Anal verrucous carcinoma is not related to infection with human papillomaviruses and should be distinguished from giant condyloma (Buschke-Löwenstein tumour).

AIMS: Verrucous carcinoma (VC) is a variant of well-differentiated squamous cell carcinoma and in the anal region is regarded as synonymous with giant condyloma (Buschke-Löwenstein tumour) (BLT). Aetiology, diagnostic criteria and clinical behaviour of both lesions are controversial. Recent studies suggest that VC at other sites is not associated with human papillomaviruses (HPV). We hypothesized that anal VC is also not related to HPV, while BLT is a HPV-induced lesion. METHODS AND RESULTS: Ten cases of VC and four cases of BLT were included. Several techniques were used for HPV detection: in-situ hybridization for HPV6, 11, 16 and 18, six different polymerase chain reaction (PCR) protocols for detection of at least 89 HPV types from alpha-, beta-, gamma- and mu-PV genera and in-situ hybridization for high-risk HPV E6/E7 mRNA; p16 immunohistochemistry and morphometric analysis were also performed. Alpha-, gamma- and mu-PVs were not found in any case of VC, while HPV6 was detected in all cases of BLT. p16 overexpression was not present in any of the lesions. Among microscopic features, only the absence of koilocytosis and enlarged spinous cells seem to be useful to distinguish VC from BLT. CONCLUSIONS: Our results suggest that anal VC, similarly to VC at other sites, is not associated with HPV infection, and must be distinguished from BLT, which is associated with low-risk HPV. Only with well-set diagnostic criteria will it be possible to ascertain clinical behaviour and optimal treatment for both lesions.

Verrucous carcinoma of the head and neck - not a human papillomavirus-related tumour?

Association between verrucous carcinoma (VC) of the head and neck and human papillomaviruses (HPV) is highly controversial. Previous prevalence studies focused mostly on α-PV, while little is known about other PV genera. Our aim was to investigate the prevalence of a broad spectrum of HPV in VC of the head and neck using sensitive and specific molecular assays. Formalin-fixed, paraffin-embedded samples of 30 VC and 30 location-matched normal tissue samples were analysed, by using six different polymerase chain reaction-based methods targeting DNA of at least 87 HPV types from α-PV, ß-PV, γ-PV and µ-PV genera, and immunohistochemistry against p16 protein. α-PV, γ-PV and µ-PV were not detected. ß-PV DNA was detected in 5/30 VC (16.7%) and in 18/30 normal tissue samples (60.0%): HPV-19, -24 and -36 were identified in VC, and HPV-5, -9, -12, -23, -24, -38, -47, -49 and -96 in normal tissue, whereas HPV type was not determined in 2/5 cases of VC and in 6/18 normal tissue samples. p16 expression was detected in a subset of samples and was higher in VC than in normal tissue. However, the reaction was predominantly cytoplasmic and only occasionally nuclear, and the extent of staining did not exceed 75%. Our results indicate that α-PV, γ-PV and µ-PV are not associated with aetiopathogenesis of VC of the head and neck. ß-PV DNA in a subset of VC and normal tissue might reflect incidental colonization, but its potential biological significance needs further investigation.

Differential expression of microRNAs miR-21, miR-31, miR-203, miR-125a-5p and miR-125b and proteins PTEN and p63 in verrucous carcinoma of the head and neck.

AIMS: To investigate the expression of microRNAs miR-21, miR-31, miR-203, miR-125a-5p and miR-125b and proteins phosphatase and tensin homologue (PTEN) and p63 in verrucous carcinoma (VC) of the head and neck. METHODS AND RESULTS: Thirty cases of VC, 50 cases of conventional squamous cell carcinoma (SCC) and 30 samples of normal epithelium of the head and neck were included. Real-time polymerase chain reaction and immunohistochemistry were used to analyse the expression of microRNAs and proteins, respectively. In comparison to normal epithelium, miR-21 was overexpressed in both VC and SCC and miR-31 was overexpressed in VC and in well- and moderately differentiated SCC. Levels of miR-203 were elevated in VC but unaltered or reduced in SCC, and levels of miR-125a-5p and miR-125b were reduced in VC but unaltered in SCC. PTEN was down-regulated in both VC and SCC, whereas p63 was down-regulated in VC but up-regulated in SCC. Differential expression of p63 in VC correlated inversely with the expression of miR-21 and miR-203. CONCLUSIONS: Differences between VC, SCC and normal epithelium in expression profiles of investigated molecules indicate their association with the pathogenesis and clinicopathological characteristics of VC. Our results suggest that some microRNAs and proteins, particularly miR-125b, miR-203 and p63, might be useful in the diagnosis of VC.

Comparative evaluation of the Abbott RealTime High Risk HPV test and INNO-LiPA HPV Genotyping Extra test for detecting and identifying human papillomaviruses in archival tissue specimens of head and neck cancers.

INTRODUCTION: The Abbott RealTime is a novel real-time PCR assay designed for concurrent individual genotyping of HPV16 and HPV18 and pooled detection of 12 HPV genotypes: HPV31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68 in cervical swab specimens. In this study, the performance of RealTime for detecting HPV in formalin-fixed, paraffin-embedded tissue specimens of head and neck cancers was compared to the Innogenetics INNO-LiPA assay, which allows identification of 28 HPVs, including all 14 covered by RealTime. METHODS: A total of 60 FFPE tissue specimens obtained from the same number of patients with histologically confirmed cancer of the oral cavity or oropharynx were included in the study. Following DNA extraction using a Qiagen DNA Mini Kit, RealTime and INNO-LiPA were performed on all samples, as instructed by the manufacturers. RESULTS: A 136-bp fragment of human beta-globin serving as an internal control in RealTime was successfully amplified from all 60 tissue samples included in the study. RealTime and INNO-LiPA showed 100% agreement and detected HPV DNA in 5/60 (8.3%) of the cancer samples, which all contained genotype HPV16. CONCLUSIONS: RealTime assay is a reliable, sensitive, and specific diagnostic tool for the detection and partial genotyping of targeted HPV genotypes in FFPE tissue specimens of oral and oropharyngeal cancer.

Cyclooxygenase in normal human tissues--is COX-1 really a constitutive isoform, and COX-2 an inducible isoform?

Cyclooxygenase (COX) is a key enzyme in prostanoid synthesis. It exists in two isoforms, COX-1 and COX-2. COX-1 is referred to as a 'constitutive isoform', and is considered to be expressed in most tissues under basal conditions. In contrast, COX-2 is referred to as an 'inducible isoform', which is believed to be undetectable in most normal tissues, but can be up-regulated during various conditions, many of them pathological. Even though the role of COX in homeostasis and disease in now well appreciated, controversial information is available concerning the distribution of COX isoforms in normal human tissues. There is mounting evidence that it is much more complex than generally believed. Our aim was therefore to analyse the expression and distribution of COX isoforms in normal human tissues, using immunohistochemistry, Western blotting and real-time RT-PCR. Autopsy samples from 20 healthy trauma victims and samples from 48 biopsy surgical specimens were included. COX-1 was found in blood vessels, interstitial cells, smooth muscle cells, platelets and mesothelial cells. In contrast, COX-2 was found predominantly in the parenchymal cells of many tissues, with few exceptions, for example the heart. Our results confirm the hypothesis that the distribution of COX isoforms in healthy tissues is much more complex than generally believed. This and previous studies indicate that both isoforms, not only COX-1, are present in many normal human tissues, and that both isoforms, not only COX-2, are up-regulated in various pathological conditions. We may have to revise the concept of 'constitutive' and 'inducible' COX isoforms.