KNOWLEDGE OF DENTAL PRACTITIONERS IN SAUDI ARABIA CONCERNING HUMAN PAPILLOMA VIRUS (HPV) AND ITS CORRELATION WITH ORAL CANCERS

Abstract

The dental profession has historically been active in preventive approaches, playing an important role in the efforts related to a number of health concerns, including tobacco use, diabetes, cardiovascular disease, human immunodeficiency virus, and eating disorders [16,17]. The questionnaire consisted of a total of 16 questions divided into four sections: demographic data (participants' age, gender, education level, clinical experience, and specialty); questions on the etiology of OSCC, knowledge of HPV-associated OSCC, and site of occurrence; questions on the transmission routes of HPV infection and the importance of distinguishing HPV-associated OSCC from other OSCC; dentists' willingness to educate patients about OSCC; their knowledge on OSCC education programs was also evaluated in the last section. Data collection The questionnaire was distributed electronically to 204 participants to collect their demographic data, and to evaluate their knowledge of the HPV-OSCC link, HPV vaccine, and their willingness to educate patients about the HPV-OSCC relation. Education was significantly associated with participant responses to chronic mechanical irritation as a cause of oral cancer (p < 0.01), identifying warts as a common manifestation of oral HPV infection (x22 = 15.35; p = 0.000), HPV as a sexually-transmitted infection (x22 = 11.44; p < 0.01), educating patients (x22 = 25.47; p = 0.000), and awareness of the availability of the HPV vaccine in Saudi Arabia (x22 = 9.21; p = 0.01).

Headnote

Abstract

Introduction: The most common sexually-transmitted viral infection is human papillomavirus (HPV). HPV-16 is highly associated with oropharyngeal squamous cell carcinomas. The aim of the present study was to evaluate the awareness and knowledge of oral health practitioners (OHPs) in Saudi Arabia concerning HPV and its association with oral squamous cell carcinoma (OSCC), and also OHPs' perceived role in HPV prevention. Materials and methods: A cross-sectional, electronic-based, validated questionnaire survey was conducted among dental practitioners between 8 July and 1 August 2018. Results and discussion: Out of a total number of 204 participants, 51.5% stated that the virus was not a causative factor for OSCC. Lateral border of the tongue was identified by 44.6% of the participants as the typical site for HPV-related OSCC. Only 22.5% of them were aware of the availability of the HPV vaccine in Saudi Arabia, while most (93.1%) agreed that dentists need education programs and preventive strategies to fight OSCC. Conclusions: The current study revealed that more than half of the participants (51.5%) believed that the virus is not a causative factor for OSCC. Only 38.2% of them have informed their patients about HPV and its association with OSCC. Clearly, a systematic awareness campaign is required for OHPs regarding the relation between HPV and OSCC.

Keywords: human papilloma virus, oral squamous cell carcinoma, HPV vaccination.

1.INTRODUCTION

Globally, oral cancer represents 2-4% of all cancer cases [1,2]. Oral cancer includes a group of diseases affecting any area of the oral cavity, pharyngeal areas, and salivary glands. The most frequent type of oral cancer is oral squamous cell carcinoma (OSCC), estimated to account for more than 90% of all oral neoplasms [3]. The most common etiologic factor for OSCC is the use of tobacco [4,5]. In the past, head and neck malignancy was most frequently observed in adults with a history of tobacco and alcohol use [6]. Due to the reduction in tobacco use, the incidence of recently-diagnosed tobacco-related head and neck tumours is declining [6].

Recently, head and neck cancer mainly affects middle-aged men with or without previous hazard factors, such as tobacco and alcohol use. This progression is identified with human papillomavirus (HPV) [7]. Around 6 million individuals are diagnosed each year, and roughly 9-13% of the total population (630 million individuals) are already infected with the disease [8]. HPV is considered the best-known sexually-transmitted virus [9]. The infection is often asymptomatic and transient, and 90% of HPV cases are eliminated by body's immune system within 2 years of infection [10]. "Low-risk" HPV may cause genital warts, while "high-risk" HPV may cause cancer. HPV is known to have independent risk factors for a subset of head and neck squamous cell carcinoma (HNSCC), most significantly associated with oropharyngeal squamous cell carcinomas (OPSCC) [11].

OSCC related to HPV has a better prognosis than tobacco-related OSCC [12]; it responds well to chemo-radiation therapy. Early identification and improved awareness can result in a decrease in mortality and morbidity of these patients. Notably, around 63% of all oropharyngeal cancers are caused by HPV and may therefore be prevented [13,14].

In response to the large public health concerns about HPV-related oropharyngeal cancer, the American Dental Association (ADA) issued a statement urging oral health practitioners to educate themselves and their patients about the relationship between HPV and oropharyngeal cancer [15]. The dental profession has historically been active in preventive approaches, playing an important role in the efforts related to a number of health concerns, including tobacco use, diabetes, cardiovascular disease, human immunodeficiency virus, and eating disorders [16,17]. The HPV vaccine, which forestalls diseases caused by HPV-16 and 18, known to cause 70% of the cervical malignancy cases, may prompt further abatement [18,19]. Up to now, information about the positive efficacy of the HPV vaccine in preventing OSCC has not been widely disseminated. While it has been approved for males and females 9-26 years of age to prevent other malignancies, and strongly recommended for 11 and 12 year-old ones [20,21], many dentists remain unaware of the HPV-OSCC association and of the role of the HPV vaccine in OSCC prevention worldwide [22].

This study aimed at evaluating the awareness and knowledge of Saudi dentists regarding HPV-related OSCC and their current knowledge of preventive procedures.

2.MATERIALS AND METHODS

Study design

A cross-sectional electronic-based questionnaire, based on a questionnaire validated in a previous study (12), was administered in Saudi Arabia from 8 July to 1 August 2018. The questionnaire consisted of a total of 16 questions divided into four sections: demographic data (participants' age, gender, education level, clinical experience, and specialty); questions on the etiology of OSCC, knowledge of HPV-associated OSCC, and site of occurrence; questions on the transmission routes of HPV infection and the importance of distinguishing HPV-associated OSCC from other OSCC; dentists' willingness to educate patients about OSCC; their knowledge on OSCC education programs was also evaluated in the last section.

Ethical approval

Ethical approval for this study was granted by the Ethical Committee of the College of Dentistry in "Prince Sattam Bin Abdul-Aziz" University in Al-Kharj Province, Riyadh, Saudi Arabia.

Data collection

The questionnaire was distributed electronically to 204 participants to collect their demographic data, and to evaluate their knowledge of the HPV-OSCC link, HPV vaccine, and their willingness to educate patients about the HPV-OSCC relation. Participants included general dental practitioners (GP), specialists in oral medicine (OM)/ oral pathology (OP), and in other dental fields in academic settings.

Statistical analysis

Data was introduced with a spreadsheet software and analysed using Statistical Package for Social Sciences (SPSS, IBM, 21). Demographic characteristics and frequency distribution of participant responses were calculated. Pearson's chi-square tests and logistic regression models were used for inferential statistical analysis.

3.RESULTS

A total number of 204 survey responses were collected. Most of the respondents were 20-30 year-old (n = 149; 73.0%) (Table 1). The ratio of male-to-female respondents was 1.06, with slightly more male (n=105; 51.5%) than female (n=99; 48.5%) respondents.

Approximately one-third of the survey sample group were interns (n=72; 35.3%) and another third were general dentists (n=75; 36.8%). Nearly 10% of the respondents reported a specialty in oral medicine or pathology (n=20; 9.8%); 37 respondents (18.1%) reported specializing in another field. The majority held a bachelor's degree (n=148; 72.5%) and had less than 5 years of experience (n=149; 73.0%). Thirty-eight respondents (18.6%) reported between 5 and 10 years of experience, 10 (4.9%) reported more than 10 years of experience, and 7 (3.4%) reported more than 20 years of experience.

When asked what they thought on the causes of oral cancer, 84.3% (n=172) of them correctly identified chewing powdered products like gutkha, and 77.0% (n=157) identified smoking as a potential cause (Fig. 1). Over three-fourths (n=156; 76.5%) selected human papillomavirus (HPV) when asked which virus can cause oral squamous cell carcinoma (OSCC), or oral cancer (Table 2). Regarding HPV, most of the respondents recognized that the most common oral manifestation of HPV infection is the appearance of warts (n=145; 71.1%) and that HPV is a sexually-transmitted infection (n=166; 81.4%); only half (n=103; 50.5%) of them thought that sexual contact was the most common route of transmission. Most participants (n=91; 44.6%) thought that the lateral border of the tongue was the most affected site. Approximately one-third (n=78; 38.2%) of the participants identified a better prognosis for HPV than for OSCC as one of the reasons to differentiate among them.

When asked about prevention strategies, only 38.2% of participants (n=78) reported that they inform their patients about HPV and the risk of oral cancer. Over half (n=114; 55.9%) of them were aware that cancers caused by HPV can be prevented by a vaccine, yet only 22% (n=46; 22.5%) were aware that the HPV vaccine is available in Saudi Arabia. Almost all participants (n=190; 93.1%) agreed that there is a need to offer continuing education to dentists, focusing on advanced and preventive strategies in the fight against oral cancer.

Contingency tables and Pearson's chi-square test (x2) were used to determine possible correlations between correct responses to the knowledge (e.g., awareness of HPV vaccine) or prevention strategy (e.g., educating patients about HPV and risk of associated cancers) variables and participant demographics. The results are presented in Table 3. A significant correlation between gender and whether participants educate their patients about HPV and associated risks was found out (p = 0.02). Education was significantly associated with participant responses to chronic mechanical irritation as a cause of oral cancer (p < 0.01), identifying warts as a common manifestation of oral HPV infection (x22 = 15.35; p = 0.000), HPV as a sexually-transmitted infection (x22 = 11.44; p < 0.01), educating patients (x22 = 25.47; p = 0.000), and awareness of the availability of the HPV vaccine in Saudi Arabia (x22 = 9.21; p = 0.01).

The position participants hold (e.g., intern, general dentist, specialist) was also found to be significantly associated with several outcome variables (Table 3). Likewise, the number of years of experience (categorical) that participants reported was significantly correlated with numerous knowledge and prevention variables (Table 3). Logistic regression models were analysed to determine whether the odds of certain responses differed according to participant demographics (e.g., gender, education); the results are presented in Table 4.

Logistic regression models were analyzed to determine whether the odds of certain responses differed by participant demographics (e.g., gender, education), the results being presented in Table 4.

4. DISCUSSION

The present study was meant at determining the awareness and extent of knowledge among dentists regarding HPV's correlation with the incidence of OSCC. The mortality and morbidity of patients related to the HPV-OSCC link can be decreased by improved awareness among dentists and by an early diagnosis (23,24). Several reports have shown that HPV is considered a risk factor associated with OSCC. Data from several studies revealed that dentists do not possess adequate knowledge about the HPV-OSCC link (10-12). In our research, 204 Saudi dentists agreed to participate (22), 51.5% of whom were males and 48.5% females. The question related to the willingness to educate patients was gender-related.

Dentists can play an integral role in the prevention of HPV-related OSCC, by informing patients about HPV and its link to oral cancer, focusing on the avoidance, vaccination, self-screening instructions and treatment, and urging them to get HPV immunization. Avoiding OSCC may be a strong incentive for patients to do so. Previous research has found that chewing tobacco is an etiologic factor in the occurrence of OSCC (4,5). A study published by Arora et al. in 2018 investigated the awareness of HPV's correlation with oral cancers among oral health professionals in the university of SEGi in Malaysia (12). Their research found out a large agreement among participants as to the causative factors of OSCC. Almost 92% of the sample claimed that chewing tobacco is a causative factor of OSCC. In the same way, our study showed that 84.3% of participants also thought that chewing tobacco is one of the major causative factors of OSCC. The current study shows that 156 participants agreed that HPV may cause oral squamous cell carcinoma, indicating that 76.5% of the sample knew the association between HPV and OSCC. A strong relationship between HPV-OSCC and dentist knowledge was also reported by Arora et al., showing similar responses (12). In our study, 28.9% of the participants correctly identified the posterior portion of the tongue and oropharynx as the part of the mouth most commonly affected by HPV-related cancers. The responses according to professionals holding higher degrees showed masters and PhDs at 0.99 and 0.15, respectively. (The response of PhDs was less than of other levels, because they had the lowest number of participants, 6.4% (n = 13).) Nearly half of the participants, 44.6% (n = 91), thought that the lateral border of the tongue was most affected. On the other hand, there was a conflict with the study of Arora et al., as they reported 44% correctly answering as to the most affected site of HPV-related cancers, while 29% stated that the lateral border of the tongue is the most affected site (12). Over half of the participants, 55.9% (n = 114), were aware that cancers caused by HPV could be prevented by a vaccine, while 44.1% (n = 90) answered that a vaccine cannot prevent HPV.

Results of this study indicate a lack of knowledge regarding the importance of vaccine in prevention of HPV related to OSCC. Moreover, such results raised an essential question about the nature of the vaccine as a preventive measure, which is in line with the findings of Petrosky et al., namely that the impact of the vaccine is unknown. (20)

An interesting finding related to preventive measures was that only 38.2% (n=78) of the participants stated that they educate their patients about HPV, suggesting that considerable effort needs to be done to increase patient education. The same finding was reported by Arora et al.: only 41% (n = 67) of their participants educate their patients about HPV (12). Almost all participants, 93.1% (n = 190), agreed that there is a need to provide continuing education to dentists, focusing on the advances and preventive strategies in the fight against oral cancer.

5. CONCLUSIONS

Most results indicate a lack of knowledge and awareness of HPV and its association with OSCC. Studies on larger samples related to the various preventive methods are needed for understanding the current extent of knowledge concerning HPV and for extending dentists' understanding of its association with OSCC, as well as patients' awareness.

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