RESEARCH
oral cancer
An alarming lack of public
awareness towards oral cancer
K. A. A. S. Warnakulasuriya,1 C. K. Harris,2 D. M. Scarrott,3 R. Watt,4 S. Gelbier,5
T. J. Peters,6 and N. W. Johnson,7
Objective To determine public awareness and knowledge of oral
cancer in Great Britain.
Design The respondents were selected according to a systematic
probability sample designed to be representative of all adults in
Great Britain (GB). The overall design was similar to previous
omnibus surveys carried out by National Opinion Poll (NOP). The
survey was carried out in ten regions of GB in September 1995 and
was commissioned by the Health Education Authority (HEA).
Subjects and methods A random sample of 1,894 members of
the public over the age of 16 years were asked in face-to-face
interviews their knowledge relating to cancer, with particular
reference to oral cancer, its causes and those at high risk and general
attitudes to cancer.
Results Oral cancer was one of the least heard of cancers by the
public with only 56% of the participants being aware, whereas 96%
had heard of skin cancer, 97% lung cancer and 86% cervical cancer.
There was a 76% awareness of the link between smoking and oral
cancer but only 19% were aware of its association with alcohol
misuse. Whereas 94% agreed that early detection can improve the
treatment outcome, a disheartening 43% believed that whether a
person developed a cancer or not was a matter of chance and
therefore was unavoidable.
Conclusions This survey highlights a general lack of awareness
among the public about mouth cancer and a lack of knowledge
about its causation especially the excess risk associated with alcohol.
Recommendations There is a clear need to inform and educate
the public in matters relating to the known risk factors associated
with oral cancer. A media campaign informing the public about oral
cancer is clearly required. The need for the reduction in the
incidence of oral cancer should be included in ‘Our healthier
nation’ targets. An overall health promotion strategy to reduce
cancers should include oral cancer as a priority. In addition the
European Code against Cancer which aims to improve prevention,
the early detection of oral cancer and the necessity for fast track
referral should be made more widely known. Recognition of oral
cancer in local strategies for oral health should be encouraged.
Each year there are over 2,500 cases of oral cancer (cancers of the lip,
tongue and other parts of mouth and oropharynx ) in the UK. About
50% will die of or with the disease.1,2 More than 80% of cancers in
these sites occur in people more than 45 years of age.1 However, there
is evidence of an increasing incidence of, and mortality from, tongue
1Reader, 2Research Associate, 7Professor, Department of Oral Medicine &
Pathology/ WHO Collaborating Centre for Oral Cancer and Precancer 5Professor,
Department of Dental Public Health 6Professor, Department of Clinical
Biochemistry & Psychological Medicine, The Guy’s, King’s and St Thomas’
Schools of Medicine and Dentistry of King’s College London, Caldecot Road,
London SE5 9RW; 3Head, Education and Science, British Dental Association,
64 Wimpole Street, London W1M 8AL; 4Consultant, Oral Health, Health
Education Authority, Trevelyan House, London SW1P 2HW
REFEREED PAPER
Received 18.12.98; accepted 01.07.99
© British Dental Journal 1999; 187: 319–322
BRITISH DENTAL JOURNAL VOLUME 187, NO. 6, SEPTEMBER 25 1999
cancer in younger age groups in a number of Western European
countries including the UK.3 Oral cancer occurs more commonly in
men possibly because of differences in the risk habits.4
The vast majority of malignant neoplasms in the mouth are squamous cell carcinomas. For these cancers the major aetiological factors
are tobacco and excess alcohol use.4 The disease is largely preventable.5 Earlier diagnosis greatly increases a patient’s chances of
survival as the mouth is very accessible for a clinical or even self examination. However, there is poor public awareness of the signs and
symptoms of oral malignant and premalignant lesions.6 Although it
is at least half as common as cervical cancer in England and Wales,7
very little is spoken or written about it in the lay literature. A poor
compliance to attend for oral cancer screening following invitation
(25.7%) has been linked to probable lack of public awareness of this
disease.8 As far as we are aware the level of public awareness of risk factors or early symptoms in Great Britain is not known. Reported here
are the results of a National Opinion Poll (NOP) commissioned in
1995 by the Health Education Authority (HEA) to enquire into the
public’s attitudes and awareness on the subject of oral cancer.
Materials and methods
To assess public awareness of oral cancer, particularly its association
with tobacco and alcohol use, NOP Consumer Market Research
carried out a national survey of adults over the age of 16 years.9 This
survey was part of a larger random omnibus survey which NOP
conducts on a yearly basis. All NOP research is considered and
approved by the appropriate ethics committees. The research methodology was fully tested based on extensive field experience from former
surveys. The respondents were selected according to a systematic
probability sample representative of all adults in Great Britain. A
detailed and elaborate sampling technique is used by NOP to ensure a
representative sample is achieved. The sample was selected from 180
sampling points evenly distributed across the following ten regions:
South West England, South East England, London, East Anglia, Wales,
Midlands, Yorkshire, Lancashire, North East England, and Scotland.
The stratified random sampling design consisted of three stages. Initially names were drawn at random from electoral registers. The resulting samples of electors were then supplemented by a random sample of
non-electors drawn from the households of the selected electors.
Finally a weighting process was undertaken to ensure that the final
sample was representative of known population. A detailed description of the sampling method used is outlined in a NOP sampling manual.10 A letter explaining details of research was first sent to each
household. Informed consent was obtained prior to interview. Faceto-face interviews were conducted in the respondents’ homes by fully
trained and experienced market research interviewers. The Health
Education Authority (HEA) was responsible for developing and testing out the questions prior to the full survey. All interviewing used the
latest Computer Assisted Personal Interviewing Techniques. To assess
the reliability of interview data completed interviews were subjected to
a 10% field check by a process of re-interviews.
The interviews consisted of nine questions presented on showcards.
Respondents were asked three questions on their awareness of oral
319
RESEARCH
oral cancer
compared with other cancers, its causes and what might constitute a
high risk group; five questions assessed respondents smoking and
drinking habits; and one question focused upon general attitudes to
cancer. The questionnaire used is available on request from the authors.
The data were analysed according to socio-demographic, geographic
and own smoking /alcohol use. For comparison of categorical variables
between groups, the chi-squared test was used. If the effects of sociodemographic variables were minimal, the findings for all persons are presented. Alternatively, if differences are cited between subgroups with
varying characteristics, they attain both statistical and social significance, in terms of critical health knowledge, unless otherwise noted.
Table 2 Percentage of respondents
aware of cancer in different anatomic
sites of the body
Lung cancer
Skin cancer
Cervical cancer
Prostate cancer
Cancer of the colon
Oral cancer
Cancer of the pelvis
Table 3 Regional differences in awareness of oral cancer
Results
A total of 1,894 subjects participated in the survey which amounts to a
94.7% response rate. Table 1 shows the demographic aspects of the
respondents. The first showcard asked ‘Which, if any, of these types of
cancer would you say you have heard of?’ The results are given in Table
2. There were no gender differences in the knowledge of the existence
of oral cancer The greatest awareness was among adults in the age
group 35–64 years (61–64%), those in the youngest group (16–24
years) being significantly less aware (43% ; χ2 = 24.57; df = 1;
P < 0.0001). The knowledgeable proportion also fell in the oldest
group. Those in socio-economic groups 1 and 2 had the highest
knowledge (69%). People from Scotland, East Anglia and Wales had
higher awareness, with more than 60% having heard of oral cancer,
but the regional differences observed were not statistically significant
(χ2 = 15.34; df = 9; P = 0.08) (Table 3). When the answers to this
question were structured against the subjects own alcohol and smoking habits there was a tendency towards increased awareness of the
disease among smokers and those who drank alcohol daily (Table 4).
Total abstainers were the least aware group (38%), being significantly
different from the rest (χ2 = 45.71; df = 1: P < 0.0001).
The second showcard asked ‘Thinking now just about oral cancer,
here is a list of things which may or may not be linked with oral cancer.
Could you tell me which if any of these you think may be linked to oral
cancer?’ There was a high awareness (76%) of the smoking link, but
only a low (19%) awareness of the link with alcohol. There was a 27%
link with car exhaust fumes and even a 13% link with dental fillings.
Social classes 1 and 2 had a higher awareness of risk factors at 87% for
smoking (χ2 = 5.48; df = 3; P < 0.0001) and 25% for drinking alcohol
(χ2 = 8.13; df = 3; P = 0.04), being significantly higher than all other
social class groups. When cross tabulated by age the 25–34 year age
group had the highest knowledge at 82% and 24%, for respectively,
smoking and alcohol.
The third question asked ‘Which of the following groups of people are
most likely to have a greater chance of developing the disease?’ While
75% answered ‘Heavy smokers’, only 22% responded ‘People who
Table 1 Socio-demographic data of survey subjects
(n = 1,894)
Number
Gender
Male
Female
Age
16–24
25–34
35–44
45–54
55–64
65+
Class –
I/II
III non-manual
III manual
lV/V
Marital status:
married
single
widow/divorced/separated
320
926
968
291
383
320
293
241
367
325
520
422
627
1152
444
298
Per cent
49
51
15
20
17
15
13
19
17
27
22
33
61
23
16
97
96
86
78
62
56
38
Scotland
North East England
Lancashire
Yorkshire
Midlands
Wales
East Anglia
London
South East England
South West England
Respondents
Aware (n)
211
115
226
231
263
177
112
366
142
57
116
51
122
99
174
90
92
188
103
33
Aware (%)
62
50
57
54
55
61
62
50
58
59
drink heavily’. Social classes 1 and 2, with 87% and 27%, respectively,
and the age range 25–34 years with 81% and 23%, respectively, were
the highest score of all the groups. Thirty per cent of the total sample
surveyed thought that people aged 50 years and older were most
prone (χ2 = 17.86; df = 5; P = 0.003)
For the statement ‘Early detection of some cancers can improve the
chances of successfully treating them’ the sample were asked whether
they agreed or disagreed. Forty-five per cent agreed strongly and 49%
agreed slightly. There were significant variations by age and social
class with at least half of those in age groups 25–54 agreeing strongly
(χ2 = 21.96; df =5; P = 0.0005) compared with other age groups and
56% of social classes 1 and 2, agreeing strongly (χ2 = 24.40; df = 3;
P < 0.0001) compared with other classes.
To the statement posed, ‘Who develops cancer and who doesn’t is a
matter of chance, so there’s nothing anybody can do to avoid it?’ 43% agreed
strongly or slightly, while 45% disagreed slightly or strongly. Fifty-one
per cent of the oldest age group (65+) agreed strongly, significantly more
than other age groups as did the social classes 4 and 5 at 55%.
The final statement was ‘Some people can make changes in the way
they live to reduce their risk of developing cancer’, 82% agreed to some
extent as opposed to only 11% who disagreed. In the age group 35–44,
86% agreed and in the socio-economic groups 1 and 2, 92% showed
agreement.
Discussion
The high response rate (95%) achieved reflects the high profile of
NOP surveys conducted in Great Britain, the approach of contacting
clients by letter prior to the interview and conducting interviews at
residences as prearranged. Owing to the elaborate sampling technique using electoral registers and the high response rate the results
derived can be generalised to the residents of Great Britain. This survey highlights the general lack of awareness about mouth cancer and
its causation. Little more than half were aware of mouth cancer compared with more than 85% being aware of cancer afflicting other body
organs/sites. The level of public awareness reported here is similar to a
study on Londoners by Bhatti et al.11 which showed that little more
than two-thirds of respondents knew about mouth cancer. Residents
of London and North East England were least aware of oral cancer
(50%) but Scots and Welsh had a higher awareness (61–62%) compared with other regions. The Health Education Board in Scotland
and Pecyn Gwybodeth in Wales have been active in initiatives towards
preventing oral cancer.12
BRITISH DENTAL JOURNAL VOLUME 187, NO. 6, SEPTEMBER 25 1999
RESEARCH
oral cancer
Table 4 Knowledge on oral cancer and risk factors categorised by own smoking and drinking status
Smoking status
Reported status
Awareness of oral cancer
Aware of smoking being a risk factor
Aware of alcohol being a risk factor
Alcohol use
Reported use
Aware of oral cancer
Aware of smoking being a risk factor
Aware of alcohol being a risk factor
Current smoker (%)
Non smoker (%)
30
58
77
23
Almost every day
70
55
75
18
Several times a week
%
11
69
79
21
There is a clear need to inform and educate the public in matters relating to the known risk factors. Whereas the danger of smoking was recognised by many people, the association between alcohol and oral cancer
was known to only a few.13 Health education campaigns appear to have
been successful in that the majority of the population — non smokers as
well as smokers — now perceive the habit of smoking to be harmful to
health. The British Social Attitude Survey conducted in 1990, exploring
health beliefs, reported that being a non-smoker is seen by far the most
important factor in improving general health.14 The Drinkwise
Campaign is claimed to have achieved success in making a large percentage of the population aware of the number of units considered safe (21
for the male and 14 for the female),15 but appears to have failed to identify the link with oral cancer . Horowitz et al.16 recorded equally disappointing but remarkably similar results in the US where tobacco use was
the only risk factor correctly identified by most adults. In a pilot study on
the Polish public’s knowledge 95% identified tobacco in any form as a
risk factor and only 25% indicated alcohol.17 These finding contrasts
markedly with a recent Spanish study by Rebollo-Palencia et al. in which
69% of the subjects knew of the positive association between excess alcohol and cancer.18 In a study of alcohol and substance misuse in South
London by Harris et al. it was found that well over 90% of alcohol misusers were also smokers of tobacco.19 This combination is known to
increase the odds ratio for oral cancer up to 44 times compared with non
smokers and occasional drinkers.20 Information to the public on synergism of tobacco and alcohol in causation of oral and pharyngeal cancer is
highly desirable. With such well known risk factors as alcohol and
tobacco (carrying an attributable risk close to 75–95%), it is possible to
prevent a large number of oral cancers. Raising public awareness could
contribute to achieving a significant reduction in its incidence.
Several questionnaire-based surveys of UK dentists have shown
consistently that few dentists routinely inquire about the smoking
and drinking habits of their patients and even when they enquire they
rarely include such information in patient’s clinic records.21–24 Sensible drinking, cessation of tobacco and inclusion of fresh fruits and
vegetables in the diet are the cornerstones of cancer prevention. Dentists are in a strong position to motivate their clients on tobacco cessation and alcohol moderation. A recent demonstration programme on
smoking cessation has described an intervention model that can be
adopted by UK dentists for control of oral cancer.25
Cancer fatalism often plays a pivotal role in people either not
accepting professional advice on avenues for prevention or arriving
too late for therapy. Cancer fatalism needs prompt identification26,27
and there is a duty of healthcare providers to offer information on
how early therapy saves lives. Forty-three per cent of the public surveyed was of the opinion that whether an individual develops cancer
is a matter of chance. A fatalistic attitude to health might be a critical
obstacle to changing lifestyles28 and in this study associations with old
age and social class were evident in ‘fatalism’. Education of the public,
particularly young people,29 may help to change the common attitude that cancer affliction is a matter of chance. There is now suffi-
BRITISH DENTAL JOURNAL VOLUME 187, NO. 6, SEPTEMBER 25 1999
%
32
63
82
24
Once a week
Less frequent
None
%
16
57
73
17
%
24
53
76
15
%
17
38
68
19
cient scientific evidence to conclude that cancer of the mouth and
pharynx is largely related to life style.4 Only 11 per cent of the present
sample disagreed that people can make changes to their life style to
reduce the risk of developing cancer. This positive approach needs to
be harnessed by providing the basic factual information about oral
cancer, thereafter allowing people to make their choices which are
more likely to be healthier ones.
The determinants that contribute to patient and professional delay
in diagnosis for oral cancer are documented.30 The earlier detection
of oral cancer by opportunistic screening should afford patients
greater survival times, and more certainly less radical treatment.31 In
April 1998, the Report of the Scientific Committee on Tobacco and
Health recommended mandatory training of primary dental care
professionals in the detection of oral cancers and consideration of reintroduction of the free dental examination in the General Dental
Services of the NHS.32 Although there is a great deal of professional
Fig. 1 Professional educational material available for UK dentists
and other professionals on the subject of oral cancer
Fig. 2 Public education leaflet on oral cancer produced by Cancer
Research Campaign (CRC)
321
RESEARCH
oral cancer
educational material about (fig. 1) we lack suitable material for public
use. Recently the Cancer Research Campaign has produced a public
education leaflet (fig. 2). A leaflet by The British Dental Health Foundation was circulated in 1991. Their availability at large and in particular to where most needed is questionable. Most patients with oral
symptoms that are likely to be suspicious of mouth cancer are likely to
consult their medical practitioner11 but the professional information
on oral cancer so far has been mostly delegated toward the dental profession.33 Recent publications in the British Medical Journal on oral
cancer and about risk factors that are often unrecognised by the medical profession would provide a useful resource to fill this gap.34,35
Media presentations through magazine and newspaper articles,
while reaching only certain sections of the population, will at least target some of those people not seeking regular medical/dental care. A
further recourse is through television, where AIDS and drug messages
seem to have found their goal. On three occasions when a professional
body such as The Royal College of Physicians targeted the public by
issuing a declaration warning about adverse effects of tobacco, considerable gains were noted in subsequent periods where the smoking
rates fell significantly.36 Several media based campaigns have been
conducted in the USA and Australia. Mass media advertisements and
unpaid publicity on ill health associated with smoking appear to have
contributed to provoking adult cessation.37 The media also play a role
in effecting policy changes towards smoking control.38 Professional
lobbying for this aim through national dental organisations is timely.
Concise information needed by the professionals on the subject of
oral cancer is available in two fact sheets published by the British Dental Association and the Cancer Research Campaign.39,40
The present study revealed several aspects of public uncertainty
and ignorances with regard to the causation of oral cancer which need
to be emphasised in future public education programmes, particularly using mass media. Future programmes attempting to educate
the public, such as the European Code against Cancer, need to contain
a focus on issues related to oral cancer control.
The following messages are appropriate:
• Do not smoke: avoid smokeless tobacco products
• Moderate alcohol intake: 21 units per week for men, 14 for women
• Avoid excessive exposure to sunlight to prevent lip cancer
• Eat green and yellow fresh fruit and vegetables as a source of β carotene
• White and red patches of oral mucosa are surrogate markers
• Have regular mouth check ups with your dentist
• Seek immediate professional advice on discovering any lumps or
ulcers persisting over 2 weeks.
In addition to public education a comprehensive health promotion
strategy to reduce smoking and excess alcohol consumption is essential to halt increases in oral cancer trends. The Government White
Paper on smoking prevention, published in December 1998 provides
a welcome stimulus for effective policy developments.
The results of this survey provide benchmark measures against
which changes in attitudes on oral cancer and its causation among the
UK public can be measured.
The authors thank the Health Education Authority for giving us access to the data set
originating from the NOP survey undertaken in September 1995 with media
assistance from Munro and Forster.
7
8
9
10
11
12
13
14
15
16
17
18.
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
1
2
3
4
5
6
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