Malignant anal tumours

Role of Sentinel Lymph Node Biopsy for Skin Cancer Based on Clinical Studies

The sentinel lymph node is the first lymph node from the primary tumor. Sentinel lymph node biopsy (SLNB) is a surgical procedure that can detect occult nodal metastasis with relatively low morbidity. It may also have a therapeutic effect via regional disease control. The Multicenter Selective Lymphadenectomy-I (MSLT-I) trial revealed a prognostic benefit from SLNB in melanoma patients. However, it remains unclear whether there is a prognostic benefit from SLNB in patients with nonmelanoma skin cancer owing to a lack of randomized prospective studies. Nevertheless, SLNB provides important information about nodal status, which is one of the strongest factors to predict prognosis and may guide additional nodal treatment. Currently, SLNB is widely used in the management of not only patients with melanoma but also those with nonmelanoma skin cancer. However, the utilization and outcomes of SLNB differ among skin cancers. In addition, SLNB is not recommended for routine use in all patients with skin cancer. In this review, we provide a summary of the role of SLNB and of the indications for SLNB in each skin cancer based on previously published articles.

A stem cell population at the anorectal junction maintains homeostasis and participates in tissue regeneration

At numerous locations of the body, transition zones are localized at the crossroad between two types of epithelium and are frequently associated with neoplasia involving both type of tissues. These transition zones contain cells expressing markers of adult stem cells that can be the target of early transformation. The mere fact that transition zone cells can merge different architecture with separate functions implies for a unique plasticity that these cells must display in steady state. However, their roles during tissue regeneration in normal and injured state remain unknown. Here, by using in vivo lineage tracing, single-cell transcriptomics, computational modeling and a three-dimensional organoid culture system of transition zone cells, we identify a population of Krt17+ basal cells with multipotent properties at the squamo-columnar anorectal junction that maintain a squamous epithelium during normal homeostasis and can participate in the repair of a glandular epithelium following tissue injury.

Assessing the Reliability and Positive Predictive Value of p16 as a Surrogate for Human Papillomavirus-Mediated E6/7 mRNA Expression in Squamous Cell Carcinoma of the Anal Canal

BACKGROUND

Human papillomavirus has been implicated in the carcinogenesis of squamous cell carcinoma of the anal canal. p16 expression and the presence of human papillomavirus DNA have been used to define human papillomavirus-positive patients, but neither approach has been validated against the standard of human papillomavirus E6/7 mRNA expression at this disease site.

OBJECTIVE

This study aimed to evaluate the acceptability of p16 immunohistochemistry as a surrogate to E6/7 mRNA expression in identifying human papillomavirus-mediated squamous cell carcinoma of the anal canal.

DESIGN

This was a retrospective analysis of a previously constructed tissue microarray.

SETTINGS

This study was conducted at a tertiary academic center.

PATIENTS

Biopsies and resection specimens from patients diagnosed with squamous cell carcinoma of the anal canal at the study institution from 2005 to 2015 were reviewed for sample adequacy.

MAIN OUTCOME MEASURES

Concordance between p16 positivity by immunohistochemistry and E6/7 mRNA expression by in situ hybridization was evaluated. Sensitivity, specificity, and positive predictive value were assessed.

RESULTS

Among the 25 patients evaluated, p16 and E6/7 mRNA results were concordant in 24 of 25 specimens (96%). Of the 24 concordant samples, there were 23 true positives (p16+ and E6/7+) and 1 true negative (p16- and E6/7-). One specimen was discordant (p16- and E6/7+) between p16 and E6/7 mRNA (4%). This resulted in a sensitivity of 96% and a specificity of 100%. Positive predictive value of p16 immunohistochemistry for E6/7 mRNA expression was 100%.

LIMITATIONS

This study was limited by its retrospective nature and small sample size. It only assessed diagnostic parameters rather than prognostic implications.

CONCLUSIONS

In this study, the clinically prevalent method of p16 immunohistochemistry showed excellent concordance with the standard of E6/7 mRNA expression and demonstrated its potential to serve as a surrogate for identifying human papillomavirus-induced squamous cell carcinoma of the anal canal. See Video Abstract at http://links.lww.com/DCR/B448.

EVALUANDO LA CONFIABILIDAD Y EL VALOR PREDICTIVO POSITIVO DE P, COMO SUSTITUTO DE LA EXPRESIN DE ARNM DE E / , MEDIADA POR EL VIRUS DEL PAPILOMA HUMANO, EN CARCINOMA DE CLULAS ESCAMOSAS DEL CANAL ANAL

ANTECEDENTES:El virus del papiloma humano se ha relacionado en la carcinogénesis del carcinoma de células escamosas del canal anal. La expresión de p16 y la presencia de ADN del virus del papiloma humano, se han utilizado para definir a los pacientes positivos al virus del papiloma humano. Pero ninguno de estos enfoques, han sido validados frente al estándar de oro de la expresión del ARNm del virus del papiloma humano E6 / 7, en este sitio de la enfermedad.OBJETIVO:El estudio tuvo como objetivo, evaluar la aceptabilidad de la inmunohistoquímica del p16, como sustituto de la expresión de ARNm de E6 / 7, en la identificación del carcinoma de células escamosas del canal anal, mediada por virus del papiloma humano.DISEÑO:Fue un análisis retrospectivo de un microarreglo de tejido previamente construido.AJUSTE:El estudio se realizó en un centro académico terciario.PACIENTES:Se revisaron biopsias y muestras de resección de pacientes diagnosticados con carcinoma de células escamosas del canal anal, en la institución del estudio, entre 2005 y 2015 para determinar la idoneidad de la muestra.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluó la concordancia entre la positividad de p16 por inmunohistoquímica y la expresión de ARNm de E6 / 7 por hibridación in situ. Se evaluaron la sensibilidad, especificidad y valor predictivo positivo.RESULTADOS:Entre los 25 pacientes evaluados, los resultados del ARNm de p16 y E6 / 7 fueron concordantes en 24/25 muestras (96%). De las 24 muestras concordantes, hubo 23 positivos verdaderos (p16 + y E6 / 7 +) y un negativo verdadero (p16- y E6 / 7-). Una muestra fue discordante (p16- y E6 / 7 +) entre p16 y ARNm de E6 / 7 (4%). Esto resultó en una sensibilidad del 96% y una especificidad del 100%. El valor predictivo positivo de la inmunohistoquímica de p16 para la expresión de ARNm de E6 / 7 fue del 100%.LIMITACIONES:El estudio estuvo limitado por su naturaleza retrospectiva y por el tamaño pequeño de la muestra. Solamente evaluó los parámetros de diagnóstico, en lugar de las implicaciones pronosticas.CONCLUSIONES:En este estudio, el método clínico prevalente de inmunohistoquímica p16, mostró una excelente concordancia con el estándar de oro de la expresión de ARNm de E6 / 7 y demostró su potencial para servir, como sustituto para identificar el carcinoma de células escamosas del canal anal, inducido por el virus del papiloma humano. Consulte Video Resumen en http://links.lww.com/DCR/B448.

Dosimetric comparison of organs at risk using different contouring guidelines for definition of the clinical target volume in anal cancer

Background

There are different contouring guidelines for definition of the clinical target volume (CTV) for intensity-modulated radiation therapy (IMRT) of anal cancer (AC). We conducted a planning comparison study to evaluate and compare the dose to relevant organs at risk (OARs) while using different CTV definitions.

Methods

Twelve patients with a primary diagnosis of anal cancer, who were treated with primary chemoradiation (CRT), were selected. We generated four guideline-specific CTVs and subsequently planned target volumes (PTVs) on the planning CT scan of each patient. An IMRT plan for volumetric arc therapy (VMAT) was set up for each PTV. Dose parameters of the planned target volume (PTV) and OARs were evaluated and compared, too.

Results

The mean volume of the four PTVs ranged from 2138 cc to 2433 cc. The target volumes contoured by the authors based on the recommendations of each group were similar in the pelvis, while they differed significantly in the inguinal region. There were no significant differences between the four target volumes with regard to the dose parameters of the cranially located OARs. Conversely, some dose parameters concerning the genitals and the skin varied significantly among the different guidelines.

Conclusion

The four contouring guidelines differ significantly concerning the inguinal region. In order to avoid inguinal recurrence and to protect relevant OARs, further investigations are needed to generate uniform standards for definition of the elective clinical target volume in the inguinal region.

Have we achieved adequate recommendations for target volume definitions in anal cancer? A PET imaging based patterns of failure analysis in the context of established contouring guidelines

Background

There are different contouring guidelines for the clinical target volume (CTV) in anal cancer (AC) which vary concerning recommendations for radiation margins in different anatomical regions, especially on inguinal site. PET imaging has become more important in primary staging of AC as a very sensitive method to detect lymph node (LN) metastases. Using PET imaging, we evaluated patterns of LN spread, and examined the differences of the respective contouring guidelines on the basis of our results.

Methods

We carried out a retrospective study of thirty-seven AC patients treated with chemoradiation (CRT) who underwent FDG-PET imaging for primary staging in our department between 2011 and 2018. Patients showing PET positive LN were included in this analysis. Using a color code, LN metastases of all patients were delineated on a template with “standard anatomy” and were divided indicating whether their location was in- or out-field of the standard CTV as recommended by the Radiation Therapy Oncology Group (RTOG), the Australasian Gastrointestinal Trials Group (AGITG) or the British National Guidance (BNG). Furthermore, a detailed analysis of the location of LN of the inguinal region was performed.

Results

Twenty-two out of thirty-seven AC patients with pre-treatment PET imaging had PET positive LN metastases, accumulating to a total of 154 LN. The most commonly affected anatomical region was inguinal (49 LN, 32%). All para-rectal, external/internal iliac, and pre-sacral LN were covered by the recommended CTVs of the three different guidelines. Of forty-nine involved inguinal LN, fourteen (29%), seven (14%) and five (10%) were situated outside of the recommended CTVs by RTOG, AGITG and BNG. Inguinal LN could be located up to 5.7 cm inferiorly to the femoral saphenous junction and 2.8 cm medial or laterally to the big femoral vessels.

Conclusion

Pelvis-related, various recommendations are largely consistent, and all LN are covered by the recommended CTVs. LN “misses” appear generally cranially (common iliac or para-aortic) or caudally (inguinal) to the recommended CTVs. The established guidelines differ significantly, particular regarding the inguinal region. Based on our results, we presented our suggestions for CTV definition of the inguinal region. LN involvement of a larger number of patients should be investigated to enable final recommendations.

Dosimetric quantification of the incidental irradiation of the 'true' (deep) ano-inguinal lymphatic drainage of anal cancer patients not described in conventional contouring guidelines

INTRODUCTION

The ano-inguinal lymphatic drainage (AILD) is located in the subcutaneous adipose tissue of the proximal medial thigh. Findings from fluorescence methods give us new information about anatomical conditions of the AILD. Current contouring guidelines do not advise the inclusion of the 'true' AILD into the clinical target volume (CTV). Aim of this work was the retrospective analysis of the incidental dose to the AILD in an anal cancer (AC) patient cohort who underwent definitive chemoradiation (CRT) therapy with Volumetric Arc Therapy - Intensity Modulated Radiation Therapy (VMAT-IMRT).

METHODS

VMAT-IMRT plans of 15 AC patients were analyzed. Based on findings from new fluorescence methods we created a new volume, the expected AILD. The examined dosimetric parameters were the minimal, maximal and mean dose and V10-V50 that were delivered to the AILD, respectively.

RESULTS

The median volume of AILD was 1047 cm³. Mean D_min, D_max and D_mean were 7.5 Gy, 58.9 Gy and 40.8 Gy for AILD. The clinical relevant dose of 30.0 Gray covered in mean 76% of the volume of the AILD, respectively.

CONCLUSIONS

Only 76% of the AILD-volume received at least an expected required treatment dose of 30 Gy incidentally. Concerning the low number of loco-regional relapses in AC patients after definitive CRT one has to balance increased side effects against a rigid oncological-anatomical interpretation of the local lymphatic drainage by including the AILD into the standard CTV.

Loss of Raf kinase inhibitor protein expression is associated with human papillomavirus 16 infection in anal tumors

There has been an increase in the incidence of anal cancer in the past two decades, with squamous cell carcinoma (SCC) being the most frequent histological type identified. Among the risk factors, high-risk human papillomavirus (HPV) infection is the most pervasive. Raf kinase inhibitor protein (RKIP) is expressed in a number of normal human tissues and previous studies have demonstrated the prognostic value of the loss of RKIP expression in several gastrointestinal tumors. Therefore, the present study aimed to evaluate the clinical implications of RKIP expression in a series of neoplastic lesions of the anal canal. The resected tumors of 48 patients [8 high-grade intraepithelial lesions (HSILs), 14 adenocarcinomas and 26 squamous cell carcinomas (SCCs)] were immunohistochemically evaluated for RKIP expression, and the results were correlated with clinicopathological data. The results identified a decreased 5-year overall survival rate in patients with adenocarcinoma (40.8%) compared with patients with SCC (76.7%), and a decreased 5-year disease-free survival rate in patients at clinical stages III/IV (37.3 vs. 62.5 and 82.6% for clinical stages 0 and I/II, respectively). Low RKIP expression was revealed in 62.5% of HSILs, 88.5% of SCCs and 100.0% of the adenocarcinomas. High RKIP expression was associated with patient ethnicity (37.5% in non-Caucasians vs. 7.5% in Caucasians) and patient age (33.3% in younger patients vs. 0.0% in older patients). Finally, high RKIP expression was correlated with HPV16 infection status (40% in HPV^- vs. 5.3% in HPV⁺ patients). A correlation was identified between high RKIP expression and lesions with a generally improved prognosis, such as those diagnosed in younger patients, in situ lesions and lesions of lower clinical grades; there was also a negative correlation between high RKIP expression and HPV16 positivity in patients.

Low mutation percentage of KRAS and BRAF genes in Brazilian anal tumors

Anal cancer is a rare type of digestive tract disease, which has had a crescent incidence in a number of regions. Carcinomas are most frequently found, with squamous cell carcinoma (SCC) comprising ~95% of all anal tumors. The major risk factor for development of this type of tumor is human papillomavirus (HPV) infection. However, previous studies have identified patients with anal cancer that are HPV‑/p16‑and observed that they have a poorer outcome compared with HPV+/p16+ patients. This suggests that molecular profile may drive anal cancer progression. The aim of the present study was to evaluate the mutational status of two important oncogenes, KRAS and BRAF, in a series of anal cancer lesions. Resected tumors of the anal canal (n=43) were evaluated, nine of these were high‑grade squamous intra‑epithelial lesion cases (HSIL), 11 were adenocarcinomas, and 23 SCCs. Direct sequencing of KRAS proto‑oncogene, GTPase (KRAS; codons 12 and 13) and B‑Raf proto‑oncogene, serine/threonine kinase (BRAF; codon 600) was performed and associated with patient clinicopathological and molecular features. There was a trend of poorer prognosis of adenocarcinoma compared with HSIL and SCC. Analysis indicated one SCC patient (2.3%) exhibited a KRAS p.G13D mutation, and one adenocarcinoma patient (2.3%) exhibited a BRAF p.V600E mutation. It was observed that, these mutations are rare in anal tumors, and certain patients may be at a disadvantage using targeted therapies based on KRAS and BRAF mutational status. As there is a low mutation percentage in SCCs, adenocarcinomas and HSIL, there may exist other underlying molecular alterations that result in anal cancer development, which require further elucidation.

[HPV-induced anal lesions]

Human papillomavirus (HPV) infections belong to the most common sexually transmitted infections. To date, more than 200 completely classified HPV-types have been reported, and those belonging to the genus alpha predominantly infect the anogenital region. Condylomata acuminata are caused by the two low-risk types HPV6 and HPV11 in more than 90 % of cases. Treatment of genital warts might be either ablative (e.g. electrocautery, surgical excision, or laser therapy) or topical (e.g. podophyllotoxine, trichloroacetic acid, or imiquimod), and depends on the size, location, morphology and anatomical region. Recurrences after treatment are frequent. Therefore, combination therapies (e.g. topical and ablative) play an important role in daily routine. HIV-infected individuals, especially HIV-positive MSM, have a strongly increased risk for anal dysplasia and anal cancer. Condylomata acuminata and a large proportion of anal dysplasia and anal carcinoma are preventable by prophylactic HPV-vaccination.

A Case of Rectal Squamous Cell Carcinoma Mistaken for Rectal Adenocarcinoma

<title>Abstract We report a case of anal squamous cell carcinoma extended to the rectal mucosa that was clinically mistaken for rectal adenocarcinoma and literature reviwed. Sigmoidoscopic finding showed spherical shaped elevated lesion with central ulceration, interpreted as rectal adenocarcinoma in the distal portion of rectum. Anal squamous cell carcinoma is very rare among gastrointestinal cancer. Pathological study of the biopsy specimen demonstrated squamous cell carcinoma and normal rectal glands. Sigmoidoscopic finding of the presented case showed the ulcerarive lesion contineuosly extended from anal verge upward to the rectum. We postulate that the presented case is primarilly originated from the anal squamous cell carcinoma extended proximally to the rectum. Immunohistochemical stain(p-63) of the biopsy specimens showed squamous cell carcinoma. This patient has been completely recovered after treartment of chemoradiation and trans-anal excision. We present a case of anal squamous cell carcinoma invading rectal mucosa clinically mistaken for rectal adenocarcinoma and literature reviewed.</p>

The role of MRI in the assessment of the local status of anal carcinomas and in their management

This study aims to define the role of Magnetic Resonance (MR) examinations in the assessment and therapy of anal cancer (AC), and to present the main features of the MR examinations and the typical tumor spread pattern. The MR examinations of 67 anal cancer patients with histologically confirmed planocellular cancer were analyzed retrospectively. The tumor size and the signal intensity, the nodal status were examined before and after the treatment, and in recidive tumors (N = 13). At the time of the diagnosis the primary tumor was in early stage (Tis, T1, T2) in 71.5 % of the cases, and it was localized in 97 %. In 97.4 % of the cases the tumor had relatively increased signal intensities compared to the adjacent muscles. Patients received chemo-radiotherapy (CRT). After CRT in 26 out of 39 patients (66.7 %) the size of the tumor decreased (in 75 %), and the signal intensity decreased on the T2 weighted (T2w) images. In the residual tumor cases (19/39) verified 6 patients out of 19 had further decrease in size, and signal intensity a year after the end of the therapy. The MR examination plays a key role in the therapy of AC, by assessing the precise local status, the possible recidive tumors, and monitoring the therapy.

Regional and national guideline recommendations for digital ano-rectal examination as a means for anal cancer screening in HIV positive men who have sex with men: a systematic review

Background

Although anal cancer is common in HIV positive men who have sex with men, few centres offer systematic screening. Regular digital ano-rectal examination (DARE) is a type of screening that has been recommended by some experts. How widely this forms part of HIV management guidelines is unclear.

Methods

The protocol was registered prospectively (CRD42013005188; http://www.crd.york.ac.uk/PROSPERO/). We systematically reviewed 121 regional and national HIV guidelines and searched for guidelines from http://hivinsite.ucsf.edu/global?page=cr-00-04#SauguidelineX, PubMed and Web of Science databases up to 5^th August 2013 for recommendations of DARE as a means of anal cancer screening in HIV positive MSM. Guidelines were examined in detail if they were clinical guidelines, including both prevention and treatment protocols and were in English. Guidelines were excluded if they were restricted to limited areas (e.g. antiretroviral therapy only, children or pregnant women, strategies for prevention/testing). Information was extracted regarding recommendation of DARE as a screening method, the frequency of DARE recommended, target population for screening and the strength of evidence supporting this.

Results

30 regional and national guidelines were included and examined in detail. Only 2 recommended DARE. The ‘European AIDS Clinical Society Guidelines’ recommends DARE every 1–3 years for HIV positive MSM whilst the ‘US Guideline for prevention and treatment of opportunistic infections in HIV-infected adults and adolescents’ recommends an annual DARE for the HIV + population in general. None of these guidelines specify the age of commencing screening. In each case, the highest level of evidence supporting these two recommendations was expert opinion.

Conclusions

Few HIV guidelines discuss or recommend DARE as a means of anal cancer screening. Studies of the efficacy, acceptability and cost-effectiveness of DARE are needed to assess its role in anal cancer screening.

[Anorectal malignant tumors in the hospital environment in Ouagadougou: epidemiological and diagnostic aspects]

Le but de notre étude était de décrire les caractéristiques épidémiologiques et diagnostiques des tumeurs malignes anorectales en milieu hospitalier à Ouagadougou. Il s'est agi d'une étude rétrospective et transversale qui a concerné les patients vus en endoscopie digestive basse au cours de la période allant du 29/09/1999 au 04/10/2008. À l'aide d'une fiche de collecte, nous avons recueilli, dans 4 structures sanitaires et 3 laboratoires d'anatomie et de cytologie pathologiques de la ville de Ouagadougou, les données à partir des comptes-rendus d'endoscopie digestive basse et des registres d'anatomie et de cytologie pathologiques. Durant la période de notre étude, 645 patients ont été examinés en anorectoscopie et 882 cas d'affections anorectales colligés. Les tumeurs malignes anorectales avec 61 cas (6,9%) occupaient la quatrième place après la maladie hémorroïdaire (45,6%), les anites (21,1%) et les fissures (13,9%). Elles regroupaient les cancers du rectum (4,2%) et les cancers de l'anus (2,7%). Vingt cancers anorectaux ont été histologiquement confirmés parmi lesquels l'adénocarcinome était le type histologique le plus retrouvé avec 17 cas. Les tumeurs malignes, quatrième affection anorectale la plus fréquente au cours de notre étude, constituent une préoccupation du fait de leur fréquence croissante, leur diagnostic souvent tardif et les difficultés liées à leur prise en charge surtout dans nos pays avec une population à faible revenu. La sensibilisation de la population et la prescription plus large de l'endoscopie digestive basse devraient permettre une meilleure prise en charge des patients.

Inguinal lymph node recurrence in the untreated groin of patients with anal carcinoma

BACKGROUND

Inguinal lymph node metastasis is predictive of locoregional recurrence and poor overall survival in anal carcinoma. Metachronous lymph node metastasis occurs in 10% of all anal cancer patients, but multiple studies have shown that the benefit of elective irradiation of the groin depends on T-stage, and the toxicity of groin irradiation must not be underestimated.

OBJECTIVE

To analyze the inguinal recurrence rates among patients with anal carcinoma (T1-4, N0-1) who did not receive elective irradiation therapy to the groin and to determine predictors of inguinal recurrence.

DESIGN

Data on 119 patients treated between 1987 and 2005 were retrospectively analyzed. Patients were treated with 3-dimensional radiotherapy. The median dose was 60 Gy. During radiotherapy, 108 patients also received chemotherapy (5-fluorouracil and mitomycin-C).

RESULTS

AJCC staging showed a distribution of 21 T1 (18%), 58 T2 (49%), 27 T3 (23%), 13 T4 (11%), 101 N0 (85%) and 18 N1 (15%) tumors. The median follow up was 65 months (range, 1-240 months). The 5-year inguinal recurrence rate was 0% for T1, 10% for T2, 21% for T3 and 19% for T4 tumors (p = 0.034). T2 tumors of the perianal skin and the anal canal had 5-year inguinal recurrence rates of 12% and 8%, respectively. The 5-year inguinal recurrence rate was 21% for tumors ≥4 cm vs. 2% for tumors <4 cm in size (p = 0.003).

LIMITATIONS

Eleven patients did not receive chemotherapy.

CONCLUSIONS

Elective irradiation of the groin should be considered for local control in patients (N0-N1) with T2 tumors ≥4 cm in size and/or located in the perianal skin, and in all patients with T3 and T4 tumors.

The role of ¹⁸fluoro-deoxy glucose combined position emission and computed tomography in the clinical management of anal squamous cell carcinoma

AIM

Anal squamous cell carcinoma (SCC) is uncommon in the western world but continues to increase in incidence. Optimal treatment and outcome are dependent upon pretreatment staging strategies. We evaluate the role of ¹⁸fluoro-deoxyglucose (¹⁸FDG) combined position emission and computed tomography (PETCT) in the management of anal SCC.

METHOD

Patients with a histologically confirmed anal SCC underwent standard staging investigations, including computed tomography, Magnetic resonance imaging and examination under anaesthetic. A tumour, node, metastasis (TNM) system was used. All patients subsequently underwent additional whole-body ¹⁸FDG PETCT scanning. Management was planned accordingly, blinded to ¹⁸FDG PETCT findings, at a multidisciplinary meeting, and reviewed again following disclosure of PETCT results.

RESULTS

Forty patients (24 men), with a median age of 57 years (range 38-87 years), were prospectively recruited. All primary tumours were ¹⁸FDG avid. PETCT did not alter the T stage but did result in disease upstaging (N and M stages). Management was altered in five (12.5%) patients: one patient was identified to have an isolated distant metastasis, and four patients had ¹⁸FDG-avid lymph nodes not otherwise detected, all of which were tumour-positive on fine needle aspiration cytology/biopsy.

CONCLUSION

PETCT upstages anal SCC and influences subsequent management. PETCT should be considered in the staging of anal SCC, although the definitive benefit of such a strategy requires further evaluation.

Anal carcinomas: the role of endoanal ultrasound and magnetic resonance imaging in staging, response evaluation and follow-up

Anal carcinoma is an important but rare condition, managed in specialist centres. Both endoanal ultrasound and magnetic resonance imaging (MRI) can be used in the locoregional staging and follow-up of patients with anal cancer, and both may assist in treatment planning and prognosis. Recent guidelines published by the European Society for Medical Oncology have recommended MRI as the technique of choice for assessment of locoregional disease. This paper describes the techniques for both endoanal ultrasound and MRI, and compares the relative merits and disadvantages of each in the local assessment of anal carcinoma.

Identification of epithelial label-retaining cells at the transition between the anal canal and the rectum in mice

In certain regions of the body, transition zones exist where stratified squamous epithelia directly abut against other types of epithelia. Certain transition zones are especially prone to tumorigenesis an example being the anorectal junction, although the reason for this is not known. One possibility is that the abrupt transition of the simple columnar epithelium of the colon to the stratified squamous epithelium of the proximal portion of the anal canal may contain a unique stem cell niche. We investigated whether the anorectal region contained cells with stem cell properties relative to the adjacent epithelium. We utilized a tetracycline-regulatable histone H2B-GFP transgenic mice model, previously used to identify hair follicle stem cells, to fluorescently label slow-cycling anal epithelial cells (e.g., prospective stem cells) in combination with a panel of putative stem cell markers. We identified a population of long-term GFP label-retaining cells concentrated at the junction between the anal canal and the rectum. These cells are BrdU-retaining cells and expressed the stem cell marker CD34. Moreover, tracking the fate of the anal label-retaining cells in vivo revealed that the slow-cycling cells only gave rise to progeny of the anal epithelium. In conclusion, we identified a unique population of cells at the anorectal junction which can be separated from the other basal anal epithelial cells based upon the expression of the stem cell marker CD34 and integrin alpha6, and thus represent a putative anal stem cell population.

Infectious complications of cancer chemotherapy in HIV patients

The outcome for HIV-infected patients with cancer has dramatically improved in the highly active antiretroviral therapy (HAART) era, probably due to improvements in immune status and bone marrow function that allow the possibility of increased drug-dose intensity with a higher complete remission rate. Although data regarding the optimal management of these cancers are lacking, current studies suggest that patients with HIV-associated malignancies could be treated using approaches similar to those for their counterparts in the general population (ie, with chemotherapy, radiation, and appropriate use of supportive measures). In the HAART era, the AIDS-related mortality rate has decreased by approximately 70%, and so the cause of the growing number of reports of cancers in HIV patients is unclear. Clearly, non-AIDS-defining malignancies account for more morbidity and mortality than AIDS-defining malignancies. Prevention strategies are needed to adequately deal with HIV-associated cancers in an aging and growing HIV-positive population.

[Anal intraepithelial neoplasia and anal carcinoma: an increasing problem in HIV patients]

Anal dysplasia is common in HIV patients, especially in HIV-positive men having sex with men (MSM). High-grade anal dysplasia can progress to invasive anal cancer. As in cervical carcinoma, there is a cause and effect relationship between anal cancer and human papillomavirus (HPV) infection, especially with high-risk types such as HPV16. Several experts have recommended screening programs for anal cancer, including anal cytology along the lines of the Pap smear in women. Such screenings should only be performed if pathological findings result in further diagnostic steps and, if necessary, appropriate treatment. Clinical inspection, lesion biopsy, and treatment of anal dysplasia are performed under high-resolution anoscopy. Anal cancer is divided into cancer of the anal margin and cancer of the anal canal. This classification is important because of the difference in treatment regimens. Early cancer of the anal margin is excised akin to squamous cell cancer of the exposed skin, whereas cancer of the anal canal is treated by radiochemotherapy. HIV-positive and HIV-negative patients have similar response rates to combined radiochemotherapy. However, side effects, especially acute post-irradiation skin toxicity, early local recurrences, and abdominoperineal rectal excision are more common in HIV-positive patients. Physicians working in the field of HIV/AIDS should regularly screen their patients for the presence of anal dysplasia and anal cancer. Basic diagnostic workup includes clinical inspection of the perianal area, digital rectal examination, and anal cytology.

Sentinel node biopsy by indocyanine green retention fluorescence detection for inguinal lymph node staging of anal cancer: preliminary experience

BACKGROUND

There is some evidence that sentinel lymph node (SLN) biopsy guided by dye injection and/or radioisotopes can improve staging of inguinal lymph nodes (LNs) in anal cancer. This study was performed to investigate the feasibility of fluorescence detection of SLN and lymphatic mapping in anal cancer.

METHODS

Twelve patients with anal cancer without evidence for inguinal LN involvement were included in the study. Intraoperatively, all patients received a peritumorous injection of 25 mg indocyanine green (ICG) for fluorescence imaging of the SLN with a near-infrared camera. For comparison, conventional SLN detection by technetium-(99)m-sulfur radiocolloid injection in combination with blue dye was also performed in all patients. The results of both techniques and the effect on the therapeutic regimen were analyzed.

RESULTS

Overall, ICG fluorescence imaging identified at least one SLN in 10 of 12 patients (detection rate, 83%). With the combination of radionuclide and blue dye, SLN were detected in 9 of 12 patients (detection rate, 75%). Metastatic involvement of the SLN was found in 2 of 10 patients versus 2 of 9 patients. Patients with metastatic involvement of the SLN received extended radiation field with inguinal boost.

CONCLUSIONS

ICG fluorescence imaging allows intraoperative lymphatic mapping and transcutaneous SLN detection for selective biopsy of inguinal SLN in anal cancer. This technique should be further evaluated in comparative studies with larger patient numbers.

Anal carcinoma in human immunodeficiency virus-positive men: results of a prospective study from Germany

BACKGROUND

Anal intraepithelial neoplasia (AIN), a human papillomavirus (HPV)-associated potential precursor lesion of anal cancer, is frequent among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). There is a paucity of data published on the progression of high-grade AIN to invasive cancer as well as on clinical and virological characteristics comparing anal margin and anal canal carcinoma.

OBJECTIVES

To search for anal carcinoma and AIN in a large series of HIV-positive MSM, to assess treatment response of anal carcinoma, and to analyse lesional HPV spectrum of anal cancers.

METHODS

Detection of anal carcinoma and AIN was performed using cytology, high-resolution anoscopy, and histology in case of abnormal findings. Additionally, HPV analyses for 36 high- and low-risk α-HPV types were performed in patients with anal carcinoma.

RESULTS

In total, 446 German HIV-positive MSM were examined within an observation period of 5 years and 10 months. Of these, 116 (26·0%) patients had normal findings, 163 (36·5%) had low-grade AIN, 156 (35·0%) had high-grade AIN, and 11 (2·5%) had anal carcinoma as evidenced by the highest grade of cytology/histology. Five patients with anal cancer, who had refused treatment of their precancerous lesions, had progressed from high-grade AIN to invasive cancer within a median time of 8·6 months. All anal cancers carried high-risk α-HPV types. All five squamous cell carcinomas (SCCs) of the anal canal were HPV16 positive. In contrast, only one of the four anal margin SCCs were HPV16 positive (HPV31, HPV33 and HPV33 + HPV68 were found in the other three anal margin SCCs). HPV59 was found in two adenocarcinomas, one of which additionally carried HPV33. In contrast to the cancer biopsies, a broad spectrum of surface high- and low-risk HPV types was found in anal swabs of the patients. Surgical excision resulted in long-term disease control of all anal margin carcinomas, whereas combined chemoradiotherapy in carcinomas of the anal canal was associated with high recurrence rates, high toxicity, and high mortality.

CONCLUSIONS

Anal carcinoma and AIN are frequent in HIV-positive men, even in patients participating in anal cancer prevention programmes. High-grade dysplasia in these patients can progress to invasive cancer within a short period of time. Anal margin carcinoma and anal canal carcinoma differ substantially in their lesional HPV spectrum, prognosis and treatment response.

Infiltrating adenocarcinoma arising in a villous adenoma of the anal canal

Primary neoplasms arising in the anal canal are relatively unusual. In particular, adenomas and adenocarcinomas are distinctly rare entities in this region. We describe an infiltrating, well-differentiated adenocarcinoma arising in a villous adenoma from the distal anal canal, in an otherwise healthy patient at low risk for gastrointestinal malignancy. This is the case of an octogenarian man with a several year history of hemorrhoids and intermittent rectal bleeding, more recently complaining of continuous hematochezia. Examination revealed a blood-covered pedunculated mass with a long stalk protruding from the anus. The lesion was amputated at the bedside. Microscopic evaluation revealed an infiltrating well-differentiated adenocarcinoma, arising from a villous adenoma. This was further evaluated under anesthesia and complete excision of distal anal tissue was performed. Our report is the first describing the possible malignant degeneration of a villous adenoma in the anal canal.

Improved screening for anal neoplasia by immunocytochemical detection of minichromosome maintenance proteins

PURPOSE

Early detection of anal intraepithelial neoplasia (AIN) and anal squamous cell carcinoma (SCC) by screening will improve clinical outcome. Assessment of anal cytology samples using routine Papanicolaou testing suffers from shortcomings in sensitivity and/or specificity, suggesting that screening tests based on biomarkers may be of value. We tested the suitability in this context of minichromosome maintenance (MCM) proteins, accurate markers of the deregulated cell cycle entry that characterizes malignancy and premalignancy.

EXPERIMENTAL DESIGN

We undertook an initial immunohistochemical study of 54 anal tissue samples and validated our findings using an independent prospective cohort study of 235 anal cytology samples from 144 subjects.

RESULTS

In the progression from normal anal epithelium through AIN to SCC, there was increasing expression of MCM2 and MCM5, including in the superficial epithelial third, the source of the majority of cells collected by anal swab. The median labeling indices (LI) for MCM2 and MCM5 in the superficial third of AIN2/3 and SCCs combined were 90.2% and 84.0%, respectively. MCM LIs in the superficial layers were significantly greater than LIs for Ki67, an alternative marker of cell cycle entry (P<0.0001). By immunocytochemistry using a mixture of anti-MCM2 and anti-MCM5 antibodies, immunopositive cells were readily identified in anal cytology samples, even at low magnification. MCM testing showed sensitivity for AIN2/3 of 84% (95% confidence interval, 75,93) and for AIN1/viral changes of 76% (68, 84), with overall specificity (for any lesion) of 77% (64, 90).

CONCLUSIONS

MCMs are promising biomarkers for improving detection of AIN and SCC in anal cytology samples.

Pelvic phased-array MR imaging of anal carcinoma before and after chemoradiation

The aim of this study was to evaluate the MR findings of anal carcinoma using an external pelvic phased-array coil before and after chemoradiation treatment. 15 patients with carcinoma of the anal canal underwent T(2) weighted and short-tau inversion recovery (STIR) imaging before and after chemoradiation. Images were reviewed in consensus by two radiologists. At pre-treatment imaging, the tumour size and stage, signal intensity and infiltration of adjacent structures were recorded. MR imaging was repeated immediately after chemoradiation, every 6 months for the first year and then yearly. Tumour response was assessed by recording change in tumour size and signal intensity. Prior to treatment, the mean tumour size was 3.9 cm (range, 1.8-6.4 cm). Tumours appeared mildly hyperintense at T(2) weighted and STIR imaging. There was good agreement in T staging between clinical examination and MR imaging (kappa = 0.68). In 12 responders with long disease remission, a greater percentage reduction in the size of MR signal abnormality in the tumour area was observed at 6 months (mean 54.7%; 46-62%) than immediately after treatment (mean 38.6%; 30-46%) (p = 0.002, t-test). 7/12 showed stabilization of T(2) signal reduction in the tumour area after 1 year, and 5/12 showed complete resolution of signal alterations at 2 years. Pelvic phased-array MR imaging is useful for local staging of anal carcinoma and assessing treatment response. After treatment, a decrease in tumour size accompanied by reduction and stability of the MR T(2) signal characteristics at 1 year after chemoradiation treatment was associated with favourable outcome.

Lymphatic mapping and sentinel lymph node biopsy in epidermoid carcinoma of the anal canal

AIM

Although 15-25% of patients with anal cancer present with superficial inguinal lymph node metastases but the routine application of groin irradiation is controversial because of serious side effects. Inguinal sentinel lymph node biopsy (SLNB) can be used to select patients appropriately for inguinal radiation. The study evaluates the efficiency and clinical impact of SLNB.

METHODS

Forty patients with anal cancer underwent 1 ml Tc(99m)-Nanocolloid injection in four sites around the tumour. Patients with inguinal radio colloid enrichment were selected for sentinel lymph node biopsy (SLNB). Lymph node status was examined by haematoxylin and eosin (H&E) as well as immunohistochemistry-staining. All SLN-positive patients were scheduled for inguinal radiation; SLN-negative patients with T1 and early T2 tumours were not scheduled for inguinal radiation.

RESULTS

SLN were detected in 36/40 patients. Three common patterns of lymphatic drainage were observed: mesenterial, iliacal and inguinal. Twenty patients with inguinal SLN underwent SLN-biopsy. 6/20 patients were SLN-positive. In 10/20 patients SLNB altered the therapy plan--four patients with T1-tumours and positive SLN had additional groin irradiation, whereas 6 patients with small T2-tumors and tumour-free inguinal SLN did not undergo inguinal irradiation.

CONCLUSIONS

Inguinal sentinel node biopsy in anal cancer is efficient and could assist in the decision for inguinal radiation. The validity and safety of the proposed therapeutic algorithm has to be proven by a larger, prospective study.

Bone morphogenetic protein signaling suppresses tumorigenesis at gastric epithelial transition zones in mice

Bone morphogenetic protein (BMP) signaling is known to suppress oncogenesis in the small and large intestine of mice and humans. We examined the role of Bmpr1a signaling in the stomach. On conditional inactivation of Bmpr1a, mice developed neoplastic lesions specifically in the squamocolumnar and gastrointestinal transition zones. We hypothesized that the regulation of epithelial cell fate may be less well defined in these junctional zones than in the adjacent epithelium and found that the mucosa at the squamocolumnar junction in mice shows a lack of differentiated fundic gland cell types and that foveolar cells at the gastrointestinal junctional zone lack expression of the foveolar cell marker Muc5ac. Precursor cell proliferation in both transition zones was higher than in the surrounding epithelium. Our data show that BMP signaling through Bmpr1a suppresses tumorigenesis at gastric epithelial junctional zones that are distinct from the adjacent gastric epithelium in both cellular differentiation and proliferation.

Anal intraepithelial neoplasia and anal cancer in dermatological practice

Anal intraepithelial neoplasia is considered to be a precursor lesion of invasive anal cancer. It is now increasingly recognized in high-risk groups, such as men who have sex with men and HIV-infected patients. Human papillomaviruses are considered to be an important aetiological agent in both anal intraepithelial neoplasia and anal cancer. Dermatologists are likely to encounter these conditions among the differential diagnoses to be considered in high-risk patients presenting with perianal and anal lesions. Anal cancer rates are also increasing among the HIV-infected and HIV-non-infected population. The successful treatment of anal intraepithelial neoplasia may reduce the risk of subsequent development of anal cancer. However, current therapies for anal intraepithelial neoplasia may be associated with treatment-related morbidity and are not well validated. It is currently not proven that they reduce the likelihood of the development of anal cancer. Nevertheless, screening for anal intraepithelial neoplasia is being advocated for high-risk groups and may become standard dermatological care for these patients. In view of recent developments in the understanding of this condition, this article reviews the current understanding of anal intraepithelial neoplasia and its treatment from a dermatological perspective.

Bilan préthérapeutique initial du carcinome épidermoïde invasif de l’anus

Anal epidermoid carcinoma is a rare malignant tumor, comprising less than 5% of all carcinomas of the colon, rectum, and anus. The primary therapy now includes radiotherapy, often in combination with chemotherapy. Radical surgery is now rarely indicated. Therapeutic indications are based on locoregional staging, the presence of visceral metastases and an evaluation of the medical history. Anorectal endosonography is helpful in evaluating locoregional extension. In addition, magnetic resonance imaging, positron emission tomography scanning and inguinal sentinel lymph node procedure should play a role in a more selective approach in patients with anal carcinoma.

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.

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.

Sentinel Lymph Node Biopsy in Patients with Extramammary Paget's Disease

BACKGROUND

Patients with invasive extramammary Paget's disease appear to have a risk of regional lymph node metastasis. Despite the poor prognosis for patients with lymph node metastasis, management of extramammary Paget's disease without clinical evidence of involved nodes is controversial.

OBJECTIVE

To evaluate the usefulness of sentinel lymph node biopsy, patients with extramammary Paget's disease underwent sentinel lymph node biopsy using preoperative lymphoscintigraphy and intraoperative patent blue dye injection with a handheld gamma-detecting probe.

METHODS

Thirteen patients with primary genital extramammary Paget's disease were included in the study. Sentinel nodes identified were excised and examined by hematoxylin and eosin staining. All sentinel lymph nodes were also subjected to immunohistochemical staining for carcinoembryonic antigen, MUC1, cytokeratin 7, and gross cystic disease fluid protein-15.

RESULTS

A total of 23 nodes were removed successfully. Tumor cells were detected in 4 nodes from four patients by hematoxylin and eosin staining. No additional lymph nodes were positive by immunohistochemistry. Three of the four sentinel-node-positive patients developed distant metastases. All nine patients without node involvement were free from disease during the follow-up period.

CONCLUSION

Sentinel lymph node biopsy was safe and feasible method and may have an important role in the management of extramammary Paget's disease with clinically N0 status. To establish the optimal management of inguinal lymph nodes in extramammary Paget's disease, additional studies in large number of patients are needed.

Cancer of the anal canal

Anal cancer is an uncommon tumour that represents 4% of all cancers of the lower gastrointestinal tract. Its pathogenesis and treatment have undergone substantial reassessment over the past two decades, and this is likely to continue. Anal cancer can be cured by synchronous chemoradiotherapy, a treatment that both enables anal continence to be retained and reserves abdominoperineal resection of the rectum and anal canal (with formation of a permanent colostomy) for recurrent or residual disease after primary chemoradiotherapy. Overall, survival from anal cancer is now around 70-80% at 5 years. Future challenges will be influenced by an increasing incidence due to human papillomavirus and HIV infection, more accurate characterisation and treatment of early (in situ) disease, and optimisation of chemoradiation regimens.

Inguinal sentinel lymph node biopsy for staging anal cancer

BACKGROUND AND AIMS

The optimal treatment of clinically negative inguinal lymph nodes in patients with primary anal cancer has not yet been clearly defined. The presence of metastases in the inguinal lymph nodes is an adverse prognostic factor for anal cancer. In the present study the feasibility of sentinel lymph node biopsy (SLNB) for staging anal cancer was investigated.

PATIENTS AND METHODS

From September 1999 to March 2002, 8 patients with biopsy proven primary anal cancer underwent lymphoscintigraphy and dual-agent guided inguinal SLNB for nodal staging before starting multimodality treatment.

RESULTS

Inguinal SLNB was successful in all 8 patients (13 groins). A total of 20 hot and blue SLNs (mean 1,5 (1-2) per groins) were removed. In 2 patients (25%) the SLN was positive for metastasis.

CONCLUSIONS

Lymphoscintigraphy followed by dual-agent guided inguinal SLNB is technically feasible for staging patients with primary anal cancer. The detection of metastases in the removed sentinel lymph node(s) may alter the treatment and thus may improve the locoregional control and overall survival of these patients.

Squamous cell carcinoma of the anal margin with pruritus ani of long duration

BACKGROUND

Anal margin is an unusual location for squamous cell carcinoma (SCC). On rare occasions, anal margin carcinoma is the cause of pruritus ani.

OBJECTIVE

To describe a case of SCC of the anal margin with pruritus ani of long duration.

RESULTS

A 52-year-old man had been aware of perianal itching for over 10 years. Examination of the perianal area revealed a reddish, eroded, hard nodule that was 2.0 x 1.5 x 0.3 cm in size located in the 3 o'clock position. The histopathologic diagnosis was well-differentiated SCC. The nodule was totally excised with a 1-cm margin. No recurrence or metastases were observed for 7 months.

CONCLUSION

When pruritus ani does not respond to conservative therapy and when symptoms have existed for a long time, we should suspect the presence of malignancy.

Sentinel lymph node biopsy for squamous cell carcinoma of the anal canal

BACKGROUND

The current Trans-Tasman Radiation Oncology Group (TROG) protocol for T1 and T2 anal cancers is combination chemotherapy and radiotherapy excluding the inguinal region from the field. Several centres worldwide irradiate both inguinal regions as there is a small incidence of involvement with early stage tumours. The presence of inguinal lymph node metastases is not accurately detected using clinical and most radiological assessment modalities. We have developed a method of sampling the sentinel node in the groin using established node mapping techniques.

METHODS

A combination of radio-labelled Antimony Sulphide and Patent Blue dye injected around the anal cancer enable identification of the sentinel node in the groin, using a gamma probe and direct visualization of the blue node.

RESULTS

This technique has been used in four patients. A groin sentinel node was identified and removed in three of these, with pathological assessment excluding metastatic disease in the inguinal region. The fourth patient had a sentinel node mapped to a meso-rectal node. This was not sampled.

CONCLUSIONS

The application of this effective technique will allow accurate staging of anal cancers to better plan future treatment regimes.

[Anal metastasis of colonic adenocarcinoma?]

Two cases of sigmoid and anal adenocarcinoma are reported. The two patients were treated by abdominoperineal resection of the rectum and resection of the sigmoid colon. The relationship between colonic adenocarcinoma and anal adenocarcinoma is not obvious but possible. The various mechanisms of tumoral spread are discussed and the most frequent mechanism seems to be cellular exfoliation.