Human papilloma virus (HPV) antigens and local immunologic reactivity in oral squamous cell tumors and hyperplasias

Benign proliferative epithelial lesions of oral mucosa are infrequently associated with α-, β-, or γ human papillomaviruses

BACKGROUND

Oral papillomas and verruca vulgaris have been associated with human papillomavirus (HPV) infection. However, approximately half of these have remained HPV-negative when tested for mucosal HPV genotypes. In this study, we evaluated presence of α-, β-, and γ-HPVs in benign papillary and verrucous lesions.

METHODS

Eighty-three clinical lesions with suspected HPV etiology were analyzed for HPV types of genus α (n = 24), β (n = 46), and γ (n = 52). Immunohistochemistry was used for p16 as a possible surrogate marker of high-risk HPV, accompanied by Ki-67 proliferation marker.

RESULTS

Altogether, α-HPVs were detected in 6.4%, β-HPVs in 2.4%, and γ-HPV in 4.8%. The following genotypes were identified: HPV6, 8, 11, 16, 22, 161, and 170. Neither Ki-67 nor p16 positivity alone were associated with HPV but combined staining showed significant inverse association (P = .042).

CONCLUSION

HPV infection is found only in a minority of benign verrucous and papillary oral lesions, with the predominance of α-HPVs.

LEVEL OF EVIDENCE

4.

Human papillomavirus infections and oral tumors

In the past 20 years, there has been an increasing interest in human papillomaviruses (HPV) because of their potential role in the pathogenesis of malignant tumors. In 1983, we published the first evidence that HPV might be involved in oral squamous cell carcinomas. The identification of morphological similarities between oral and cervical mucosa lead us to this original proposal. In a recent meta-analysis, HPV was indeed confirmed as an independent risk factor for oral carcinoma. To date, totally more than 100 types of HPV have been identified. As in anogenital cancers, HPV type 16 is the most prevalent type in oral carcinomas. The benign oral lesions, associated with HPV infection, include squamous cell papilloma, condyloma acuminatum, verrucca vulgaris and focal epithelial hyperplasia (FEH). Papillomas and condylomas are mostly caused by HPV type 6 or 11, while oral verrucas are associated with the skin types 2 or 4. A family history of FEH has been suggested. The FEH lesions are caused by HPV types 13 and 32, only detected in oral epithelium. In immunocompromised patients, benign HPV-induced lesions are characterized by atypical morphology and the simultaneous detection of multiple HPV types. Oral benign HPV lesions are mostly asymptomatic, and may persist or regress spontaneously.