Abstract
Objective: Dental and medical practitioners play a pivotal role in detecting early stages of oral cancers. Hence, future dental and medical practitioners need to have adequate knowledge of oral cancer. This study was conducted to assess the current level of knowledge, attitude and practices regarding oral cancer among dental and medical students of a Malaysian private university. Methods: A cross-sectional study was conducted on third-, fourth- and final-year students of the dental and medical courses of MAHSA University, Malaysia. A total of 557 students participated in the survey. Oral cancer awareness, knowledge about risk factors, signs and symptoms of oral cancer, attitude and practices towards oral cancer were assessed using 43 questions. The questionnaire was pretested, and internal consistency, assessed using Cronbach’s alpha, was acceptable (α > 0.7). The data were analysed using IBM SPSS version 21. The chi-square test was used to analyse the difference in oral cancer awareness between medical and dental students. Results: Among 557 participants, there were 351 (63%) medical students and 206 (37%) dental students. Based on the results obtained, dental students had a higher level of knowledge than medical students regarding oral cancer (P < 0.05). More than 90% of the dental students were able to identify smoking, alcohol consumption, betel quid chewing, human papilloma virus infection and exposure to radiation as risk factors associated with oral cancer compared to more than 50% of medical students (P < 0.05). Conclusions: Through education and training, awareness amongst medical students can be reinforced, which will promote early detection of precancerous lesions and oral cancers.
Key words: Knowledge, awareness, risk factors, dental students, medical students
INTRODUCTION
Oral cancers develop mainly in the lip, oral cavity, nasopharynx and pharynx1. As more than 90% of oral cancers are oral squamous cell carcinoma, the term oral cancer is used synonymously with oral squamous cell carcinoma2. Cancers of the lip, oral cavity and pharynx together rank in incidence as the seventh most frequent cancer3. In 2012, the worldwide incidence and mortality for lip, oral and pharyngeal cancers were reported to be 529,500 and 292,300, respectively, representing 3.8% of all cancer cases and 3.6% of cancer deaths4. The Asian region alone accounts for more than 50% of oral cancers worldwide, with an estimate of 168,850 new cases annually; about 11% of the population of the Asian region is found South-East Asia,5 which has an especially high incidence of oral cancers and the highest mortality-to-incidence ratio6, 7.
Tobacco use, excessive consumption of alcohol and betel quid chewing are considered to be the major individual aetiological factors in the development of oral potentially malignant disorders and cancers8. Human papilloma virus (HPV) is also associated with oropharyngeal cancers9, 10. Oral cancer is of major concern in South-East Asia, primarily because of the high prevalence of risk factors11. Risk of oral cancer in individuals exposed to multiple risk factors is fifty times higher than that in unexposed individuals12. Early detection via screening and awareness will reduce morbidity and mortality from cancer and improve quality of life compared with late detection and progression of advanced disease. Nevertheless, both health-care professionals and the patients themselves are responsible for the delay in diagnosis of oral cancer13, 14.
Patients’ lack of knowledge in understanding oral cancer has caused a delay in treatment15, 16. In the Malaysian context, there is moderate awareness of oral cancer among dental patients17, 18, compared with other countries19, 20, 21, 22; however, there is lack of awareness of risk factors and early signs and symptoms among Malaysians23. By contrast, health-care professionals should have the awareness, knowledge and skills to identify the risk factors, signs, symptoms and lesions of oral cancer24. With increasing knowledge and skill, practitioners are more likely to be confident in screening and providing advice25. Another challenge is prioritising implementation of such practices26.
Health-care professionals, especially medical and dental practitioners, have great responsibilities in preventing oral cancer and detecting it in its early stages. It is very important to motivate patients to quit harmful habits that may lead to oral cancer, which is as important as treating the disease itself. Medical and dental undergraduate students are the future practitioners. Therefore, their knowledge of oral cancer needs to be constantly upgraded. Studies conducted on oral cancer knowledge and awareness among dental and medical students are well documented across various countries27, 28, 29, 30, 31, 32, 33, 34 but few such studies have been carried out in Malaysian public universities24, 35, 36, 37. Moreover, GLOBOCAN 2018 prediction data shows an overall increase in the incidence and mortality of cancer of the lip and oral cavity by 2040 for most of the South-East Asian countries. The incidence rates for Malaysia will increase by 106.6% according to this data38. The World Health Organization clearly states that reduction of oral cancer incidence requires a comprehensive approach through health education and literacy, risk factor reduction and early diagnosis1. In this context, this study evaluated oral cancer awareness and provides a detailed assessment of current knowledge regarding oral cancer among health professionals.
Specifically, the aim of this study was to assess oral cancer awareness among undergraduate dental and medical students of a Malaysian private university by evaluating their knowledge, attitude and practices on the prevention and early detection of oral cancer. The results obtained in this survey will allow institutional evaluation of two groups of participants (medical students and dental students) and indicate necessary improvements to the existing curriculum. It will also assist in the planning and implementation of an effective education programme for both medical and dental students in the various universities in Malaysia or, even better, a national- or international-level collaborative approach, thereby increasing the likelihood of early detection of precancerous lesions and oral cancer, and reduction of morbidity and mortality.
METHODS
A cross-sectional study was conducted among dental and medical undergraduate students of MAHSA University, Malaysia, for the academic year 2017–2018 during the period 6 November 2017 to 26 January 2019. Prior to conducting the study, the study was independently reviewed and approved by the Ethics Committee of MAHSA University. The research was conducted in accordance with the World Medical Association Declaration of Helsinki. A convenience sampling technique was used to select the study subjects, and those who gave verbal consent were included. Verbal consent was approved by the Ethics Committee. The questionnaire was distributed, after lecture hours, to a total of 744 students (in years 3, 4 and 5) from both Dental and Medical faculties of MAHSA University. The objectives of the study were explained to the students before administration of the questionnaire. The students were informed that no incentives would be provided for participation in the study and that their personal data would not be disclosed. Participants were given enough time to complete the questionnaire.
Questionnaire
The questionnaire was prepared by modifying questions from Carter & Ogden28 and Awan et al.24, with additional questions added. The questionnaire was written in English, the language used for teaching in this University. The information elicited included participants’ demographics (age, gender, faculty and year of study), and questions related to knowledge (31 items), attitude (seven items) and practice (five items). A total of 43 questions (one open-ended and 42 close-ended) were asked to assess students’ habits of oral examination, knowledge on signs and symptoms of oral cancer, risk factors, their perception of the disease and those affected by it and the referral path of oral cancer patients, as well as the students’ desire to receive further information on oral cancer. Responses were given as ‘Yes’, ‘No’ or ‘Do not know’. Pretesting on 80 dental and medical students was carried out to ensure that the questionnaire was clear and could be understood. The internal consistency of the questionnaire, checked using Cronbach’s alpha, was acceptable (α > 0.70). The questionnaire was validated by measuring sampling adequacy using the Kaiser–Meyer–Olkin (KMO) test (the value of 0.87 obtained is adequate), and Bartlett’s test of sphericity was found to be statistically significant (P < 0.001). As the responses were not latent constructs, construct validity, such as confirmatory factor analysis (CFA), was performed.39
Statistical analysis
The data were entered, cleaned, coded and analysed using IBM SPSS Statistics for Windows, version 21 (IBM Corp., Armonk, NY, USA). Demographic characteristics were analysed using descriptive statistics. The results were analysed using the Pearson chi-square test to examine differences between the groups. Linear regression was used to assess the predictors associated with oral cancer knowledge. Any difference and/or relationship found were considered significant at P < 0.05.
RESULTS
A total of 557 participants – 351 (63.0%) medical students and 206 (37.0%) dental students – responded to the questionnaires (response rate = 74.8%). slightly more than half (54.7%) of the participants were 22–24 years of age. Just under two-thirds (63.4%) of the participants were female and slightly more than one-third (36.6%) were male. The participants’ demographic characteristics are summarised in Table 1.
Table 1.
Demographic characteristics of the participants
| Characteristic | Participants n (%) |
|---|---|
| Age (years) | |
| ≤21 | 49 (6.6) |
| 22–24 | 407 (54.7) |
| ≥25 | 101 (13.6) |
| Gender | |
| Male | 204 (36.6) |
| Female | 353 (63.4) |
| Medical students | 351 (63.0) |
| 3rd year | 71 (12.8) |
| 4th year | 159 (28.5) |
| 5th year | 121 (21.7) |
| Dental students | 206 (37.0) |
| 3rd year | 72 (12.9) |
| 4th year | 68 (12.2) |
| 5th year | 66 (11.9) |
As the objective of the study was to assess the participants’ knowledge, the responses ‘No’ and ‘Do not know’ were combined into one response, ‘No’, during the chi-square analysis. Questions on knowledge were divided into general awareness, risk factors and signs and symptoms. Overall, the difference in general awareness of oral cancer between medical and dental students was statistically significant (P < 0.05). The largest disparity was observed when the students were asked ‘Do you know the various ways of detecting oral cancer’, as only 112 (31.9%) medical students responded positively, compared with 150 (72.8%) dental students (Table 2). For the open-ended question about the various ways of detecting oral cancer, varied responses were given by the participants, including biopsy, clinical examination, history taking, self-examination, radiographs, computed tomography scan, magnetic resonance imaging, Vizilite, staining methods and tumour markers.
Table 2.
General awareness of the respondents towards oral cancer
| Questions | Medical students n (%) |
Dental students n (%) |
P-value | ||
|---|---|---|---|---|---|
| Yes | No | Yes | No | ||
| Have you heard of oral cancer? | 303 (86.3) | 48 (13.7) | 204 (99.0) | 2 (1.0) | <0.001 |
| Is oral cancer preventable? | 260 (74.1) | 91 (25.9) | 191 (92.7) | 15 (7.3) | <0.001 |
| Is oral cancer treatable? | 188 (53.6) | 163 (46.4) | 178 (86.4) | 28 (13.6) | <0.001 |
| Does risk of oral cancer increase with age? | 242 (68.9) | 109 (31.2) | 171 (83.0) | 35 (17.0) | <0.001 |
| Does oral cancer spread to other parts of the body? | 229 (65.2) | 122 (34.8) | 180 (87.4) | 26 (12.6) | <0.001 |
| Do you know the various ways of detecting oral cancer? | 112 (31.9) | 239 (68.1) | 150 (72.8) | 56 (27.2) | 0.093 |
Chi-square test, P < 0.05 (statistically significant).
The majority (>90%) of the dental students were able to identify the established risk factors for oral cancer. Interestingly, a higher percentage of medical students than dental students agreed that consumption of red or processed meat increased the risk of oral cancer (43.4% medical students vs 40.3% dental students; Figure 1). More than 90% of dental students knew how oral cancer appears clinically, but fewer knew the common sites where oral cancer may occur. When asked to state the most common site in the mouth for oral cancer, 186 (53.1%) medical students reported that the floor of the mouth is the most common site for oral cancer, followed by the cheeks [171 (49.3%)], the tongue [167 (47.7%)] and the palate [158 (45.5%)]. By comparison, dental students reported that the tongue was the most common site for oral cancer [178 (86.4%)], followed by the cheeks [144 (69.9%)], the floor of the mouth [129 (62.6%)] and the palate [100 (48.5%)]. Overall, a higher percentage of medical students than dental students did not know the various signs and symptoms of oral cancer (Table 3). Based on multiple linear regression, for every additional one point in the score, the mean knowledge score decreased among medical students compared with dental students when adjusted for age and gender [b (95% CI) = −21.02 (−23.874 to −18.180), P < 0.001] (Table 4).
Figure 1.
Knowledge of the correct response regarding risk factors of oral cancer among the respondents.
Table 3.
Knowledge of the respondents regarding signs and symptoms of oral cancer
| Questions | Medical students n (%) |
Dental students n (%) |
P-value | ||
|---|---|---|---|---|---|
| Yes | No | Yes | No | ||
| Can oral cancer manifest without initial complaint or symptoms? | 272 (77.5) | 79 (22.5) | 185 (89.8) | 21 (10.2) | <0.001 |
| Can oral cancer appear as a red lesion? | 249 (71.1) | 101 (28.9) | 189 (91.7) | 17 (8.2) | <0.001 |
| Can oral cancer appear as a white lesion? | 202 (57.7) | 148 (42.3) | 191 (92.7) | 15 (7.3) | <0.001 |
| Can oral cancer appear as a mixture of red and white lesion? | 228 (65.1) | 122 (34.9) | 200 (97.1) | 6 (2.9) | <0.001 |
| Is swelling a sign/symptom of oral cancer? | 257 (73.4) | 93 (26.6) | 190 (92.2) | 16 (7.8) | <0.001 |
| Is an ulcer that does not heal for more than 2 weeks a sign/symptom of oral cancer? | 268 (76.6) | 82 (23.4) | 203 (98.5) | 3 (1.5) | <0.001 |
| Is numbness of the tongue or other areas of the mouth a sign of oral cancer? | 188 (53.7) | 162 (46.3) | 140 (68.0) | 66 (32.0) | <0.001 |
| Is tongue the most common site for oral cancer? | 167 (47.7) | 184 (52.3) | 178 (86.4) | 28 (13.6) | <0.001 |
| Is floor of the mouth the most common site for oral cancer? | 186 (53.1) | 165 (46.9) | 129 (62.6) | 77 (37.4) | <0.001 |
| Are cheeks the most common site for oral cancer? | 171 (49.3) | 180 (50.7) | 144 (69.9) | 62 (30.1) | <0.001 |
| Is palate the most common site for oral cancer? | 158 (45.5) | 193 (54.5) | 100 (48.5) | 106 (51.5) | <0.001 |
Chi-square test, P < 0.05 (statistically significant).
Table 4.
Predictors associated with oral cancer knowledge by linear regression
| Variable | Simple linear regression (univariable analysis) |
Multiple linear regression (multivariable analysis) |
||||
|---|---|---|---|---|---|---|
| Unadjusted b | 95% CI | P-value | Adjusted b | 95% CI | P-value | |
| Age | −0.74 | −3.999 to 2.515 | 0.655 | – | – | – |
| Gender | −0.27 | −3.757 to 3.225 | 0.881 | – | – | – |
| Course | −20.95 | −18.107 to −23.791 | <0.001 | −21.02 | −18.180 to −23.874 | <0.001 |
b, regression coefficient.
A higher percentage of medical students (19.6%) than dental students (11.7%) reportedly knew someone who has oral cancer but unfortunately a higher percentage of medical students (18.7%) than dental students (8.3%) would deny treatment to such patients. Regarding this, 265 (83.9%) medical students reported feeling incompetent at detecting oral cancer (Table 5). Just over two-thirds [240 (67.9%)] of the medical students reported never informing their patients about the risk factors of oral cancer compared with only 73 (35.4%) dental students (Table 6). Fewer than half [144 (42%)] of the medical students referred patients with suspicious lesions to ear, nose and throat specialists, and more than two-thirds [139 (67.5%)] of dental students would refer such patients to dentists.
Table 5.
Attitude of the respondents towards oral cancer
| Questions | Medical students n (%) |
Dental students n (%) |
P-value | ||
|---|---|---|---|---|---|
| Yes | No | Yes | No | ||
| Do you know anyone who has oral cancer? | 68 (19.6) | 283 (80.4) | 24 (11.7) | 182 (88.3) | <0.001 |
| Do you think you are competent to detect oral cancer? | 56 (16.1) | 265 (83.9) | 71 (34.5) | 135 (65.5) | <0.001 |
| Will you deny treatment to patients with oral cancer? | 65 (18.7) | 286 (81.3) | 17 (8.3) | 189 (91.7) | <0.001 |
| Would you go for screening for oral cancer for yourself? | 261 (75.2) | 90 (24.8) | 175 (85.0) | 31 (15.0) | <0.001 |
| Would you advise your friends and family to go for oral cancer screening routinely? | 267 (76.9) | 84 (23.1) | 182 (88.3) | 24 (11.7) | <0.001 |
| Do you feel that oral cancer awareness campaigns are effective? | 162 (46.7) | 189 (53.3) | 117 (56.8) | 89 (43.2) | <0.001 |
| Do you think more oral cancer awareness campaigns should be carried out? | 253 (72.9) | 98 (27.1) | 183 (88.8) | 23 (11.2) | <0.001 |
Chi-square test, P < 0.05 (statistically significant).
Table 6.
Practices of the respondents towards oral cancer
| Questions | Medical students n (%) |
Dental students n (%) |
P-value | ||
|---|---|---|---|---|---|
| Yes | No | Yes | No | ||
| Have you ever informed your patients about the risk factors of oral cancer? | 111 (32.1) | 240 (67.9) | 133 (64.6) | 73 (35.4) | <0.001 |
| Have you ever advised patients to avoid the risk factors of oral cancer? | 170 (49.1) | 281 (50.9) | 158 (76.7) | 48 (23.3) | <0.001 |
| Do you routinely examine the patient’s oral cavity for signs of oral cancer? | 204 (59.0) | 147 (41.0) | 177 (85.9) | 29 (14.1) | <0.001 |
| Do you record tobacco and alcohol use in personal history? | 299 (86.4) | 52 (13.6) | 199 (96.6) | 7 (3.4) | <0.001 |
| Do you examine head and neck lymph nodes of suspicious patients? | 267 (77.2) | 84 (22.8) | 196 (95.1) | 10 (4.9) | <0.001 |
Chi-square test, P < 0.05 (statistically significant).
DISCUSSION
The risk of developing oral cancer is higher among individuals exposed to multiple established risk factors5, 11, and some of these risk factors are highly prevalent in South-East Asia8. Patient awareness and practitioner knowledge are essential for early detection and prevention of oral cancer. Dental and medical practitioners play a pivotal role in diagnosing oral cancer and its premalignant lesions. Therefore, this study was conducted to investigate knowledge, attitude and practices of oral cancer among medical and dental undergraduate students of MAHSA University.
The study identified an inequality in gender distribution, with a majority of students in both the medical and dental fields being female, similarly to previous studies conducted in Malaysian public universities24, 37. This trend, noted internationally, has not changed much from previous studies27, 28, 29, 32, 33, 34, 40. Also similarly to previous studies conducted in Malaysian public universities24, 37, the group of medical students was larger than that of dental students, possibly because Malaysian universities usually have a much larger intake of medical students than dental students. This pattern was also noted in the University of Dundee, Scotland28.
The results found that 86.3% of medical students were aware of oral cancer, substantially higher than the 36.6% reported in a previous Scottish study28; this could be a positive sign of increasing awareness. The results showed higher agreement of medical (74.1%) and dental (92.7%) students on the question of oral cancer being preventable, although with a statistically significant difference between the two groups, which is in contrast to Sitheeque et al.37, who found that more medical students than dental students (66.7% vs 55.6%, respectively) reported oral cancer as being preventable. A majority (68.9%) of the medical students agreed that oral cancer risk increases with age, which is similar to the proportion reported by Al-Dubai et al.35 On the other hand, 83% of dental students agreed that oral cancer risk increases with age, compared with 62.1% in Keser et al.32 and 28.6% in Soares et al.34
Tobacco (smoking and smokeless), alcohol, betel quid chewing and HPV have been identified as established and emerging risk factors for oral cancer41. In the present study, a majority (>90%) of dental students identified greater numbers of risk factors than did medical students (P < 0.05), a finding similar to that reported in other studies24, 28, 37. However, conflicting results are noted in other studies conducted in Malaysia24, 35, 36, 37, which could be a result of curriculum differences between faculties and universities. Although the results on betel quid chewing are similar to those of Awan et al.24, they face the challenge of conflicting data from other studies27, 28, 31, 32, 33, 36, 37.
A significantly smaller number of medical students than dental students identified HPV as a risk factor, which contrasts with Sitheeque et al.37 Nevertheless, medical student groups in Sitheeque et al.37 and this study showed a low level of identification of HPV as a risk factor. This could be due to lack of emphasis on HPV as a risk factor in the current medical education curriculum; however, with newer studies showing an association of HPV with oropharyngeal cancer9, 10, there is a need to highlight the role of HPV in future curricula.
Halawany et al.31 conducted a multinational survey involving dental students in four different Asian countries and found a particularly low level of identification of various oral cancer risk factors. Overall, all of these points highlight a need to emphasise knowledge of oral cancer risk factors, especially among medical students.
This study discovered that more than 90% of dental students knew how oral cancer appears clinically; on the contrary, a higher percentage of medical students than dental students lack knowledge about the common sites and clinical appearance of oral cancer. Sitheeque et al.37 found low self-evaluation of oral cancer knowledge in both medical and dental students, whereas Awan et al.24 found that 12.3% of medical students and 53.3% of dental students felt that they had adequate knowledge about prevention and detection of oral cancer. In India, only 25.8% of medical students30 and 7.5% of dental students29 felt that they had sufficient knowledge of oral cancer. In a positive light, most of the respondents had the desire for more knowledge24, 29, 30, 36. Therefore, seminars, lectures and training courses should be conducted to support them.
The study noted that 85.9% and 59.0% of dental and medical students, respectively, routinely examine the oral mucosa, which is similar to other research findings24, 28, 29. Studies conducted in India revealed that 67.7% (186) of undergraduate medical students in Himachal Pradesh routinely recorded their patient’s tobacco or alcohol use30, whereas 99% (107) of undergraduate dental students in H. P. Government Dental College, Shimla did so29. Awan et al.24 found that 59.6% and 95.6% of medical and dental students, respectively, recorded their patient’s tobacco or alcohol use; in this study, tobacco or alcohol use in patients was recorded by 86.4% of medical students and 96.6% of dental students. Based on the findings of these studies, it is obvious that dental students routinely record tobacco and alcohol history. These differences may be associated with different teaching styles and prioritising of abovementioned practices.
The level of knowledge and awareness of oral cancer is higher among dental students than medical students. In MAHSA University, general aspects of cancer are taught in the second year to both medical and dental students. Preventive aspects of oral cancer are taught by dental public health specialists during year 2; risk factors, aetiopathogenesis, diagnosis, clinical features and management aspects are taught in year 3 by specialists in oral pathology and medicine and in year 5 by specialists in oral surgery. Various aspects of oral cancer are taught in years 3, 4 and 5 for undergraduates through lectures, clinical exposure, problem-based learning, case-based discussion and workshops for dental students. However, exposure of medical students to oral cancer-related topics remains limited.
We suggest that medical practitioners gain awareness and adequate knowledge on examination of oral mucosa and refer suspicious lesions and high-risk patients to dental colleagues for further examination and investigation. A collaborative multidisciplinary approach to health care would be beneficial to patients. Ogden et al.42 suggested that an interprofessional examination should be conducted for medical students and examined by final-year dental students as a plausible form of peer-group teaching.
In Malaysia, the Oral Cancer Research and Coordinating Centre (OCRCC) is highly committed to increasing awareness among the public by organising an annual event – Mouth Cancer Awareness Week (MCAW) – in collaboration with the Oral Health Division, Ministry of Health, and public and private dental schools of Kuala Lumpur and Selangor43. MAHSA University, being one of the collaborative partners, motivates the dental students to participate in various activities, such as free poster and video presentations, and exposure on mass media.
In summary, the results of the study showed a trend where medical students possess a lower level of knowledge and poorer attitude and practice concerning oral cancer than dental students. Following the theory of reasoned action, and as suggested by Saleh et al.25, a high level of knowledge will probably lead to positive attitude and practice. However, correct attitude is important for the translation of this knowledge into behaviour change. Hence, the knowledge and awareness of oral cancer by undergraduate medical students should be enforced through lectures, workshops and clinical intervention. Additionally, we suggest that emphasis is placed on examination and diagnosis of precancerous lesions, especially during clinical rotations in Oral and Maxillofacial Surgery, Otorhinolaryngology, and Oncology. Furthermore, students may be motivated to participate in organising anti-oral cancer campaigns, which may further raise awareness, not only amongst students but also amongst the general public.
As this study was conducted in a single private health-care university in Malaysia, it faces limitations as the results cannot be generalised to represent other institutions. Furthermore, the present study faced limitations in the response rates of students, as many third-year medical students declined to participate in the study, which could have affected the results. For future research, we suggest a wide-scoped inter-institutional study to assess the knowledge of dental and medical students about oral cancer.
CONCLUSION
With the increase in incidence of oral cancer worldwide, it is imperative that both medical and dental practitioners have adequate knowledge about the detection and management of this disease. In the present study, it was seen that awareness of oral cancer is lower amongst medical students than among dental students, which presents an issue to be addressed with appropriate future improvements in teaching curricula and clinical experience.
Acknowledgements
The authors would like to thank Mdm. Nur Sulwana for her help with statistical analysis and Ms. Sivaashinii A/P Maniyarasu for their help with data collection, as well as all the participants for taking part in the study.
Conflict of interest
The authors declare that they have no competing interests.
Funding
The authors did not receive any funding to undertake this study.
REFERENCES
- 1.World Health Organization. Oral Cancer. Available from: http://www.who.int/cancer/prevention/diagnosis-screening/oral-cancer/en. Accessed 24th March 2019
- 2.Thomas GJ. In: Encyclopedia of Cancer. 4th ed. Schwab M, editor. Springer; Heidelberg: 2017. Oral squamous cell carcinoma; pp. 2650–2654. [Google Scholar]
- 3.Stewart BW, Wild CP. In: World Cancer Report 2014. 1st ed. Thompson LD, editor. International Agency for Research on Cancer; Lyon: 2014. Head and neck cancers; pp. 422–423. [Google Scholar]
- 4.Ferlay J, Soerjomataram I, Dikshit R, et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int J Cancer. 2015;136:E359–E386. doi: 10.1002/ijc.29210. [DOI] [PubMed] [Google Scholar]
- 5.Warnakulasuriya S. Global epidemiology of oral and oropharyngeal cancer. Oral Oncol. 2009;45:309–316. doi: 10.1016/j.oraloncology.2008.06.002. [DOI] [PubMed] [Google Scholar]
- 6.Alwan A, MacLean DR, Riley LM, et al. Monitoring and surveillance of chronic non-communicable diseases: progress and capacity in high-burden countries. Lancet. 2010;376:1861–1868. doi: 10.1016/S0140-6736(10)61853-3. [DOI] [PubMed] [Google Scholar]
- 7.Ng CJ, Teo CH, Abdullah N, et al. Relationships between cancer pattern, country income and geographical region in Asia. BMC Cancer. 2015;15:613–621. doi: 10.1186/s12885-015-1615-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Kumar M, Nanavati R, Modi TG, et al. Oral cancer: etiology and risk factors: a review. J Can Res Ther. 2016;12:458–463. doi: 10.4103/0973-1482.186696. [DOI] [PubMed] [Google Scholar]
- 9.Chaturvedi AK, Engels EA, Pfeiffer RM, et al. Human papillomavirus and rising oropharyngeal cancer incidence in the United States. J Clin Oncol. 2011;29:4294–4301. doi: 10.1200/JCO.2011.36.4596. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Panwar A, Batra R, Lydiatt WM, et al. Human papilloma virus positive oropharyngeal squamous cell carcinoma: a growing epidemic. Cancer Treat Rev. 2014;40:215–219. doi: 10.1016/j.ctrv.2013.09.006. [DOI] [PubMed] [Google Scholar]
- 11.Petti S, Masood M, Scully C. The magnitude of tobacco smoking-betel quid chewing-alcohol drinking interaction effect on oral cancer in South-East Asia. A meta-analysis of observational studies. PLoS ONE. 2013;8:e78999–e79006. doi: 10.1371/journal.pone.0078999. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Notani PN. Role of alcohol in cancers of the upper alimentary tract: use of models in risk assessment. J Epidemiol Community Health. 1988;42:187–192. doi: 10.1136/jech.42.2.187. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Khoo SP, Shanmuhasuntharam P, Mahadzir WM, et al. Factors involved in the diagnosis of oral squamous cell carcinoma in Malaysia. Asia Pac J Public Health. 1998;10:49–51. doi: 10.1177/101053959801000111. [DOI] [PubMed] [Google Scholar]
- 14.McGurk M, Chan C, Jones J, et al. Delay in diagnosis and its effect on outcome in head and neck cancer. Br J Oral Maxillofac Surg. 2005;43:281–284. doi: 10.1016/j.bjoms.2004.01.016. [DOI] [PubMed] [Google Scholar]
- 15.Hollows P, McAndrew PG, Perini MG. Delays in the referral and treatment of oral squamous cell carcinoma. Br Dent J. 2000;188:262–265. doi: 10.1038/sj.bdj.4800449. [DOI] [PubMed] [Google Scholar]
- 16.McLeod NM, Saeed NR, Ali EA. Oral cancer: delays in referral and diagnosis persist. Br Dent J. 2005;198:681–684. doi: 10.1038/sj.bdj.4812381. [DOI] [PubMed] [Google Scholar]
- 17.Moin NA, Zulkiffli S, Kallarakkal TG. Prevalence of oral potentially malignant disorders and awareness on oral cancer among dental patients. Ann Dent UM. 2016;23:38–47. [Google Scholar]
- 18.Saini R, Ghani ZI, Rahman NA. The awareness of oral cancer in adult patients attending School of Dental Sciences, Universiti Sains Malaysia: a preliminary study. Singapore Dent J. 2006;28:34–39. [PubMed] [Google Scholar]
- 19.Babiker TM, Osman KA, Mohamed SA, et al. Oral cancer awareness among dental patients in Omdurman, Sudan: a cross-sectional study. BMC Oral Health. 2017;17:69–77. doi: 10.1186/s12903-017-0351-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Eltayeb AS, Satti A, Sulieman AM. Oral cancer awareness in Sudan: assessment of knowledge, attitude and treatment seeking behavior. Asian Pac J Cancer Prev. 2017;18:1645–1649. doi: 10.22034/APJCP.2017.18.6.1645. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Formosa J, Jenner R, Nguyen-Thi MD, et al. Awareness and knowledge of oral cancer and potentially malignant oral disorders among dental patients in Far North Queensland, Australia. Asian Pac J Cancer Prev. 2015;16:4429–4434. doi: 10.7314/apjcp.2015.16.10.4429. [DOI] [PubMed] [Google Scholar]
- 22.Razavi SM, Tahani B, Nouri S, et al. Oral cancer knowledge and practice among dental patients and their attitude towards tobacco cessation in Iran. Asian Pac J Cancer Prev. 2015;16:5439–5444. doi: 10.7314/apjcp.2015.16.13.5439. [DOI] [PubMed] [Google Scholar]
- 23.Ghani WM, Doss JG, Jamaluddin M, et al. Oral cancer awareness and its determinants among a selected Malaysian population. Asian Pac J Cancer Prev. 2013;14:1957–1963. doi: 10.7314/apjcp.2013.14.3.1957. [DOI] [PubMed] [Google Scholar]
- 24.Awan KH, Khang TW, Yee TK, et al. Assessing oral cancer knowledge and awareness among Malaysian dental and medical students. J Cancer Res Ther. 2014;10:903–907. doi: 10.4103/0973-1482.138011. [DOI] [PubMed] [Google Scholar]
- 25.Saleh A, Kong YH, Vengu N, et al. Dentists’ perception of the role they play in early detection of oral cancer. Asian Pac J Cancer Prev. 2014;15:229–237. doi: 10.7314/apjcp.2014.15.1.229. [DOI] [PubMed] [Google Scholar]
- 26.Saleh A, Kong YH, Haron N, et al. Oral cancer screening in private dental practices in a developing country: opportunities and challenges. Community Dent Oral Epidemiol. 2017;45:112–119. doi: 10.1111/cdoe.12266. [DOI] [PubMed] [Google Scholar]
- 27.Brzak BL, Canjuga I, Baričević M, et al. Dental students’ awareness of oral cancer. Acta Stomatol Croat. 2012;46:50–58. [Google Scholar]
- 28.Carter LM, Ogden GR. Oral cancer awareness of undergraduate medical and dental students. BMC Med Educ. 2007;7:44–51. doi: 10.1186/1472-6920-7-44. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Fotedar S, Bhardwaj V, Manchanda K, et al. Knowledge, attitude and practices about oral cancers among dental students in H.P government Dental College, Shimla-Himachal Pradesh. South Asian J Cancer. 2015;4:65–67. doi: 10.4103/2278-330X.155643. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Fotedar V, Fotedar S, Gupta M, et al. Oral cancer knowledge, attitudes and practices: a survey of undergraduate medical students in Himachal Pradesh, India. J Clin Diagn Res. 2015;9:XC05–XC08. doi: 10.7860/JCDR/2015/12752.6406. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Halawany HS, Jacob V, Abraham NB, et al. Oral cancer awareness and perception of tobacco use cessation counseling among dental students in four Asian countries. Asian Pac J Cancer Prev. 2013;14:3619–3623. doi: 10.7314/apjcp.2013.14.6.3619. [DOI] [PubMed] [Google Scholar]
- 32.Keser G, Pekiner FN. Assessing oral cancer awareness among dental students. J Cancer Educ. 2018;33:1–7. doi: 10.1007/s13187-018-1332-x. [DOI] [PubMed] [Google Scholar]
- 33.Ogden GR, Mahboobi N. Oral cancer awareness among undergraduate dental students in Iran. J Cancer Educ. 2011;26:380–385. doi: 10.1007/s13187-010-0170-2. [DOI] [PubMed] [Google Scholar]
- 34.Soares TR, Carvalho ME, Pinto LS, et al. Oral cancer knowledge and awareness among dental students. Braz J Oral Sci. 2014;13:28–33. [Google Scholar]
- 35.Al-Dubai SA, Ganasegeran K, Alabsi AM, et al. Awareness and knowledge of oral cancer among university students in Malaysia. Asian Pac J Cancer Prev. 2012;13:165–168. doi: 10.7314/apjcp.2012.13.1.165. [DOI] [PubMed] [Google Scholar]
- 36.Bhagavathula AS, Zakaria N, Jamshed SQ. Knowledge of future dental practitioners towards oral cancer: exploratory findings from a public university in Malaysia. Int J Dent. 2015;2015:1–6. doi: 10.1155/2015/218065. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Sitheeque M, Ahmad Z, Saini R. Awareness of oral cancer and precancer among final year medical and dental students of Universiti Sains Malaysia (USM), Malaysia. Arch Orofac Sci. 2014;9:53–64. [Google Scholar]
- 38.International Agency for Research on Cancer. Cancer Tomorrow. Available from: http://gco.iarc.fr/tomorrow/home. Accessed 24th March 2019
- 39.Schreiber JB, Nora A, Frances K, et al. Reporting structural equation modeling and confirmatory factor analysis results: a review. J Educ Res. 2006;99:323–338. [Google Scholar]
- 40.Mortazavi SM, Nejad HR. Serious gender imbalance in medical and dentistry majors: how to prevent a crisis. J Med Educ. 2005;8:11–16. [Google Scholar]
- 41.Warnakulasuriya S. Causes of oral cancer – an appraisal of controversies. Br Dent J. 2009;207:471–475. doi: 10.1038/sj.bdj.2009.1009. [DOI] [PubMed] [Google Scholar]
- 42.Ogden GR, Green M, Ker JS. The use of interprofessional peer examiners in an objective structured clinical examination: can dental students act as examiners? Br Dent J. 2000;189:160–164. doi: 10.1038/sj.bdj.4800711. [DOI] [PubMed] [Google Scholar]
- 43.Oral Cancer Research & Coordinating Centre. About Us. Available from: http://www.um.edu.my/oral-cancer-research-and-coordinating-centre/about-us. Accessed 24th March 2019