Laser capture microdissection shows HPV11 as both a causal and a coincidental infection in cervical cancer specimens with multiple HPV types

Abstract

Aims: To identify, by laser capture microdissection (LCM), the cellular localization of HPV11 when present with carcinogenic HPV in invasive cervical cancer (ICC) specimens, and to relate this to p16(INK) (4a) expression.

Methods and results: Three squamous cell ICC specimens showing coinfection with HPV11 and carcinogenic HPV16 or HPV31 were selected from the Institut Català d'Oncologia international survey of anogenital carcinomas, and coinfection was confirmed by SPF10 -DEIA-LiPA25 analysis. In two cases LCM-PCR identified HPV11 in low-grade and high-grade squamous intraepithelial lesions (SILs) adjacent to the ICC, and HPV16 or HPV31 in the ICC. In one case, HPV11 was the only genotype found in the ICC. P16(INK) (4a) expression was diffuse in ICC associated with carcinogenic HPV, but focal in ICC with HPV11.

Conclusions: Our results confirm that a single cervical, cancerous or precancerous lesion is associated with a single HPV type. Detecting low-risk HPV as a coinfection in whole tissue from ICC does not prove a causal association. HPV11 may be found only in an adjacent SIL with carcinogenic HPV in the ICC. It is also found alone in carcinoma. LCM-PCR and differential P16(INK) (4a) expression can clarify the causal role of each type when multiple HPVs are present in whole tissue from carcinomas.

Keywords: HPV11; low-risk HPV; multiple HPV infections.