Squamous cell carcinoma of the conjunctiva is associated with a number of risk factors, including HIV infection, iatrogenic immunosuppression and atopy. In addition, several studies have suggested an involvement of HPV, based on the presence of viral DNA, but did not establish whether there was active infection or evidence of causal disease association. In this manuscript, thirty one cases of conjunctival in situ squamous cell carcinoma were classified as HPV DNA-positive or -negative, before being analysed by immunohistochemistry to establish the distribution of viral and cellular biomarkers of HPV gene expression. Our panel included p16INK4a, TP53 and MCM, but also the virally encoded E4 gene product, which is abundantly expressed during productive infection. Subsequent in situ detection of HPV mRNA using an RNAscope approach, confirmed that early HPV gene expression was occurring in the majority of cases of HPV DNA-positive conjunctival in situ squamous cell carcinoma, with all of these cases occurring in the atopic group. Viral gene expression correlated with TP53 loss, p16INK4a elevation, and extensive MCM expression, in line with our general understanding of E6 and E7's role during transforming infection at other epithelial sites. A characteristic E4 expression pattern was detected in only one case. HPV mRNA was not detected in lower grades of dysplasia, and was not observed in cases that were HPV DNA-negative. Our study demonstrates an active involvement of HPV in the development of a subset of conjunctival in-situ squamous cell carcinoma. No high-risk HPV types were detected other than HPV16. It appears that the conjunctiva is a vulnerable epithelial site for HPV-associated transformation. These cancers are defined by their pattern of viral gene expression, and by the distribution of surrogate markers of HPV infection.

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Cervical cancer prevention has undergone dramatic changes over the past decade. With the introduction of human papillomavirus (HPV) vaccination, some countries have seen a dramatic decline in HPV‐mediated cervical disease. However, widespread implementation has been limited by economic considerations and the varying healthcare priorities of different countries, as well as by vaccine availability and, in some instances, vaccine hesitancy amongst the population/government. In this environment, it is clear that cervical screening will retain a critical role in the prevention of cervical cancer and will in due course need to adapt to the changing incidence of HPV‐associated neoplasia. Cervical screening has, for many years, been performed using Papanicolaou staining of cytology samples. As our understanding of the role of HPV in cervical cancer progression has advanced, and with the availability of sensitive detection systems, cervical screening now incorporates HPV testing. Although such tests improve disease detection, they are not specific, and cannot discriminate high‐grade from low‐grade disease. This has necessitated the development of effective triage approaches to stratify HPV‐positive women according to their risk of cancer progression. Although cytology triage remains the mainstay of screening, novel strategies under evaluation include DNA methylation, biomarker detection and the incorporation of artificial intelligence systems to detect cervical abnormalities. These tests, which can be partially anchored in a molecular understanding of HPV pathogenesis, will enhance the sensitivity of disease detection and improve patient outcomes. This review will provide insight on these innovative methodologies while explaining their scientific basis drawing from our understanding of HPV tumour biology.

Human Papillomaviruses have co-evolved with their human host, with each of the over 200 known HPV types infecting distinct epithelial niches to cause diverse disease pathologies. Despite the success of prophylactic vaccines in preventing high-risk HPV infection, the development of HPV anti-viral therapies has been hampered by the lack of enzymatic viral functions, and by difficulties in translating the results of in vitro experiments into clinically useful treatment regimes. In this review, we discuss recent advances in anti-HPV drug development, and highlight the importance of understanding persistent HPV infections for future anti-viral design. In the infected epithelial basal layer, HPV genomes are maintained at a very low copy number, with only limited viral gene expression; factors which allow them to hide from the host immune system. However, HPV gene expression confers an elevated proliferative potential, a delayed commitment to differentiation, and preferential persistence of the infected cell in the epithelial basal layer, when compared to their uninfected neighbours. To a large extent, this is driven by the viral E6 protein, which functions in the HPV life cycle as a modulator of epithelial homeostasis. By targeting HPV gene products involved in the maintenance of the viral reservoir, there appears to be new opportunities for the control or elimination of chronic HPV infections.