Detection and typing of human papillomavirus in anal epidermoid carcinomas: sequence variation in the E7 gene of human papillomavirus Type 16

Clinicopathological aspects and prevalence of human papillomavirus in anal cancer

Anal cancer is relatively rare; however, its incidence has increased in recent years. Several risk factors are associated with the development of anal cancer, including age older than 50 years, low-fiber diet, chronic anal fistulas, smoking, multiple partners, anal intercourse practice, Human Immunodeficiency Virus infection and immunosuppression. However, the presence of human papillomavirus represents the main risk factor for the development of anal cancer. The aim of this study was to evaluate the clinicopathological aspects of a series of patients with anal carcinomas diagnosed in Hospital Araújo Jorge, Goiânia-Goiás, as well as the prevalence of human papillomavirus genome in these tumors. Clinical, pathological and socio-demographic data were collected from the respective medical files and paraffin blocks containing anal carcinomas specimens were used for DNA extraction and detection of human papillomavirus, by means of polymerase chain reaction, using short PCR fragment primers. Forty-three cases were selected and had the data analyzed, while 38 cases were tested for human papillomavirus genome detection. Among the evaluated patients, 62.8% were women; 53.4% of tumors were squamous cell carcinoma and 46.5% of the patients were aged between 60 and 75 years. Risk factors, such as smoking (39.5%) and alcoholism (20.9%) were recorded in the studied group. Lymph node metastases were detected in 30.2% of cases and 7.0% had distant metastasis. The detection of human papillomavirus DNA was positive in 76% of cases assessed and this was significantly associated with squamous cell carcinomas. Aggressive behavior and advanced stage of anal cancer described in this study highlight the need for preventive measures that contemplate these tumors, including vaccination against human papillomavirus.

Genetic variations in E6, E7 and the long control region of human papillomavirus type 16 among patients with cervical lesions in Xinjiang, China

Background

Xinjiang is one of the areas with the highest incidence of cervical cancer in China. Genetic variation in Human papillomavirus type 16 (HPV16) may increase the ability of the virus to mediate carcinogenesis and immune escape, which are risk factors for the progression of cervical cancer. We investigated polymorphism in HPV16 and the distribution of its sub-lineages in the region by analyzing the E6, E7 and long control region (LCR) gene sequences from women with HPV16-positive cervical samples in Xinjiang.

Methods

A total of 138 cases of cervical lesions and squamous cell carcinoma with infection of HPV16 virus were collected. The E6 and E7 genes and LCR of HPV16 virus were sequenced and compared with the HPV16 European prototype reference and other HPV16 mutants for single nucleotide polymorphisms. Neighbor-joining phylogenetic trees were constructed using E6, E7 and LCR sequences.

Results

Fourteen missense mutations were found in the E6 gene; the loci with the highest mutation frequency were T350G (36/75, 48%) and T178G (19/75, 25.3%). In the E7 gene, the locus with the highest mutation frequency was A647G (18/75, 24%). A total of 33 polymorphic sites were found in the LCR, of which T7447C (39/95, 40.1%) was the most frequent.

Conclusion

HPV16 in Xinjiang is mainly of the European variant, followed by the Asian variant type; no Africa 1, 2 or Asia–America variant types were found.

Burden of Human papillomavirus (HPV)-related disease and potential impact of HPV vaccines in the Republic of Korea

Background

We aimed to review the burden and the potential impact of human papillomavirus (HPV) vaccines on HPV-related diseases in the Republic of Korea and to discuss cervical cancer prevention practices in this country.

Methods

Cancer burden statistics were retrieved from GLOBOCAN-2018 and Statistics Korea. HPV disease burden was assessed via systematic review. Vaccine types relative contribution (RC) was estimated using data from an international project using formalin-fixed paraffin-embedded specimens.

Results

Despite a downtrend in cervical cancer in recent years, Korean rates remain high. In contrast, oropharyngeal cancer incidence has gradually increased and other anogenital cancers remain rare.

In Korea, HPV prevalence in general population is around 20%. In cervical cancer, RC of HPVs 16/18 (74.0%) increased to 92.0% when including HPVs 31/33/45/52/58. Limited information was available for other HPV-related cancer sites.

Regarding prevention, since the inclusion of the HPV vaccine into the National Immunization Program, almost half (49%) of the target cohort in 2016 had received the first dose of vaccine. Further, percentage of women screened with pap has increased from 41.1%-2009 to 53.0%-2016.

Conclusions

HPV-related disease burden in Korea is significant. Results suggest that the combination of effective and high coverage HPV vaccination and screening programmes could substantially impact on HPV-related disease in Korea.

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HPV-related disease burden (cancer and genital warts) in Korea is significant.

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HPV16 is the most frequent genotype, causing itself more than 60% of HPV-related cancers.

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HPV vaccine types 16/18/31/33/45/52/58/6/11 cause 92.0% of cervical cancers.

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HPV vaccines could significantly impact on the HPV-related disease burden.

The economic burden of human papillomavirus-related precancers and cancers in Sweden

Background

High-risk (HR) human papillomavirus (HPV) infection is an established cause of malignant disease. We used a societal perspective to estimate the cost of HR HPV-related cervical, vulvar, vaginal, anal, and penile precancer and cancer, and oropharyngeal cancer in Sweden in 2006, 1 year before HPV vaccination became available in the country.

Materials and methods

This prevalence-based cost-of-illness study used diagnosis-specific data from national registries to determine the number of HR HPV-related precancers and cancers. The HR HPV-attributable fractions of these diseases were derived from a literature review and applied to the total burden to estimate HR HPV-attributable costs. Direct costs were based on health care utilization and indirect costs on loss of productivity due to morbidity (i.e., sick leave and early retirement) and premature mortality.

Results

The total annual cost of all HR HPV-attributable precancers and cancers was €94 million (€10.3/inhabitant). Direct costs accounted for €31.3 million (€3.4/inhabitant) of the total annual cost, and inpatient care amounted to €20.7 million of direct costs. Indirect costs made up €62.6 million (€6.9/inhabitant) of the total annual cost, and premature mortality amounted to €36 million of indirect costs. Cervical precancer and cancer was most costly (total annual cost €58.4 million). Among cancers affecting both genders, anal precancer and cancer, and oropharyngeal cancer were the most costly (€11.2 million and €11.9 million, respectively). For oropharyngeal cancer, males had the highest health care utilization and represented 71% of the total annual cost. Penile precancer and cancer was least costly (€2.6 million).

Conclusion

The economic burden of HR HPV-related precancers and cancers is substantial. The disease-related management and treatment costs we report are relevant as a point of reference for future economic evaluations investigating the overall benefits of HPV vaccination in females and males in Sweden.

Identificação do papilomavírus humano em doentes com carcinoma de células escamosas do canal anal e sua relação com o grau de diferenciação celular e estadiamento

OBJETIVO: Identificar os tipos de papilomavírus humano (HPV) nos portadores de carcinoma do canal anal (CCA), relacionando-os ao grau de diferenciação celular e estadiamento da lesão, em pacientes do Belém, Pará, entre 1998 e 2000. MÉTODOS: Foi realizado um estudo de caso-controle com 75 pacientes, divididos em: Grupo Teste, com 33 portadores de carcinoma do canal anal, e o Grupo Controle, com 42 portadores de doenças não-neoplásicas do canal anal. Os tipos virais foram identificados por PCR e dot blot. O teste exato de Fischer foi utilizado para avaliar a ocorrência de HPV. Adotou-se a tabela de contingência 3x2 para representar a distribuição dos tipos de HPV. Nos testes de hipóteses, foi prefixado o nível de significância α=0,05 para a rejeição da hipótese de nulidade. RESULTADOS: A prevalência do HPV foi significante entre os Grupos Teste (60,6%) e Controle (26,2%) (p=0,0027). Os tipos virais mais comuns foram 16 (42,4%) e 18 (15,2%). Observaram-se diferenças entre grupos na prevalência do HPV 16 (p=0,027) e 18 (p=0,043) no Grupo Teste, e o tipos 16 (19,0%,) e 18 em (2,4%) no Grupo Controle. No Grupo Teste, avaliou-se a distribuição dos tipos de HPV em relação ao estadiamento e ao grau de diferenciação celular, não apresentando diferenças estatisticamente significativas. CONCLUSÃO: O carcinoma de células escamosas do canal anal está associado à presença de HPV, e os tipos 16 e 18 são os mais frequentes

Anal intraepithelial neoplasia and other neoplastic precursor lesions of the anal canal and perianal region

Anal cancer is rare and this helps to explain why anal pre-neoplastic conditions are poorly understood, especially with regard to their natural history and management. Anal intraepithelial neoplasia is closely linked to human papillomavirus infection and is particularly common in homosexuals and in immunosuppressed patients, especially those with HIV/AIDS. The high regression rates of low-grade anal intraepithelial neoplasia may simply reflect inconsistent pathologic reporting. Higher grades of anal intraepithelial neoplasia may remain static for long periods of time in immunocompetent patients, but those with HIV/AIDS show early and rapid malignant transformation. In general, most anal pre-neoplastic conditions are best diagnosed by biopsy and treated by surgical excision, although local recurrence is a problem. In anal Paget's disease, it is important to ascertain, at the time of diagnosis, whether it is due to a primary in-situ apocrine-type of neoplasia of the anus or if the disease is secondary to an invasive primary carcinoma of the rectum.

Squamous cell carcinoma arising from recurrent anal fistula

Here, we report on a patient with squamous cell carcinoma (SCC) arising from recurrent anal fistula. The patient was a 57-year-old woman who had 32-year history of having a recurrent perianal abscesses that ruptured spontaneously. Six months before her admission to our hospital, anal pain developed. She had no history of inflammatory bowel disease. Physical examination revealed three external fistulous openings at the two o'clock position, 2 cm from the anal verge. One internal opening in the lower rectum was found with proctoscopy. The patient underwent fistulectomy. Microscopic examination showed SCC arising from the anal fistula, which was accompanied by vessel invasion. The tumor was observed to be continuous from the external opening but was not exposed to the internal opening of the rectal mucosa. Because human papillomavirus (HPV) infection was suspected, immunohistochemical analysis was performed, but showed no HPV infection. Two weeks after fistulectomy, abdominoperineal resection with lymph node dissection was performed. Histopathological examination revealed no remnant cancer tissue or lymph node metastasis. She was discharged after surgery without complications. Eight years after the operation, she complained of constant pain during micturition. Urological examination revealed urinary bladder cancer, and transurethral resection of the bladder tumor was performed. Histopathological examination revealed transitional cell carcinoma of the urinary bladder. Two years later, the patient died of metastatic urinary bladder cancer, without recurrence of the fistula cancer. Because the patients mother had died of urinary bladder cancer and she herself had metachronous urinary bladder cancer in addition to fistula cancer, we investigated whether microsatellite instability (MSI) and chromosomal instability correlated with fistula cancer development. Immunohistochemical analysis of formalin-fixed, paraffin-embedded surgical tumor specimens for p53, MLH1, and MSH2 was performed. The tumor specimens showed no MLH1 expression but did show normal MSH2 expression. p53 was not expressed. Five microsatellite loci were examined using the tumor specimens to detect MSI, namely two loci with mononucleotide runs (i.e., BAT25 and BAT26) and three loci with dinucleotide repeats (i.e., APC, Mfd15, and D2S123). The tumor specimens showed alternations in the repeated sequences of two loci (i.e., BAT26 and D2S123). As a result, the tumor was classified as MSI-H (high) according to the Bethesda criteria. Our patient had MSI and one of the smallest reported SCCs arising from recurrent anal fistulae.

Molecular biology of squamous cell carcinoma of the anus

BACKGROUND

Squamous cell carcinoma of the anal canal provides a model for studying the contribution of human papillomavirus (HPV) and human immunodeficiency virus (HIV) infection to the development of neoplasia. This paper reviews the existing literature relating to the molecular biology of anal squamous cell carcinoma and proposes a theory of pathogenesis.

METHODS

A Medline literature search was performed to identify English articles on the pathogenesis of squamous cell carcinoma of the anus; further articles were obtained from the references quoted in the literature initially reviewed.

RESULTS

HPV infection and subsequent HPV DNA integration are necessary, but not sufficient, to cause cancer progression. Loss of heterozygosity at 11q23 is the most consistent genomic change observed. Loss of heterozygosity at 17p, 18q and 5q is frequently observed in tumours of HIV-negative patients, but not in those of HIV-positive patients. Current data suggest that mutations in p53, DCC and APC tumour suppressor genes contribute to the stepwise progression of anal squamous cell carcinoma in immunocompetent individuals.

CONCLUSION

In comparison with immunocompetent individuals, HIV-positive patients have persistent HPV infection in the anal canal. In this population, microsatellite instability, rather than chromosomal instability, appears to be a preferred pathway for rapid progression towards invasive carcinoma.

Squamous cell carcinoma of the anal canal

Squamous cell carcinoma (SCC) of the anal canal is a rare condition with increasing incidence rates in the United States population in the past several decades. This review article provides a complete overview of the etiology, anatomy and the approach to the multidisciplinary management of the patient with anal SCC. Chemoradiation therapy for the treatment of SCC of the anal canal provides excellent disease control and survival while preserving anal sphincter function in the majority of patients. The surgeon plays a key role in the diagnosis and follow-up of this disease. Surgical salvage with APR for disease persistence or recurrence in carefully selected patients can result in reasonable 5-year survivals.

Interobserver agreement in the interpretation of anal intraepithelial neoplasia

BACKGROUND

Anal carcinoma incidence is increasing, and is highest among men with human immunodeficiency virus (HIV) infection who have sex with men. Anal carcinoma and anal intraepithelial neoplasia (AIN) are ascertained on tissue histology, but requires invasive procedures. Screening for AIN using anal cytology was suggested. The authors evaluated agreement on cytologic and biopsy specimens from HIV-positive men undergoing anal carcinoma screening.

METHODS

One hundred twenty-nine HIV-positive men with a history of anal-receptive intercourse underwent anal cytology, anoscopy, and biopsy. Four pathologists independently assessed cytology and biopsy specimens and reached consensus for discordant cases.

RESULTS

Each pathologist evaluated 120 cytology and 155 biopsy specimens. The weighted kappa value for overall agreement was 0.54 (95% confidence interval [CI], 0.49-0.59) for cytology specimens and 0.59 (95%CI, 0.55-0.63) for biopsy specimens. The median kappa values for pairwise agreement among pathologists and for agreement with consensus were, respectively, 0.69 and 0.77 for cytology and 0.66 and 0.75 for biopsy. At least 3 pathologists were in agreement for 92 (76.7%) cytology and 134 (86.5%) biopsy specimens. Reliability for the Bethesda classification system was at least moderate, except for the cytologic category of atypical squamous cells of undetermined significance (kappa = 0.12). Fourteen of 29 (48.3%) cytology specimens and 36 of 47 (76.6%) biopsy specimens with consensus interpretation of high-grade squamous intraepithelial lesions (HSIL) were interpreted originally as HSIL by > or = 3 pathologists. The kappa value for agreement with consensus distinguishing HSIL from non-HSIL ranged from 0.55 to 0.88 for cytology specimens and from 0.76 to 0.94 for biopsy specimens.

CONCLUSIONS

Agreement for cytologic and biopsy interpretations was generally at least moderate. Nevertheless, these results supported the need for disease indicators with greater reliability.

Anal intraepithelial neoplasia

Background

Anal intraepithelial neoplasia (AIN) is believed to be a precursor of anal squamous cell cancer and its incidence is rising in high-risk groups, particularly those infected with the human immunodeficiency virus (HIV). The natural history of AIN is unclear and management strategies are lacking.

Methods

This review is based on a literature search (Medline and PubMed) with manual cross-referencing of all articles related to AIN.

Results and conclusions

The aetiology of AIN is intricately linked with human papilloma viruses. The pathological processes involved in the progression of AIN are becoming clearer but the natural history, particularly the rate of progression to invasive cancer, remains unknown. There is no standard management for AIN and this is mainly due to difficulties in both diagnosis and treatment. A variety of treatment options have been tried with varying success. Surgery is associated with significant recurrence, particularly in HIV-positive patients. Non surgical approaches with imiquimod, photodynamic therapy and vaccination are appealing, and further work is required. Long-term follow-up of these patients is essential until the natural history of AIN becomes clearer.

Human papillomavirus: a review

Human papillomavirus infection remains a great source of morbidity and mortality. Progress in understanding the structure of HPV and its pathogenesis has led to a wide variety of possible new treatment modalities to combat HPV-related disease. Most HPV infections (whether high risk or low risk) resolve without any medical intervention. Persistent or progressive disease, however, remains difficult to treat. Although currently available therapies have proved efficacious and tolerable in the treatment of nongenital and genital warts, no single therapy is uniformly effective in eradicating persistent HPV infection. Cytodestructive methods, such as cryotherapy, remain the primary treatment modality for nongenital warts. Immune response modifiers, such as imiquimod, currently show the greatest promise in treating HPV-induced anogenital lesions, both with respect to complete response and in preventing recurrence. Human papillomavirus infection is one of the most common sexually transmitted diseases in the world, and cervical cancer still causes significant morbidity and mortality. Pap smear tests have greatly reduced the incidence and mortality of cervical cancer in developed countries. Additional research will focus on primary and secondary prevention strategies. Vaccines against high-risk HPV types are promising modalities currently under investigation to prevent HPV infections and possibly to treat them.