人乳头瘤病毒DNA相关序列与p53基因突变对大肠癌生物学行为的影响50例报告

目的探讨人乳头瘤病毒（ＨＰＶ）ＤＮＡ相关序列与ｐ５３基因突变及ｐ５３蛋白表达的关系及其对大肠癌生物学行为的影响。方法采用ＰＣＲ方法检测大肠癌及癌旁组织、肝转移灶中ＨＰＶＤＮＡ相关序列。并应用ＰＣＲＳＳＣＰ及免疫组化技术分别检测ｐ５３基因突变及ｐ５３蛋白表达。结果在５０例大肠癌中,检出ＨＰＶ１６、１８ＤＮＡ相关序列２６例（５２０％）,其中ＨＰＶ１６ＤＮＡ４例（８０％）,ＨＰＶ１８ＤＮＡ２２例（４４０％）。ｐ５３基因突变率为５６０％。ｐ５３蛋白表达阳性率为４２０％。ＨＰＶＤＮＡ相关序列与ｐ５３基因突变及ｐ５３蛋白表达呈正比关系。结论ＨＰＶＤＮＡ相关序列可促进细胞转化、致ｐ５３基因突变、抑制细胞的凋亡,与大肠癌的发生发展有密切关系。     

Expression of p53 protein related to human papillomavirus and DNA ploidy in superficial esophageal carcinoma

We examined the p53 protein and human papilloma virus (HPV) by immunohistochemistry and DNA ploidy by cytofluorometry in paraffin-embedded esophageal carcinoma tissue specimens. Sixty-one patients with superficial esophageal carcinoma were operated on between 1983 and 1991 without any prior treatment. Immunostaining of the anti-p53 protein antibody (CM1) was positive in 32 carcinomas (52%). Patients with p53-positive tumors had a poorer outcome than those with p53-negative tumors (P<0.05). In addition, patients with p53-positive tumors did not have any characteristic site of relapse. Only 5 of the 61 patients (8.2%) had HPV-positive tumors. One of these 5 carcinomas expressed both p53 protein and HPV. Three patients with HPV-positive tumors which had invaded the submucosal layer died of relapse. A determination of DNA ploidy revealed 30 patients with aneuploid tumors, 13 with polyploid tumors and 18 with diploid tumors. The outcome of the patients with aneuploid tumors was worse than that of the patients with diploid tumor (P<0.05). p53 protein expression was not associated with DNA ploidy; however, the 16 patients who had both p53-positive and aneuploid tumors had a worse prognosis than patients with p53-negative and aneuploid tumors (P<0.01). These findings suggest that p53 protein expression in conjunction with DNA ploidy may be a useful indicator in evaluating the prognosis of patients with superficial esophageal carcinoma.     

Detection of human papillomavirus DNA in cancer of the urinary bladder by in situ hybridisation.

The association of the human papillomavirus (HPV) with cancer of the urinary bladder was assessed by in situ hybridisation using probes selective for HPV types 6/11 and 16/18 DNA. No hybridisation signal was detected with the type 6/11 probe on 100 formalin-fixed, paraffin-embedded bladder tumours sampled. However, when the same samples were hybridised with the HPV type 16/18 DNA probe, 11 of 66 (16.6%) papillary and 1 of 10 (10%) solid transitional cell carcinomas gave positive signals. These results suggest the involvement of HPV in cancer of the bladder, although the frequency of multiple HPV types in these tumours is uncertain.     

Detection of human papillomavirus DNA and expression of p16, Rb, and p53 proteins in small cell carcinomas of the uterine cervix

Human papillomavirus (HPV) has been implicated as an etiologic agent for the development of primary small cell carcinoma of the uterine cervix, a rare but highly aggressive malignancy. It has been shown that the HPV E6 and E7 oncoproteins are able to inactivate the tumor suppressor functions of p53 and Rb. In squamous cell carcinoma and adenocarcinoma of the cervix, HPV infection is also associated with overexpression of p16, a cyclin-dependent kinase inhibitor. In this study, 22 cases of primary small cell carcinoma of the uterine cervix were subjected to broad-spectrum HPV DNA amplification and typing, and immunohistochemically examined for the expression of p16, Rb, and p53 proteins. The results show that HPV DNA was detected in every case (100%), with 18 cases (82%) harboring type 18. The tumor cells exhibited strong nuclear staining for p16 in 20 cases (91%). This was associated with a complete loss of Rb nuclear staining in tumor cells in 16 cases (73%). The p53 protein was essentially undetectable in all cases. In contrast, HPV DNA was not detected in 9 colorectal and 8 urinary bladder small cell carcinomas included in this study for comparison. While similar p16 and Rb expression patterns were observed in these HPV-negative tumors, a different expression pattern for p53 was noted where strong nuclear staining was seen in 8 cases (47%; P = 0.0004 compared with cervical tumors). These observations indicate that different mechanisms are involved in the pathogenesis of small cell carcinomas of the uterine cervix and support the notion that nuclear p16 overexpression serves as an indication of Rb defunctioning in tumor cells, which may or may not result from high-risk HPV infection.     

Most basal-like breast carcinomas demonstrate the same Rb-/p16+ immunophenotype as the HPV-related poorly differentiated squamous cell carcinomas which they resemble morphologically

Basal-like carcinomas (BLCs) of the breast share discriminatory morphologic features with poorly differentiated high-risk human papilloma virus (HPV)-related squamous cell carcinomas of the oropharynx, penis, and vulva. Because HPV E7 protein inactivates the retinoblastoma (Rb) protein, diffuse p16 expression is a surrogate marker for these high-risk HPV-related carcinomas. HPV E6 protein also inactivates p53, further compromising the G1-S cell cycle checkpoint. The Rb/p16/p53 immunohistochemical profile of BLC of the breast has not been well characterized. Tissue microarrays containing 71 invasive ductal carcinomas (IDCs) of the breast were immunolabeled for p16, Rb, p53, and Ki-67. The cases included 4 distinct groups of IDCs having surrogate immunohistochemical profiles corresponding to categories defined by gene expression profiling (17 luminal A, 7 luminal B, 14 HER-2+, and 21 BLC), along with 12 unclassifiable triple negative carcinomas (UTNCs). Twenty-five of the 71 IDC were Rb negative/p16 diffuse positive (Rb-/p16+). These included 15 of 21 BLC and 9 of 12 UTNC, but only 1 of 14 HER-2 positive cases and none of the 17 luminal A or 7 luminal B cases (P<0.01, BLC or UTNC vs. others). Six of the Rb-/p16+ IDC also had a significant ductal carcinoma in situ component. The ductal carcinoma in situ in 4 of these 6 cases showed the same Rb-/p16+ phenotype as the associated IDC. BLC and UTNC had the highest Ki-67 indices of the 5 groups, even when matched for grade. The Rb-/p16+ phenotype and the Rb-/p16+/p53 overexpressing phenotype correlated with increased proliferation within the BLC group. In conclusion, BLC and UTNC, but not HER-2, luminal A, or luminal B carcinomas, frequently demonstrate an Rb-/p16+ phenotype, similar to the HPV-related squamous cell carcinomas that BLC resemble morphologically. This subset may represent a more homogenous group than BLC as defined currently.     

Detection of human papillomavirus DNA and p53 gene mutations in human prostate cancer

The relationship between integration with human papillomavirus (HPV) and p53 gene mutations in tissues of prostate cancer was examined. Tissue samples analyzed were obtained by total prostatectomy (29 stage B cancer cases) and from autopsy (22 endocrine therapy-resistant metastatic disease cases). HPV DNA was detected in 8 of 51 (16%, 5 in stage B and 3 in autopsy cases) by polymerase chain reaction (PCR) using consensus primers on L1 region. Genotypes of HPV were entirely type 16. Structural abnormalities of p53 gene were detected in 7 of the 22 autopsy cases (32%) by PCR-single-strand conformation polymorphism analysis and direct sequencing. No p53 gene mutation was found in stage B cancer cases. Analysis of mutation spectra revealed clear differences between Japanese and Westerners. There was a significant difference in the mutation frequency between stage B and autopsy cases (P < 0.01, Fisher's exact test). One case showed both integration of HPV and p53 gene mutation in different cancer foci. However, the other cases revealed an inverse correlation between the presence of HPV DNA and p53 gene mutations. These data show that p53 genetic alteration is correlated with the progression of prostate cancer, in contrast to the integration of HPV that may occur in a relatively early stage. In conclusion, this study may indicate that either p53 gene mutation or the presence of HPV's oncogenic protein E6 is involved in the development of prostate cancer. © 1996 Wiley-Liss, Inc.     

Prevalence of high-risk human papillomavirus DNA in nonkeratinizing (cylindrical cell) carcinoma of the sinonasal tract: a distinct clinicopathologic and molecular disease entity

Carcinomas of the nose and paranasal sinuses are a heterogeneous group of neoplasms that differ histologically, biologically, and clinically. Some of these tumors are known to harbor high-risk human papillomavirus (HPV) DNA. In an attempt to identify specific phenotypes associated with HPV infection, 39 cases of sinonasal carcinomas were evaluated by PCR for the presence of HPV DNA. The tumors were also studied with a panel of immunohistochemical stains, including p16, p53, and Ki-67 antibodies. Twenty-one cases were identified as keratinizing squamous cell carcinoma (KSCC) with a male-to-female ratio of 3:1. Eight cases were nonkeratinizing (cylindrical cell) carcinoma (NKCa) with a male-to-female ratio of 1:1. Ten cases were sinonasal undifferentiated carcinoma (SNUC), and 9 of these patients were men. HPV DNA, particularly type 16, was detected in 9 cases: 4 of 21 (19%) of KSCC, 4 of 8 (50%) of NKCa, and 1 of 10 (10%) of SNUC. In addition to a higher prevalence of HPV DNA in NKCa, the tumors also showed a distinct immunophenotype characterized by strong and diffuse staining for p16, high labeling scores for Ki-67, and negative or low reactivity to p53. On the other hand, KSCC and SNUC were either negative or weakly reactive to p16 antibodies. KSCC cases were more likely to be positive and more strongly reactive to p53 stain. Unlike KSCC, SNUC had high Ki-67 labeling scores. These observations suggest that NKCa of the sinonasal tract is a distinct histopathologic and molecular disease entity, which should be added to the list of upper aerodigestive tract tumors with strong etiologic relationship to high risk HPV.     

Anal cloacogenic and squamous carcinomas. Comparative histologic analysis using in situ hybridization for human papillomavirus DNA

In order to evaluate the morphologic and possible etiologic distinctions between anal cloacogenic and squamous carcinomas, we performed histologic examination and in situ hybridization for human papillomavirus (HPV) DNA on anal canal and anal verge carcinomas from 37 patients. Twenty-one neoplasms were invasive or in situ squamous carcinomas, 14 were invasive cloacogenic carcinomas, and two were unclassified. In situ hybridization was positive for HPV types 16/18 in 12 cases and for types 6/11 in two cases of anal squamous carcinoma (67% HPV positivity overall). All 14 cases classified as anal cloacogenic carcinoma were negative for HPV DNA by this technique. One of the two unclassified carcinomas was positive for type 16/18 DNA. We conclude that anal cloacogenic and squamous carcinomas are histologically similar but distinct neoplasms. Differential expression of HPV DNA in these lesions may be a manifestation of separate mechanisms of pathogenesis, or it may be due to varying degrees of tumor cell differentiation.     

IMMUNOHISTOCHEMICAL DETECTION OF p53 PROTEIN OVEREXPRESSION VERSUS GENE SEQUENCING IN URINARY BLADDER CARCINOMAS

PURPOSE: Mutations of p53 tumor suppressor gene and nuclear accumulation of p53 protein are common in bladder tumors. The prognostic significance of p53 alterations in bladder tumors has not been established. The aim of the present study was to evaluate an immunohistochemical (IHC) method for the routine determination of p53 protein overexpression in human bladder tumors and to determine the relation between nuclear accumulation of p53 with the traditional prognostic indicators and patient survival. MATERIALS AND METHODS: 104 transitional cell carcinomas of the bladder were analyzed simultaneously by immunohistochemistry for p53 protein overexpression and direct DNA sequencing for p53 gene mutations. RESULTS: The overexpression of p53 protein was reported in 30.8% of the cases and mutations of p53 gene in 23.0%. A significant association was observed between p53 alterations established either by IHC or direct DNA sequencing and stage (p<0.0001), grade (p<0.001), vascular invasion (p = 0.0005), DNA ploidy (p = 0.0002) and carcinoma in situ (p<0.0001). The correlation between the p53 gene mutations and p53 nuclear reactivity as detected by IHC was highly significant (p<0.0001). Univariate statistical analysis showed that the expression of p53 was significantly correlated to poor prognosis (p<0.0001). However, in multivariate analysis, only stage was significantly correlated to prognosis (p<0.0001). CONCLUSIONS: The IHC method was highly sensitive and specific and simple to apply for the routine examination of p53 overexpression in bladder tumors. However, overexpression of p53 as determined immunohistochemically, does not appear to have a better predictive prognostic value than stage in bladder tumors.     

Human papillomavirus and p53 protein immunoreactivity in condylomata acuminatum and squamous cell carcinoma of penis

Aim: To determine the immunoreactive pattern of human papillomavirus (HPV) antigen and p53 protein in condylomata acuminatum (CA) and squamous cell carcinoma (SCC) of penis. Methods: Immunohistochemistry for HPV and p53 were performed in 40 specimens of formalin fixed, paraffin embedded tissues using a polyclonal (rabbit) antibody against HPV and a monoclonal (mouse) antibody against human p53 protein. Twenty one cases of CA and nineteen cases of SCC were examined. Results: HPV antigen was detected in all 21 CA and 2 penile SCC. p53 protein overexpression was observed in 12 of 19 (63%) SCC in which 6 cases were strong positive. Five of 21 CA (24%) showed low-grade p53 protein overexpression. Conclusion: CA is related to HPV infection and some cases show p53 protein low-grade overexpression. In contrast, p53 protein overexpression is common in penile SCC, which is seldom related to HPV infection.     

Human papillomavirus (HPV)-related oropharyngeal nonkeratinizing squamous cell carcinoma: characterization of a distinct phenotype.

We have recently shown that HPV-positive tonsillar carcinoma in young patients exhibits nonkeratinizing basaloid morphology and a characteristic immunophenotype. The purpose of this study was to review a large number of cases of oropharyngeal carcinomas, in all age groups, and to identify tumors with nonkeratinizing morphology. Using polymerase chain reaction (PCR) the prevalence and type of HPV DNA was determined in representative cases and in a control group of conventional keratinizing squamous cell carcinomas. The tumors were further characterized with a panel of immunohistochemical stains. A total of 235 carcinomas were reviewed; 141 of the tonsils and 94 in the base of tongue. Ninety (36%) of the tonsillar and 30 (32%) of the base of tongue carcinomas were nonkeratinizing (NKCa) with basal cell features; the rest were classical keratinizing squamous cell carcinomas (KSCC). HPV DNA, particularly type 16, was identified in 10 (100%) of 10 of NKCA and in only 2 (20%) of 10 of KSCC (P = .0014). NKCas were strongly reactive to p16 antibodies while KSCC showed weak and focal reactivity. Higher Ki67 and lower p53 staining scores were observed in NKCa as compared to KSCC. It is concluded that NKCa of the tonsils and base of tongue is a distinct subtype of squamous cell carcinoma of the head and neck with high prevalence of HPV DNA and a characteristic immunophenotype.     

Association of DNA aneuploidy with human papillomavirus-induced malignant transformation of sinonasal transitional papillomas

The nuclear DNA content of 19 transitional papillomas of the sinonasal region and 9 maxillary squamous cell carcinomas was studied by flow cytometry; the presence of human papillomavirus (HPV) DNA types 11 and 16 was determined by the in situ hybridization technique from paraffin-embedded tissue. Thirteen (68%) of the papillomas and none of the carcinomas contained HPV genome. Six (32%) of the papillomas and 4 (44%) of the carcinomas had an aneuploid DNA content. The relative DNA content (DNA index) of the aneuploid maxillary carcinomas was larger than that of aneuploid papillomas (p = 0.004). Three of the papillomas underwent malignant transformation, all three of which contained HPV type 16 DNA; two were also aneuploid. Data indicate that papillomas containing HPV type 16 DNA have a tendency (p = 0.06) to undergo malignant transformation, and that this tendency is greater if DNA aneuploidy or HPV type 11 DNA is also present (p = 0.02).     

Detection of human papillomavirus in small cell carcinomas of the anus and rectum

Small cell carcinomas represent <1% of colorectal/anal carcinomas and have a poor prognosis. Anorectal squamous cell carcinomas are often associated with high-risk human papillomavirus (HPV) infection, similar to squamous and small cell carcinomas of the uterine cervix. In HPV infection, the oncoprotein E7 inactivates the tumor suppressor Rb, leading to p16 upregulation; however, in small cell carcinomas, the Rb pathway is often blocked by other mechanisms; thus, increased p16 may not indicate HPV infection. P16 immunohistochemistry (IHC) may have a limited role in evaluating small cell carcinomas for HPV infection. Formalin-fixed, paraffin-embedded tissue sections of previously diagnosed small cell carcinomas of the anus (n=5) and rectum (n=11) were subjected to IHC for p16, CDX2, and p63, followed by in situ hybridization for high-risk HPV. All (100%) cases of anal and rectal small cell carcinomas were positive for p16, and 100% of anal and 82% of rectal small cell carcinomas were positive for high-risk HPV. The majority of cases showed low or very low HPV copy numbers. In 6 cases, HPV was detected only by using the HPV-16 genotype-specific assay detecting very low copy numbers (1 to 2 viral copies). The majority of tumors expressed p63, which was more pronounced in the anal tumors. CDX2 expression was observed predominantly in rectal tumors. High-risk HPV can be detected using in situ hybridization in the majority of anorectal small cell carcinomas, which are uniformly p16 positive by IHC. HPV-targeted therapy could result in better control of these aggressive neoplasms.     

乳腺癌中p53基因DNA水平突变与核蛋白水平突变的比较

目的研究ｐ５３基因ＤＮＡ水平和蛋白水平的突变。方法分别采用多聚酶链反应单链构象多态分析银染方法和链酶亲和素生物素过氧化物酶复合物（ｓｔｒｅｐａｖｉｄｉｎｂｉｏｔｉｎｐｅｒｏｘｉｄａｓｅｃｏｍｐｌｅｘ,ＳＡＢＣ）免疫组化方法,检测了５４例乳腺浸润性导管癌标本。结果２２例在ＤＮＡ水平突变阳性,突变率为４１％;３２例在核蛋白水平突变,突变率５７％。其中２２例ＤＮＡ突变阳性者,核蛋白突变均阳性;而３２例ＤＮＡ水平突变阴性者,核蛋白突变阳性者９例,占２８％。ｐ５３ＤＮＡ突变与核蛋白突变之间有显著相关性,并且两者都与患者的淋巴结转移以及雌、孕激素受体表达有关（Ｐ＜００１）。结论免疫组化是一种快速检测ｐ５３是否存在异常的有效方法。但是在蛋白水平突变阳性者中存在一定的假阳性。ｐ５３突变阳性患者预后较差     

No evidence of human papillomavirus DNA in breast carcinoma in Tunisian patients

The aim of this study was to evaluate the prevalence of broad range of anogenital HPVs in a series of 123 Tunisian breast carcinoma cases. PCR assays were performed to amplify regions within the L1, E1, E6 and E7 open reading frames of a broad range of anogenital HPVs and specific types HPV16, 18, 31 and 33. In addition, we performed an in situ hybridization analysis using HPV biotinylated DNA probes for the detection of broad spectrum of anogenital HPV types, high-risk HPV types (16 and 18), intermediate-risk HPV types (31 and 33) and low-risk HPV types (6 and 11). None of the 123 breast carcinoma samples showed PCR amplification of HPV DNA using the broad spectrum consensus primer-pairs E1-350L/E1-547R and GP5+/GP6+ primers. Furthermore, neither high risk nor low-risk HPV types were detected in any of these cases. Moreover, using in situ hybridization for the detection of HPVs, we failed to detect a positive signal in neoplastic cells in any case. Our results suggest that anogenital papillomaviruses are unlikely to play a role in the development of breast carcinomas in Tunisian patients.     

Prevalence of human papillomavirus type 16 DNA in squamous cell carcinoma of the palatine tonsil, and not the oral cavity, in young patients: a distinct clinicopathologic and molecular disease entity

Squamous cell carcinoma of the head and neck commonly affects patients in their sixth decade and older, particularly those with a prolonged history of alcohol and tobacco abuse. Less frequently, carcinomas occur in young individuals even in the absence of known risk factors. The purpose of this study is to investigate a possible relationship between these tumors and human papilloma virus (HPV). Thirty-three cases of squamous cell carcinoma of the head and neck in young patients under the age of 40 years were studied: 15 oral, 11 tonsillar, and 7 laryngeal. HPV DNA was detected by polymerase chain reaction in 10 tonsillar and 2 laryngeal carcinomas and in none of the oral tumors. Of the 12 HPV-positive tumors, 11 were HPV16 and 1 was HPV31. HPV-positive tumors had a distinct nonkeratinizing basal cell morphology, they stained diffusely and strongly with p16 antibodies, had higher Ki-67 and lower p53 staining scores as compared with the conventional keratinizing HPV negative carcinomas. It is concluded that in young patients high-risk HPV, particularly HPV16, is strongly associated with tonsillar squamous cell carcinoma and some cases of laryngeal, but not oral, tumors. The HPV-positive carcinomas have a distinct histopathologic and immunophenotypic features.     

Use of combined molecular biomarkers for prediction of clinical outcomes in locally advanced tonsillar cancers treated with chemoradiotherapy alone

Background.

Environmental exposures to tobacco, alcohol, human papillomavirus (HPV) and/or Epstein‐Barr virus (EBV), all of which can perturb multiple cell cycle proteins or tumor suppressors, have been implicated in the pathogenesis of different subsets of head and neck cancers. The aim of this study was to investigate to which extent the virus infection by itself, and/or the altered cell cycle proteins, contributes to prognosis in locally advanced tonsillar squamous cell carcinomas (TSCCs) treated with concurrent chemoradiotherapy (CCRT) alone.

Methods.

Serial tumor tissue arrays from archival samples were tested for the presence of HPV genome integration or EBV episome by means of DNA sequencing, real‐time polymerase chain reaction (PCR), and in situ hybridization. Alterations of cell cycle proteins (p53, pRb, and p21) were evaluated by immunohistochemical staining. The association of viral presence with altered cell cycle proteins was correlated to clinical outcomes.

Results.

Of the 46 patients with the same T2N2bM0 stage IVA among consecutive patients with TSCC, 23 (50%) had integrated HPV DNA and only 1 (2%) had EBV episome. The HPV types detected were almost all HPV‐16. A reduced expression pattern of p53, pRb, and p21 was noted in HPV‐positive tumors, and the incremental number of alterations in the 3 proteins was significantly associated with HPV‐negative tumors. The presence or absence of HPV together with the number of altered expression of the 3 cell cycle markers resulted in further identification of 4 biologically and clinically distinct subgroups with different outcomes after CCRT.

Conclusions.

Use of combined biomarkers of oncogenic HPV and tumor suppressors of p53, pRb, and p21 in advanced TSCC provides prognostic molecular classification superior to the TNM stage system and identifies low‐risk patients for organ preservation by CCRT alone and high‐risk patients who might benefit from planned tonsillectomy and neck dissection before or after CCRT. © 2008 Wiley Periodicals, Inc. Head Neck, 2009     

Expression of p16(INK4A), p53, and Rb proteins are independent from the presence of human papillomavirus genes in oral squamous cell carcinoma.

BACKGROUND: The overexpression of p16(INK4A) and suppression of p53 and Rb proteins are key features of oncogenic transformation by human papillomaviruses (HPV) in anogenital cancers. HPV genomes are often detected in cancers of the oral cavity, but it is unclear whether HPV has a specific oncogenic role there. OBJECTIVES: The objectives of the study were to investigate the expression of p53, Rb, and p16(INK4A) proteins and identify HPV infection and viral integration into the host genome. METHODS: Seventy-nine cases of oral squamous cell carcinoma (OSCC) were studied by immunohistochemistry. Polymerase chain reaction (PCR) was performed to identify HPV DNA from the samples. The results were correlated with clinical data. RESULTS: Thirty-three cases were HPV positive for high-risk HPV (HR-HPV) types, of which 27 harbored HPV16. In 25 of 27 HPV16-positive tumors, the HPV16 genome was fully integrated into the host genome, as evidenced by the lack of PCR-amplifiable E2 gene sequences. Forty-five patients were p53 overexpressing, 20 with HR-HPV-positive and 25 with HR-HPV-negative tumors. p16(INK4A) protein was overexpressed in 4 of 31 HR-HPV-positive and 9of 45 HR-HPV-negative cases. Twenty-six of 32 HR-HPV-positive and 37 of 44 HR-HPV-negative samples exhibited pRb nuclear staining. These differences between HR-HPV-positive and -negative tumors were not statistically significant. No correlation was found between these biological factors and tumor location, stage, differentiation grade, or alcohol or tobacco abuse. CONCLUSIONS: A tumor immunophenotype, similar to HPV-related anogenital cancers, is not present in OSCC and highly oncogenic HPV types are therefore unlikely to be specific or independent risk factors for oral cancer.     

Human papillomavirus and gene mutations in head and neck squamous carcinomas

Background: Human papillomavirus (HPV) infection is implicated as an aetiological factor in head and neck squamous carcinomas (HNSCC), especially in the tonsils of the oropharyngeal region. This study investigates the frequency of HPV infection, p16 and p53 tumour profile and mutations in epidermal growth factor receptor (EGFR), Kirsten RNA Associated Rat Sarcoma 2 Virus (KRAS) and B‐Raf proto‐oncogene serine/threonine protein kinase (BRAF) genes in tonsillar and non‐tonsillar HNSCCs and correlates with clinical outcome and histopathological parameters in previously unstudied cohort of patients. Methods: A retrospective clinical study was performed utilising the demographic data and pathological specimens from 60 out of 726 head and neck cancer patients. Smoking and alcohol history, tumour staging, treatment and outcomes were recorded. Histopathology and immunochemistry for p16 and p53 was performed and HPV DNA was detected with polymerase chain reaction. Genomic DNA from all cancers were analysed for somatic mutations of EGFR, BRAF and KRAS genes. Results: 20 (33%) of 60 cases were tonsillar squamous carcinomas and 38 (66%) were non‐tonsillar. 19 (95%) of the 20 tonsillar cancers and three (8%) of 38 non‐tonsillar patients were patients who were HPV 16‐positive. Nine (47%) of the 19 HPV 16‐positive tonsillar cases were p16 positive. Gene mutations were rare. There was a statistically significant (P < 0.05) improved survival of patients with HPV positive tonsillar tumours, younger age and non‐smokers. Conclusion: Although limited in numbers, this study reinforces the role of HPV infection in HNSCC and its association with a more favourable clinical course in younger non‐smokers worldwide. Gene mutation frequencies were low in all cancers tested and routine testing not recommended.     

CORRELATION OF p53 PROTEIN EXPRESSION IN HUMAN UROTHELIAL TRANSITIONAL CELL CANCERS WITH MALIGNANT POTENTIAL AND PATIENT SURVIVAL

The p53 gene product has been detected frequently in various human malignancies. We have studied the expression of p53 protein in urothelial transitional cell cancers (TCCs) and examined its correlation with pathologic grade, stage(pT) and patient survival. Specimens from 69 surgically-resected TCCs (38 cases of urinary bladder cancer, 17 cases of ureteral cancer and 14 cases of renal pelvic cancer) were examined by immunohistochemical staining, using two anti-p53 monoclonal antibodies, PAb1801 and PAb240, and a polyclonal antibody, CM-1. Twenty-six TCCs (37.6%) were positively stained by at least one of the three antibodies. Statistical analysis showed a significant correlation between p53 expression and high pathologic grade (p less than 0.05, p less than 0.001) or progressive pathologic stage (p less than 0.01). In addition, in 51 of the patients who were available for follow-up (23 cases of urinary bladder cancer, 13 cases of ureteral cancer, and 15 cases of renal pelvic cancer), the correlation between p53 protein expression and prognosis was examined. The survival of patients exhibiting positive p53 protein expression was significantly worse than those with p53-negative tumors (p less than 0.05). These results suggest that an immunohistochemical test for p53 protein may be a useful method of evaluating the malignant potential of TCCs. Additionally, expression of p53 protein in TCCs is an indicator of a poor prognosis which should be considered in drawing up treatment strategies.