Sensitivity and specificity of antibodies against HPV16 E6 and other early proteins for the detection of HPV16-driven oropharyngeal squamous cell carcinoma.

To determine the sensitivity and specificity of HPV16 serology as diagnostic marker for HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), 214 HNSCC patients from Germany and Italy with fresh-frozen tumor tissues and sera collected before treatment were included in this study. Hundred and twenty cancer cases were from the oropharynx and 94 were from head and neck cancer regions outside the oropharynx (45 oral cavity, 12 hypopharynx and 35 larynx). Serum antibodies to early (E1, E2, E6 and E7) and late (L1) HPV16 proteins were analyzed by multiplex serology and were compared to tumor HPV RNA status as the gold standard. A tumor was defined as HPV-driven in the presence of HPV16 DNA and HPV16 transformation-specific RNA transcript patterns (E6*I, E1∧ E4 and E1C). Of 120 OPSCC, 66 (55%) were HPV16-driven. HPV16 E6 seropositivity was the best predictor of HPV16-driven OPSCC (diagnostic accuracy 97% [95%CI 92-99%], Cohen's kappa 0.93 [95%CI 0.8-1.0]). Of the 66 HPV-driven OPSCC, 63 were HPV16 E6 seropositive, compared to only one (1.8%) among the 54 non-HPV-driven OPSCC, resulting in a sensitivity of 96% (95%CI 88-98) and a specificity of 98% (95%CI 90-100). Of 94 HNSCC outside the oropharynx, six (6%) were HPV16-driven. In these patients, HPV16 E6 seropositivity had lower sensitivity (50%, 95%CI 19-81), but was highly specific (100%, 95%CI 96-100). In conclusion, HPV16 E6 seropositivity appears to be a highly reliable diagnostic marker for HPV16-driven OPSCC with very high sensitivity and specificity, but might be less sensitive for HPV16-driven HNSCC outside the oropharynx.

Pathogenic role of the eight probably/possibly carcinogenic HPV types 26, 53, 66, 67, 68, 70, 73 and 82 in cervical cancer.

Eight HPV types (HPV26, 53, 66, 67, 68, 70, 73 and 82) that are phylogenetically closely related to 12 WHO-defined high-risk (HR) HPV have been rarely but consistently identified as single HPV infections in about 3% of cervical cancer (CxCa) tissues. Due to lack of biological data, these types are referred to as probable/possible (p) HR-HPV. To analyse their biological activity in direct comparison to HR-HPV types, we selected 55 formalin-fixed, paraffin-embedded (FFPE) CxCa tissues harbouring single pHR-HPV infections (2-13 cases per type) and 266 tissues harbouring single HR-HPV (7-40 cases per type) from a worldwide, retrospective, cross-sectional study. Single HPV infection was verified by two genotyping methods. Presence of type-specific spliced E6*I mRNA transcripts and expression of cellular proteins indicative of HPV transformation were assessed in all cases. In 55 CxCa tissues with pHR-HPV, E6*I mRNA expression was 100%; high p16(INK4a) , 98%; low pRb, 96%; low CyD1, 93%; and low p53, 84%. Compared to HPV16 tissues as a reference, individual frequencies of these five markers did not differ significantly, either for any of the eight pHR-HPV and the 11 other HR types individually or for the groups of pHR and HR types without HPV16. We conclude that the eight pHR-HPV types, when present as a single infection in CxCa, are biologically active and affect the same cellular pathways as any of the fully recognized carcinogenic HR-HPV types. Therefore we have provided molecular evidence of carcinogenicity for types currently classified as probably/possibly carcinogenic. Although this evidence is crucial for HPV-type carcinogenicity classification, per se it is not sufficient for inclusion of these HPV types into population-wide primary and secondary prevention programmes. Such decisions have to include careful estimation of effectiveness and cost-benefit analyses.

HPV-related methylation signature predicts survival in oropharyngeal squamous cell carcinomas.

High-risk types of human papilloma virus (HPV) are increasingly associated with oropharyngeal squamous cell carcinoma (OPSCC). Strikingly, patients with HPV-positive OPSCC are highly curable with ionizing radiation and have better survival compared with HPV-negative patients, but the underlying molecular mechanisms remain poorly understood. We applied an array-based approach to monitor global changes in CpG island hypermethylation between HPV-negative and HPV-positive OPSCCs and identified a specific pattern of differentially methylated regions that critically depends on the presence of viral transcripts. HPV-related alterations were confirmed for the majority of candidate gene promoters by mass spectrometric, quantitative methylation analysis. There was a significant inverse correlation between promoter hypermethylation of ALDH1A2, OSR2, GATA4, GRIA4, and IRX4 and transcript levels. Interestingly, Kaplan-Meier analysis revealed that a combined promoter methylation pattern of low methylation levels in ALDH1A2 and OSR2 promoters and high methylation levels in GATA4, GRIA4, and IRX4 promoters was significantly correlated with improved survival in 3 independent patient cohorts. ALDH1A2 protein levels, determined by immunohistochemistry on tissue microarrays, confirmed the association with clinical outcome. In summary, our study highlights specific alterations in global gene promoter methylation in HPV-driven OPSCCs and identifies a signature that predicts the clinical outcome in OPSCCs.

Identification of oropharyngeal squamous cell carcinomas with active HPV16 involvement by immunohistochemical analysis of the retinoblastoma protein pathway.

Viral oncogene RNA expression is regarded as reliable biomarker to identify oropharyngeal squamous cell carcinomas (OPSCC) with active HPV16 involvement. This study addressed whether the expression profile of the cellular proteins p16(INK4a), pRb, Cyclin D1 and p53 provide surrogate marker combinations that identify OPSCC with active HPV16 in situations where only formalin-fixed biopsies are available. Protein expression was analyzed by immunohistochemistry on tissue microarrays created from 188 OPSCC of which the HPV16 DNA and RNA status had been established previously from snap-frozen biopsies. Associations of single markers and of marker combinations with HPV16 DNA, viral RNA expression patterns and overall survival as primary end point were evaluated by statistical analysis. Most tumors with active HPV16 involvement (RNA(+) group; n = 40) showed a specific protein pattern, that is, high p16(INK4a) (80%), low pRb (85%), low Cyclin D1 (95%) and normal p53 (73%). This pattern was significantly different from the pattern observed in HPV DNA-negative tumors (HPV(-) group) and in HPV16 DNA-positive tumors lacking viral RNA expression patterns (RNA(-) group). The combination of high p16(INK4a) and low pRb levels was distinctly superior to p16(INK4a) alone; it was strongly associated with RNA(+) tumors (OR 41.4, 95%CI 10.7-162.5), with improved survival (HR 0.37, 95%CI 0.2-0.8) and had best predictive values (78% sensitivity, 93% specificity, 78% PPV, 93% NPV). In conclusion, if only formalin-fixed biopsy material is available, the marker combination high p16(INK4a) /low pRb is well suited to identify OPSCC with biologically active HPV16 which represent a distinct OPSCC entity with improved prognosis.

Biological activity of probable/possible high-risk human papillomavirus types in cervical cancer.

Judging the carcinogenicity of human papillomavirus (HPV) types rarely found in cervical cancer (CxCa) is hindered by lack of studies of their biological activity in cancer tissues. To asses transcriptional activity of HPV types, we have developed ultra-short amplimer, splice-site specific, E6*I mRNA RT-PCR assays for 12 high-risk (HR)-HPV (IARC Group 1) and eight probable/possible high-risk (pHR)-HPV types (IARC Group 2A/B carcinogens). Previously unreported E6*I splice sites of the six pHR-HPV types 26, 53, 67, 70, 73 and 82 were identified by cloning and sequencing. We analyzed 97 formalin-fixed paraffin-embedded (FFPE) Mongolian CxCa biopsies for presence of HPV DNA by two sensitive genotyping assays, for E6*I transcripts of all HR-/pHR-HPV types identified and for expression of HPV surrogate markers p16(INK4a), pRb and p53. E6*I of at least one HR-/pHR-HPV was expressed in 94 (98%) of cancer tissues including seven with pHR-HPV types 26, 66, 70 or 82 as single transcribed types. Fifty-eight of E6*I mRNA transcribing cases were analyzable by immunohistochemistry and displayed p16(INK4a) overexpression in 57 (98%), pRb downregulation in 56 (97%) and p53 downregulation in 36 (62%) tissues. The newly developed E6*I mRNA RT-PCR assays appeared to be highly sensitive method to analyze HPV transcription in FFPE materials. Our finding of viral oncogene transcription of pHR-HPV types 26, 66, 70 and 82 in cervical tumors, in the absence of any other transcriptionally active HR-type and with p16(INK4a) overexpression and pRb downregulation, may support a reassessment of the carcinogenicity classification of these pHR-HPV types.

Viral RNA patterns and high viral load reliably define oropharynx carcinomas with active HPV16 involvement.

Oropharyngeal squamous cell carcinomas (OPSCC) that are associated with human papilloma virus (HPV) infection carry a more favorable prognosis than those that are HPV-negative. However, it remains unclear which biomarker(s) can reliably determine which OPSCC specimens are truly driven by HPV infection. In this study, we analyzed 199 fresh-frozen OPSCC specimens for HPV DNA, viral load, RNA expression patterns typical for cervical carcinomas (CxCaRNA(+)), and the HPV-targeted tumor suppressor protein p16(INK4a) as markers for HPV infection. In this set of specimens, there was a 49% prevalence of DNA for the cancer-associated HPV type 16 (HPV(+)). However, there was only a 16% prevalence of high viral load and only a 20% prevalence of CxCaRNA(+), a marker of HPV16 carcinogenic activity. Among the CxCaRNA(+) tumors, 78% of the specimens exhibited overexpression of p16(INK4a), which also occurred in 14% of the HPV-negative tumors. Using a multivariate survival analysis with HPV negativity as the reference group, CxCaRNA(+) as a single marker conferred the lowest risk of death [HR = 0.28, 95% confidence interval (CI), 0.13-0.61] from oropharyngeal cancer, closely followed by high viral load (HR = 0.32, 95% CI, 0.14-0.73). In contrast, a weaker inverse association was found for OPSCC that were HPV(+) and p16(INK4a) high (HR = 0.55, 95% CI, 0.29-1.08). In summary, our findings argued that viral load or RNA pattern analysis is better suited than p16(INK4a) expression to identify HPV16-driven tumors in OPSCC patient populations.

Aberrant expression of p53, p16INK4a and Ki-67 as basic biomarker for malignant progression of oral leukoplakias.

BACKGROUND: The risk of malignant progression of oral leukoplakia with and without dysplasia is unpredictable. MATERIALS AND METHODS: Leukoplakias without dysplasia of 35 patients, leukoplakias with dysplasia of 4 patients, and similar lesions obtained from tumor patients were retrospectively examined by immunohistochemistry for the expression of the proteins pRb, p53, p16(INK4a), Cyclin D1 and Ki-67. The predictive power of combined aberrant expression patterns for the progression of leukoplakias without dysplasia was examined. RESULTS: Increased expression of p53, Ki-67 and Cyclin D1, and loss of p16(INK4a) occurred in 45.9%, 38.9%, 29.4% and 32.4% of the leukoplakias without dysplasia, respectively. All alterations increased with progression but had poor positive predictive value. However, the combined p53/p16(INK4a)/Ki-67 aberration occurred in only three (9%) cases, of which two patients (66.7%) experienced progression to dysplasia and carcinoma in situ. The combined p53/p16(INK4a)/Ki-67 alteration had a negative predictive value (NPV) and sensitivity of 100%, specificity of 97% and positive predictive value (PPV) of 67%. By contrast, the combined p53/p16(INK4a)/Cyclin D1 alteration had 97% NPV and sensitivity of 50%, specificity of 90% and only 25% PPV. Loss of pRb and concomitant overexpression of p16(INK4a) were not observed arguing against an involvement of HPV in oral leukoplakia. CONCLUSIONS: We propose the combined p53/p16(INK4a)/Ki-67 alteration as a basic marker to define high risk leukoplakia patients. Lesions not showing this alteration appear to be harmless. Future studies should validate these findings and search for proteins which can further improve the PPV of the proposed basic marker.

Reference spectra from squamous epithelium and connective tissue allow whole section proteomics analysis.

We reasoned that micro-dissection of tumour cells for protein expression studies should be omitted since tumour-stroma interactions are an important part of the biology of solid tumours. To study such interactions in head and neck squamous cell carcinoma (HNSCC) development, we generated reference protein spectra for normal squamous epithelium and connective tissue by SELDI-TOF-MS. Calgranulins A and B, Annexin1 and Histone H4 were found to be strongly enriched in the epithelium. The alpha-defensins 1-3 and the haemoglobin subunits were identified in the connective tissue. Tumour-distant epithelia, representing early pre-malignant lesions, showed up-regulated expression of the stromal alpha-defensins, whereas the epithelial Annexin 1 was down-regulated. Thus, tumour microenvironment interactions occur very early in the carcinogenic process. These data demonstrate that omitting micro-dissection is actually beneficial for studying changes in protein expression during development and progression of solid tumours.

Robust gridding of TMAs after whole-slide imaging using template matching.

Tissue microarrays (TMAs) represent an important approach for the high-throughput cellular analysis of large numbers of tissue samples on one single slide in research related to diagnostics and oncology. Whole-slide imaging now enables full scanning and subsequent image analysis of such TMAs. In contrast to automatically spotted RNA microarrays, TMAs are fabricated manually and mechanically by arranging hundreds of tissue cores in a single paraffin block. This procedure frequently results in quality problems severely hampering the later automatic image analysis of TMAs after whole-slide imaging. We therefore set out to (a) determine the extent of these quality issues in exemplary TMAs and (b) to develop a robust gridding method to identify the logical position coordinates of each TMA core on a virtual TMA slide. We present the first robust method identifying these coordinates by shifting a template grid over all cores of the TMA (template matching) and thereby measuring in how far the grid matches a predefined list of cores on the virtual TMA Slide. Analysis of 20 TMAs from Breast Cancer as well as 40 Head-and-Neck Cancer showed that frequent TMA layout issues comprise low staining, debris, core displacement, nonuniform background, missing cores, and rotated subarrays. On this highly demanding test comprising chromogen as well as fluorescence stained TMAs, our template matching method achieved an excellent position analysis. Of 8900 cores, 8864 (99.59%) were assigned properly. In all 60 slides of the test set, no localization error occurred. The automatic grid analysis of TMAs after whole-slide imaging is highly demanding and requires dedicated algorithms. We demonstrate such a method and evaluate its performance. © 2010 International Society for Advancement of Cytometry.

Proteomic analysis of field cancerization in pharynx and oesophagus: a prospective pilot study.

'Field cancerization' in head and neck squamous cell carcinoma (HNSCC) is poorly understood and it may extend from the pharynx into the oesophagus. Both local recurrences and second primary carcinomas/second field tumours may originate from field cancerization. Our prospective pilot study aimed at the identification of patients suffering from field cancerization on the basis of mucosal protein profiles. Five mucosal biopsies from the oropharynx, hypopharynx and from three regions of the oesophagus were taken from 24 patients. Protein profiles were generated from the mucosal biopsies. After classifier learning, using the profiles of the patients without tumour diagnosis (n = 9), we were able to discriminate between the different mucosal sites and between healthy mucosa and HNSCC using tumour and healthy tissue samples. Mucosal biopsies of tumour patients (n = 15) revealed changes in the protein profiles similar to those in the tumours. During 42 months median follow-up, six tumour patients experienced local recurrences and second field tumours, of which three occurred in the oesophagus. In all six cases, tumour relapse was correctly predicted by altered mucosal protein profiles (p = 0.007, Fisher's exact test, two-tailed). Consequently, molecular field cancerization had a strong impact on progression-free survival (p = 0.007, log-rank test). Protein profiles of small diagnostic biopsies hold great promise to improve personalized risk assessment in HNSCC. Larger studies are needed to further substantiate these findings.

Epigenetic silencing of interferon-kappa in human papillomavirus type 16-positive cells.

We have investigated interferon-kappa (IFN-kappa) regulation in the context of human papillomavirus (HPV)-induced carcinogenesis using primary human foreskin keratinocytes (HFK), immortalized HFKs encoding individual oncoproteins of HPV16 (E6, E7, and E6/E7), and cervical carcinoma cells. Here, IFN-kappa was suppressed in the presence of E6, whereas its expression was not affected in HFKs or E7-immortalized HFKs. Transcription could be reactivated after DNA demethylation but was decreased again upon drug removal. Partial reactivation could also be accomplished when E6 was knocked down, suggesting a contribution of E6 in IFN-kappa de novo methylation. We identified a single CpG island near the transcriptional start site as being involved in selective IFN-kappa expression. To prove the functional relevance of IFN-kappa in building up an antiviral response, IFN-kappa was ectopically expressed in cervical carcinoma cells where protection against vesicular stomatitis virus-mediated cytolysis could be achieved. Reconstitution of IFN-kappa was accompanied by an increase of p53, MxA, and IFN-regulatory factors, which was reversed by knocking down either IFN-kappa or p53 by small interfering RNA. This suggests the existence of a positive feedback loop between IFN-kappa, p53, and components of IFN signaling pathway to maintain an antiviral state. Our in vitro findings were further corroborated in biopsy samples of cervical cancer patients, in which IFN-kappa was also downregulated when compared with normal donor tissue. This is the first report showing an epigenetic silencing of type I IFN after HPV16 oncogene expression and revealing a novel strategy on how high-risk HPVs can abolish the innate immune response in their genuine host cells.

Frequent high telomerase reverse transcriptase expression in primary oral squamous cell carcinoma.

BACKGROUND: Gene copy number gain of chromosomal arm 5p is frequently found in oral squamous cell carcinoma (OSCC) suggesting the activation of proto-oncogenes. TERT is a candidate gene encoding for human telomerase reverse transcriptase (hTERT). The aim of the present study was to elucidate the relevance of TERT copy number gain and high hTERT expression in OSCC. METHODS: Fluorescence in situ hybridization (FISH) for TERT and immunohistochemistry (IHC) for hTERT were performed to analyze TERT copy numbers and hTERT expression, respectively, on tissue microarray (TMA) sections including n = 247 OSCC and n = 105 pharyngeal and laryngeal squamous cell carcinomas (PSCC/LSCC). RESULTS: Increased hTERT protein expression was more frequently found in OSCC (71.1%, 155/218) than in PSCC/LSCC (36.0%, 35/89) (P < 0.001). By contrast, specific TERT amplifications were less common in OSCC (2.1%, 4/191) compared with PSCC/LSCC (9.9%, 8/81) (P = 0.047). CONCLUSIONS: High hTERT expression is a frequent finding in OSCC. It might be a promising target for the development of specific anti-neoplastic therapy approaches.

Refined characterization of head and neck squamous cell carcinomas expressing a seemingly wild-type p53 protein.

BACKGROUND: A fraction of head and neck squamous cell carcinomas (HNSCC) reveal overexpression of the p53 protein although sequence analysis failed to detect mutations in the core region of the protein. The functional and clinical status of p53 in these tumors is unclear. METHODS: In 31 HNSCC, allelic imbalances (AI) at TP53 and other chromosome 17 loci were analyzed by microsatellite marker analysis. Expression of p16(INK4a) protein was analyzed by immunohistochemistry. Seven tumors were re-examined for sequence alterations by the Affymetrix p53 GeneChip. RESULTS: About 54.8% of these tumors showed AI at TP53; 41.9% showed loss of p16, an overlapping fraction of 35.5% demonstrated AI and p16 loss. Six of seven such tumors revealed heterozygous missense mutations. CONCLUSIONS: A large proportion of HNSCC with presumed wild-type p53 overexpression are false-negative cases. These results strengthen the established strong association of p53 protein overexpression with missense mutations. AI at TP53 and p16 loss are useful surrogate markers for genetic alterations of TP53 in HNSCC.

Transcript and proteome analysis reveals reduced expression of calgranulins in head and neck squamous cell carcinoma.

The calcium-binding proteins of the S100 and the annexin protein families have been implicated in a variety of important physiological functions including membrane remodeling, calcium-related intracellular signaling, cytoskeleton dynamics, tissue homeostasis, and formation of the cornified envelope in differentiating keratinocytes. Deregulated expression of members of these families has been reported in different types of neoplasia and other diseases, but the results were not consistent. Here we have applied a combination of cDNA microarrays, quantitative reverse transcriptase-PCR (qRT-PCR) and surface enhanced laser desorption ionisation-time of flight mass spectrometry (SELDI-TOF MS) to study differential expression of these genes in head and neck squamous cell carcinoma (HNSCC). The calgranulins A and B and annexins 1 and 2 were found to be down-regulated in HNSCC, compared with normal mucosa, at both the mRNA and protein level. Upon validation of the differential gene expression by tissue microarray immunohistochemistry, we detected novel expression patterns of calgranulins A and B both in normal mucosa as well as in HNSCC. In contrast to squamous cancer of skin and other cancers in which the calgranulins were found to be up-regulated, most HNSCC showed reduced and widely deranged staining patterns including heterogeneous nuclear, cytoplasmic and membranous staining, and even enhanced staining in the tumor stroma. These observations suggest that the normal function of the calgranulins A and B in mucosa might be different from that in skin.

E-cadherin is a selective and strongly dominant prognostic factor in squamous cell carcinoma: a comparison of E-cadherin with desmosomal components.

E-cadherin-mediated and desmosomal cell-cell adhesion have been implicated in the suppression of invasive and metastatic behavior of squamous cell carcinomas. Whether the adhaerens junction represented by E-cadherin and the desmosomes interplay or have distinct and separate roles in squamous cell cancer progression is still unclear. We have studied a cohort of 200 primary tumors and 56 lymph node metastases from different anatomic sites of the head and neck region for changes in synthesis of E-cadherin, desmoplakin and desmoglein by immunohistochemistry (IHC). Selected cases were studied by indirect immunofluorescence (IIF) and electron microscopy (EM). Only frozen sections were evaluated since they gave stronger and reproducible staining results. IHC data obtained were compared to clinical parameters. While some reduction in immunostaining was found in virtually all invasive tumors, at least partial expression, including that of E-cadherin, persisted in most late stage tumors and in lymph node metastases. Reduced desmosomal staining correlated with desmosomes reduced in numbers, size or in structural defects by EM analysis. By univariate analysis, reduction in synthesis of both E-cadherin and the desmosomal components that were generally linked (i.e., they showed positive rank correlations) were significantly associated with clinical parameters including overall and disease-free survival. However, by multivariate analysis including a Cox proportional hazards regression model (backward selection), the desmosomal components were not significant as independent prognostic factors. By contrast, E-cadherin was strongly associated with patient prognosis. In line with the highly significant association of reduced E-cadherin synthesis with an increased relative risk of follow up events, i.e., regional lymph node (p = 0.0007) and distant metastasis (p < 0.0001), as well as local recurrences (p < 0.0001), the prognostic strength of E-cadherin was independent of and stronger than histological grading, N stage, tumor site, and even stronger than the TNM stage. Based on these results, evaluation of E-cadherin in squamous cell carcinomas by immunostaining is recommended as a significant prognostic marker.

Head and neck tumor sites differ in prevalence and spectrum of p53 alterations but these have limited prognostic value.

The tumor site is a strong clinical factor in head and neck squamous cell carcinoma (HNSCC). To clarify the biologic and clinical role of p53 alterations in HNSCC, we have examined the prevalence and the nature of p53 alterations in a large cohort of tumors from the different sites. For immunohistochemical analysis of p53 protein expression, we introduced tyramide signal amplification immunohistochemistry (TSA-IHC) on a tissue microarray. This allowed the discrimination between normal low-level expression and reduced or lost expression. Two hundred fifty-three tumors were subjected to mutational analysis by genomic DNA sequencing, employing also the p53 GeneChip from Affymetrix. The prevalence of all p53 alterations, i.e., mutations, overexpression and loss of expression, was significantly higher in hypopharyngeal tumors than in the other sites (p = 0.001). Laryngeal tumors showed the lowest rate of p53 alterations, but revealed a distinct mutation spectrum: most mutations affected exon 5 (p = 0.013) and the S2' domain (p = 0.002), and most hot-spot 248 mutations occurred in the larynx (p < 0.001). Sequencing by p53GeneChip technology was shown to be only insignificantly more sensitive than dideoxy sequencing. In agreement with p53 mutations occurring prior to invasiveness, their prevalence did not increase with tumor stage, and all mutation classes lacked prognostic significance. The large patient cohort of this study showed that p53 is differentially affected in the different tumor sites of the head and neck, but its mode of inactivation does not play a major role in tumor progression.

p53-positive tumor-distant squamous epithelia of the head and neck reveal selective loss of chromosome 17.

OBJECTIVES/HYPOTHESIS: The progression of clinically manifest premalignant lesions in the head and neck region to primary or second primary cancer is characterized by numerical and structural chromosomal aberrations. However, many tumors arise from histologically inconspicuous mucosal sites. The objective was to investigate whether chromosomal aberrations can be detected in tumor-distant mucosa and whether they can help predict the risk of second primary malignancy. STUDY DESIGN: A retrospective series of 72 clinically healthy, arbitrarily taken mucosal samples from 53 patients with squamous cell carcinoma of the head and neck was studied. A previous analysis of the p53 protein status had revealed both p53-positive and p53-negative samples. METHODS: The samples were analyzed by fluorescence in situ hybridization (FISH) using centromeric probes specific for the chromosomes 1, 10, 17, and 18. RESULTS: Tumor-distant mucosa generally showed increased numerical chromosomal aberrations, which consisted mainly of monosomies. In the group of patients with p53-positive epithelia, all aberrations including gains of chromosomes (trisomies, tetrasomies) were more frequent. Monosomy for chromosome 17 was most significantly and selectively enhanced in this group (Wilcoxon Scores [rank sum] test, P =.0002). CONCLUSION: Detectable chromosomal aberrations occur in clinically healthy epithelia in patients at risk for secondary head and neck cancer. Specifically, unbalanced chromosome 17 monosomy in conjunction with p53 protein overexpression may constitute a valuable biomarker for progressive "field cancerization."

Distinct site-specific oncoprotein overexpression in head and neck squamous cell carcinoma: a tissue microarray analysis.

BACKGROUND: Tissue microarray (TMA) analysis is a high-throughput approach that allows the screening of large tumor collectives for cytogenetic aberrrations. In this study, a TMA of a large collection of clinically well-defined primary squamous cell carcinomas of the head and neck (HNSCC) was used to determine the expression of several oncoproteins. MATERIALS AND METHODS: A TMA containing 547 primary HNSCC was used for the analysis of cyclinD1, c-myc, erbb1 and erbb2 expression by immunohistochemistry (IHC). RESULTS: CyclinD1 and c-myc were overexpressed at higher frequencies in primary pharyngeal and laryngeal carcinomas compared with primary oral carcinomas (p < 0.001 and p < 0.001), while erbb1 and erbb2 overexpression was associated with oral site (p < 0.001 and p = 0.04, respectively). Furthermore, cyclinD1 overexpression correlated with stage IV primary carcinomas (p = 0.04). CONCLUSION: HNSCC is a heterogenous group of tumors, which, depending on anatomic sites and clinical stage, shows variable expressions of the oncoproteins described. This indicates a specific pathogenic role of these oncoproteins in different subtypes of HNSCC and may have therapeutic implications.

Tissue microarray analysis reveals site-specific prevalence of oncogene amplifications in head and neck squamous cell carcinoma.

Fluorescence in situ hybridization was applied on a collection of 609 squamous cell carcinomas of the head and neck (HNSCCs),including 511 primary carcinomas of different clinical stage and anatomical localization and 98 recurrent carcinomas, second primary carcinomas, and regional metastases on a tissue microarray. The overall prevalence of amplifications of five oncogenes analyzed was 34.5% for CCND1, 12.7% for EGFR, 8.8% for MYC, 6.2% for ZNF217, and 3.6% for ERBB2. CCND1 amplifications were associated with the pharyngeal site in primary carcinomas (P < 0.001), whereas amplifications of ZNF217 were less frequent in pharyngeal carcinomas as compared with primary oral and laryngeal carcinomas (P = 0.02). The amplification pattern of these oncogenes suggests that different molecular pathways are involved in HNSCCs of different localizations.

Involvement of intact HPV16 E6/E7 gene expression in head and neck cancers with unaltered p53 status and perturbed pRb cell cycle control.

We have identified parameters which define a causal role of HPV16 in head and neck cancer. Twenty-eight tumours which were typed positive for HPV16 DNA, were comprehensively analysed for expression of the viral oncogenes E6 and E7, the status of the p53 gene, and the protein status of pRb and p16(INK4a). In a subset of cases, we have searched for integrated viral DNA, and have determined the genomic status of the E6 gene. Expression of E6/E7 was found in 12 tumours most of which were derived from the oropharynx, whereas p53 mutations were present in 13 tumours from various sites. The tumours either carried p53 mutations but did not express E6/E7, or they did express E6/E7 but were p53-wild-type. Coexistence of E6/E7 expression with a mutated p53 was found in only one case. Strikingly, in most p53-mutated tumours without E6/E7 expression, we found the E6 gene to be disrupted. E6/E7 expression was associated with reduced pRb and overexpressed p16(INK4a). Viral-cellular fusion transcripts were found in two cases. Our data demonstrate that HPV16 DNA-positivity in head and neck cancers is not indicative of a causal role. A causal role of HPV16 in head and neck cancer is defined by: E6/E7 expression, viral integration with an intact E6 gene, and perturbation of pRb cell cycle control. Mostly, the p53 gene is wild-type.