Anal human papillomavirus and anal cancer

Post-transplant malignancy: Focusing on virus-associated etiologies, pathogenesis, evidence-based management algorithms, present status of adoptive immunotherapy and future directions

Modern immunosuppression has led to a decrease in rejection rates and improved survival rates after solid organ transplantation. Increasing the potency of immunosuppression promotes post-transplant viral infections and associated cancers by impairing immune response against viruses and cancer immunoediting. This review reflects the magnitude, etiology and immunological characteristics of various virus-related post-transplant malignancies, emphasizing the need for future research. A multidisciplinary and strategic approach may serve best but overall literature evidence targeting it is sparse. However, the authors attempted to provide a more detailed update of the literature consensus for the prevention, diagnosis, management and surveillance of post-transplant viral infections and associated malignancies, with a focus on the current role of adoptive immunotherapy and the way forward. In order to achieve long-term patient and graft survival as well as superior post-transplant outcomes, collaborative research on holistic care of organ recipients is imperative.

Characteristics of anal canal squamous cell carcinoma as an HPV-associated cancer in Japan

The definition of the anal canal was revised in the TNM classification (8th edition). The Japanese Society for Cancer of the Colon and Rectum (JSCCR) conducted a retrospective multi-institutional study to clarify the characteristics of anal canal cancer (ACC) in Japan. The diagnoses of 1781 patients treated for ACC were squamous cell carcimoma (SCC; n = 428; 24.0%), adenosquamous cell carcinoma (n = 7; 0.4%), and adenocarcinoma (n = 1260; 70.7%). Anal carcinoma is associated with human papillomavirus (HPV) infection and is risk factor for anal SCC. Among 40 cases analyzed at Takano Hospital and 47 cases analyzed at National Cancer Center Hospital, 34 cases (85.0%) and 40 cases (85.1%), respectively were infected with HPV; HPV-16 was the most common genotype (79.4% and 82.5%). In the JSCCR retrospective multi-institutional study, the prognosis analysis by stage was performed for anal SCC cases (202 cases treated by CRT and 91 cases treated by surgery). The 5-year overall survival (OS) rates by stage did not differ between the two treatment groups to a statistically significant extent. Regarding the results of cancer treatment of patients who underwent HPV infection tests, although the 5-year OS rates by stage did not differ to a statistically significant extent due to the small number of cases, HPV-positive patients had better survival. While an HPV vaccine for anal canal SCC has already been approved internationally, HPV vaccination has already been implemented in Japan as a national immunization program for young women but not for men at present. An HPV vaccination for men is urgently needed.

Maternal HPV Infection and the Estimated Risks for Adverse Pregnancy Outcomes—A Systematic Review

Background: Human Papilloma Virus (HPV) represents the most prevalent genital infection in young women of reproductive age. Objective: This systematic review aims to estimate the effect of HPV infection during pregnancy and assess the correlation between HPV and adverse pregnancy outcomes. Materials and methods: The search strategy has been developed based on the PICOS framework: Population (pregnant women infected with HPV), Intervention (HPV infection confirmed by molecular tests), Comparator (pregnant women without HPV infection), Outcomes (adverse pregnancy outcomes) and Study design (observational studies). We searched PubMed, Web of Science, and Scopus databases on 8 January 2022 by using the following keywords: “HPV”, “prematurity”, “preterm birth”, “miscarriage”, “premature rupture of membranes”, “adverse pregnancy outcome”, “low birth weight”, “fetal growth restriction”, “pregnancy-induced hypertensive disorders”, “preeclampsia”. Selection criteria were HPV infection confirmed within maximum 2 years before pregnancy with a molecular test and adverse pregnancy outcomes. (Results: Although numerous studies are conducted on this topic, data are still controversial regarding identifying maternal HPV infection as a risk factor for adverse pregnancy outcomes. More prospective large cohort studies are needed to prove a causative relationship.

Characteristics of anal canal cancer in Japan

Anal canal cancer (ACC) has been reported to be an uncommon cancer in Japan, as in the USA, Europe, and Australia. This retrospective multi‐institutional study was conducted to clarify the characteristics of ACC in Japan. First, the histological ACC type cases treated between 1991 and 2015 were collected. A detailed analysis of the characteristics of anal canal squamous cell carcinoma (SCC) cases was then conducted. The results of the histological types revealed that of the 1781 ACC cases, 435 cases (24.4%) including seven cases of adenosquamous cell carcinomas were SCC and 1260 cases (70.7%) were adenocarcinoma. However, the most common histological type reported in the USA, Europe, and Australia is SCC. Most ACC cases are adenocarcinomas and there is a low incidence of SCC in Japan which is different from the above‐mentioned countries. Moreover, we reclassified T4 into the following two groups based on tumor size: T4a (tumor diameter of 5 cm or less) and T4b (tumor diameter of more than 5 cm). The results of the TNM classification of SCC revealed that the hazard ratio (HR) to T1 of T2, T3, T4a, and T4b was 2.45, 2.28, 2.89, and 4.97, respectively. As T4b cases had a worse prognosis than T4a cases, we propose that T4 for anal canal SCC in Japan be subclassified into T4a and T4b.

Cervical Intraepithelial Neoplasia Grade 3 in a HPV-Vaccinated Patient: A Case Report

Persistent infection with human papillomavirus (HPV) causes almost all cervical precancerous lesions and cancers. Bivalent, quadrivalent, and nonavalent HPV vaccines effectively prevent high-grade cervical intraepithelial neoplasia (CIN3). The effectiveness of HPV vaccination against CIN3 is 97–100% in HPV-naïve populations and 44–61% in the overall population. Although HPV vaccination has substantially reduced the incidence of cervical cancers, several cases of precancerous cervical lesions in HPV-vaccinated patients have been reported. We report the clinical case of a 19-year-old woman whose first Pap smear was diagnosed as a high-grade squamous intraepithelial lesion (HSIL) after quadrivalent HPV vaccination. Colposcopy and cervical biopsy were performed, revealing HSIL/CIN3. Our multidisciplinary team decided to take a conservative approach with follow-up visits with cervical biopsies of this young patient. After six months, spontaneous regression of high-grade cervical dysplasia was observed. Although HPV immunization has shown to be extremely effective in preventing a high proportion of cervical precancerous lesions and cervical cancers, HPV vaccines do not protect against all oncogenic high-risk HPV genotypes. Consequently, healthcare providers must encourage HPV-vaccinated women to still regularly attend national cervical screening programs.

Human Immunodeficiency Virus Infection Promotes Human Papillomavirus-Mediated Anal Squamous Carcinogenesis: An Immunologic and Pathobiologic Review

BACKGROUND

Anal squamous cell carcinoma (SCC) is a rare gastrointestinal malignancy with rising incidence, both in the United States and internationally. The primary risk factor for anal SCC is human papillomavirus (HPV) infection. However, there is a growing burden of disease in patients with human immunodeficiency virus (HIV) and HPV coinfection, with the incidence of anal SCC significantly increasing in this population. This is particularly true in HIV-infected men. The epidemiologic correlation between HIV-HPV coinfection and anal SCC is established; however, the immunologic mechanisms underlying this relationship are not well understood.

SUMMARY

HIV-related immunosuppression due to low circulating CD4+ T cells is one component of increased risk, but other mechanisms, such as the effect of HIV on CD8+ T lymphocyte tumor infiltration and the PD-1/PD-L1 axis in antitumor and antiviral response, is emerging as significant contributors. The goal of this article is to review existing research on HIV-HPV coinfected anal SCC and precancerous lesions, propose explanations for the detrimental synergy of HIV and HPV on the pathogenesis and immunologic response to HPV-associated cancers, and discuss implications for future treatments and immunotherapies in HIV-positive patients with HPV-mediated anal SCC. Key Messages: The incidence of anal squamous cell carcinoma is increased in human immunodeficiency virus (HIV)-infected patients, even in patients on highly active antiretroviral therapy. Locoregional HIV infection may enhance human papillomavirus oncogenicity. Chronic inflammation due to HIV infection may contribute to CD8+ T lymphocyte exhaustion by upregulating PD-1 expression, thereby blunting cytotoxic antitumor response.

Role of Microbial Infection-Induced Inflammation in the Development of Gastrointestinal Cancers

There has been increasing evidence that a local inflammatory response stimulates tumor cells to acquire metastatic potential, and the concept of inflammatory oncotaxis has been spreading in recent years. However, the interaction between microbial inflammation and the development of gastrointestinal cancer is still unclear. This review summarizes the present knowledge on the role of microbial inflammation in the development of gastrointestinal cancers from the perspective of molecular biological findings. Chronic inflammation caused by bacterial infection is known to induce cancers as exemplified by Helicobacter pylori, which is associated with the development of gastric cancer via the activation of the TLR4 pathway by bacterial lipopolysaccharide followed by cancer growth through CagA-MET signaling. In addition, the development of inflammatory bowel diseases has been known to become a risk factor for colorectal cancers, where inflammation caused by certain bacterial infections plays a key role. It is also known that the cancer microenvironment is associated with cancer growth. Moreover, infectious complication after surgery for gastrointestinal cancers may promote tumor progression via the stimulation of pathogen-associated molecular patterns and various inflammatory mediators secreted by immunocytes. Further research on the link between microbial inflammation and cancer progression is needed to drive a paradigm shift in cancer treatment.

A Novel Model for Papillomavirus-Mediated Anal Disease and Cancer Using the Mouse Papillomavirus

Up to 95% of all anal cancers are associated with infection by human papillomavirus (HPV); however, no established preclinical model exists for high-grade anal disease and cancer mediated by a natural papillomavirus infection. To establish an infection-mediated model, we infected both immunocompromised NSG and immunocompetent FVB/NJ mice with the recently discovered murine papillomavirus MmuPV1, with and without the additional cofactors of UV B radiation (UVB) and/or the chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). Infections were tracked via lavages and swabs for MmuPV1 DNA, and pathology was assessed at the endpoint. Tissues were analyzed for biomarkers of viral infection and papillomavirus-mediated disease, and the localization of viral infection was investigated using biomarkers to characterize the anal microanatomical zones.

Feasibility and safety study of a high resolution wide field-of-view scanning endoscope for circumferential intraluminal intestinal imaging

Global anal cancer incidence is increasing. High resolution anoscopy (HRA) currently screens for anal cancer, although the definitive test remains unknown. To improve on intraluminal imaging of the anal canal, we conducted a first-in-human study to determine feasibility and safety of a high-resolution, wide field-of-view scanning endoscope. Fourteen patients, under an IRB-approved clinical study, underwent exam under anesthesia, HRA, and imaging with the experimental device. HRA findings were photographed using an in-line camera attached to the colposcope and compared with the scanning endoscope images. Patients were followed up within 2 weeks of the procedure. The imaging device is inserted into the anal canal and the intraluminal surface is digitally photographed in 10 s and uploaded to a computer monitor for review. Ten patients completed imaging with the device. Three patients were not imaged due to severe anal stenosis. One patient was not imaged due to technical device malfunction. The device images were compared to the HRA images. No adverse event attributable to the device was reported. The intraluminal scanning endoscope can be used for circumferential anal canal imaging and is safe for clinical use. Future clinical studies are needed to evaluate the performance of this device.

Analysis of the prevalence of human papillomavirus and abnormal anal cytology in women at risk

Our aim was to analyze the association between anal human papillomavirus (HPV) infection and abnormal anal cytology in women with high-grade cervical intraepithelial neoplasia (CIN 2+). We also analysed what other risk factors might be significant. We carried out a prevalence study from April 2015 to March 2017 at La Paz University Hospital. Genotyping of HPV, anal cytology and high-resolution anoscopy were performed. Of 171 patients recruited, 53 cases (31%) were diagnosed as histological CIN 2+: there were no statistically significant differences in the prevalence of anal HPV (OR = 0.8), nor the prevalence of abnormal anal cytology (OR = 2.15, 95% CI 0.8-5.7) compared to women with CIN 1 or no cervical dysplasia. Immunosuppression (OR = 2.51, 95% CI 1-6.3, p < .05), cervical HPV (OR = 3.9, 95% CI 1.9-8.0, p < .01) and being older than 40 years old (p < .05) were also associated with anomalous anal results.Impact StatementWhat is already known on this subject? Anal HR-HPV and abnormal anal cytology may precede anal intraepithelial neoplasia (AIN): a premalignant lesion that may progress to anal cancer. It is known that there are four populations which present a higher risk of developing anal cancer compared to the general population: human immunodeficiency virus (HIV)-positive patients, other immunocompromised populations, men who have sex with men and women with a history of disease secondary to HPV infection.What do the results of this study add? This study allowed us to compare the prevalence of anal HPV and abnormal anal cytology in women with CIN 2+: it analysed whether these women already presented alterations in anal tests at the moment of the diagnosis of the preneoplastic cervical lesion. It also provides information for the management of the populations at a higher risk of developing anal cancer; specifically, the group of women with a prior history of HPV-associated anogenital disease.What are the implications of these findings for clinical practice and/or further research? Our findings improve the existing evidence on anal HPV infection and anal cytology on the least studied population at risk. Data could be useful for further research in order to clarify the role of anal screening in this population and standardise the clinical practice.

The situation of vaccines for the prevention of infections in adults: An opinion paper on the situation in Spain

The childhood immunization schedule is well known and generally well implemented in developed countries. For various reasons, the same is not true of vaccines aimed at preventing infections in adults, in which vaccination coverage is incomplete and generally very deficient. In order to assess the situation of adult vaccination in Spain, the Fundación de Ciencias de la Salud has brought together a series of experts in different fields, including doctors, nurses, representatives of patient associations, health managers and economists, health authorities and journalists to deal with this issue. The format was that of a round table in which a series of questions previously formulated by the coordinators were to be answered and debated. The document presented is not an exhaustive review of the topic, nor is it intended to make recommendations, but only to give a multidisciplinary opinion on topics that could be particularly debatable or controversial. The paper reviews the main vaccine-preventable adult diseases, their clinical and economic impact, the possibilities of reducing them with vaccination programmes and the difficulties in carrying them out. The role of nursing, pharmacy services, patient associations and the health administration itself in changing the current situation was discussed. Prospects for new vaccines were discussed and we speculated on the future in this field. Finally, particularly relevant ethical aspects in decision-making regarding vaccination were discussed, which must be faced by both individuals and states. We have tried to summarize, at the end of the presentation of each question, the environment of opinion that was agreed with all the members of the table.

Human papillomavirus infection in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the American Society of Transplantation Infectious Diseases Community of Practice update the epidemiology and management of human papillomavirus (HPV) infections in organ transplant recipients. HPV is one of the most common sexually transmitted infections and is associated with cancers of the anogenital region. Increasing evidence suggests an association with head and neck cancers as well. Solid organ transplant recipients have a higher risk of HPV infection than the general population. Infection manifests as premalignant lesions, warts, or cancer of the cervix, penis, vulva, scrotum, and anal canal. Most are asymptomatic initially, so diagnosis can be difficult without screening. A vaccine is available though not effective in preventing all cancer-causing strains. Organ transplant recipients should be screened for HPV-associated cancers and appropriate therapy initiated in a timely manner. Further studies are warranted to delineate the most effective screening methods and therapeutic modalities, including whether changes in immunosuppression are effective in attenuating disease.

Multidisciplinary Approach to the Management and Treatment of Anal Dysplasia

The incidence of anal intraepithelial neoplasia (AIN) has been increasing over the years. AIN acts as a precursor lesion for anal squamous cell cancer. Factors leading to progression of AIN into malignancy are complex and involve grade of the lesion, human papillomavirus and HIV coinfection, as well as patient-related risk factors such as immunocompromised state and men who have sex with men. The multifaced aspects of this disease make its management challenging, as it involves several disciplines including pathology, primary care, infectious disease, and colorectal specialties. Each of these fields brings its own expertize to the management of AIN, and their collaborative, coordinated work culminates into best practice and optimized outcomes in the care of the AIN patient.

Interest of cytology combined with Xpert® HPV and Anyplex® II HPV28 Detection human papillomavirus (HPV) typing: differential profiles of anal and cervical HPV lesions in HIV-infected patients on antiretroviral therapy

OBJECTIVES

The aim of the study was to assess the interest to combine cytological examination and human papillomavirus (HPV) typing of anal and cervical Papanicolaou (Pap) smears of HIV-infected patients on combination antiretroviral therapy (cART), to evaluate whether differences in prevalence exist between anal and cervical squamous intraepithelial lesions in patients with high-risk oncogenic HPV infection.

METHODS

Anal and/or cervical Pap smears were obtained by anoscopy and/or colposcopy in 238 subjects recruited consecutively in 2015: anal smears were obtained from 48 male and female patients [42 men; 35 men who have sex with men (MSM)] and cervical smears from 190 female patients. Cytological Bethesda classification was coupled with HPV typing. HPV typing was performed, on the same smears, using the Xpert^® HPV Assay, which detects only high-risk HPV (hrHPV), and the Anyplex^® II HPV28 Detection assay, which detects hrHPV and low-risk (lr) HPV.

RESULTS

Our data showed clear-cut differences between the anal and cervical samples. Compared with the cervical samples, the anal samples exhibited (1) more numerous cytological lesions, which were histologically proven; (2) a higher hrHPV infection prevalence; (3) a higher prevalence of multiple hrHPV coinfections whatever HPV typing kit was used; (4) a predominance of HPV16 and HPV18/45 types. Overall, there was an almost perfect agreement between the two HPV typing assays (absolute agreement = 90.3%).

CONCLUSIONS

Co-testing consisting of cytology and HPV typing is a useful screening tool in the HIV-infected population on cART. It allows detection of prevalence differences between anal and cervical HPV-related lesions. As recently recommended, anal examination should be regularly performed especially in HIV-infected MSM but also in HIV-infected women with genital hrHPV lesions.

Human Papillomavirus in Kidney Transplant Recipients

Human papillomavirus (HPV) is a common infection in kidney transplant recipients. HPV causes cervical, anal, vulvar, vaginal, penile and head and neck cancers. Kidney transplant recipients have a disproportionate burden of disease given prolonged immunosuppression. Given the long pre-invasive state of precancer lesions such as cervical intraepithelial neoplasia (CIN) and anal intraepithelial neoplasia (AIN) most HPV-cancers are preventable with screening and targeted treatment of disease. Pre-transplant vaccination of age-eligible kidney transplant recipients is otherwise ideal.

HPV-16 in a distinct subset of oral epithelial dysplasia

Human papillomavirus (HPV) 16 is the most common high-risk HPV type identified in oropharyngeal and cervical neoplasia. Recently, HPV-associated oral epithelial dysplasia with specific histopathologic features and demographics similar to HPV-oropharyngeal carcinoma has been identified. The objective of this study was to evaluate histopathologically all cases of HPV-oral epithelial dysplasia seen in one center and identify HPV types in a subset of cases. Cases with specific histopathology for HPV-oral epithelial dysplasia that were positive both by immunohistochemical studies for p16 and by in situ hybridization for high-risk types of HPV were further analyzed using QIAamp DNA Tissue Kits (Qiagen, Hilden, Germany). DNA was extracted, amplified, and digested with restriction enzymes and run on a polyacrylamide gel. Digestion patterns were visually compared with a database of known HPV digestion patterns for identification. There were 53 specimens included in the analysis. There were 47 males and six females (7.8:1), with a median age of 55 years (range 41-81). The most common site of involvement was the tongue/floor of mouth (77% of cases). Of the 53 cases, 94% exhibited parakeratosis and/or hyperkeratosis. All the cases featured karyorrhexis, apoptosis, and characteristics of conventional carcinoma in situ. The quantity of DNA extracted was sufficient for analysis in 22 cases. HPV-16 was identified in 20/22 (91%) cases. One case was associated with HPV-33 and one with HPV-58 (5% each). Eight of the 53 cases (15%) were associated with invasive squamous cell carcinomas.

Anal Neoplasia in Inflammatory Bowel Disease: Classification Proposal, Epidemiology, Carcinogenesis, and Risk Management Perspectives

Patients with inflammatory bowel disease [IBD] may develop, similarly to individuals from general population, rare cases of human papilloma virus [HPV]-related anal canal squamous cell carcinoma [SCC] and intra-epithelial precursor lesions, as well as very rare cases of anal canal adenocarcinoma. Patients with chronic perianal Crohn's disease [CD] are at substantial risk of developing SCC or adenocarcinoma from the fistula-lining epithelium, as well as SCC or adenocarcinoma arising from chronic anorectal ulcerations or strictures. Based on this lesion stratification, we provide in this review tailored incidence estimates and we propose an IBD-specific classification of all types of anal neoplasia that may occur in patients with IBD. After reviewing putative carcinogenesis of all types of neoplasia, we conclude that HPV vaccination could reduce the incidence of HPV-related lesions, although an anal screening programme related to these lesions is not mandatory on the sole basis of IBD. By contrast, we point out that all patients with chronic perianal CD should be explored in depth, including biopsies under anaesthesia and fistula curettage when necessary, in case of any change in anal symptoms ─in particular new, increasing, unexplained pain. Finally, we conclude that there is an urgent need for elaborating and evaluating surveillance algorithms in patients with chronic perianal CD, in order to avoid cancers with late diagnosis and poor prognosis.

Risk of Anal Cancer in People Living with HIV: Addressing Anal Health in the HIV Primary Care Setting

Anal health and anal cancer are rarely addressed in HIV primary care. We sought to understand factors that impeded or promoted addressing anal health in HIV primary care from providers' perspectives. In this exploratory study, HIV primary care providers from the Mid-South region of the United States participated in brief individual interviews. We analyzed transcribed data to identify barriers and facilitators to addressing anal health. Our study sample included five physicians and four nurse practitioners. The data revealed a number of barriers such as perception of patient embarrassment, provider embarrassment, external issues such as time constraints, demand of other priorities, lack of anal complaints, lack of resources, and gender discordance. Facilitators included awareness, advantageous circumstances, and the patient-provider relationship. Anal health education should be prioritized for HIV primary care providers. Preventive health visits should be considered to mitigate time constraints, demands for other priorities, and unequal gender opportunities.

Microanatomy of the cervical and anorectal squamocolumnar junctions: a proposed model for anatomical differences in HPV-related cancer risk

Human papilloma virus (HPV) infection causes cancers and their precursors (high-grade squamous intraepithelial lesions) near cervical and anal squamocolumnar junctions. Recently described cervical squamocolumnar junction cells are putative residual embryonic cells near the cervical transformation zone. These cells appear multipotential and share an identical immunophenotype (strongly CK7-positive) with over 90% of high-grade squamous intraepithelial lesions and cervical carcinomas. However, because the number of new cervical cancers discovered yearly world wide is 17-fold that of anal cancer, we posed the hypothesis that this difference in cancer risk reflects differences in the transition zones at the two sites. The microanatomy of the normal anal transformation zone (n=37) and topography and immunophenotype of anal squamous neoplasms (n=97) were studied. A discrete anal transition zone was composed of multilayered CK7-positive/p63-negative superficial columnar cells and an uninterrupted layer of CK7-negative/p63-positive basal cells. The CK7-negative/p63-positive basal cells were continuous with-and identical in appearance to-the basal cells of the mature squamous epithelium. This was in contrast to the cervical squamocolumnar junction, which harbored a single-layered CK7-positive/p63-negative squamocolumnar junction cell population. Of the 97 anal intraepithelial neoplasia/squamous cell carcinomas evaluated, only 27% (26/97) appeared to originate near the anal transition zone and only 23% (22/97) were CK7-positive. This study thus reveals two fundamental differences between the anus and the cervix: (1) the anal transition zone does not harbor a single monolayer of residual undifferentiated embryonic cells and (2) the dominant tumor immunophenotype is in keeping with an origin in metaplastic (CK7-negative) squamous rather than squamocolumnar junction (CK7-positive) epithelium. The implication is that, at birth, the embryonic cells in the anal transition zone have already begun to differentiate, presenting a metaplasia that-similar to vaginal and vulvar epithelium-is less prone to HPV-directed carcinogenesis. This in turn underscores the link between cancer risk and a very small and discrete population of vulnerable squamocolumnar junction cells in the cervix.

Human papillomavirus genotypes in human immunodeficiency virus-positive patients with anal pathology in Madrid, Spain

BACKGROUND

We studied anal specimens to determine the distribution of human papillomavirus (HPV) genotypes and co-infection occurrence. This information will contribute to the knowledge of HPV genotype distributions and provide an estimate of the prevalence of different oncogenic HPV genotypes found in patients in Madrid (Spain).

METHODS

We studied a total of 82 anal biopsies from the Hospital General Universitario Gregorio Marañón of Madrid. These included 4 specimens with benign lesions, 52 specimens with low-grade anal squamous intraepithelial lesion, 24 specimens with high-grade anal squamous intraepithelial lesions and 2 specimens with invasive anal carcinoma. HPV genotyping was performed with PCR amplification and reverse dot blot hybridization.

RESULTS

We detected 33 different HPV genotypes, including 16 HPVs associated with a high risk of carcinogenesis, 3 HPVs associated with a highly likely risk of carcinogenesis and 14 HPVs associated with a low-risk of carcinogenesis. In two specimens, an uncharacterized HPV genotype was detected. The most frequent HPV genotypes found were HPV-16 (10.3%; 95% CI: 6.6%-15.1%), HPV-52 (8.5%; 95% CI: 5.2%-13%) and HPV-43/44 (7.6%; 95% CI: 4.5%-11.9%). HPV-18 was only detected in 0.9% (95% CI: 0.1%-3.2%) of the total viruses detected in all lesions. HPV co-infections were found in 83.9% of all types of lesions. The majority of cases (90.2%) were concomitantly infected with the human immunodeficiency virus (HIV).

CONCLUSION

The prevalence of high-risk carcinogenic genotypes in anal pathological samples was remarkable. Therefore, further studies that include a greater number of samples, particularly invasive carcinoma cases are needed to evaluate the potential influence of these HPV genotypes in the appearance of anal carcinomas. Also, the influence of other accompanying infections should be evaluated clarify the appearance of this type of carcinoma.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2075238024106058.

A systematic review of anal squamous cell carcinoma in inflammatory bowel disease

AIM

The aim of this systematic review was to determine the incidence, aetiology and clinical characteristics of anal squamous cell carcinomas (SCC) presenting in patients with inflammatory bowel disease.

METHOD

A systematic review of the literature was undertaken using Medline, Embase, Cochrane and Web of Science.

RESULTS

A total of 33 cases of anal SCC were described, 7 in ulcerative colitis (UC) and 26 in Crohn's disease (CD). The annual incidence of anal SCCs was 0.9/100,000 and 2.0/100,000 in patients with UC and CD respectively. The gender ratio in CD was 3M:17F with a median age of 42 years, the main presenting symptom was anal pain and 85% of CD cases had peri-anal disease. No studies described anal intra-epithelial neoplasia. The human papilloma virus was found to be positive in 2 out of 5 (40%) cases. The majority of patients (73%) with CD received radical surgery as their first line treatment. The cumulative overall and disease free survival in CD was 37 per cent at five years.

CONCLUSION

The findings of this review when contrasted with the data from cancer registries suggests that there is a higher incidence of anal SCC, an earlier age of presentation and poorer outcomes in patients with Crohn's disease compared to the general population implying a more aggressive neoplastic process. This review supports the hypothesis that peri-anal disease plays a contributing role in anal SCCs and as such targeted surveillance in patients with longstanding peri-anal disease should be considered.

Changing patterns of anal canal carcinoma in the United States

PURPOSE

Persistent human papillomavirus infection is associated with squamous cell carcinoma of the anal canal (SCCA). With changing sexual behaviors, SCCA incidence and patient demographics may also have changed in recent years.

METHODS

The Surveillance, Epidemiology, and End Results public-use data set from 1973 to 2009 was analyzed to determine incidence trends for and demographic factors characterizing SCCA. Joinpoint analyses identified time points when incidence rates changed. For comparison, similar analyses were conducted for anal adenocarcinoma.

RESULTS

Joinpoint analyses identified 1997 as the single inflection point among 11,231 patients with SCCA, at which the slope of incidence rates statistically increased (1997 to 2009 v 1973 to 1996: risk ratio [RR], 2.2; 95% CI, 2.1 to 2.3). Annual percent change (APC) increased for all SCCA stages and was the greatest for anal carcinoma in situ (CIS; APC, 14.2; 95% CI, 10.2 to 18.4). Demographic changes characterizing later versus earlier time period included younger age at diagnosis and rising incidence rates in all stage, sex, and racial groups. During 1997 to 2009, women were less likely to present with CIS (RR, 0.3; 95% CI, 0.3 to 0.3) but more likely to present with localized (RR, 1.2; 95% CI, 1.1 to 1.3) and regional SCCA (RR, 1.5; 95% CI, 1.4 to 1.7). In contrast, adenocarcinoma APCs among 1,791 patients remained stable during this time period.

CONCLUSION

CIS and SCCA incidence increased dramatically after 1997 for men and women, although men were more likely to be diagnosed with CIS. These changes likely resulted from available screening in men and argue for efforts to identify high-risk individuals who may benefit from screening.

Detection of Immunoglobulin G against E7 of Human Papillomavirus in Non-Small-Cell Lung Cancer

Background. A significant number of non-small-cell lung cancers (NSCLC) have human papillomavirus (HPV) DNA integrated in their genome. This study sought to further establish HPV's possible etiologic link to NSCLC by evaluating an immune response to HPV's oncogene, E7, in patients with NSCLC. Patients and Methods. Antibodies (IgG) in serum against E7 for HPV 16 and 18 in 100 patients with NSCLC were examined by enzyme-linked immunosorbent assay (ELISA). Results. Sixteen NSCLC patients were found to have a high titration of IgG for HPV oncogenic E7 protein. 23.5% of adenocarcinomas (AC,) and 15.4% of squamous cell carcinomas (SCC) were positive for IgG against HPV E7. HPV-18 (11%) had a slightly higher frequency than HPV-16 (6%). Of the six positive cases for HPV-16, 3 were AC, 2 SCC, and 1 NOS (not otherwise specified). For the 11 HPV-18 positives, 7 were AC, and 4 SCC. The one case with IgG against HPV 16 and 18 was AC. One case had high cross-reactive levels against E7 of HPV 16 and 18. Two (28%) of 7 patients who reported never smoking were positive for HPV, and 12 (13.6%) of 88 smokers were HPV positive. Conclusions. The study detected high levels of IgG against E7 in 16% of NSCLC patients. This adds evidence to a potential role of HPV in the pathogenesis of NSCLC.

Epidemiology, natural history and risk factors for anal intraepithelial neoplasia

Studies conducted in HIV-seropositive individuals have enhanced our understanding of the natural history of anal intraepithelial neoplasia (AIN) and of factors predictive of progression to high-grade AIN, the immediate precursor to anal cancer. AIN is frequently detected in HIV-seropositive individuals. Factors that increase the risk for AIN include HIV infection, low current or nadir blood CD4+ cell counts, receptive anal intercourse, oncogenic human papillomavirus (HPV) infection, persistent anal HPV infection, multiple HPV type infections and high anal HPV viral load. This review confirms the importance of high-grade AIN in HIV-seropositive individuals and HIV-seronegative men having sex with men.

HPV-related (pre)malignancies of the female anogenital tract in renal transplant recipients

Renal transplantations (RTs) are performed routinely in many countries. After RT, the administration of lifelong immunosuppressive therapy is required. As a consequence, renal transplant recipients (RTRs) have a high risk to develop virus-associated (pre)malignancies, such as Human papillomavirus (HPV) related anogenital (pre)malignancies. It is known that the majority of the RTRs are infected with HPV and that these women have a 14-fold increased risk of cervical cancer, up to 50-fold of vulvar cancer and up to 100-fold of anal cancer. Often, treatment of these lesions requires concessions and may be suboptimal as radiation therapy and extensive surgery may damage the renal transplant. Therefore, prognosis may be compromised due to inadequately treated malignancies. Especially for these immunocompromised patients prevention is of utmost importance. Yearly cervical cancer screening for RTRs is advised, but appears to be executed poorly. For the future, optimizing screening and prevention of anogenital (pre)malignancies is an important issue for women after RT. This review gives a broad overview of all aspects regarding HPV-related (pre)malignancies of the female anogenital tract in RTRs.

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

Activation of AKT and nuclear accumulation of wild type TP53 and MDM2 in anal squamous cell carcinoma

Human papilloma virus (HPV) infection is considered as an important aetiological factor for anal squamous cell carcinoma (ASCC) but is not sufficient for tumour progression. This carcinoma is poorly understood at the molecular level. Using the largest cohort of cases to date we investigated the molecular mechanisms underlying ASCC development, in particular the roles of TP53, MDM2 and AKT. Viral infection in our cohort occurred at high frequency (73%, 94/128) with HPV16 accounting for the majority (86%, 81/94) of infected cases. Only 4% (5/119) of ASCCs showed TP53 (exons 5-8) mutations, but a high frequency (91%, 100/110) of nuclear protein expression of TP53 was observed. There was a significant association (p < 0.001) between nuclear accumulation of TP53 and MDM2 protein although no MDM2 mutations were found, and copy number was normal. Cellular accumulation of phosphorylated-AKT was observed in 66% (82/125) of ASCCs and an association demonstrated between nuclear accumulation of MDM2 and activated AKT (p < 0.001). We observed a high frequency of copy number gain at PIK3CA (47%), and some coding sequence mutations (4%). Amplification of PIK3CA was associated with presence of phosphorylated-AKT (p= 0.008). There was no association between virus infection and TP53 nuclear accumulation (p = 0.5). However, a significant association was found between infection and MDM2 nuclear staining, and between infection and activated AKT (p = 0.04, p = 0.01, respectively). We propose that activation of AKT, possibly through the PI3K-AKT pathway, is an important component of ASCC tumorigenesis that contributes to MDM2 and TP53 accumulation in the nucleus.

Anal cancer in renal transplant patients

PURPOSE

A comprehensive literature review was performed to examine the prevalence of anal cancer, anal intraepithelial neoplasia (AIN) and anal human papillomavirus (HPV) infection in renal transplant recipients who are at risk of anal cancer due to iatrogenic immunosuppression.

METHODS

Pertinent articles were identified from searches performed on the National Center for Biotechnology Information database using the following keywords: anal cancer, AIN, screening, renal transplant (or kidney transplant), organ transplant recipients and post-transplant malignancies.

RESULTS

The prevalence of AIN is 20% in renal transplant patients. The prevalence of anal HPV infection in established transplant patients is 47%, and the prevalence of anal HPV infection in new transplant patients is 23%. The relative risk for anal cancer in renal transplant patients is 10.

CONCLUSIONS

As compared to HIV-positive male patients who practise anal intercourse, renal transplant patients showed a modest rise in relative risk for anal cancer. Screening programmes to detect AIN in HIV-positive patients who practise anal intercourse have been introduced on a preliminary basis in sexual health clinics in the US and may become standard practise in this population. The case for screening in renal transplant patients is unclear and would merit further investigation, especially with reference to the prevalence of anal HPV infection in this population. It may transpire that renal transplant patients would benefit more from HPV prophylaxis rather than screening for AIN.

DECENA - cervical cancer primary screening program in Vojvodina

Hc2 DNA test for detection of 13 oncogenic human papillomavirus genotypes (16/18/31/33/35/39/45/51/52/56/58/59/68) is a real partner to cytology, concerning improvement and better detection of premalignant and malignant cervical diseases. Reliable cytology combined with HPV testing is a useful parameter to gynecologists, in case of various dilemmas: questionable Pap test, follow up of patients with low-grade squamous intraepithelial lesions (LSIL) and also postoperative control of patients after the treatment of high-grade squamous intraepithelial lesions (HSIL). HPV status is important additional parameter, especially when making decision about the most adequate treatment protocols and in case of nullparae who have CIN2. In last few years, numerous studies indicate many advantages of using this molecular-diagnostic test in primary screening of cervical carcinoma. In the pilot study of DECENA (detection of cervical neoplasia) program we tested 980 women, in the period from August 2006 to April 2007. DECENA program is based on primary screening of cervical cancer. It is supported with segments of great importance: data base of examined women, data base and communication with all medical professionals included in cervical cancer screening, education of women and their partners, and public education.

Histological features of human papilloma virus 16 and its association with the development and progression of anal squamous cell carcinoma

PURPOSE

To investigate the development of anal squamous cell carcinoma (SCC) and the expression patterns of human papillomavirus (HPV).

METHODS

We performed typing of HPV-DNA using a polymerase chain reaction (PCR), and amplified the Duchenne muscular dystrophy (DMD) genes simultaneously, to investigate the tumor DNA state. The expression patterns of HPV in the cancer cell nuclei was investigated by in situ hybridization (ISH) using HPV probes.

RESULTS

Amplification of DMD genes was confirmed in 8 of 20 patients with anal SCC, suggesting that tumor DNA was preserved in these patients. In seven of these eight patients, only HPV16 was detected by both PCR and ISH, suggesting HPV16-induced carcinogenesis. In two patients with carcinoma in situ (CIS), the cancer cells showed only a diffuse pattern (DP), and in two patients with invasive cancer, the cancer cell showed only an oligo-dot pattern (OP). In one patient with lesions ranging from CIS to invasive cancer, the histologic features varied in each area, from DP to OP. This change originated in the deep part of the microinvasive area.

CONCLUSIONS

These findings show that HPV16 infection is closely involved in the development of anal SCC and suggest that the change in the genome occurs at the stage of microinvasive cancer.

Anal carcinomas in HIV-positive patients: high-dose chemoradiotherapy is feasible in the era of highly active antiretroviral therapy

BACKGROUND

Anal carcinoma, a common disease in HIV-positive patients, is usually treated with chemoradiotherapy. Generally tolerance was poor before the availability of highly active antiretroviral therapies. We report our experience of treating anal carcinoma in the era of new antiviral drugs.

PATIENTS AND METHODS

Between 1997 and 2001, nine men on highly active antiretroviral therapies with good immune status before chemoradiotherapy received concomitant chemoradiotherapy consisting of 5-fluorouracil and cisplatinum, and high-dose radiotherapy (60-70 Gy) for anal carcinoma. Six cancers were Stage I, two were Stage II, and one was Stage III. CD4+ cell counts were <200/ml for four patients, between 200/ml and 500/ml for four, and >500/ml for one.

RESULTS

All patients received the planned dose of radiation (> or = 60 Gy). The chemotherapy dose was reduced 25 percent in six patients. Overall treatment time was 58 days. Grade 3 hematologic or skin toxicity occurred in four patients. No association was observed between high-grade toxicity and CD4+ cell count. None of the patients developed opportunistic infections during follow-up. Eight patients were disease-free after a median follow-up of 33 months. Among them, four had no or minor anal function impairment at the last follow-up visit. One patient with T4N2 disease relapsed locally one year after treatment and underwent salvage abdominoperineal excision.

CONCLUSION

High-dose chemoradiotherapy for anal carcinomas is feasible with low toxicity in HIV-positive patients treated with highly active antiretroviral therapies. Local control is similar to that obtained for HIV-negative patients.

Differential expression of anti-apoptotic protein Bcl-2 in keratinizing versus non-keratinizing squamous cell carcinoma of the anus

BACKGROUND

Histologically, tumors of the anal region are either keratinizing (K) or non-keratinizing (NK) squamous cell carcinomas (SCCA). We hypothesized that these two variants might represent, not only morphologically, but also biologically, dissimilar malignancies. The present study was undertaken to compare the expression of apoptosis-regulating proteins Bcl-2 and p53 in K versus NK SCCA.

METHODS

We performed an immunohistochemical analysis on 98 pre-treatment biopsies of patients with anal canal cancers. Tissue sections were examined immunohistochemically for expression of proteins Bcl-2 (clone 124, DAKO, 1:100) and p53 (clone DO7, DAKO, 1:200). Expression of p53 and Bcl-2 was considered positive when >5% of tumor cells were stained. Tumor histology was correlated with protein expression as well as with other clinical variables.

RESULTS

There were 64 NK and 34 K SCC. The proportion of Bcl-2 positive tumors was statistically higher in NK carcinomas (51.5 vs. 23.5%, p=0.009). In addition, women were more likely than men to present with NK carcinomas (71 vs. 45%, p=0.03) as well as with Bcl-2 positive tumors (47 vs. 29%, p=0.05). The more distal the tumor is (anal margin), the more frequently the keratinizing subtype is observed (87 vs. 23%, p=0.0002). By contrast, there was no correlation between p53 and tumor histology (p=0.83).

CONCLUSIONS

Our data demonstrate that non-keratinizing and keratinizing SCCA differ in their Bcl-2 expression. In addition, significant differences were observed in the distribution of these two histological subtypes according to gender and tumor sublocation. These findings may indicate possible differences in the carcinogenesis process of these two histological subtypes.

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.

Anal cancer incidence and survival: the surveillance, epidemiology, and end results experience, 1973-2000

BACKGROUND

Anal cancer is a rare malignancy of the anogenital tract that historically has affected women at a greater rate than men.

METHODS

The authors analyzed changing trends in incidence rates and 5-year relative survival percentages for patients with anal cancer. The publicly available data used in the current study were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program, a system of population-based tumor registries in the United States.

RESULTS

The incidence of anal cancer was similar for men and women between 1994 and 2000 (2.04 per 100,000 and 2.06 per 100,000, respectively), the most recent period for which data were available, whereas men had lower rates than did women between 1973 and 1979 (1.06 per 100,000, compared with 1.39 per 100,000), the earliest period for which data were available. In addition, recently, black men had higher incidence rates than did other race-specific and gender-specific groups (2.71 per 100,000). From the earliest period for which data were available to the most recent period, relative 5-year survival improved from 59% to 73% among women, was unchanged among men ( approximately 60%), and decreased from 45% to 27% among black men. Eighteen percent of patients who had distant disease were alive at 5 years, compared with 78% of patients who had localized disease.

CONCLUSIONS

The incidence of anal cancer in the United States increased between 1973 and 2000, particularly among men. There were higher incidence rates and lower survival rates for black men compared with other race-specific and gender-specific groups. Later disease stage was inversely associated with the survival rate, indicating that earlier detection may improve the survival of patients with anal cancer.

Anal cancer: an HIV-associated cancer

Although not yet included in the Centers for Disease Control definition of AIDS, anal cancer clearly occurs more commonly in HIV-infected patients. An effective screening program for those groups who are at highest risk might be expected to impact rates of anal cancer just as significantly as did cervical Pap screening programs for the incidence of cervical cancer. Despite a relatively low rate of progression from AIN to invasive cancer, the scope of the problem is enormous based on the prevalence of anal HPV infection and the size of the HIV-infected, at-risk population. Thus, the potential benefits of screening, detection, and the development of more effective therapy also are enormous. Currently, therapeutic HPV vaccines for AIN represent an exciting avenue of research in HPV-related anogenital disease. Invasive anal cancer and HSIL (which is believed to be the precursor lesion) are expected to become increasingly important health problems for both HIV-infected men and women as their life expectancy lengthens. Although HAART may have improved the ability of many to tolerate CMT, it appears that toxicity of this therapy continues to be a problem for a proportion of HIV-infected subjects. The acute side effects present specific challenges to the clinician and patient, have an immediate impact on the patient's plan of care and dose intensity of the treatment, and ultimately may impact the outcome of the planned treatment. Late toxicity may influence the long-term quality of life. Small patient numbers, variable radiation therapy doses, limited information about viral load, and a potential confounding effect of higher CD4+ levels make it difficult to draw any conclusions about the effect of HAART on anal cancer outcome. Large, prospective studies will be required before solid conclusions about the impact of various factors on anal cancer prognosis and outcome can be drawn.

Human papillomavirus infection as a risk factor for anal and perianal skin cancer in a prospective study

Human papillomavirus has emerged as the leading infectious cause of cervical and other anogenital cancers. We have studied the relation between human papillomavirus infection and the subsequent risk of anal and perianal skin cancer. A case-cohort study within two large Nordic serum banks to which about 760 000 individuals had donated serum samples was performed. Subjects who developed anal and perianal skin cancer during follow up (median time of 10 years) were identified by registry linkage with the nationwide cancer registries in Finland and Norway. Twenty-eight cases and 1500 controls were analysed for the presence of IgG antibodies to HPV 16, 18, 33 or 73, and odds ratios of developing anal and perianal skin cancer were calculated. There was an increased risk of developing anal and perianal skin cancer among subjects seropositive for HPV 16 (OR=3.0; 95%CI=1.1-8.2) and HPV 18 (OR=4.4; 95%CI=1.1-17). The highest risks were seen for HPV 16 seropositive patients above the age of 45 years at serum sampling and for patients with a lag time of less than 10 years. This study provides prospective epidemiological evidence of an association between infection with HPV 16 and 18 and anal and perianal skin cancer.

Anorectal manifestations of sexually transmitted infections

Sexually transmitted infections have a wide range of clinical presentations, including involvement of the anal verge, anal canal and rectum. This review focuses on anorectal sexually transmitted infections which may cause diagnostic difficulty when encountered by the coloproctologist. An approach to the diagnosis of a variety of sexually transmitted infections is set out, with a discussion of the role of biopsy and a summary of relevant histopathological findings. The value of early antibiotic treatment is discussed. Problems related to HIV/AIDS are highlighted, as clinical presentation may be atypical in immunosuppressed individuals. Sexually transmitted oncogenic viruses and their role in anal neoplasia are also briefly summarized.

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

INTRODUCTION

Human papillomavirus, particularly Type 16, plays a central role in the development of anogenital squamous-cell carcinomas. A common sequence variation of human papillomavirus Type 16 in cervical cancer cell lines and in cervical cancer tissues from Korean patients was recently reported. The present study was performed to determine the integration type of human papillomavirus DNA in anal epidermoid carcinoma and to identify the common sequence variations in the human papillomavirus Type 16 E7 gene that had been previously reported.

METHODS

Twenty-one formalin-fixed, paraffin-embedded specimens collected from 29 patients with anal epidermoid carcinomas treated at the Seoul National University Hospital over a ten-year period (1989-1998) were investigated. Genomic DNA from the 21 specimens was extracted and analyzed using the polymerase chain reaction with a general primer and a type-specific primer for human papillomavirus Types 16 and 18. Direct sequencing was performed. As a control, 13 normal anal epithelia available from these patients were microdissected. As another control, 21 hemorrhoidal squamous epithelia obtained from a demographically adjusted group were also analyzed.

RESULTS

Human papillomavirus Type 16 DNA was present in all 21 anal epidermoid carcinomas. All controls were negative for human papillomavirus DNA. Sequence analysis revealed that 57 percent (12/21) specimens showed two types of sequence variation in the E7 gene. One variant with a single nucleotide change at position 647 (amino acid 29, AAT-->AGT, asparagine to serine) was found in 38 percent (8/21) of the samples. This variant has been detected in cervical cancers from Korean patients: 19 (39 percent) of 49 cervical cancer tissues and 6 (50 percent) of 12 cervical cancer cell lines. Another single nucleotide change at position 645 (amino acid 28, TTA-->TTC, leucine to phenylalanine) was found in 19 percent (4/21) of the samples. These two variants exhibit a change of amino acid affecting the critical sites for Rb binding.

CONCLUSION

Human papillomavirus Type 16 was found to be present in all 21 anal epidermoid carcinomas. Furthermore, in the Korean population, the most common sequence variant found in cervical

Anal carcinoma: histology, staging, epidemiology, treatment

Our understanding of the pathogenesis and management of squamous cell carcinoma of the anal canal has undergone profound change over the last 30 years. Epidemiologic studies have demonstrated that infection with human papillomavirus is most likely responsible for the majority of cases. Primary treatment with concomitant chemotherapy and radiation cures the majority of patients without the need for an abdominoperineal resection. Recent series have demonstrated that approximately one half of patients with a local recurrence after chemoradiation will be cured with salvage surgery. The incorporation of cisplatin into the primary chemoradiation treatment of patients with carcinoma of the anal canal is the focus of current studies.

Anorectal miscellany: pilonidal disease, anal cancer, Bowen's and Paget's diseases, foreign bodies, and hidradenitis suppurativa

Pilonidal disease commonly is seen by all primary care practitioners, and guidelines for office management and referral are provided. Less commonly seen entities, such as hidradenitis suppurativa, anal cancer, and Bowen's and Paget's diseases, also may affect this anatomic area. Knowledge that they may be encountered here helps guide the practitioner to the proper diagnosis and management. Lastly, foreign bodies are sometimes seen in the anorectal area, and information about appropriate steps to take are outlined.