Prevalence of six types of human papillomavirus in inverted papilloma and papillary transitional cell carcinoma of the bladder: an evaluation by polymerase chain reaction

The association between human papillomavirus and bladder cancer: Evidence from meta-analysis and two-sample mendelian randomization

INTRODUCTION

Bladder cancer (BCa) is the 10th most common type of cancer worldwide, and human papillomavirus (HPV) is the most common sexually transmitted infection. However, the relationship between HPV infection and the risk of BCa is still controversial and inconclusive.

METHODS

This systematic review and meta-analysis were conducted following the PRISMA 2020 reporting guideline. This study searched four bibliographic databases with no language limitation. The databases included PubMed (Medline), EMBASE, Cochrane Library, and Web of Science. Studies evaluating the interaction between HPV infection and the risk of BCa from inception through May 21, 2022, were identified and used in this study. This study estimated the overall and type-specific HPV prevalence and 95% confidence intervals (95% CI) using Random Effects models and Fixed Effects models. In addition, this study also calculated the pooled odds ratio and pooled risk ratio with 95% CI to assess the effect of HPV infection on the risk and prognosis of bladder cancer. Two-sample mendelian randomization (MR) study using genetic variants associated with HPV E7 protein as instrumental variables were also conducted.

RESULTS

This study retrieved 80 articles from the four bibliographic databases. Of the total, 27 were case-control studies, and 53 were cross-sectional studies. The results showed that the prevalence of HPV was 16% (95% CI: 11%-21%) among the BCa patients, most of which were HPV-16 (5.99% [95% CI: 3.03%-9.69%]) and HPV-18 (3.68% [95% CI: 1.72%-6.16%]) subtypes. However, the study found that the prevalence varied by region, detection method, BCa histological type, and sample source. A significantly increased risk of BCa was shown for the positivity of overall HPV (odds ratio [OR], 3.35 [95% CI: 1.75-6.43]), which was also influenced by study region, detection method, histological type, and sample source. In addition, the study found that HPV infection was significantly associated with the progression of BCa (RR, 1.73 [95% CI: 1.39-2.15]). The two-sample MR analysis found that both HPV 16 and 18 E7 protein exposure increased the risk of BCa (HPV 16 E7 protein: IVW OR per unit increase in protein level = 1.0004 [95% CI: 1.0002-1.0006]; p = 0.0011; HPV 18 E7 protein: IVW OR per unit increase in protein level = 1.0003 [95% CI: 1.0001-1.0005]; p = 0.0089).

CONCLUSION

In conclusion, HPV may play a role in bladder carcinogenesis and contribute to a worse prognosis for patients with BCa. Therefore, it is necessary for people, especially men, to get vaccinated for HPV vaccination to prevent bladder cancer.

Are bladder washing samples suitable for investigation of HPV infection in urinary bladder? Comparison in HPV prevalence between urine and washing samples

Although urine and bladder washing samples are commonly used for the cytological evaluation of the bladder mucosa, it has been unknown whether these samples are likely suitable to investigate human papillomavirus (HPV) prevalence in the urinary bladder. The present study aimed to elucidate the appropriateness of spontaneously voided urine or bladder washing in screening HPV infection in the urinary bladder. Urine and bladder washing samples were obtained from 201 patients who underwent transurethral bladder tumor resection. After extracting DNA from both samples, HPV-DNA was examined using a nested polymerase chain reaction with GP5+/6+ and MY09/11 primers. HPV genotyping was performed in the HPV-positive samples. In situ hybridization (ISH) was performed to observe the HPV-DNA localization in urothelial cells among cytological samples and paraffin-embedded tumor tissues in HPV-positive washing samples. HPV prevalence in urine and washing samples were 9.5% and 7.0%, respectively. High-risk HPV prevalence in urine and washing samples was 7.5% and 4.0%, respectively. The most common HPV type was HPV 16, followed by HPV 52 and HPV 18 in both samples. HPV type distribution in both samples was not in agreement (κ = -0.431). The ISH analysis revealed that HPV-DNA signal was observed in urothelial cells of five (55.7%) of nine detectable HPV-positive cytological samples. Six (66.7%) of nine HPV-positive cases had HPV-DNA signals in tumor tissue. The use of washing samples was likely applicable for investigating HPV prevalence in the urinary bladder. HPV-DNA detected in washing samples might be frequently derived from the urinary bladder.

Prevalence of Human Papilloma Virus Infection in Bladder Cancer: A Systematic Review

The etiology of bladder cancer is known to be associated with behavioral and environmental factors. Moreover, several studies suggested a potential role of HPV infection in the pathogenesis with controversial results. A systematic review was conducted to assess the role of HPV. A total of 46 articles that reported the prevalence of HPV infection in squamous (SCC), urothelial (UC), and transitional cell carcinomas (TCC) were selected. A pooled prevalence of 19% was found, with a significant difference in SCC that was mainly driven by HPV-16. Moreover, infection prevalence in case-control studies showed a higher risk of bladder cancer in HPV-positive cases (OR: 7.84; p-value < 0.00001). The results may suggest an etiologic role of HPV in bladder cancer. HPV vaccine administration in both sexes could be key to prevent the infection caused by high-risk genotypes.

A clinical and molecular review of inverted papilloma of the urinary tract: how to handle?

Inverted papilloma (IP) of the urinary tract is classified by the World Health Organisation as a non-invasive urothelial tumour with normal to minimal cytological atypia of the neoplastic cells. During the 1980s, it came under suspicion of having a premalignant or malignant potential and of being concurrent with urothelial cell carcinoma (UCC). This quandary has been proven difficult to solve, due to the fact that IP is very rare and literature mostly consists of case reports with varying levels of information, making strong meta-analyses problematic. New immunohistochemical techniques and genetic approaches are more frequently being used in the attempt to achieve better classifications, prognosis and treatment of lesions hereunder IP. This review will, in our awareness, be the first to combine the knowledge from retrospective studies with these new approaches for determining a possible premalignant potential and concurrency with UCC and subsequently outline a recommendation for follow-up.

Human papillomavirus infection and pathogenesis in urothelial cells: a mini-review

Several recent studies described that high-risk human papillomavirus (HPV) infection could have a potential role in the development of malignancies other than cervical cancer, such as laryngeal carcinoma, penile carcinoma, and anal carcinoma. However, the etiological role of HPV infection in the pathogenesis of urinary tract has not been clarified. Many epidemiological studies demonstrated that HPV infections frequently occur in the external genitalia through sexual contact; however, it was reported that HPV infection could also occur in the urinary tract, including the urethra and urinary bladder. Some morphological changes of cells associated with HPV infection and mild atypical cells, suspected to be intraneoplasia, were seen in HPV-positive samples obtained from the urinary tract. Some clinical studies and meta-analysis have indicated that HPV infection is likely to have a certain etiological correlation with the development of bladder carcinoma, although its prevalence may vary according to HPV type, study population, region, histological type, detection methods, and other variables. According to the results of previous studies, the prevalence of HPV greatly widely varies in cases of bladder carcinoma. Further research by case-control or large-scales studies is thus required to reach a more definite conclusion.

HRAS mutations are frequent in inverted urothelial neoplasms

Inverted urothelial papilloma (IUP) is an uncommon neoplasm of the urinary bladder with distinct morphologic features. Studies regarding the role of human papillomavirus (HPV) in the etiology of IUP have provided conflicting evidence of HPV infection. In addition, little is known regarding the molecular alterations present in IUP or other urothelial neoplasms, which might demonstrate inverted growth pattern like low-grade or high-grade urothelial carcinoma (UCA). Here, we evaluated for the presence of common driving somatic mutations and HPV within a cohort of IUPs, (n = 7) noninvasive low-grade papillary UCAs with inverted growth pattern (n = 5), and noninvasive high-grade papillary UCAs with inverted growth pattern (n = 8). HPV was not detected in any case of IUP or inverted UCA by either in situ hybridization or by polymerase chain reaction. Next-generation sequencing identified recurrent mutations in HRAS (Q61R) in 3 of 5 IUPs, described for the first time in this neoplasm. Additional mutations of Ras pathway members were detected including HRAS, KRAS, and BRAF. The presence of Ras pathway member mutations at a relatively high rate suggests this pathway may contribute to pathogenesis of inverted urothelial neoplasms. In addition, we did not find any evidence supporting a role for HPV in the etiology of IUP.

Human papillomavirus is not an etiologic agent of urothelial inverted papillomas

Inverted papilloma of the urinary bladder is rare, accounting for <1% of all bladder neoplasms. Although there is general consensus that inverted papilloma is benign in nature, little is known about its pathogenesis. Some have suggested that human papillomavirus (HPV) plays an etiologic role in the development of this neoplasm. These claims have not been adequately substantiated, and there is controversy as to the role of HPV in other urinary bladder neoplasms as well. To further investigate a possible etiologic role of HPV in urothelial neoplasia, we evaluated 27 inverted papillomas of the urinary bladder for the presence of HPV. Both immunohistochemical and in situ hybridization (ISH) studies for HPV and immunohistochemical analysis for p16, a surrogate marker for HPV infection, were used to assess HPV infection status. In the urinary bladder inverted papillomas of these 27 patients (age range, 35 to 78 y; M:F ratio, 11:1), no HPV was detected by HPV immunohistochemistry or by ISH. Immunoreactivity to p16 was detected in 11/27 (41%) of the cases. Expression of p16 is seen inconsistently within these neoplasms and does not correlate with the presence of HPV antigens or genes by immunohistochemistry or ISH, respectively. Therefore, p16 is not a reliable surrogate marker for HPV infection in urothelial inverted papilloma. Our findings indicate the absence of HPV in urothelial inverted papillomas. HPV testing should not be used as a diagnostic adjunct for inverted papilloma cases.

Overexpression of p16(INK4a) in urothelial carcinoma in situ is a marker for MAPK-mediated epithelial-mesenchymal transition but is not related to human papillomavirus infection

BACKGROUND

The role of human papillomavirus (HPV) in bladder carcinogenesis remains controversial. Overexpression of p16(INK4a), a surrogate marker for infection with oncogenic HPV in other tumours, has been described for urothelial carcinoma in situ (UCIS). Our goal was therefore to evaluate whether overexpression of p16(INK4a) is associated with HPV infection and to identify mechanisms of p16(INK4a) upregulation in UCIS.

MATERIALS AND METHODS

In 60 tissue specimens from a total of 45 patients (UCIS and controls), we performed p16(INK4a) immunohistochemistry followed by detection and subclassification of HPV DNA. In a subset of samples, we tested for gene amplification of p16(INK4a) applying fluorescence in situ hybridization (FISH). RAS/MAPK signalling and epithelial-mesenchymal transition (EMT) was assessed using immunohistochemistry. Finally, we transfected urothelial carcinoma cells with KRAS and examined the expression of p16(INK4a) as well as markers of EMT.

RESULTS

We found overexpression of p16(INK4a) in 92.6% of UCIS and in all cervical intraepithelial neoplasia (CIN) controls. In contrast, we detected high-risk HPV DNA in 80% of CIN, but none in UCIS. There was no gene amplification of p16(INK4a). High levels of phosphorylated kinases and urokinase plasminogen activator (uPA) and loss of membraneous E-cadherin were detected in UCIS. KRAS transfection of urothelial carcinoma cells led to upregulation of p16(INK4a) and uPA accompanied by loss of E-cadherin that could be inhibited by application of the kinase-inhibitor Sorafenib.

CONCLUSIONS

Our results show that overexpression of p16(INK4a) in UCIS is neither associated with HPV infection nor p16(INK4a) gene amplification but is a consequence of enhanced RAS/MAPK signalling that promotes EMT, possibly due to Sorafenib-sensitive paracrine secretion of the EMT activator uPA. These findings might open a novel therapeutic option for localized but aggressive urothelial cancer.

Urothelial carcinoma with prominent squamous differentiation in the setting of neurogenic bladder: role of human papillomavirus infection

Squamous cell carcinomas of the urinary bladder are rare in the Western world; the majority of cases are reported in countries endemic to Schistosoma parasitic infections. Unlike squamous tumors of the uterine cervix or oropharynx, the human papillomavirus (HPV) is not commonly associated with bladder squamous cell carcinomas. We report on two cases of HPV-positive urothelial carcinomas of the urinary bladder with extensive squamous differentiation showing the typical basaloid, poorly differentiated morphology of HPV-associated tumors. These occurred in patients with neurogenic bladders who had long-standing histories of self-catheterization with tumors that tested positive for HPV by in situ hybridization. A retrospective review of our institutional database revealed four additional patients with bladder tumors showing squamous differentiation arising in the setting of neurogenic bladder. Review of these cases showed the more common well-differentiated keratinizing appearance of squamous cell carcinomas of the bladder. These tumors showed only patchy positivity for p16 immunohistochemical stain (not the diffuse strong staining seen in HPV-positive tumors), and the one tested case was negative for HPV by in situ hybridization. HPV infection and neurogenic bladder have been independently associated with increased risk of developing carcinoma in the urinary bladder; however, this is the first report of squamous tumors arising in the setting of concurrent neurogenic bladder and HPV infection. The morphology of these tumors is similar to that of other high-risk HPV-associated squamous carcinomas with a basaloid, poorly differentiated appearance and little to no keratin formation.

Meta-analysis of studies analyzing the role of human papillomavirus in the development of bladder carcinoma

PURPOSE

We aimed to ascertain the degree of association between bladder cancer and human papillomavirus (HPV) infection.

MATERIALS AND METHODS

We performed a meta-analysis of observational studies with cases and controls with publication dates up to January 2011. The PubMed electronic database was searched by using the key words "bladder cancer and virus." Twenty-one articles were selected that met the required methodological criteria. We implemented an internal quality control system to verify the selected search method. We analyzed the pooled effect of all the studies and also analyzed the techniques used as follows: 1) studies with DNA-based techniques, among which we found studies with polymerase chain reaction (PCR)-based techniques and 2) studies with non-PCR-based techniques, and studies with non-DNA-based techniques.

RESULTS

Taking into account the 21 studies that were included in the meta-analysis, we obtained a heterogeneity chi-squared value of Q(exp)=26.45 (p=0.383). The pooled odds ratio (OR) was 2.13 (95% confidence interval [CI], 1.54 to 2.95), which points to a significant effect between HPV and bladder cancer. Twenty studies assessed the presence of DNA. The overall effect showed a significant relationship between virus presence and bladder cancer, with a pooled OR of 2.19 (95% CI, 1.40 to 3.43). Of the other six studies, four examined the virus's capsid antigen and two detected antibodies in serum by Western blot. The estimated pooled OR in this group was 2.11 (95% CI, 1.27 to 3.51), which confirmed the relationship between the presence of virus and cancer.

CONCLUSIONS

The pooled OR value showed a moderate relationship between viral infection and bladder tumors.

Coincidence of HPV11-Positive Urethral Condyloma Acuminatum and HPV-Negative Multiple Bladder Papillomas in a Female

Human papillomaviruses (HPVs) are associated with proliferative lesions in a variety of human epithelial types. A 38-year-old female presented with a diagnosis of urethral condyloma acuminatum. She underwent transurethral resection of the urethral condyloma. At that time, multiple (five) bladder tumors were simultaneously found and also removed by transurethral resection. Four of the bladder tumors were diagnosed as squamous papilloma, and the other was urothelial inverted papilloma. Postoperative course was uneventful. Genomic DNA was extracted from 10 μm thick sections of each bladder tumor as well as urethral condyloma. Then, 16 types of HPV DNA sequences were assessed with the PapiPlex method using genomic DNA samples extracted from each bladder tumor as well as urethral condyloma. HPV-11 was detected in DNA extracted from the urethral condyloma, while no HPV DNA sequences were positive in any of the genomic DNA samples extracted from the bladder tumors.

Human papillomavirus infection and bladder cancer risk: a meta-analysis

BACKGROUND

Despite an increase in the number of molecular epidemiological studies conducted in recent years to evaluate the association between human papillomavirus (HPV) infection and risk of bladder cancer, the studies remain inconclusive.

METHODS

The prevalence of HPV in bladder cancer was estimated by pooling data from 52 studies, taking into consideration the heterogeneity from major related parameters including study region, histological type, HPV DNA specimen, publication calendar period, and detection method. Moreover, the association of HPV infection with bladder cancer was tested by a meta-analysis with 19 case-control studies.

RESULTS

An HPV prevalence of 16.88% (95% confidence interval [CI], 15.53%-18.31%) among the bladder cancer cases was revealed, most of whom were high-risk HPV types (15.82% [95% CI, 14.37%-17.36%]). The prevalence varied by region, types of HPV DNA specimen, and polymerase chain reaction primers used. A significantly increased risk of bladder cancer was shown for the positivity of overall HPV (odds ratio, 2.84 [95% CI, 1.39-5.80]), which was also infuenced by HPV type, study region, HPV DNA specimen, and detection method.

CONCLUSIONS

Infection of high-risk HPV types, especially HPV16, may play a role in bladder carcinogenesis.

Etiological role of human papillomavirus infection for inverted papilloma of the bladder

The status of human papillomavirus (HPV) infection in urothelial inverted papilloma was examined in the present study. Formalin-fixed and paraffin-embedded tissues from eight cases of inverted papilloma of the bladder were studied. The presence of HPV-DNA was examined by modified GP5/6+PCR using archival tissue sections by microdissection. HPV genotype was determined with a Hybri-Max HPV genotyping kit. Immunohistochemical analysis for p16-INK4a, mcm7, HPV-E4, and L1, and in situ hybridization for the HPV genome were performed. HPV was detected in seven of eight cases (87.5%) of inverted papilloma. Three cases were diagnosed as inverted papilloma with atypia, while the remaining five were typical cases. HPV-18 was detected in two cases, including one inverted papilloma with atypia, and HPV-16 was detected in four cases, including one inverted papilloma with atypia. Multiple HPV type infection was detected in one typical case and one atypical case. High-risk HPV was present in all HPV-positive cases. Cellular proteins, p16-INK4a and mcm7, which are surrogate markers for HPV-E7 expression, were detected in all HPV-positive cases, and their levels were higher in inverted papilloma with atypia than in typical cases. In contrast, HPV-E4 and L1, which are markers for HPV propagation, were observed in some parts of the typical inverted papilloma tissue. High-risk HPV infection may be one of the causes of urothelial inverted papilloma, and inverted papilloma with atypia may have malignant potential.

Vaccination against human papilloma virus (HPV): epidemiological evidence of HPV in non-genital cancers

Recently, the vaccine against human papillomavirus (HPV) was introduced in the national vaccination programmes of several countries worldwide. The established association between HPV and the progression of cervical neoplasia provides evidence of the expected protection of the vaccine against cervical cancer. During the last two decades several studies have also examined the possible involvement of HPV in non-genital cancers and have proposed the presence of HPV in oesophageal, laryngeal, oropharyngeal, lung, urothelial, breast and colon cancers. The possible involvement of HPV in these types of cancer would necessitate the introduction of the vaccine in both boys and girls. However, the role of HPV in the pathogenesis of these types of cancer has yet to be proven. Moreover, the controversial evidence of the possible impact of the vaccination against HPV in the prevention of non-genital cancers needs to be further evaluated. In this review, we present an overview of the existing epidemiological evidence regarding the detection of HPV in non-genital cancers.

Human papillomavirus and p16 expression in inverted papillomas of the urinary bladder

Human Papillomaviruses (HPVs) have been found in association with benign and malignant growth of epithelia. The cell cycle inhibitor p16(Ink4a) has been shown to be overexpressed in HPV-positive cervical pre-malignant and malignant lesions, probably as a result of pRB targeting by the viral E7 protein. Inverted papillomas of the urinary bladder are epithelial tumors considered to be of benign nature. In this report we analyze the expression of p16(Ink4a) and the presence of HPV sequences in inverted papillomas and in non-tumoral bladder controls. Our results show no association of HPV infection and inverted papillomas. Further, no correlation between p16 overexpression and HPV positivity was found. We conclude that HPV does not play an indispensable role in the development of urinary bladder inverted papillomas and that overexpression of p16(Ink4a) does not correlate with HPV infection in these tumors.

Role of human papillomavirus types 16, 18, and 52 in recurrent cystitis and urinary bladder cancer among Egyptian patients

BACKGROUND

Bladder cancer is a common malignancy in Egypt. Human papillomavirus (HPV) could have a possible etiologic role in bladder carcinogenesis. We aimed to estimate the prevalence of HPV-16, -18, and -52 in Egyptian patients with bladder cancer or recurrent cystitis, and to study the correlation of type-specific HPV-immunoglobulin (Ig)G with polymerase chain reaction (PCR) results and different clinicopathologic parameters.

METHODS

This study was conducted on 60 inpatients of the Urosurgery Department at the Theodor Bilharz Research Institute (TBRI), who were identified histopathologically and clinically as cancer bladder (group I, 20 patients), cystitis (group II, 24 patients), and cancer bladder with cystitis (group III, 16 patients), and a fourth group of 20 healthy control subjects (for serologic testing). Patients were subjected to detection of HPV-16 and -18 DNA by PCR on bladder tissue biopsies (BTB) and buffy coat cells (BCC) and serum IgG antibodies to L1 capsids of HPV-16 and -52 IgG by enzyme-linked immunosorbent assay (ELISA).

RESULTS

HPV-16 and -18 DNA were detected in BTB (30% and 10%, respectively) with significantly higher rates (44.4%) in bladder cancer than cystitis cases (11.11%), with significant association with schistosomal affection (78.6% and 25%, respectively) and recurrence (48%, HPV-16). There was a significant association of transitional cell carcinoma (TCC) with HPV-16 in 69.2% and 61.1% of BCC and BTB, respectively. Multiple HPV types 16, 18, and 52 were significantly higher than single types (79.2% and 20.8%, respectively). The observed absolute association between seropositivity of HPV-52 (11.7%) and HPV-16 (26.7%) was significantly associated with TCC in patient groups only.

CONCLUSION

Our study confirmed the significant association of HPV-16, -18 and -52 with bladder cancer in Egyptian patients, with the suggestion of viral synergistic action in bladder carcinogenesis. Such HPV types were significantly associated with TCC tumors of low grade and high stage, with schistosomal affection and recurrence tendency. HPV serology would pave the way for better management and follow-up of patients and for optimal design and evaluation of HPV vaccination.

Análisis estadístico de la influencia del virus del papiloma humano en el desarrollo del carcinoma vesical

INTRODUCTION

The bladder cancer is an important disease by its morbi-mortality and its multifactorialidad. At the moment, between the possible aetiology agents that they have been indicated is the infection by the virus of papilloma human (VPH). The objective study is to analyse, by meta-analysis, the relationship between bladder cancer and infection by human papillomavirus.

MATERIAL AND METHODS

We made a search in the electronic data base MEDLINE of the articles published until September of the 2004 that relate the infection of the VPH to the bladder tumors. Of 414 listed articles, we selected 38 articles.

RESULTS

The articles were classified in two groups, according to they use or non methods based on the detection of the DNA. In articles based on the detection of the DNA, it was that the global proportion from the cases that had contact with the virus, through the detection of the genome was of the 19.4% (95% CI 0.160 to 0.228). Of the total of studies based on the detection of the DNA 8 were selected, to show to a group defined control, in which, the OR was investigated. If we combined the ORs, we obtain an OR estimation of 3.2 (95% CI 1.19 to 8.60) and p = 0.02.

CONCLUSIONS

Most of these studies showed the relation rose at the beginning of the study. Although the majority lacked a group defined control, is possible to analyze the value of the Odds global ratio due to the homogenous behaviour of the studies with defined cases and controls affluent. This demonstrated to association between VPH and the bladder cancer.

Meta-analysis of studies analyzing the relationship between bladder cancer and infection by human papillomavirus

PURPOSE

Studies have been done of the possibility that infection by human papillomavirus is a risk factor contributing to bladder cancer but no definite conclusions have yet been drawn. We performed a meta-analysis of observational studies published until July 2005 to ascertain the degree of association between bladder cancer and human papillomavirus infection.

MATERIALS AND METHODS

The MEDLINE database was searched using the key words bladder cancer and virus. Strict criteria were applied to select studies revealing the prevalence in serum of human papillomavirus infection or its direct detection in patients. A total of 44 articles with these methodological criteria were chosen.

RESULTS

In 39 studies the investigators determined the presence of human papillomavirus DNA, and found a prevalence of between 0% and 100% and significant homogeneity analysis (p <0.001). Pooled estimation of the presence of the infection was 16.0% (95% CI 12.8 to 19.1). Pooled OR estimation was 2.3 (95% CI 1.3 to 4.1) with no significant publication bias. In 7 studies human papillomavirus infection was studied by detecting the antigen or antibodies and a prevalence of between 14% and 60% was found with significant homogeneity analysis (p <0.001). Pooled estimation of the prevalence of infection was 32.4% (95% CI 17.0 to 47.8). Pooled OR estimation was 2.9 (95% CI 1.7 to 5.3).

CONCLUSIONS

Finding a relationship between bladder cancer and human papillomavirus depends on the method used. In the literature examined there are insufficient cases and samples compared to controls and studies rely on a combination of various microbiological techniques in the same patient and sample, making it difficult to draw any definite conclusion.

IS SURVEILLANCE NECESSARY FOR INVERTED PAPILLOMA IN THE URINARY BLADDER AND URETHRA?

BACKGROUND

A case series of inverted papilloma of the urinary bladder and urethra is presented, together with a review of the literature with respect to multiplicity, recurrence rate and association with transitional cell carcinoma, and a discussion on surveillance of the lesion.

METHODS

Cases of inverted papilloma of the lower urinary tract in a single centre were reviewed. Patient and tumour characteristics, recurrence and associated transitional cell carcinoma are reported.

RESULTS

Twenty patients were included (18 male, two female). The mean age was 60.8 years (range 35-78 years). All had solitary tumours ranging from 3 mm to 30 mm in size. Median cystoscopic follow up was 30 months (range 2-140 months). There was no recurrence. One patient was associated with subsequent transitional cell carcinoma 44 and 76 months later. Together with the present 20 cases, review of the English literature with respect to inverted papilloma of the lower urinary tract identified a total of 322 cases reported, with a recurrence rate of 3.85%. Moreover, 1.55%, 5.90% and 1.54% were associated with previous, simultaneous and subsequent transitional cell carcinoma, respectively.

CONCLUSIONS

Recurrence is not uncommon and risk of subsequent transitional cell carcinoma is not rare, such that non-invasive surveillance with flexible cystoscopy is recommended for inverted papilloma of the lower urinary tract.

Does human papillomavirus play a role in the development of bladder transitional cell carcinoma? A comparison of PCR and immunohistochemical analysis

AIM

To investigate the role of human papillomavirus (HPV) in the development of bladder transitional cell carcinoma (TCC).

METHODS

Seventy eight paraffin wax embedded TCC samples were tested for the presence of HPV by two methods. First, immunohistochemistry was carried out using a polyclonal antibody capable of detecting the capsid protein of all known papillomaviruses. The second method was a consensus GP5+/6+ primer mediated polymerase chain reaction (PCR) technique, with the products analysed by both agarose gel electrophoresis and an enzyme immunoassay using type specific oligonucleotide probes for 10 different mucosal genotypes. To exclude false negative results because of the poor quality of DNA extracted from paraffin wax embedded samples, the series was extended to include 20 further blocks for which the corresponding snap frozen unfixed tissue was available.

RESULTS

The two methods produced contrasting results, with 47 of the 78 samples positive for HPV antigen and none positive for HPV DNA. HPV DNA was not detected in the 20 additional paraffin wax embedded TCCs or in the 20 paired unfixed samples. In contrast, HPV DNA was amplified by PCR from all six of the paraffin wax embedded cervical carcinoma and anogenital wart control samples.

CONCLUSION

The disparity between the two sets of results is probably caused by false positives resulting from the non-specificity of the polyclonal antibody used for immunohistochemistry. These results suggest that HPV is unlikely to play an aetiological role in the development of bladder TCC.

Human papillomavirus infection of the epididymis and ductus deferens: an evaluation by nested polymerase chain reaction

CONTEXT

Human papillomaviruses (HPVs) play an important role in the etiology of squamous cell carcinoma of the uterine cervix. The possible role of the male urogenital tract as a reservoir of HPV infection is not fully understood. We inferred from our previous observation of HPV-31 in epididymal tissue in a case of chronic epididymitis that HPV might be commonly present in cases of epididymitis caused by sexually transmitted pathogens.

OBJECTIVE

To assess the presence of HPV in the epididymis and ductus deferens in nontuberculous epididymitis.

DESIGN

Epididymal samples obtained from 17 patients and epididymal and ductus deferens samples from 5 patients surgically treated for nontuberculous epididymitis were analyzed by nested polymerase chain reaction for the presence of HPV DNA. In positive samples, the HPV type was determined by DNA sequencing.

SETTING

Tertiary-care academic hospital and national reference laboratory for papillomaviruses.

RESULTS

Low-risk HPV type 6 and high-risk HPV types 16, 33, 35, 55, and 73 were detected in 7 patients (31%). Neither koilocytes nor dysplastic changes were found in the epididymis and ductus deferens.

CONCLUSION

Low-risk and high-risk HPV types were detected in the epididymis and ductus deferens of patients with nontuberculous epididymitis. The infection was not accompanied by koilocytic atypia or dysplasia. Our findings support the hypothesis that the male urogenital tract serves as a reservoir of HPV infection.

Transitional cell metaplasia of the uterine cervix is related to human papillomavirus: molecular analysis in seven patients with cytohistologic correlation

BACKGROUND

Transitional cell metaplasia of the uterine cervix is an under-recognized entity in cervical pathology. The underlying etiology and biologic significance remains uncertain. The thin-layer cytology findings and association with human papillomavirus (HPV) have not been studied thoroughly.

METHODS

The authors retrospectively reviewed the clinical findings, thin-layer cytology and histologic features of pure transitional cell metaplasia of the uterine cervix occurring in seven perimenopausal or postmenopausal Chinese women at Pamela Youde Nethersole Eastern Hospital, Hong Kong, during the period from January, 1998 to April, 2001. Molecular techniques for HPV screening and genotyping using polymerase chain reaction and restriction fragment length polymorphism analysis were employed in the thin-layer cytology specimens and paraffin block material.

RESULTS

In all seven patients, transitional cell metaplasia represented an incidental histologic finding. It occurred in the ectocervix, transformation zone, endocervix, or vagina. Histologically, it resembled urothelium of the urinary bladder and was comprised of multilayers of mitotically inactive, immature epithelial cells with vertically aligned oval nuclei, fine chromatin, indistinct nucleoli, and conspicuous longitudinal nuclear grooves. The superficial cells were oriented more horizontally and contained pale-staining cytoplasm similar to umbrella cells. Features consistent with transitional cell metaplasia were identified in two of seven preoperative thin-layer preparations. Cytologically, the affected parabasal cells recapitulated the features that were seen in histologic sections. In addition to the bland nuclear morphology and longitudinal nuclear grooves, the cell borders appeared distinct, and the appearance of a perinuclear cytoplasmic halo was common. Sometimes, the metaplastic cells assumed a spindle shape and appeared as cohesive, streaming cell clusters. Molecular study successfully demonstrated the presence of HPV in all seven patients, mostly in the liquid-based cytology samples. In general, the viral DNA load was relatively low; and, for samples in which HPV genotyping was feasible, HPV type 58 was the prevalent genotype.

CONCLUSIONS

The current study demonstrates that transitional cell metaplasia of the uterine cervix is related to HPV. It also carries a distinctive cytologic appearance in thin-layer preparations. Based on the limited follow-up data from a small number of reported patients, transitional cell metaplasia seems to run an indolent clinical course. However, its peculiar association with HPV and its possible correlation, both morphologic and histogenetic, with cervical intraepithelial neoplasia need further investigation.

Human papillomaviruses 6/11, 16/18 and 31/33/51 are not associated with squamous cell carcinoma of the urinary bladder

OBJECTIVE

To assess high-risk human papillomavirus (HPV), mainly HPV type 16, 18, 31 and 33 (an important aetiological factor in squamous cell carcinoma, SCC, of the anogenital region) in SCC of the urinary bladder.

MATERIAL AND METHODS

Sixteen SCC from the urinary bladder were evaluated using non-isotopic in situ hybridization with a sensitive detection system for the presence of high-risk HPV 16/18, or 31/33/51, and for HPV6/11, a low-risk type commonly found in condylomata. Previously published studies were also reviewed and assessed.

RESULTS

No high-risk HPV was found in any of the SCC of the bladder evaluated. Previous reports identified nine HPV-positive SCC of a total of 105, including the present series. In four of these positive cases, HPV types were found that are considered a high risk in anogenital carcinomas.

CONCLUSION

From the present and previous results, we conclude that HPV has no major role in the pathogenesis of SCC of the urinary bladder.