Oral HPV infection among Indigenous Australians; incidence, persistence and clearance at 12-months follow-up

Surveillance of human papillomavirus through salivary diagnostics - A roadmap to early detection of oropharyngeal cancer in men

Human papillomavirus (HPV) is the most common sexually transmitted disease. Certain strains have the potential to cause malignancy in multiple anatomical sites if not cleared by the immune system. In most infected people, HPV is cleared within two years. However, HPV may persist in susceptible individuals with certain risk factors, eventually leading to malignancy. New evidence suggests that over 75% of all oropharyngeal cancers (OPC) are directly attributable to HPV. It is estimated that prophylactic HPV vaccination alone may take at least 25 years to have a significant impact on reducing the incidence of OPC. The temporal link between detection of oral HPV, persistence of the infection and the subsequent development of OPC have been well established. Moreover, men have threefold higher risk than women for acquiring HPV-OPC. This comprehensive review focuses on OPC development in men, highlighting the risk factors associated with malignant transformation of HPV-OPC. Current evidence is insufficient to determine whether early identification of at-risk demographics, screening, and prompt diagnosis result in improved outcomes. Hitherto, the effectiveness of an oral HPV screening program in this regard has not been investigated. Nevertheless, the potential to emulate the success of the cervical screening program remains a very real possibility.

Lip, oral and oropharyngeal cancer incidence among Aboriginal and Torres Strait Islander Peoples: First report from Australian population-based cancer registry, 1999-2018

BACKGROUND

The Australian Burden of Disease Study has shown that cancer is the single most important entity responsible for the greatest cause of health burden in Australia. Unfortunately, Aboriginal and Torres Strait Islander peoples experience a greater burden of this disease, with cancer of the lung, breast, bowel and prostrate being the most common. Lip, oral cavity and pharyngeal cancer incidence is rapidly rising globally and is now the sixth most common cancer in Australia. This paper aims to summarize, for the first time, the incidence and prevalence trends of lip, oral cavity and pharyngeal cancers in Aboriginal and Torres Strait Islander Australians.

METHODS

Data were obtained from the Australian Cancer Database (ACD), which is compiled at the Australian Institute of Health and Welfare (AIHW) from 1999 to 2018 to estimate the incidence and prevalence of certain head and neck cancers (ICD-10 codes C00-C10, C14). The other variables requested were age groups and sex.

RESULTS

Results were stratified by ICD-10 code, sex and age group at diagnosis and time period (i.e. grouped years of diagnosis). The total incidence of lip, oral cavity and pharyngeal cancers increased by 1.3 times from 1999 to 2008 (107/100 000) to 2009-2018 (135/100 000). The overall 5-year prevalence of lip, oral cavity and pharyngeal cancers was 0.17% (0.24% for men and 0.09% for women).

CONCLUSIONS

The significantly increased incidence of lip, oral cavity and pharyngeal cancers in Aboriginal and Torres Strait Islander peoples in Australia is concerning and should be explored. A targeted, comprehensive and culturally safe model of care for Aboriginal and Torres Strait Islander peoples with lip, oral cavity and pharyngeal cancers is imperative.

Natural History of Oral HPV Infection among Indigenous South Australians

This study aims to describe the natural history of and identify the risk factors associated with oral human papillomavirus (HPV) infections in an Australian Indigenous cohort. A longitudinal cohort study design, with baseline (2018), 12-month, and 24-month data obtained from Indigenous Australians aged 18+ years in South Australia, was performed. Face-to-face interviews were conducted, and saliva samples for HPV testing were collected at each time point. Basic descriptive analyses were conducted to calculate prevalence, incidence, persistence, clearance, and incidence proportions of any HPV infection. Multivariable logistic regression analyses with adjusted prevalence ratios (PRs) were conducted to identify risk factors associated with oral HPV infection. Among 993 participants with valid saliva samples, 44 HPV types were identified. The prevalence of infection with any oral HPV infection was 51.3%, high-risk HPV was 11%, and types implicated in Heck's disease (HPV 13 or 32) was 37.4%. The incidence, persistence, and clearance of any and high-risk HPV infections were 30.7%, 11.8% and 33.3% vs. 9.3%, 2.8%, and 9%, respectively. Our findings indicate that the prevalence, incidence, and persistence of oral HPV infection in a large sample of Indigenous Australians were high, and clearance was low. Oral sex behaviours and recreational drug use were risk factors associated with incident high-risk HPV infection.

Disparities in Human Papillomavirus vaccination coverage among adolescents in Australia: A geospatial analysis

AIM

This ecological study aimed to examine the geographic patterns in Human Papillomavirus (HPV) vaccination rates among boys and girls aged 15 years across locations in Australia, in addition to assessing contextual area-level factors that may explain the variations in HPV vaccination coverage.

METHODS

Aggregate HPV vaccination data for Australian girls and boys aged 15 years from 2015 to 16 was obtained from the Australian Institute of Health and Welfare for each Statistical Area level 4 (SA4). A Gradient Boosting Machine learning model was applied to assess the predictors' importance for the study outcomes. Geographically weighted regression (GWR) models were run to assess whether substantially different relationships between predictors and outcomes occur at different locations in space.

RESULTS

Completed HPV vaccination across the 88 SA4 regions ranged from 57.6% to 90.6% among girls, and from 53.6% to 85.5% among boys. The 2016 SEIFA Index of Economic Resources was the variable with the highest contribution to the predictions of both girls' and boys' HPV vaccination rates. Selected predictors explained 45% and 72% of the geographic variance in vaccination rates among boys and girls, respectively. Normalised coefficients for both GWR models showed a high variation in the associations between predictors and HPV vaccination rates across regions.

CONCLUSION

Socioeconomic and education factors were important predictors for HPV vaccination rates among Australian boys and girls aged 15 years, although no variable presented a uniform effect on HPV vaccination across SA4 regions. Important spatial heterogeneity in the effect of predictors was identified across the study area.