 (25%)
 Stage III1 (5%)
 Stage IV6 (30%)
 Stage unknown1 (5%)
Tongue
n = 33 (26%)
 Stage I6 (18%)
 Stage II8 (24%)
 Stage III4 (12%)
 Stage IV10 (30%)
 Stage unknown5 (15%)
Palate (hard and soft), uvular
n = 7 (6%)
 Stage I1 (14%)
 Stage II2 (29%)
 Stage III1 (14%)
 Stage IV3 (43%)
 Stage unknown0 (0%)
Maxillary or mandibular gingiva
n = 11 (7%)
 Stage I0 (0%)
 Stage II2 (18%)
 Stage III2 (18%)
 Stage IV5 (45%)
 Stage unknown2 (18%)
Retromolar trigone
n = 7 (6%)
 Stage I0 (0%)
 Stage II2 (29%)
 Stage III0 (0%)
 Stage IV5 (71%)
 Stage unknown0 (0%)
Tonsil
n = 28 (22%)
 Stage I1 (4%)
 Stage II3 (11%)
 Stage III5 (18%)
 Stage IV19 (68%)
 Stage unknown0 (0%)
Pharynx, supraglottic, oropharynx, epiglottis
n = 15 (12%)
 Stage I0 (0%)
 Stage II1 (7%)
 Stage III2 (13%)
 Stage IV10 (67%)
 Stage unknown2 (13%)
Total127
Table 2.   Distribution of treatment modalities
Treatment typeFrequency (%)
  1. Data available for 126 of 127 patients.

Surgery only8 (6.4%)
Radiation therapy only9 (7.1%)
Surgery and radiation therapy50 (39.7%)
Chemotherapy and radiation therapy46 (36.5%)
Surgery, chemotherapy and radiation therapy13 (10.3)
Total126
Table 3.   Gender, smoking status and stage distributions of oral and oropharyngeal SCC patients at diagnosis
 Number (%)
  1. *Data available for 113 of 127 patients.

  2. #Data available for 116 of 127 patients.

Gender
 Female (average age at diagnosis 60 years)30 (23.6%)
 Male (average age at diagnosis 59 years)97 (76.4%)
 Total127
Smoking status at point of referral*
 Yes75 (66.4%)
 No38 (33.6%)
 Total113
Disease stage (TNM based)#
 I15 (12.9%)
 II24 (20.7%)
 III17 (14.6%)
 IV60 (51.7%)
 Total116

Data regarding dental history were available for 82 of the 127 patients. It was noted that date of patients’ last dental visit was recorded for 59 patients. For the remaining 23 patients, sufficient information was available in the patient’s record to ascertain the nature of that patient’s past dental history. This history was deemed poor if it was stated in the patient’s record that the patient could not remember the date of their last dental visit or would only see a dentist if there was a problem (Table 4).

Table 4.   Details of dental history of oral and oropharyngeal SCC patients
 NumberAverage date (and median) of last dental visit
Could advise5966.76 months (18 months)
<12/1229 (49%) 
>12/1230 (51%) 
Could not advise: Poor20 
Regular 3 
Total82 

No association was found between dental attendance and gender, smoking status, disease stage or age at diagnosis (Table 5).

Table 5.   Influence of gender, smoking status, disease stage and age on dental visits
 Date of last dental visit (months)
<1218–2436–480Poor#Regular^Total
  1. #Patient could not remember the date of last dental visit or would only see a dentist if there was a problem.

  2. ^No information on date of last dental visit but patient deemed to be under regular dental care.

  3. *Smoking status at presentation. Data available for 73 of 82 individuals.

  4. ∼Data available for 73 of 82 individuals.

Gender
Fisher’s Exact
p = 0.907
 Female5 (31%)3 (19%)3 (19%)5 (31%)0 (0%)16
 Male24 (36%)9 (14%)15 (23%)15 (23%)3 (5%)66
 Total29121820382
Smoking status*
Fisher’s Exact
p = 0.212
 Yes13 (30%)5 (11%)10 (23%)15 (34%)1 (2%)44
 No10 (35%)7 (24%)6 (21%)4 (14%)2 (7%)29
 Total23121619373
Disease stage∼
Fisher’s Exact p = 0.789
 I3 (33%)1 (11%)3 (33%)2 (22%)0 (0%)9
 II8 (47%)3 (18%)1 (6%)3 (18%)2 (12%)17
 III4 (36%)1 (9%)2 (18%)4 (36%)0 (0%)11
 IV10 (28%)7 (19%)10 (28%)8 (22%)1 (3%)36
Total25121617373
Age (years)
Fisher’s Exact p = 0.298
 <290 (0%)0 (0%)2 (50%)2 (50%)0 (0%)4
 30–393 (60%)2 (40%)0 (0%)0 (0%)0 (0%)5
 40–492 (16%)3 (23%)4 (31%)4 (31%)0 (0%)13
 50–599 (39%)3 (13%)6 (26%)4 (17%)1 (4%)23
 60–695 (24%)2 (10%)3 (14%)9 (43%)2 (10%)21
 70–799 (56%)2 (12%)3 (19%)2 (12%)0 (0%)16
 >801 (100)0 (0%)0 (0%)0 (0%)0 (0%)1
Total29121820382

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

In recent years, dentists have seen the introduction of devices which aim to facilitate early detection of oral cancer, sparking renewed interest in this disease and in oral cancer screening.20–22 There is no evidence at present to support the implementation of a national oral cancer screening programme due to a lack of research, low compliance with invitational cancer screening programmes and low incidence of oral and oropharyngeal SCC. However, opportunistic screening in the setting of a dental office may constitute a more logical approach.23,24 Opportunistic screening is defined as screening undertaken when patients see healthcare professionals for some other purpose, and the dental office is appealing as dentists appear better positioned than their medical colleagues in recognizing oral pathosis correctly.23,25 For example, Chandu and Smith26 identified a high proportion of oral cancer referrals from dental sources at the Oral and Maxillofacial Surgery Department at the Austin and Repatriation Medical Centre, highlighting the importance of dentists and dental specialists in the diagnosis and referral of patients with suspected oral cancer.

However, the effectiveness of opportunistic screening in the dental office in decreasing oral cancer mortality has been questioned as there is concern that high risk individuals for oral SCC may not visit the dentist often15,16 and screening of low risk individuals does not appear to be beneficial.23 While the data in this area are conflicting, on the whole it does appear to suggest that high risk patients may not visit the dentist regularly.15–17

The purpose of this study was to obtain information pertaining to dental attendance of recently diagnosed oral and oropharyngeal SCC patients as no such data are available for Australian populations. This group of individuals constitutes the ultimate at-risk cohort.

Between January 2005 and December 2009, 127 patients with oral and oropharyngeal SCCs, were referred to the Oral Medicine Clinic at the OHCWA from one major teaching hospital, which the author services, for pre-radiation therapy dental assessment. Most of these individuals were smokers, males and presented with advanced disease. The authors concentrated on oral and oropharyngeal SCC patients only as these sites are easily examined by a general dentist and conventional oral soft tissue examination should form part of every patient’s dental visit.14,23 Patients with other head and neck cancers were therefore excluded for the purpose of this study. A simple screening examination protocol for general dentists has previously been described.26

Where accurate data on past dental history were available, they indicated that most oral and oropharyngeal cancer patients did not visit dentists at recommended intervals. The ADA, in an effort to facilitate early oral cancer detection, recommends at least annual, comprehensive oral soft tissue examination.14 The mean date of the last dental visit for those patients for whom past dental history was known was 5.6 years. Although this is a more optimistic figure than the one reported by Rubright et al.18 (8.2 years), it does raise the question of feasibility of opportunistic oral cancer screening in the dental office, as the patients at ultimate risk (patients that developed oral and oropharyngeal SCC), do not appear to visit the dental office frequently.

No association was found between dental attendance and disease stage. This may be explained by low numbers of eligible records examined in this study and the fact that we predominantly considered the date of the last dental visit. For example, some patients who visited the dentist in the preceding 12 months may not necessarily have been regular dental attendees but simply visited with a problem (e.g. toothache) and dentists do not necessarily undertake comprehensive oral soft tissue examinations at that time.20 Other patients may have presented to the dentist as a result of signs and/or symptoms of their already developed SCC.

Similarly, no association was found between dental attendance and age, gender or smoking status. This again may be attributed to low numbers of eligible records examined or explained by the similar socio-demographic characteristics of oral and oropharyngeal cancer patients.

A number of limitations of this study need to be considered. This study was a retrospective, observational study using data from patients’ existing records. We were therefore limited by the accuracy of data recorded. The importance of keeping clear and concise records cannot be over-emphasized. Exclusion of incomplete records (35%) from our analysis may have affected the findings.

To the best of the authors’ knowledge, this is the first Australian study examining dental attendance of oral and oropharyngeal SCC patients. Results of this study are in keeping with other published work suggesting that high risk patients for oral and oropharyngeal SCC do not visit the dentist regularly.15,16 More should be done in Australia to encourage high risk patients to attend the dentist, giving them the opportunity to undergo annual oral soft tissue examinations as per the ADA guidelines on oral cancer screening. Accepting that at present high risk patients do not appear to visit dentists regularly, every high risk patient attending the dentist, irrespective of the nature of the consultation sought, should undergo a comprehensive oral soft tissue examination as no opportunity of early cancer detection should be missed in this patient group. The importance of good quality medical records is also highlighted. Future studies should be prospective in design such that comprehensive data are available for analysis.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References