RESUMO
Human papillomaviruses (HPV) are involved in approximately 5% of solid cancers worldwide. The mucosotropic genotypes infect the stratified epithelium of various locations, where persistent infection may lead to invasive carcinomas. While the causative role of HPV in certain anogenital and head and neck carcinomas is well established, the role of HPV in carcinomas arising in the mucosal membranes of the ocular adnexal tissue (the lacrimal drainage system and the conjunctiva) has been a topic of great uncertainty. Therefore, we conducted a series of studies to assess the correlation between HPV and carcinomas arising in the mucosa of the ocular adnexal tissue and characterize the clinical, histopathological, and genomic features of the tumors in the context of HPV status in a Danish nationwide cohort. We collected clinical and histopathological data and tumor specimens from patients with carcinomas of the conjunctiva and the lacrimal drainage system, and their potential precursors, identified in Danish nationwide registries. The HPV status of the tumors was determined by the combined use of HPV DNA polymerase chain reaction (PCR), HPV E6/E7 mRNA in-situ hybridization, and p16 immunohistochemistry. The genomic profile was investigated by high-throughput DNA sequencing targeting 523 cancer-relevant genes. The literature to date on carcinomas of the lacrimal drainage system and the conjunctiva was summarized. In the Danish cohort, 67% of all carcinomas of the lacrimal drainage system and 21% of all conjunctival carcinomas were HPV-positive. HPV16 was the most frequently implicated genotype. A full-thickness expression of the viral oncogenes E6 and E7 was evident in almost all HPV DNA-positive cases. The HPV-positive carcinomas of the conjunctiva and the lacrimal drainage system shared histopathological and genomic features distinct from their HPV-negative counterparts. The HPV-positive carcinomas were characterized by a non-keratinizing morphology, p16 overexpression, high transcriptional activity of HPV E6/E7, and frequent pathogenic variants in the PI3K-AKT signaling cascade. In contrast, the HPV-negative carcinomas were characterized by a keratinizing morphology, lack of p16 and E6/E7 expression, and frequent somatic pathogenic variants in TP53, CDKN2A, and RB1. Among the patients with conjunctival tumors, HPV positivity was associated with a younger age at diagnosis and a higher risk of recurrence. In conclusion, the results support an etiological role of HPV in a subset of conjunctival and LDS carcinomas and their precursor lesions. Our investigations have shown that the HPV-positive carcinomas of the ocular adnexa share genomic and phenotypic characteristics with HPV-positive carcinomas of other anatomical locations. Therefore, these patients may be eligible for inclusion in future basket trials and future treatment regimens tailored to the more frequently occurring HPV-positive carcinomas of other locations. Future research will further elucidate the diagnostic, prognostic, and predictive role of HPV in these carcinomas.
Human papillomavirus (HPV) forårsager ca. 5% af alle non-haematologiske cancertilfaelde på verdensplan. De slimhindeafficerende genotyper inficerer flerlagede pladeepitheler i forskellige anatomiske lokalisationer, og en persisterende infektion kan medføre cancerudvikling. Den kausale rolle for HPV i udviklingen af visse anogenitale og for hoved-hals cancer er veletableret, men rollen i udviklingen af carcinomer i det okulaere adnexa (conjunctiva og tårevejene) er stadig behaeftet med usikkerhed. Vi udførte derfor en serie af studier for at undersøge sammenhaengen mellem HPV og udviklingen af carcinom i conjunctiva og tårevejene og karakterisere den kliniske, histologiske og genetiske profil af tumorerne baseret på HPV-status i en landsdaekkende, dansk kohorte. Ved brug af landsdaekkende patientregistre, indsamlede vi kliniske og histopatologiske data samt tumormateriale fra patienter diagnosticeret med carcinom i conjunctiva eller tårevejene og deres potentielle forstadier. Undersøgelser for HPV i tumormaterialet blev foretaget ved p16 immunhistokemi, HPV DNA polymerase chain reaction (PCR) og ved HPV E6/E7 mRNA in-situ hybridisering. Den genetiske profil blev undersøgt ved high-throughput DNA-sekventering målrettet 523 cancer-relevante gener. Litteraturen omhandlende associationen mellem HPV og conjunctival intraepithelial neoplasi og carcinom blev gennemgået. I det danske materiale var 67% af tårevejscarcinomerne og 21% af alle conjunctivale carcinomer HPV-positive. I begge lokalisationer var HPV16 den hyppigste genotype. Alle HPV-positive tumorer, fraset én, udtrykte ekspression af de virale onkogener E6 og E7. Histopatologiske og genetiske undersøgelser viste at de HPV-positive carcinomer udgået fra conjunctiva og tårevejene delte genotypiske og faenotypiske traek der adskilte dem fra de HPV-negative carcinomer. De HPV-positive carcinomer var karakterisereret af en ikke-keratiniserende morfologi, p16-ekspression, udtalt ekspression af HPV E6/E7 og hyppige patogene varianter i PI3K-AKT signalleringskaskaden. Derimod var de HPV-negative carcinomer karakteriseret af en keratiniserende morfologi og hyppige patogene varianter i TP53, CDKN2A, og RB1. For at konkludere, støtter vores resultater op om at HPV spiller en kausal rolle i subgrupper af carcinomer og deres forstadier der udgår fra conjunctiva og tårevejene. Vores undersøgelser har vist, at de HPV-positive carcinomer deler genetiske og faenotypiske karakteristika med HPV-positive carcinomer i andre anatomiske lokalisationer. Det er derfor muligt, at disse patienter kan indgå i fremtidige basket-trials og kan drage nytte af de behandlingsmetoder der udvikles til hyppigere forekomne HPV-positive carcinomer. Fremtidig forskning vil videre afgøre den diagnostiske, prognostiske, og praediktive vaerdi af HPV i carcinomer i det okulaere adnexa.
