Cervical cancer. News on papillomaviruses

Increased risk of dementia in patients with genital warts: A nationwide cohort study in Taiwan

Genital warts are a common sexually transmitted disease caused by human papillomavirus (HPV) infections. The prevalence of dementia is 4-8% in those aged 65 years or older in Taiwanese community studies, with a high social and economic burden for patients, family caregivers, the community and society. Previous studies have shown that viral infections such as herpes simplex and herpes zoster were associated with dementia. This study aimed to investigate the association between dementia and HPV infections. A population-based cohort study using data from Taiwan's National Health Insurance Research Database was conducted. Fine and Grays's survival analysis was employed to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for the association between genital warts and dementia. From all of the potential participants aged 50 years or more, a total of 16 116 patients were enrolled, including 4029 genital warts-infected patients, with 12 087 sex-, age- and indexed date-matched controls (1:3). The cumulative incidences of dementia were 10.72 per 10³  person-years and 6.43 per 10³  person-years in the genital warts and control group, respectively. There were 475 dementia cases from the genital warts cohort during the follow-up period of 15 years. The adjusted HR for dementia was 1.485 (95% CI, 1.321-1.668; P < 0.001) for genital warts patients after adjusting for all of the covariates. Our study indicates that genital warts infection may increase the risk of dementia.

Risk of cancer in patients with genital warts: A nationwide, population-based cohort study in Taiwan

Background

Condyloma acuminata currently affects around 1% of sexually active adults, and its incidence is increasing. The coexistence of genital warts (GW) and certain cancers and an association between human papillomavirus (HPV) and various malignancies have been reported. Therefore, we conducted this large national study to analyze the risk of malignancies among men and women with GW in Taiwan.

Methods and findings

Between January 2000 and December 2013, approximately 3 million patients were reported to the National Health Insurance Research Database of Taiwan. Of these patients, 21,763 were diagnosed with GW. In the same time period, a total of 213,541 cancer cases were reported to the registry, of which 1002 were recorded among patients with GW. The age-specific incidence rates of GW and standardized incidence ratios (SIRs) of malignancies compared to the general population were calculated. Women acquired GW earlier than men, with a mean age at diagnosis of 32.63±12.78 years. The highest incidence rate for both genders peaked at 20–29 years. Of the 1002 patients with GW and malignancies, the SIR was 1.95 (95%CI 1.83–2.07). The most markedly increased risk was found for HPV-related cancers, with a SIR of 9.74 (95%CI 3.70–15.77). Significantly elevated risks were also noted for smoking-related cancers, anogenital cancers, cervix in situ, colon, rectum, lung, kidney, and prostate cancers. Most cancers developed within 10 years after the diagnosis of GW.

Conclusions

Patients with GW have an increased risk of HPV-related cancers, especially anogenital malignancies in Taiwan. The elevated risk of other cancers highlights differences in exposure and risk factors among patients with GW compared to the general population. Cancer screening and HPV vaccination programs should be emphasized for at-risk patients.

Is oral contraceptive associated with genital warts?

OBJECTIVE

To measure the association between oral contraceptive use and the prevalence of genital warts in women.

METHODS

Cross sectional case control study comparing oral contraceptive use in women with and without genital warts attending a city centre genitourinary medicine clinic controlling for recent sexual activity, the presence of other sexually transmitted infections, socio-economic class and history of pregnancy using a multivariate logistic regression model.

RESULTS

After controlling for potential confounding variables women with genital warts were significantly more likely to be current users of the oral contraceptive pill (OR 1.7, 95% CI 1.3-2.2).

CONCLUSION

The study suggests that women taking the oral contraceptive may be at increased risk of presenting with genital warts. Previously published papers provide some support for this hypothesis and potential biological mechanisms are discussed.

Prognostic importance of human papilloma virus typing in squamous cell papilloma of the bronchus: comparison of in situ hybridization and the polymerase chain reaction

Thirty-one solitary bronchial squamous cell papillomas (SCPs) with variable degrees of dysplasia, one combined with larynx papilloma and small cell carcinoma in the contralateral lung, and 12 papillomas combined with invasive squamous cell carcinomas (SCCs) were investigated for the presence of human papilloma virus (HPV) DNA by in situ hybridization (ISH) and the polymerase chain reaction (PCR). Benign SCPs showed an association with HPV type 11 and rarely with type 6, whereas type 16 or 18, sometimes in combination with type 31/33/35, was found in SCPs associated with SCCs. In one patient HPV type 18- and 31/33/35-positive benign SCP preceded the recurrence of HPV 18-positive SCP (this time combined with carcinoma) by 2 years. Patients with SCP exhibiting HPV 16 or 18 positivity are at high risk for the development of SCC. Virus typing seems to be a better prognostic indicator than grading of dysplasia or age relationship. Virus typing by the PCR is more sensitive compared with ISH, but positive cells cannot be determined; ISH is less sensitive than the PCR but permits a definite designation of the cell types that have integrated HPV sequences into their DNA. Our data suggest that HPV typing should be performed in every bronchial SCP.

Detection of human papillomavirus DNA and mRNA using synthetic, type-specific oligonucleotide probes

Type-specific 30'mer-36'mer oligonucleotide probes complementary to mRNA transcribed from the E6 and E7 open reading frames of HPV 6b/11, 16, 18 and 33 were designed using the published nucleotide sequences. As oligonucleotides are easily and relatively cheaply synthesized in large amounts and are free of vector DNA, they were assessed for potential use in routine clinical detection and typing of HPV. Multiple Southern and dot blots of cloned HPV 6b, 11, 16, 18, 31 and 33 DNA, and of DNA extracted from cell lines carrying integrated HPV 16 and 18 genomes were prepared. In addition, Northern and dot blots of RNA extracted from the HPV-containing cell lines HeLa, CaSki and SiHa, were also prepared. All filters were first probed with the oligonucleotide and then with the corresponding full-genomic HPV DNA probe and their relative sensitivities and specificities compared: both probe types were labelled with 32P. The oligonucleotide probes were all as specific as the full-genomic probes for Southern, DNA and RNA dot blot hybridisations. The HPV 16 and 18 oligonucleotide probes detected HPV transcripts of the appropriate sizes in the cell line RNA. For DNA detection, oligonucleotide probes were up to 10 times less sensitive than the full-genomic probes, but for RNA detection, they were more sensitive. The sensitivity for both HPV DNA and RNA detection could be improved by using two type-specific oligonucleotide probes in combination, without reducing the specificity. The ease of preparation and handling of oligonucleotide probes, together with their lack of contaminating vector DNA, suggests that they may have some advantages over full-genomic probes for the clinical detection and typing of HPV.

Characterization of HPV-16 E6/E7 transcription in CaSki cells by quantitative PCR

Human papillomavirus (HPV) is associated with specific benign and malignant lesions of the epithelial and mucosal surfaces. Of the sexually transmitted types, HPV type 16 (HPV-16) is the most commonly associated with carcinoma of the uterine cervix. Expression of the E6/E7 open reading frame of the viral genome is considered critical in the development of neoplasia. Using the CaSki cervical carcinoma cell line as a model system, we have adapted the polymerase chain reaction to quantify the transcripts expressed from this region. It was found that 97.1% of the total spliced transcript is E6*I, which putatively encodes the E7 oncoprotein, while E6*II comprises 2.9% of spliced product. The ratio of E6*I to E6*II expression may be an important parameter in evaluating the disease risk associated with HPV-16 infection.

The predictive value of human papilloma virus (HPV) typing in the prognosis of bronchial squamous cell papillomas

Five solitary squamous papillomas of bronchus with variable degrees of dysplasia, one combined with a laryngeal papilloma and with a neuroendocrine carcinoma in the contralateral lung, and five papillomas combined with invasive squamous cell carcinomas were investigated for their expression of human papilloma virus DNA by in situ hybridization. Benign squamous cell papillomas showed an association with papilloma virus type 11 and rarely type 6, whereas types 16 or 18, sometimes in combination with types 31/33/35 were found in papillomas associated with carcinomas. In one patient a benign papilloma containing human papilloma virus type 18 and 31/33/35-positive preceded a recurrence combined with carcinoma by 2 years; this recurrent papilloma and the carcinoma were also positive for human papilloma virus 18 DNA. We suggest that human papilloma virus typing should be performed in every squamous cell papilloma of bronchus. Patients with papillomas exhibiting human papilloma virus 16 or 18 positivity are at high risk for the development of squamous cell carcinoma. Furthermore, virus typing may be of prognostic importance in relation to the development of squamous carcinoma.

Conservation of HPV-16 E6/E7 ORF sequences in a cervical carcinoma

A cervical carcinoma that contained human papillomavirus (HPV)-16 homologous DNA was analyzed. Each tumor cell genome contained a single, incomplete copy of HPV-16 DNA. The E6 and E7 open reading frames (ORFs) were completely conserved relative to other published HPV-16 sequences. Much of the non-coding region (NCR) was free of base changes, including complete conservation of several regulatory elements. Multiple mutations were identified in the remaining integrated HPV-16 DNA, which was composed of parts of the L1 and E1 ORFs. The extraordinary conservation of the E6/E7 DNA sequence, as compared with other regions of the integrated HPV-16 DNA, supports the role of E6/E7 in tumorigenesis.

Human papillomavirus and c-myc/c-erbB2 in uterine and vulvar lesions

The aim of this study was to investigate papillomavirus (HPV)-DNA in precancer and cancer of the cervix, vulva, and endometrium by in situ/dot blot/Southern blot hybridization and polymerase chain reaction (PCR). Myc/erbB-2 expression was examined by Northern blot analysis. PCR was the most sensitive HPV detection method, demonstrating HPV-DNA in all pre-invasive and invasive cervical lesions (n = 21) and most (3 of 4) vulvar carcinomas in contrast to an overall rate of 60% with other techniques. Particular phenotypes (adenoid cystic/basal cell carcinoma of the vulva, cervical adenocarcinoma) were found to contain HPV. Endometrium harboured HPV not only in two cases of cervical cancer, but also in 3 of 8 primary endometrial carcinomas and 3 of 8 non-malignant conditions. Myc activation was confined to three squamous cell carcinomas, most markedly in one HPV-6-positive verrucous variant. ErbB-2 over-expression was only seen in one HPV-18 infected advanced endometrial tumour. Our findings point to a range of HPV-infected lesions broader than previously supposed and possible contributions of HPV-independent molecular events to carcinogenesis in this field.

Condylomata acuminata and risk of cancer: an epidemiological study

OBJECTIVE

To determine whether patients with condylomata acuminata have an increased risk of developing cancer.

DESIGN

Prospective cohort study on patients diagnosed as having condylomata acuminata. The number of malignant tumours in the cohort was compared with national incidences obtained from the Swedish Cancer Registry.

SETTING

Dermatology department of the Karolinska Hospital, Stockholm, Sweden.

SUBJECTS

3260 patients (2549 males and 711 females, median (range) age 23 (1-80) years) seen during 1969-84, with a mean follow up of 7.8 years.

MAIN OUTCOME MEASURES

Number of malignant tumours observed in the cohort during the study period and expected number from national incidence.

RESULTS

There were 27 malignancies in the study group. There was no significant increase genital cancer in females compared with the national incidence. Only one patient had invasive cervical cancer (relative risk = 1.8; 95% confidence interval 0 to 10.1). Seventeen women had cervical carcinoma in situ (1.5; 0.9 to 2.5) compared with an expected number of 11.5; this increase was not significant. For males 22 cancers were observed at all sites (1.6; 1.0 to 2.5). The number of genitourinary cancers observed in males was almost three times higher than expected (2.6; 1.2 to 5.0).

CONCLUSION

The results indicate that the risk of developing cervical carcinoma in situ or invasive cervical cancer after a genital human papillomavirus infection is less than previously thought. The implications of increase in the genitourinary malignancies in males are uncertain.

Prevalence of different types of human papillomavirus in cervical infection of north Italian women

We investigated the prevalences of human papillomavirus (HPV) of type 6, 11, 16, 18, 31, 33, 35 and 42 in 276 cervical tissue samples biopsied from a group of North-Italian women in which a HPV infection of the cervix had been suspected. The specimens were evaluated by conventional histological examination and by HPV typing, using Southern blot hybridization on the extracted DNA. We related different degrees of squamous cervical dysplasia, showing or not viral cytopathic effects, with the HPV types harboured in the lesions. Significant rising of HPV 16 prevalences was observed proceeding from mild to moderate and to severe dysplasias both in presence (r = 0.9623, P less than 0.01) and in absence (r = 0.879, P less than 0.05) of koilocytosis, while an opposite trend was detected for HPV 6 and 11. In our sampling we did not find HPV 35 DNA sequences; in all occasions HPV 31 was associated with mild dysplasias. The absolute prevalences of types 18, 33 and 42 were generally low (from 2 to 3%); they did not show any association with specific histological damage of the cervix or with significant patterns related with the progression of cervical dysplasia.

Detection and typing of human papillomavirus using the Vira Type "in situ" kit: comparison with a conventional dot blot technique

A new commercial kit (Vira Type "in situ", Life Technologies, Inc., Molecular Diagnostics Division, Guithersburg, Maryland, USA) for the detection of human papillomavirus (HPV) types 6, 11, 16, 18, 31, 33 and 35 in routinely processed human anogenital tissue was compared with a conventional dot blot assay for HPV 6, 11, 16 and 18. Both systems use double-stranded genomic DNA probes for the detection of type specific HPV DNA. The probes used on the dot blots were labelled with 32P and visualised autoradiographically. The Vira Type probes were labelled with biotin and visualised using a streptavidin-alkaline phosphatase conjugate with NBT-BCIP substrate. Biopsy specimens from the cervix, vagina, and vulva of 46 women were processed by both methods and compared. The histological diagnoses ranged from benign changes, to dysplasia, and invasive carcinoma. Overall, 50% of biopsy specimens were positive for HPV DNA by dot blot hybridisation; only 39% were positive by Vira Type in situ hybridisation. Three of the specimens positive by the Vira Type "in situ" kit showed no cross hybridisation and were the same HPV type as the dot blot. A further 13 showed hybridisation, but the showed cross hybridisation, but the to the dot blot results. One biopsy specimen was positive for different HPV types by the two tests and one was positive by Vira Type and negative by dot blot. Six biopsy specimens were negative by Vira Type but positive by dot blot. It is concluded that the Vira Type "in situ" kit has a similar specificity but lower sensitivity than the dot blot hybridisation method for the detection of HPV DNA.

Cytologic diagnosis of human papillomavirus infection: spindled nuclei

The classic cytologic criteria, koilocytotic atypia and dyskeratocytosis, fail to identify most cases with colposcopic and histologic evidence of cervical condylomata. The purpose of this study was to identify a novel cytologic diagnostic criterion, spindled nuclei, to predict the presence of human papillomavirus (HPV) infection of the cervical epithelium. Review of the hospital records of 100 consecutive cases with spindled nuclei on Papanicolaou smear identified 36 patients in whom a colposcopic examination and/or cervical biopsy had been performed between January 1, 1988, and March 31, 1989. Ninety-seven percent of these 36 cases were positive by colposcopy and 89% of the cases were positive by cervical biopsy for changes of condyloma or intraepithelial neoplasia. HPV DNA hybridization in situ was positive in 16 of 36 patients, and the probe for types 31/33/35 most often stained histologic sections showing condylomatous change without concurrent dysplasia. Electron microscopy of spindled nuclei showed evidence of HPV-type viral particles in the five cases examined.

Role of human papillomavirus in the pathogenesis of genital tract warts and cancer

During the last decade a large number of clinical, epidemiological, and experimental studies have elucidated the role of HPV in the pathogenesis of anogenital cancer. Although the clinical and epidemiological studies have been criticized for a variety of technical and design shortcomings, for the most part they have independently reached the same conclusion--there is a strong association between the presence of specific types of HPV and the development of anogenital cancer. Similarly, laboratory studies clearly indicate that specific types of HPV act in concert with other cellular changes to transform a variety of cell types in vitro, including human cervical epithelial cells. Over the next decade the challenge is twofold. First we need to define precisely the mechanisms by which HPV either by itself or in concert with other factors, acts to transform anogenital epithelial cells. These studies will, it is hoped, identify important cofactors in the transformation process and determine the role of host immunity. Second, we need to determine the clinical applicability of the association between HPV and anogenital cancer. Large clinical studies will determine whether HPV testing of asymptomatic patients facilitates the detection of patients at risk for developing cervical cancer and whether the presence of a specific type of HPV in a cervical cancer actually affects a patient's prognosis. As the answers to these and other questions become available, we will be in a better position to assess the clinical importance of the associations between HPV and anogenital cancer.

Effect of the menstrual cycle on detection and typing of human papillomavirus in uterine cervical cells

We observe fluctuations in human papillomavirus detection and variation in genotyping between sequential cervical cell specimens analyzed by filter in situ hybridization. Furthermore, specimen adequacy for analysis varies. To determine whether these phenomena are correlated with menstrual cycle stage at the time of sampling, we analyzed cervical cell specimens from women with cervical intraepithelial neoplasia. Specimens were categorized on the basis of a 28-day menstrual cycle and were analyzed by hybridization to combined probes for virus types 6 and 11 or types 16 and 18. Specimen adequacy was determined by hybridization to a human Alu I repetitive deoxyribonucleic acid probe. Analysis of data with chi 2 revealed that fluctuations in virus detection and type variation are unrelated to menstrual cycle stage. Specimen adequacy is stage-dependent for women who take oral contraceptives. Whereas specimens can be collected at any time other than the first week of the menstrual cycle, accurate determination of infection status requires multiple assessments.

Occurrence of human papillomavirus DNA types 16 and 18 (HPV-16/18) in cervical smears as compared to cytological findings

Cervical smears from 2336 women were examined for the presence of HPV-16/18 by dot-blot hybridization using 32P-labeled HPV-16/18 DNA under high stringency conditions. The hybridization data were compared with cytological findings classified according to Papanicolaou. The ages of the patients ranged from under 20 to over 70 years. Ninety-eight (4.4%) of the 2237 cytologically normal cervical samples (Pap I and II) were HPV-16/18 positive. Thirteen out of 32 (40.6%) samples showing signs of mild and moderate dysplasia (Pap IIID) were found to be HPV-16/18 positive. In 5 out of 7 (71.4%) samples from women with severe dysplasia or carcinoma in situ (Pap IV) and in 9 out of 25 (32.1%) samples from patients with invasive cervical carcinoma (Pap V) HPV-16/18 DNA was detected. Thirty-two smears were from women with severe unspecific cervical inflammation (Pap III). Two (6.2%) out of them were HPV-16/18 positive. Normal smears showed an apparent age-dependent pattern of HPV-16/18 positivity with a peak prevalence of 10.6% among women younger than 20 years old. The majority of premalignant lesions was detected among women younger than 40 years old; whereas all invasive lesions were from women older than 39 years. Compared to the HPV-16/18 prevalence rate in normal smears, abnormal smears harbored HPV-16/18 DNA approximately 9 times more frequently. This finding supports the hypothesis that HPV-16/18 may be involved in the development of cervical cancer.

Demonstration of multiple HPV types in normal cervix and in cervical squamous cell carcinoma using the polymerase chain reaction on paraffin wax embedded material

The prevalence of human papilloma virus (HPV) types 6, 11, 16 and 18 was investigated using the polymerase chain reaction on formalin fixed, paraffin wax embedded material in 19 cases of cervical squamous cell carcinoma and in 10 normal cervices. HPV DNA was detected in 16 of 19 carcinomas, with multiple types present in 11 of these. HPV 16 or 18, or both, were present in all cases in which HPV was shown. Six of 10 cases of normal cervix contained HPV; five of these contained two or more HPV types, including HPV 16 or 18, or both. This study shows the feasibility of using the PCR on paraffin wax embedded material and indicates a high rate of carriage of multiple HPV types in both normal and neoplastic cervix.

Preferential sites for viral integration on mammalian genome

Chromosomal localization of human papillomavirus (HPV) 16 and 18 on human cervical carcinomas and epithelial cell lines obtained after HPV transfection has uncovered a nonrandom association of viral integration and specific genome sites. Fragile sites appear to be preferential targets for viral integration because of their structural and functional characteristics through which chromosomal anomalies, alterations in protooncogene activity, and gene amplification can occur. Individually or in association, such changes lead to the acquisition of an unlimited cell growth potential but not tumorigenicity. Genetic instability and uncontrolled cell division resulting from HPV integration increase the cell's susceptibility to other exogenous carcinogenic factors that may complete the process of neoplastic development.