The global epidemiological and socioeconomic burden of oral cancer, and the need for public health education in oral cancer prevention - A literature review

INTRODUCTION

Oral cancer is a chronic, debilitating disease that primarily affects the lips, tongue, buccal mucosa, floor of the mouth, and oropharynx, posing a significant global public health challenge.^[1] Beyond its clinical impact, oral cancer imposes a substantial socioeconomic burden on individuals, families, and healthcare systems. The disease often leads to long-term functional impairments – such as difficulties in speaking, chewing, and swallowing – which significantly affect quality of life.^[2] It ranks as the 16^th most common cancer worldwide, with rising incidence and mortality rates, particularly in lowand middle-income countries (LMICs).^[3,4] Notably, LMICs are those countries whose gross national income per capita, according to the World Bank, is below $13,846.^[5]

The global distribution of oral cancer is strongly influenced by a complex interplay of risk factors, including areca nut chewing,^[6] smoked and smokeless tobacco use,^[7] alcohol consumption,^[8] and human papillomavirus infection.^[9] Despite advances in prevention, early detection, and treatments, survival rates remain low in many regions due to delayed diagnosis, socioeconomic inequalities, and limited access to healthcare services.^[10,11] In addition, the financial costs of treatment and the loss of productivity due to disability or untimely death further strain already burdened health economies, particularly in resource-limited settings.^[12-14] Therefore, understanding the global epidemiology and socioeconomic burden of oral cancer is essential to inform effective public health strategies, prioritize resource allocation, and promote early detection and prevention efforts. This review aims to provide a comprehensive overview of the current global trends in oral cancer incidence, prevalence, and mortality, while also highlighting the associated socioeconomic implications and disparities across different regions.

The global epidemiological burden of oral cancer is enormous.^[15,16] Due to the widespread inconsistencies in the case definition of oral cancer in the literature,^[16-22] the presentation of the global epidemiological burden of oral cancer in this literature review is based on the groupings of oral cancer into anatomical site clusters. That is, the burden is discussed under the group headings of “Lip and Oral Cavity Cancer” and “Oropharyngeal Cancer.”

Lip and oral cavity cancer refers to the oral cancer affecting the oral aspect of the upper and/or lower lip(s) (up to the vermillion border) and the structures within the oral cavity (this includes the floor of the mouth, retromolar pad, gingivae, hard palate, buccal mucosa, and the anterior two-thirds of the tongue).^[15,23,24] The epidemiological data presented in this sub-section on lip and oral cavity cancer are based on the 1990–2021 data of the Global Burden of Disease, Risks, and Injuries Study group;^[15] this group is a leading study group which, in collaboration with the World Health Organization, has been providing scientifically comprehensive and rigorous data on the global burden of several diseases affecting humans since 1993.^[25] Furthermore, this epidemiological data, to the best of the researchers’ knowledge, is the most recent and the most robust data on lip and oral cavity cancer in the world. To enhance a comprehensive presentation of the obtained data, the epidemiological burden is discussed under the subheadings of incidence, prevalence, and mortality.

From the year 1990 to 2021, there has been a persistently upward rise in the global trend of lip and oral cavity cancer incidence. In the year 1990, the global incidence rate of lip and oral cavity cancer was 3.26/100,000 persons.^[15] However, in 2021, the global incidence rate has risen to 5.34/100,000 persons, with the estimated annual percentage change in global lip and oral cavity cancer incidence rate being 1.60/100,000 persons.^[15] Notably, based on sociodemographic index (SDI) classification, countries with high SDI had the highest lip and oral cavity cancer incidence rate (9.59/100,000 persons) while those countries having low SDI had the lowest incidence rate of lip and oral cavity cancer (2.25/100,000 persons) in the most recent (i.e., for the year 2021) annual epidemiological data on lip and oral cavity cancer incidence [Table 1].^[15] The reasons for this disparity in lip and oral cavity cancer incidence might be due to the completeness of oral cancer data in the countries with high SDI, unlike those in the opposite extreme, where epidemiological data on lip and oral cavity cancer, and several diseases, are sparse.^[26,27] Furthermore, higher rate of exposures to some major risk factors of lip and oral cavity cancer (e.g., alcohol) in countries with high SDI could also be a major contributor to the higher incidence rates of lip and oral cavity cancer in some of those countries.^[28]

However, it was observed that the estimated annual percentage change in global lip and oral cavity cancer incidence from 1990 to 2021 was highest (2.83/100,000 persons) in those countries with middle SDI, while it was lowest among those countries with low SDI (0.36/100,000 persons) [Table 1].^[15] Notably, among all countries of the world, Palau had the highest incidence rate in 2021 (32.23/100,000 persons) while Sao Tome and Principe had the lowest rate in same year (0.07/100,000 persons).^[15]

It is also noteworthy that across all regions of the world in 2021, males had higher incidence rates of lip and oral cavity cancer, except for Western sub-Saharan Africa and Andean Latin America, where females had higher incidence rates.^[15]

From the year 1990 to 2021, there has been a persistently upward rise in the global trend of lip and oral cavity cancer prevalence.^[15] In the year 1990, the prevalence rate of lip and oral cavity cancer was 11.01/100,000 persons.^[15] However, in 2021, the global prevalence rate has risen to 19.49/100,000 persons, with the estimated annual percentage change in global lip and oral cavity cancer prevalence rate being 1.92/100,000 persons.^[15] Notably, based on SDI classification, countries with high SDI had the highest lip and oral cavity cancer prevalence rate (45.52/100,000 persons) while those countries having low SDI had the lowest prevalence rate of lip and oral cavity cancer (6.05/100,000 persons) in the most recent (i.e., for the year 2021) annual epidemiological data on lip and oral cavity cancer prevalence [Table 2].^[15] The reasons for this disparity in lip and oral cavity cancer prevalence might be due to the completeness of lip and oral cavity cancer data in the countries with high SDI, unlike those in the opposite extreme, where epidemiological data on lip and oral cavity cancer, and several diseases, are sparse.^[26,27] Furthermore, higher rate of exposures to some major risk factors of lip and oral cavity cancer (e.g., alcohol) in countries with high SDI could also be a major contributor to the higher prevalence rates of lip and oral cavity cancer in some of those countries.^[28]

However, it was observed that the estimated annual percentage change in global lip and oral cavity cancer prevalence from 1990 to 2021 was highest (3.59/100,000 persons) in those countries with middle SDI, while it was lowest among those countries with low SDI (0.88/100,000 persons) [Table 2].^[15] Notably, no epidemiological data were presented on the country or region with the highest and lowest prevalence rates of lip and oral cavity cancer in 2021 in the reviewed article.^[15]

From the year 1990 to 2021, there has been a persistently upward rise in the global trend of lip and oral cavity cancer mortality.^[15] In the year 1990, the mortality rate of lip and oral cavity cancer was 1.83/100,000 persons.^[15] However, in 2021, the global mortality rate has risen to 2.64/100,000 persons, with the estimated annual percentage change in global lip and oral cavity cancer mortality rate being 1.15/100,000 persons.^[15] Notably, based on SDI classification, countries with low-middle SDI had the highest lip and oral cavity cancer mortality rate (3.51/100,000 persons) while those countries having low SDI had the lowest mortality rate of lip and oral cavity cancer (1.55/100,000 persons) in the most recent (i.e., for the year 2021) annual epidemiological data on lip and oral cavity cancer mortality [Table 3].^[15]

However, it was observed that the estimated annual percentage change in global lip and oral cavity cancer mortality from 1990 to 2021 was highest (1.99/100,000 persons) in those countries with middle SDI, while it was lowest among those countries with low SDI (0.04/100,000 persons) [Table 3].^[15] Notably, among all countries of the world, Palau had the highest from 1990 to 2021 rate in 2021 (17.62/100,000 persons) while Sao Tome and Principe had the lowest rate in same year (0.05/100,000 persons).^[15] It is also noteworthy that across all regions of the world in 2021, males had higher incidence rates of lip and oral cavity cancer, except for Western sub-Saharan Africa and Andean Latin America where females had higher incidence rates.^[15]

Oropharyngeal cancer refers to the oral cancer type affecting the throat.^[29] Unlike lip and oral cavity cancer, which has a more recent, a unified, and a robust data on its global epidemiological burden, oropharyngeal cancer does not.^[15,30-32] Of the available global reports on the global epidemiological burden of oropharyngeal cancer, only three of them were recent peer-reviewed reports and their findings were limited – not globally representative.^[31,32] The reports by Lu et al.,^[32] and Zumsteg et al.,^[30] were based on the United Nations’ data from 1993 to 2012. Notably, the year 2012 is over a decade ago (2013–2025); this makes the data in these two reports non-contemporary. Since it is crucial to focus on the current global epidemiological burden, in relation to trends, of oropharyngeal cancer, these two reports were not considered for the critical presentation of the current epidemiological burden of oropharyngeal cancer in this review; however, they were used to build the body of information on the epidemiological trend of oropharyngeal cancer from 1993 to 2012 in this review. On the other hand, the report by Lorenzoni et al.,^[31] was based on the 2020 data of the Global Cancer Observatory (GLOBOCAN); hence, this data was used to critically present the current global epidemiological burden of oropharyngeal cancer in this review.

Due to the lack of robustness in the existing reports on the global epidemiological burden of oropharyngeal cancer, the presentation on the epidemiological burden of this oral cancer type in this review was grouped into years: “1993 to 2012” and “2013 to 2020,” as there is no known published report on the burden of disease between 2021 and 2025.

Existing reports on the global epidemiological burden of oropharyngeal cancer from 1993-2012 are insufficient, as the available reports primarily focused on its incidence, while no substantial information was provided on its prevalence and mortality.^[30-32] In the report by Zumsteg et al., (2023),^[30] a total of 156,567 new cases of oropharyngeal cancer were reported across 42 countries of the world. Among these 42 countries, Kuwait was the country with the lowest age-standardized incidence rate of oropharyngeal cancer among men (0.7 new cases/100,000 persons), while France had the highest age-standardized incidence rate among men (19.7 new cases/100,000 persons) in the year 2012 alone.^[30]

Furthermore, among these 42 countries, Bahrain was the country with the lowest age-standardized incidence rate of oropharyngeal cancer among women (0.1 new cases/100,000 persons), while Germany had the highest age-standardized incidence rate among women (5.2 new cases/100,000 persons) in the year 2012 alone.^[30] It is also noteworthy that majority of these new cases were reported among males, with the male-female incidence ratio highest in some countries in eastern and central Europe, including Lithuania (8.1:1), Croatia (7.1:1), and Slovakia (6.9:1).^[30]

It is also noteworthy that there has been a significant increase between 1993 and 2012 in the estimated annual percentage change in the incidence rate of oropharyngeal cancer.^[30] Over this period (1993–2012), only 13 countries, out of the 42 analyzed countries, had an annual percentage increase in the incidence rates of oropharyngeal cancer >3% per year.^[30] Interestingly, all these countries – Australia, Austria, Brazil, Canada, China, Denmark, Iceland, Japan, New Zealand, Norway, Republic of Korea, United Kingdom, and United States – were countries with high SDI.^[30] Overall, this shows that the epidemiological burden of oropharyngeal cancer is heavier in countries with high SDI, compared to those countries categorized under lower sociodemographic indices.^[30]

The epidemiological reports on the global incidence, prevalence, and mortality of oropharyngeal cancer from 2013 to 2020 are very sparse; however, a report from the Global Cancer Observatory is available for the year 2020.^[31] Based on this singular report, this sub-section only focused on the global epidemiology of oropharyngeal cancer in the year 2020 alone. In 2020, about 98,412 new cases of oropharyngeal cancer were reported globally: This amounts to an incidence rate of approximately 1.1/100,000 persons.^[31] European countries had high age-standardized incidence rates among both males and females, when compared to the countries across different the world regions.^[31] Among these European countries, Czechia, Denmark, Hungary, and France had the highest age-standardized incidence rates among males while Belarus, Denmark, Moldova, and Romania had the highest age-standardized incidence rates among females.^[31]

With respect to the prevalence of oropharyngeal cancer, no epidemiological data were presented in the reviewed report; however, data on the disease mortality were reported.^[31] In 2020 alone, about 48,143 new deaths from oropharyngeal cancer were reported globally.^[31] Across all the regions/sub-regions of the world, African and Western Asian countries generally had the lowest mortality rates for oropharyngeal cancer.^[31] However, among males, Belarus, Moldova, Romania, and Slovenia were the countries with the highest mortality rates globally, while Bangladesh, Denmark, Hungary, Namibia, and Montenegro had the lowest rates.^[31] Overall, this demonstrates that the fatalistic burden of oropharyngeal cancer spreads across several regions of the world.

According to a recent systematic review by^[33] which synthesized global evidence on the costs of different oral cancer types (lip cancer, oral cavity cancer, and oropharyngeal cancer), it was identified that the costs of treatment of oral cancer are enormous. Notably, only two empirical studies – from Brazil and the United Kingdom – were identified in the review to have analyzed the costs of lip cancer treatment.^[34,35] In the United Kingdom, the treatment cost of lip cancer was about £5,790 per patient, while in Brazil, the cost spent for the treatment in the entire country over a period of 9 years was a whopping sum of I$ 22.7 million.^[33]

For oral cavity cancer treatment, synthesized evidence obtained from seven empirical studies revealed that the United Kingdom, Italy, Netherlands, Thailand, and Germany spend up to (or more than) £25,311 (for up to 5 years of patient follow-up), €18,462 (for up to 2 years of patient follow-up), €35,541 (for up to 10 years of patient follow-up), THB29,531 (for >1 year of patient follow-up), and €6,4862 (for >1 year of patient follow-up), respectively, per patient.^[33-40]

For oropharyngeal cancer treatment, synthesized evidence obtained from three empirical studies revealed that Italy, Netherlands, and the United States of America spend up to €24,253 (after 2 years of patient follow-up), €35,642 (for up to 10 years of patient follow-up), and US$134,454 (for up to 2 years of patient follow-up), respectively, per patient.^{[33,36,39,41]}

Based on the above information, it can be asserted that the global socioeconomic burden associated with the treatment of oral cancer has huge financial impacts on countries and individuals.^[29,33,42] Globally, significant socioeconomic inequalities exist in the affordability of care for oral cancer; and this exists at the individual- and country-level.^[4,29,43,44] Individuals with low socioeconomic status, such as poor people and people with lower educational attainment, face the challenges of limited access to preventative oral cancer care, delayed oral cancer diagnosis, and poorer outcomes of oral cancer care.^[4,43-45] Similarly, countries with low socioeconomic status do not have adequate financial resources needed for the comprehensive care of people afflicted with oral cancer in their populations.^[4,46,47] Overall, this indicates that more attention needs to be focused on the prevention of the disease from occurring in the first instance, as this will help alleviate the global socioeconomic burden of oral cancer globally.

Oral cancer is a preventable disease. Unfortunately, if it occurs and it is either untreated, not properly treated, or not treated early, it can lead to metastasis, secondary cancers, and even death. In addition, the late- or advanced-stage oral cancer presentation requires a more intensive and costly approach compared to the early-stage presentation.^[48] However, several disadvantaging factors – particularly those factors associated with low socioeconomic status (such as illiteracy, poor access to healthcare facilities, and poverty) – have been reported to be responsible for the late clinical presentation for treatment among oral cancer patients.^[4,49-51] Therefore, the need to address the rising scourge of oral cancer incidence and its late-stage clinical presentation across various populations through public health education interventions targeting both primary and secondary prevention of oral cancer cannot be overemphasized.^[52,53]

The use of public health education for oral cancer prevention will help alleviate both the global epidemiological and socioeconomic burdens of the disease, and this has been a recommendation over the years and across different parts of the world.^[47] Interestingly, public health education interventions have been proven to play a very significant role in disease prevention.^[54] A notable example of such was the use of mass media (including radio and television), social media (including Facebook®, WhatsApp®, and Telegram®), print materials (including posters and flyers) in the education of the public during the recent Coronavirus Disease 2019 (COVID-19) outbreak on the risk/etiological factors of the disease, its clinical features, its prevention strategies, and its treatment options; through these educational interventions, the global infection rates and fatalities of COVID-19 were drastically minimized.^[55] The COVID-19 public education example is one of the biggest success stories of public health education in human history; other notable examples of such health education interventions were those on human immunodeficiency virus infection, Ebola virus infection, and malaria infection.^[56-58]

Overall, the above notes imply that the public can be effectively enlightened on the risk factors, signs and symptoms, and preventive and curative measures against oral cancer through a comprehensive and inclusive health education on the disease. It is also interesting to note that public health education on oral cancer is a preventative strategy that has been widely embraced across the general populations of the world; hence, it should be more utilized across board.^[59-61] However, most of the current public health education interventions ever done on oral cancer were not comprehensive and inclusive, as most of them did not engage relevant stakeholders in the development and delivery.^[62-65] Furthermore, only very few adopted the use of state-ofthe-art technologies (such as artificial intelligence, mobile health applications, augmented reality, and teledentistry) as delivery tools; this underutilization of these technologies has made many educational interventions on oral cancer less effective.^[65-72] Notably, in the adoption of these state-of-theart technologies in public health education on oral cancer, it is highly recommended that further research, including empirical studies and systematic reviews, is conducted to explore innovative ways through which these technologies could be deployed to ensure that those interventions adopting them are more accessible for public use.

CONCLUSION

Oral cancer remains a growing global health concern with rising incidence, prevalence, and mortality, specifically in LMICs with low-resource settings. This literature review provided an overview of the global epidemiological and socioeconomic burden of oral cancer with the latest literature. This literature review presented an overview of the current global epidemiological and socioeconomic burden of oral cancer based on the latest evidence. The findings highlight a significant disparity in disease distribution, with high-SDI countries reporting the highest incidence and prevalence rates, while low- and middle-SDI countries experience the highest mortality and face major challenges in prevention, early detection, and access to treatment. Furthermore, the socioeconomic burden of oral cancer is considerable yet remains underreported, with limited data on healthcare costs and economic impact, especially in resource-constrained settings.

This review underscores the urgent need for more comprehensive and up-to-date data on public awareness, epidemiological patterns, and the financial burden associated with oral cancer. Strengthening global surveillance systems, investing in targeted public health education, and addressing inequalities in healthcare access are critical steps toward reducing the global burden. Future research should focus on bridging existing knowledge gaps, particularly around socioeconomic determinants and regional disparities, to inform effective policies, early intervention strategies, and equitable resource allocation.