Human Papillomavirus-type distribution in anogenital lesions of prepubertal children.

BACKGROUND: In contrast to adults, only limited data are available on the human papillomavirus (HPV)-type spectrum in anogenital warts (AGW) of children. OBJECTIVE: This study aimed to evaluate the HPV-type spectrum in AGW of prepubertal children. MATERIALS & METHODS: In a retrospective German multicentre study, HPV genotyping was performed in AGW biopsies of 55 1- to 12-year-old children using HPV group-specific PCRs followed by hybridization with type-specific probes or sequence analysis. RESULTS: Human papillomavirus-DNA was found in 53 of the 55 AGW. In 58.5% (31/53) of the HPV-positive AGW, mucosal HPV types were detected. HPV6 (27/53, 50.9%) was the predominant type. 43.4% (23/53) of the lesions were induced by cutaneous HPV types (HPV2, HPV27, HPV57). Mucosal HPV types were significantly more common in children under 5 years of age than in children 5 years of age and older (22/25, 88.0% [95% CI: 70.0-95.8] vs. 9/28, 32.1% [95% CI: 17.9-50.7], P < 0.001). In contrast, cutaneous HPV types were significantly more prevalent in the 5- to 12-year age group (4/25, 16.0% [95% CI 6.4-34.7] vs. 19/28, 67.9% [95% CI 49.3-82.1], P < 0.001). CONCLUSION: Anogenital warts in 5- to 12-year-old children are frequently associated with cutaneous HPV types, possibly due to horizontal transmission. HPV typing, in addition to comprehensive clinical and psychosocial evaluation, can potentially help in the assessment of these cases.

Left-sided laterality of Merkel cell carcinoma in a German population: more than just sun exposure.

BACKGROUND: Lateral distribution of cancer has been observed previously. Most evident is this laterality in ultraviolet (UV)-induced skin cancer, based on an unequally distributed UV exposure. OBJECTIVES: The aim of this study was to explore whether patients from Germany also show asymmetrical lateral distribution of Merkel cell carcinoma (MCC). METHODS: In total, 115 patients with MCC were studied for laterality of the primary tumour. Correlation of clinical variables with lateral distribution of MCC was investigated as well. RESULTS: In 64/115 (55.7%) patients, primary tumours were present on the left side, in 37/115 (32.2%) on the right side, and in 14/115 (12.2%) in the midline (P < 0.0001). Excluding the latter localization occurrence of left-sided MCCs (64 of 101/63.4%) was significantly (P = 0.0072) more often observed (1.73-fold) when compared to right-sided tumours (37 of 101/36.6%). The excess of left-sided tumours was found on the head with a left-right ratio of 1.8, trunk of 8, arm of 1.2, and leg of 1.8. There was no significant association between laterality and gender, age, MCPyV status, and anatomic localization of primary tumours including the occurrence in sun-exposed sites. CONCLUSIONS: Occurrence of left-sided MCCs was significantly more often observed when compared to right-sided tumours. Laterality was not associated with tumour presentation at chronically ultraviolet-exposed sites. Hence, the reason for laterality in MCC remains obscure, but likely goes beyond UV exposure.

Prognostic relevance of high atonal homolog-1 expression in Merkel cell carcinoma.

BACKGROUND: It has recently been reported that atonal homolog 1 (ATOH1) gene is down-regulated in Merkel cell carcinoma (MCC) and thus may represent a tumor suppressor gene. OBJECTIVES: We aimed to test for ATOH1 gene mutations and expression levels in MCC tissues and cell lines. METHODS: Genomic DNA isolation and amplification via PCR was successfully performed in 33 MCCs on formalin-fixed paraffin-embedded tissue and three MCC cell lines, followed by Sanger sequencing of the whole ATOH1 gene to detect genomic aberrations. ATOH1 mRNA levels were determined by RT-PCR. Immunohistochemistry of ATOH1 was performed to quantify protein expression in tumor samples and cell lines. RESULTS: Neither in any of the 33 MCC tissue samples nor in the three cell lines ATOH1 mutations were present. ATOH1 was expressed in all lesions, albeit at different expression levels. Univariate analysis revealed that the total immunohistology score significantly correlated with the occurrence of tumor relapse (r = 0.57; P = 0.0008). This notion was confirmed in multivariate analysis suggesting that ATOH1 expression is a potential independent predictor for tumor relapse in MCC patients (P = 0.028). MCC-related death also correlated with ATOH1 expression (r = 0.4; P = 0.025); however, ATOH1 expression did not retain its predictive value in the regression model. CONCLUSIONS: In contrast to anecdotal reports ATOH1 expression is not lost by genetic alterations in MCC. However, protein expression of ATOH1 is increased in advanced MCC indicating that ATOH1 is involved in MCC progression.

Correlation of Merkel cell polyomavirus positivity with PDGFRα mutations and survivin expression in Merkel cell carcinoma.

BACKGROUND: Merkel cell carcinoma (MCC) is a neuroendocrine cancer of the skin postulated to originate through Merkel cell polyomavirus (MCPyV) oncogenesis and/or by mutations in molecules implicated in the regulation of cell growth and survival. Despite the fact that MCPvV is detected more broadly within the population, only a part of the infected people also develop MCC. It is thus conceivable that together, virus and for example mutations, are necessary for disease development. However, apart from a correlation between MCPyV positivity or mutations and MCC development, less is known about the association of these factors with progressive disease. OBJECTIVES: To analyze MCPyV positivity, load and integration in MCC as well as presence of mutations in PDGFRα and TP53 genes and correlate these with clinical features and disease progression to identify features with prognostic value for clinical progression. METHODS: This is a study on a MCC population group of 64 patients. MCPyV positivity, load and integration in parallel to mutations in the PDGFRα and TP53 were analyzed on genomic DNA from MCC specimens. In addition, expression of PDGFRα, survivin and p53 proteins was analyzed by immunodetection in tissues specimens. All these parameters were analyzed as function of patient's disease progression status. RESULTS: 83% of MCCs were positive for the MCPyV and among these 36% also displayed virus-T integration. Viral load ranged from 0.006 to 943 viral DNA copies/ß-globin gene and was highest in patients with progressive disease. We detected more than one mutation within the PDGFRα gene and identified two new SNPs in 36% of MCC patients, whereas no mutations were found in TP53 gene. Survivin was expressed in 78% of specimens. We could not correlate either mutations in PDGFR or expression of PDGFR, p53 and surviving either to the disease progression or to the MCPyV positivity. CONCLUSIONS: In conclusion, our data indicate that the viral positivity when associated with high viral load, correlates with poor disease outcome. Frequent mutations in the PDGFRα gene and high survivin expression were found in MCC independent of the viral positivity. These data suggest that these three factors independently contribute to Merkel cell carcinoma development and that only the viral load can be used as indicator of disease progression in virus positive patients.

Prevalence of human polyomaviruses in common and rare types of non-Merkel cell carcinoma skin cancer.

BACKGROUND: Little is known about the association of human polyomaviruses (HPyVs) other than Merkel cell polyomavirus (MCPyV) with nonmelanoma skin cancer. OBJECTIVES: To evaluate the presence of HPyV6, HPyV7, trichodysplasia spinulosa-associated polyomavirus (TSV), also called HPyV8, and the recently discovered HPyV9 in basal cell carcinoma (BCC), actinic keratosis (AK), squamous cell carcinoma in situ (SCCis), squamous cell carcinoma (SCC), keratoacanthoma (KA), microcystic adnexal carcinoma (MAC) and atypical fibroxanthoma (AFX). METHODS: Archival paraffin-embedded samples (n = 193: 41 BCC, 31 AK, 8 SCCis, 52 SCC, 42 KA, 5 MAC and 14 AFX) were analysed for the presence of the respective HPyV by polymerase chain reaction (PCR). HPyV DNA loads (HPyV DNA copies per ß-globin gene copy) were determined in all HPyV-positive samples by quantitative real-time PCR. Immunohistochemical analysis of MCPyV large T-antigen (LTA) expression was performed using the monoclonal antibody CM2B4. RESULTS: MCPyV DNA was found in 29% of BCC, 19% of AK, 25% of SCCis, 27% of SCC, 29% of KA, 0% of MAC and 29% of AFX. MCPyV DNA loads never exceeded 0·3 MCPyV DNA copies per ß-globin gene copy (median 0·004). In the immunohistochemical analysis of MCPyV LTA expression, all evaluated samples (32 MCPyV DNA-positive samples) were LTA negative. HPyV6 DNA was found in 7% of BCC, 3% of AK, 12% of SCCis, 4% of SCC, 5% of KA, and 0% of MAC and AFX. HPyV6 DNA loads never exceeded 0·7 HPyV6 DNA copies per ß-globin gene copy (median 0·015). None of the 193 samples was positive for HPyV7, TSV or HPyV9 DNA. CONCLUSIONS: Our findings argue against a pathogenic role for MCPyV, HPyV6, HPyV7, TSV and HPyV9 in the analysed types of non-Merkel cell carcinoma skin cancer.