p16 INK4A overexpression is frequently detected in tumour-free tonsil tissue without association with HPV.

AIMS: Oncogenic human papillomavirus (HPV) type 16 has been strongly associated with tonsillar squamous cell carcinoma (TSCC) and appears to be of prognostic significance. Because HPV+ TSCC also accumulates p16(INK4A), this cyclin-dependent kinase inhibitor has been proposed as a potential biomarker for HPV in clinical diagnosis. The aim of this study was to determine the prevalence of HPV in tumour-free tonsillar tissue and the value of p16(INK4A) overexpression in predicting its presence. METHODS AND RESULTS: p16(INK4A) overexpression was detected by immunohistochemistry in tissue sections of tumour-free tonsils of 262 patients. They were treated for non-oncological reasons (snoring or chronic/recurrent tonsillitis) consisting of tonsillectomy. Genomic DNA isolated from these tissues was subjected to HPV-specific polymerase chain reaction (PCR) analysis. p16(INK4A) immunoreactivity was detected in 28% of samples in both crypt epithelium (49/177) and lymphoid germinal centres (52/187), which correlated with each other (P < 0.0001). No reactivity was observed in superficial squamous cell epithelium. HPV16 and 18 were detected by PCR analysis in 2/195 cases (1%), which, however, were negative on fluorescence in situ hybridization analysis and discrepant on p16(INK4A) immunostaining. CONCLUSIONS: No proof was found for the presence of HPV in tumour-free tonsil tissue, despite increased p16(INK4A) expression in a quarter of tonsil cases. Other mechanisms than HPV infection are therefore implicated in p16(INK4A) up-regulation.

Genetic signatures of HPV-related and unrelated oropharyngeal carcinoma and their prognostic implications.

PURPOSE: Patients with human papillomavirus (HPV)-containing oropharyngeal squamous cell carcinomas (OSCC) have a better prognosis than patients with HPV-negative OSCC. This may be attributed to different genetic pathways promoting cancer. EXPERIMENTAL DESIGN: We used comparative genomic hybridization to identify critical genetic changes in 60 selected OSCC, 28 of which were associated with HPV-16 as determined by HPV-specific PCR and fluorescence in situ hybridization analysis and positive p16(INK4A) immunostaining. The results were correlated with HPV status and clinical data from patients. RESULTS: Two thirds of OSCC harbored gain at 3q26.3-qter irrespective of HPV status. In HPV-negative tumors this alteration was associated with advanced tumor stage (P=0.013). In comparison with HPV-related OSCC, the HPV-negative tumors harbored: (a) a higher number of chromosomal alterations and amplifications (P=0.03 and 0.039, respectively); (b) significantly more losses at 3p, 5q, 9p, 15q, and 18q, and gains/amplifications at 11q13 (P=0.002, 0.03; <0.001, 0.02, 0.004, and 0.001, respectively); and (c) less often 16q losses and Xp gains (P=0.02 and 0.03). Survival analysis revealed a significantly better disease-free survival for HPV-related OSCC (P=0.02), whereas chromosome amplification was an unfavorable prognostic indicator for disease-free and overall survival (P=0.01 and 0.05, respectively). Interestingly, 16q loss, predominantly identified in HPV-related OSCC, was a strong indicator of favorable outcome (overall survival, P=0.008; disease-free survival, P=0.01) and none of these patients had a tumor recurrence. CONCLUSIONS: Genetic signatures of HPV-related and HPV-unrelated OSCC are different and most likely underlie differences in tumor development and progression. In addition, distinct chromosomal alterations have prognostic significance.

Penile intraepithelial neoplasia is frequent in HIV-positive men with anal dysplasia.

Anogenital human papillomavirus (HPV)-infection is common in HIV-infected men who have sex with men (HIV+MSM). These patients have a strongly increased risk of HPV-induced anal cancer and its precursor lesion, anal intraepithelial neoplasia (AIN), and a moderately increased risk for penile cancer. Only limited data exist on penile intraepithelial neoplasia (PIN) in HIV+MSM. We determined the prevalence and evaluated the virologic characteristics of PIN and AIN in 263 HIV+MSM. In case of histologically confirmed PIN (and AIN), HPV-typing, HPV-DNA load determination, and immunohistochemical staining for p16(INK4a) were performed. PIN was detected in 11 (4.2%) and AIN in 156 (59.3%) patients. Ten PIN patients also had AIN within the observation period. Four clinical types of PINs could be distinguished. High-risk-alpha-HPV-DNA was found in 10 PIN lesions, with HPV16 being the most frequent type. Infections with multiple HPV-types were common. All high-grade lesions had high-risk-HPV-DNA-loads > or = 1 HPV-copy/beta-globin-gene-copy. Cutaneous beta-HPVs were found in PIN and AIN, but beta-HPV-DNA loads were very low, irrespective of the histological grade. p16(INK4a) Expression was detectable in all PIN lesions and correlated both with the histological grade and with high-risk HPV-DNA loads. In view of the PIN prevalence found in our study, all HIV+MSM should be screened for PIN in addition to AIN screening.

Combined analysis of HPV-DNA, p16 and EGFR expression to predict prognosis in oropharyngeal cancer.

Molecular prognostic indicators for oropharyngeal squamous cell carcinoma (OSCC), including HPV-DNA detection, epidermal growth factor receptor (EGFR) and p16 expression, have been suggested in the literature, but none of these are currently used in clinical practice. To compare these predictors, 106 newly diagnosed OSCC for the presence of HPV-DNA and expression of p16 and EGFR were analyzed. The 5-year disease-free survival (DFS) and overall survival (OS) were calculated in relation to these markers and a multivariate Cox analysis was performed. Twenty-eight percent of the cases contained oncogenic HPV-DNA and 30% were positive for p16. The p16 expression was highly correlated with the presence of HPV-DNA (p < 0.001). Univariate analysis of the 5-year DFS revealed a significantly better outcome for patients with p16-positive tumors (84% vs. 49%, p = 0.009). EGFR-negative tumors showed a tendency toward a better prognosis in DFS (74% vs. 47%, p = 0.084) and OS (70% vs. 45%, p = 0.100). Remarkable and highly significant was the combination of p16 and EGFR expression status, leading to 5-year DFS of 93% for p16+/EGFR- tumors vs. 39% for p16-/EGFR+ tumors (p = 0.003) and to a 5-year OS of 79% vs. 38%, respectively (p = 0.010). In multivariate analysis p16 remained a highly significant prognostic marker for DFS (p = 0.030) showing a 7.5-fold increased risk for relapse in patients with p16-negative tumors. Our data indicate that p16 expression is the most reliable prognostic marker for OSCC and further might be a surrogate marker for HPV-positive OSCC. HPV+/p16+ tumors tended to have decreased EGFR expression, but using both immunohistological markers has significant prognostic implications.

Imiquimod treatment of anal intraepithelial neoplasia in HIV-positive men.

OBJECTIVE: To evaluate the treatment of anal intraepithelial neoplasia (AIN) with the local immune response modifier imiquimod in human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). DESIGN: Prospective, nonrandomized, open-label pilot study, with a mean follow-up time of 9(1/2) months. SETTING: Dermatology department of a university hospital. Patients Twenty-eight consecutive HIV-positive MSM with histologically confirmed perianal (n = 23) or intra-anal (n = 5) AIN. Intervention Overnight treatment with self-applied imiquimod cream (perianal AIN) or suppositories (intra-anal AIN) 3 times a week for 16 weeks. MAIN OUTCOME MEASURES: Response to treatment was documented using clinical, cytologic, and histologic criteria. Human papillomavirus (HPV) typing and HPV DNA load determination for the high-risk HPV types 16, 18, 31, and 33 were performed. RESULTS: Seventeen (61%) of all 28 patients included in the study and 17 (77%) of the 22 patients with AIN, who applied imiquimod as instructed, showed clinical and histologic clearance at the end of therapy. Four patients had residual AIN and 1 patient did not improve. Clinical response was accompanied by a sharp decline in HPV DNA loads and by a reduction in the number of HPV types, but long-term HPV clearance was rarely achieved. In the follow-up period, AIN cleared in 3 patients with residual AIN. Fourteen (78%) of 18 imiquimod responders with at least 5 five months of follow-up had a normal cytologic and clinical picture at the end of the follow-up period. Three primary responders developed a recurrence. In 6 noncompliant patients, there was no clinical or morphological improvement and the HPV DNA loads remained high. CONCLUSIONS: Imiquimod appears to be a safe and effective treatment option for AIN in HIV-positive MSM. Clinical response is accompanied by a significant decrease in high-risk HPV DNA load. These results should encourage controlled randomized studies of imiquimod treatment of AIN.

Clinical spectrum and virologic characteristics of anal intraepithelial neoplasia in HIV infection.

BACKGROUND: Anal intraepithelial neoplasia (AIN) represents a precursor lesion of invasive squamous cell carcinoma with a clear association to high-risk human papillomavirus (HPV) types. HIV infection is strongly associated with a higher prevalence of genital HPV infection, a higher incidence of AIN, and, consecutively, an increased risk for anal cancer. OBJECTIVE: The aim of this study was to determine the clinical spectrum of AIN and lesional HPV colonization in a cohort of homosexual men who were HIV positive and had a history of receptive anal intercourse. METHODS: In all, 103 men who were HIV-1 positive were screened by using clinical, proctologic, cytologic, histologic, and HPV DNA testing. RESULTS: Of all patients, 86% had anal HPV infection at their first visit. HPV-16 (53%), HPV-18 (27%), HPV-58 (22%), and HPV-83 (22%) were the most frequently found HPV types. AIN was diagnosed in 20 of the 103 patients (19.4%). High-risk HPV types were present in all AIN cases with up to 7 different high-risk and up to 5 different low-risk types per lesion. Histologically, 7 (35%), 7 (35%), and 6 (30%) of the patients had AIN grade I, II, or III, respectively. Four different types of clinical presentation could be distinguished in the 20 patients with AIN: bowenoid (1 case, 5%); erythroplakic (2 cases, 10%); verrucous (6 cases, 30%); and leukoplakic (11 cases, 55%). All verrucous lesions were graded as high-grade intraepithelial lesions in cytology, whereas 6 of the 11 leukoplakic lesions (55%) were low grade. All verrucous AIN carried at least 4 different HPV types, always including HPV-16, and the mean number of HPV types was higher in verrucous lesions than in leukoplakic lesions (5.5 vs 3.8, respectively). CONCLUSION: These data confirm the high incidence and prevalence of AIN in patients who are HPV positive with HIV infection. Four different clinical types of AIN can be distinguished that might have prognostic implications. Standardized screening programs for anal cancer prevention and treatment protocols for AIN in patients infected with HIV must be implemented.

Expression of p16 protein is associated with human papillomavirus status in tonsillar carcinomas and has implications on survival.

Our recent analysis of papillomavirus (HPV) DNA in different malignant head and neck tumors revealed that HPV infections occurred most frequently in tonsillar carcinomas (58%) and that 84% of positive cases contained the highly oncogenic HPV type 16. We could also present data in favor of the hypothesis that in view of their clinical behavior and the involved risk factors HPV-positive and HPV-negative tonsillar carcinomas may represent two separate tumor entities. Looking for a surrogate marker, which in further epidemiological studies could replace the laborious and expensive HPV detection/typing we analyzed p16 protein expression in 34 tonsillar carcinomas for their correlation with HPV status. p16 is an inhibitor of cyclin-dependent kinases 4 and 6 which activate the negative cell cycle regulator protein pRB which in turn downregulates p16 expression. It could be shown that in neoplastic cells of the cervix uteri E7 protein of the high-risk HPVs can interfere with this regulatory circuit by its virtue to inactivate pRB and thus lead to the overexpession of p16. We found 53% of the tested tonsillar carcinomas to be HPV positive. 56% of all tumors tested were immunohistochemically positive for the p16 protein. In 16 of 18 of the HPV-positive carcinomas diffuse p16 expression was observed. In contrast, only 1 of the HPV-negative carcinomas showed focal p16 staining (p < 0.001). Clinical outcome analysis revealed a significant correlation of p16 expression with increased disease-free survival (p = 0.02). These data indicate that p16 is a technically simple immunohistological marker, applicable for routine pathological histology, and its prognostic value for survival is fully equivalent to HPV DNA detection.

Human papillomavirus-positive tonsillar carcinomas: a different tumor entity?

Human papillomavirus (HPV) infections are thought to be one of the causal factors in the development of head and neck squamous cell carcinomas (HNSCC), particularly in tumors arising from the Waldeyer's tonsillar ring. We screened 98 carefully stratified HNSCC and different control tissues for the presence of HPV DNA by nested polymerase chain reaction (PCR) specific for genital- and Epidermodysplasia verruciformis (EV)-associated HPVs and by HPV16-specific single step PCR. Typing was performed by direct sequencing and/or sequencing of cloned amplimers. On average HNSCC showed rather low HPV DNA prevalences; 18% of the oral cavity cancers, 8% of nasopharyngeal cancers, 25% of hypopharyngeal cancers and 7% of laryngeal cancers were HPV DNA positive. In contrast, HPV sequences could be detected in 45% of the oropharyngeal cancers, particularly tonsillar carcinomas (58%). Tonsillar carcinomas were significantly more likely to be HPV positive than tumors from any other site ( P<0.001). All tonsillar cancers contained oncogenic HPV types, predominantly HPV16 (13 of 14; 93%). Unaffected tonsils were available from two of these patients, but both tested negative for HPV DNA. Furthermore, no HPV DNA could be found in tonsillar biopsy specimens from control groups. Localization and load of HPV DNA was determined in HPV16-positive tonsillar carcinomas, their metastases and in unaffected mucosa using laser-assisted microdissection and subsequent real time fluorescence PCR. We demonstrated that the HPV genome is located in the cancer cells, whereas the infection of normal mucosa is a rare event. Quantification of HPV16 DNA in samples of seven patients yielded viral loads from 6 to 153 HPV DNA copies per beta-globin gene copy and the load values in both locations were roughly comparable. These loads are comparable with data shown for other HPV-associated lesions. Statistical evaluation of data related to clinicopathological parameters showed a significant correlation of the HPV positivity of tonsillar carcinomas with tumor grading ( P=0.008) and alcohol consumption ( P=0.029). Taken together our findings show a preferential association of HPV DNA with tonsillar carcinomas. Furthermore our results argue for HPV-positive tonsillar carcinomas representing a separate tumor entity, which is less dependent on conventional HNSCC risk factors.

Expression of p16 protein identifies a distinct entity of tonsillar carcinomas associated with human papillomavirus.

Recent analyses of head and neck squamous cell carcinomas revealed frequent infections by oncogenic human papillomavirus (HPV) type 16 in tonsillar carcinomas. Concerning involvement of risk factors, clinical course of the disease, and prognosis there are strong indications arguing that the HPV-positive tonsillar carcinomas may represent a separate tumor entity. Looking for a surrogate marker, which in further epidemiological studies could replace the laborious and expensive HPV detection and typing we analyzed p16 protein expression in 34 tonsillar carcinoma for correlation to HPV status and load of viral DNA. p16 has been shown to be of diagnostic value for clinical evaluation of cervical dysplasia. We found 53% of the tested tonsillar carcinomas to be HPV-positive. Fifty-six percent of all tumors tested were immunohistochemically positive for the p16 protein. In 16 of 18 of the HPV-positive carcinomas diffuse p16 expression was observed. In contrast, only one of the HPV-negative carcinomas showed focal p16 staining (P < 0.001). As determined by laser-assisted microdissection and quantitative real-time polymerase chain reaction, p16 expression correlated with the presence of HPV-DNA in the individual tumor specimens. Clinical outcome analysis revealed significant correlation of p16 expression with increased disease-free survival (P = 0.02). These data indicate that p16 is a technically simple immunohistological marker, applicable for routine pathological histology, and its prognostic value for survival is fully equivalent to HPV-DNA detection.