Human papillomavirus genotyping, human papillomavirus mRNA expression, and p16/Ki-67 cytology to detect anal cancer precursors in HIV-infected MSM

An update on anal neoplasia

Although anal cancer remains a relatively uncommon tumour its frequency is rising, especially in high-risk groups. It is now well recognized that anal squamous cell carcinoma, the largely predominant tumour type, shares many similarities with cancer of the uterine cervix, with a major role for oncogenic human papilloma viruses in both tumours. Anal squamous precancerous lesions have now to be classified with the same criteria and terminology as their cervical counterparts, by using the Lower Anogenital Squamous Terminology (LAST) proposal. Only p16 protein is a useful marker in this setting at the present time. As most cases of anal cancer are treated by non-surgical procedures, pathology has a limited role in the staging of the disease, except for early lesions treated by local excision, and when the sentinel lymph node procedure is undertaken that is still under evaluation. A variety of other tumour types can occur more rarely, with difficult diagnostic issues, solved in most cases by immunohistochemistry.

Screening for Anal Cancer in Women

OBJECTIVE

The incidence of anal cancer is higher in women than men in the general population and has been increasing for several decades. Similar to cervical cancer, most anal cancers are associated with human papillomavirus (HPV), and it is believed that anal cancers are preceded by anal high-grade squamous intraepithelial lesions (HSIL). Our goals were to summarize the literature on anal cancer, HSIL, and HPV infection in women and to provide screening recommendations in women.

METHODS

A group of experts convened by the American Society for Colposcopy and Cervical Pathology and the International Anal Neoplasia Society reviewed the literature on anal HPV infection, anal SIL, and anal cancer in women.

RESULTS

Anal HPV infection is common in women but is relatively transient in most. The risk of anal HSIL and cancer varies considerably by risk group, with human immunodeficiency virus-infected women and those with a history of lower genital tract neoplasia at highest risk compared with the general population.

CONCLUSIONS

While there are no data yet to demonstrate that identification and treatment of anal HSIL leads to reduced risk of anal cancer, women in groups at the highest risk should be queried for anal cancer symptoms and required to have digital anorectal examinations to detect anal cancers. Human immunodeficiency virus-infected women and women with lower genital tract neoplasia may be considered for screening with anal cytology with triage to treatment if HSIL is diagnosed. Healthy women with no known risk factors or anal cancer symptoms do not need to be routinely screened for anal cancer or anal HSIL.

Use of human papillomavirus genotyping and biomarkers for targeted screening of anal dysplasia in human immunodeficiency virus-infected patients

BACKGROUND

Screening for anal dysplasia in human immunodeficiency virus (HIV)-infected patients is not standardized. High-resolution imaging is not adequate for mass screening, and anal cytology requires expertise. New biomarkers, selected because of their use in cervical cancer mass screening, have been originally tested for targeted and easy-to-perform screening.

METHODS

120 HIV-infected individuals (males 96.4%, mean age 47±11 years) were referred for clinical examination, anoscopy, and cytological studies on anal swab. Dysplasia grading, Human Papilloma Virus genotyping, E6/E7mRNA detection and p16(INK4A)/Ki-67 immunostaining were performed. High-grade lesions were histologically confirmed by anal biopsies after high-resolution anoscopy.

RESULTS

Among the 120 anal swabs analyzed, 36 (30%) had low grade and 6 (5%) had high-grade lesions. Virus genotype was identified in 88 patients (73.3%), and 77 (64.2%) were positive for high-risk genotype(s). High-risk genotype was associated to low-grade or high-grade lesions with a sensitivity of 0.93 and a specificity of 0.51. For E6/E7mRNA, sensitivity and specificity for low-grade and high-grade lesions were, respectively, 0.88 and 0.78. Combination of genotyping, E6/E7mRNA and p16(INK4A)/Ki-67 appropriately ruled out dysplasia in 55% of patients.

CONCLUSIONS

Three routine biomarkers may avoid unnecessary invasive procedures with the perspective of an improvement of patient compliance. A decision making algorithm, based on the combination of these three biomarkers, is proposed.

Human papillomavirus mRNA testing for the detection of anal high-grade squamous intraepithelial lesions in men who have sex with men infected with HIV

Currently, screening for anal high-grade squamous intraepithelial lesions (anal HSIL) relies on anal cytology and high-resolution anoscopy. Since this approach has limited sensitivity and specificity for detecting anal HSIL, there is increasing interest in the role of biomarkers for predicting anal HSIL. The aim of this study is to evaluate the diagnostic accuracy of HPV E6/E7-mRNA expression for the detection of anal HSIL in MSM infected with HIV, in comparison to DNA-HR-HPV and anal cytology. This cross-sectional screening study included 101 MSM followed at the HIV-unit of La Paz University Hospital. Intra-anal swabs from patients participating in a screening program including cytology, high-resolution anoscopy and histology were analyzed. HR-HPV-DNA detection was performed by means of the CLART® HPV2 assay (GENOMICA S.A.U., Madrid, Spain). E6/E7-mRNA detection of HR-HPV-types 16, 18, 31, 33, and 45 was performed using the NucliSENS-EasyQ assay (BioMérieux, Marcy ĺEtoile, France). HR-HPV DNA and HPVE6/E7 mRNA were detected in 82% and 57% of the anal smears respectively. Anal cytology screening was abnormal in 70.3%. For the detection of HSIL sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 71.7%, 55.6%, 57.9%, and 69.8% for E6/E7-mRNA testing, respectively, compared to 100%, 31.5%, 55.4%, and 100% for HR-HPV-DNA testing and to 83%, 40.7%, 54.9%, 73.3% of cytology testing. In comparison with the other tests, HPVE6/E7 mRNA testing yielded a lower clinical sensitivity but a higher clinical specificity and PPV for the detection of anal HSIL in MSM infected with HIV.

Oncogenic human papillomavirus is not helpful for cytology screening of the precursor lesions of anal cancers in Taiwanese men who are infected with human immunodeficiency virus

BACKGROUND

Homosexual men infected with human immunodeficiency virus (HIV) are at increased risk of developing anal cancer. The aim of this study was to assess the clinical sensitivity of anal cytology analysis and oncogenic human papillomavirus (HPV) detection for predicting histological anal intraepithelial neoplasia.

METHODS

Between March 2011 and December 2013, we enrolled 196 HIV-positive men in Taoyuan General Hospital, Taiwan. We analyzed the results of thin-preparation anal Pap smears, HPV genotyping, and histology of anoscopic biopsy samples.

RESULTS

The mean age (±standard deviation) was 31.43 (±8.74) years. The proportion (95 % confidence interval) with abnormal thin-preparation anal cytology was 36.2 % (29.8-43.2 %): 16.8 % (12.2-22.7 %) atypical squamous cells of undetermined significance, 14.8 % (10.5-20.4 %) low-grade squamous intraepithelial lesions, and 4.6 % (2.4-8.5 %) high-grade squamous intraepithelial lesions. At least one HPV genotype was detected in 90.8 % of subjects, and the mean number of HPV infection types was 4.41 (±3.24).The frequency of histological high-grade anal intraepithelial lesions was 7.14 % (95 % confidence interval 4.3-11.6 %). Anal cytology yielding atypical squamous cells of undetermined significance or higher grades resulted in a sensitivity of 64.3 %, specificity of 65.9 %, positive predictive value of 12.7 %, and negative predictive value of 96 %. Using both oncogenic HPV and cytology did not provide better performance.

CONCLUSIONS

Anal cytology yielding atypical squamous cells of undetermined significance or higher grades could detect two-thirds of high-grade anal intraepithelial neoplasias in HIV-infected men and should be promoted for anal cancer prevention.

HPV and anal cancer in HIV-infected individuals: a review

HIV infection is one of the strongest risk factors for anal squamous cell cancer (ASCC). Most ASCC are caused by HPV, and most HPV-associated ASCC are caused by HPV-16. Anal HPV infections are very common in men who have sex with men (MSM), and nearly universal among HIV-infected MSM. High-grade anal intraepithelial neoplasia (HGAIN), the precursor for ASCC, is present in about 30 % of HIV+ MSM, but neither the progression rate to ASCC nor the regression rate are known. The incidence rate of ASCC among HIV-infected people has risen in the first decade after cART became available, but appears to be plateauing recently. Anal cytology has poor sensitivity and specificity. High resolution anoscopy (HRA) is advocated by some as a screening tool in high-risk groups, but is cumbersome and time-consuming and it is unknown whether HRA followed by treatment of HGAIN prevents ASCC. More research is needed on progression and regression rates of HGAIN, on effective therapy of HGAIN, and on biomarkers that predict HGAIN or anal cancer. HPV vaccination and earlier start of cART may prevent most anal cancers in the long run.

Analytic and clinical performance of cobas HPV testing in anal specimens from HIV-positive men who have sex with men

Anal human papillomavirus (HPV) infections are common, and the incidence of anal cancer is high in HIV-infected men who have sex with men (MSM). To evaluate the performance of HPV assays in anal samples, we compared the cobas HPV test (cobas) to the Roche Linear Array HPV genotyping assay (LA) and cytology in HIV-infected MSM. Cytology and cobas and LA HPV testing were conducted for 342 subjects. We calculated agreement between the HPV assays and the clinical performance of HPV testing and HPV genotyping alone and in combination with anal cytology. We observed high agreement between cobas and LA, with cobas more likely than LA to show positive results for HPV16, HPV18, and other carcinogenic types. Specimens testing positive in cobas but not in LA were more likely to be positive for other markers of HPV-related disease compared to those testing negative in both assays, suggesting that at least some of these were true positives for HPV. cobas and LA showed high sensitivities but low specificities for the detection of anal intraepithelial neoplasia grade 2/3 (AIN2/3) in this population (100% sensitivity and 26% specificity for cobas versus 98.4% sensitivity and 28.9% specificity for LA). A combination of anal cytology and HPV genotyping provided the highest accuracy for detecting anal precancer. A higher HPV load was associated with a higher risk of AIN2/3 with HPV16 (P(trend) < 0.001), HPV18 (P(trend) = 0.07), and other carcinogenic types (P(trend) < 0.001). We demonstrate that cobas can be used for HPV detection in anal cytology specimens. Additional tests are necessary to identify men at the highest risk of anal cancer among those infected with high-risk HPV.

Use of human papillomavirus DNA, E6/E7 mRNA, and p16 immunocytochemistry to detect and predict anal high-grade squamous intraepithelial lesions in HIV-positive and HIV-negative men who have sex with men

Background

Men who have sex with men (MSM) are at high risk of having anal cancer. Anal high-grade squamous intraepithelial lesion (HSIL) is the precursor of anal cancer. We explored the use of different biomarkers associated with human papillomavirus (HPV) infection and HPV-mediated cell transformation to detect and predict HSIL among HIV-positive and HIV-negative MSM.

Methodology/Principal Findings

A total of 123 HIV-positive and 123 HIV-negative MSM were enrolled and followed for 12 months. High-resolution anoscopy (HRA) with biopsies were performed at every visit along with anal sample collection for cytology, high-risk HPV DNA genotyping, HPV E6/E7 mRNA, and p16 immunocytochemistry. Performance characteristics and area under the receiver operator characteristics curve were calculated for these biomarkers at baseline, and Cox regression compared the usefulness of these biomarkers in predicting incident HSIL. High-risk HPV DNA, E6/E7 mRNA, and p16 immunocytochemistry each identified 43–46% of MSM whose baseline test positivity would trigger HRA referral. E6/E7 mRNA had the highest sensitivity (64.7%) and correctly classified the highest number of prevalent HSIL cases. With the exception of p16 immunochemistry, most tests showed significant increases in sensitivity but decreases specificity versus anal cytology, while the overall number of correctly classified cases was not significantly different. Baseline or persistent type 16 and/or 18 HPV DNA was the only test significantly predicting incident histologic HSIL within 12 months in models adjusted for HIV status and low-grade squamous intraepithelial lesions at baseline.

Conclusions/Significance

Countries with a high HIV prevalence among MSM and limited HRA resources may consider using biomarkers to identify individuals at high risk of HSIL. E6/E7 mRNA had the highest sensitivity for prevalent HSIL detection regardless of HIV status, whereas type 16 and/or 18 HPV DNA performed best in predicting development of incident HSIL within 12 months.

Progression to and spontaneous regression of high-grade anal squamous intraepithelial lesions in HIV-infected and uninfected men

OBJECTIVE

To quantify incidence of, and risk factors for, progression to and spontaneous regression of high-grade anal squamous intraepithelial lesions (ASILs).

DESIGN

Retrospective review of patients at St Vincent's Hospital Anal Cancer Screening Clinic during a period when high-grade ASILs were not routinely treated (2004-2011).

METHODS

All patients who had an anal Papanicolaou smear or high-resolution anoscopy were included, except for patients with previous anal cancer. High-grade anal intraepithelial neoplasia (HGAIN) was defined as a composite of histologically confirmed grade 2 or 3 anal intraepithelial neoplasia (AIN2/3) and/or high-grade squamous intraepithelial lesion on anal cytology. Analyses were repeated restricting to histologically confirmed AIN3.

RESULTS

There were 574 patients: median age 45 years (interquartile range, IQR 36-51), 99.3% male and 73.0% HIV-infected [median HIV duration was 13.8 years (IQR 6.4-19.8), median CD4+ T-lymphocyte count was 500 cells/μl (IQR 357-662), 83.5% had undetectable plasma HIV viral load]. Median follow-up was 1.1 years (IQR 0.26-2.76). Progression rate to HGAIN was 7.4/100 person-years (95% confidence interval, CI 4.73-11.63). No risk factor for progression to HGAIN was identified; progression to AIN3 was more likely with increasing age (Ptrend = 0.004) and in those who were HIV-infected [hazard ratio 2.8 (95% CI 1.18-6.68) versus HIV-uninfected; P = 0.019], particularly in those whose nadir CD4+ T-lymphocyte count was less than 200 cells/μl (Ptrend = 0.003). In 101 patients with HGAIN, 24 (23.8%) patients had spontaneous regression [rate 23.5/100 person-years (95% CI 15.73-35.02)], mostly to AIN1. Regression was less likely in older patients (Ptrend = 0.048). Two patients with HGAIN developed anal cancer.

CONCLUSION

High-grade ASILs frequently spontaneously regress. Longer-term, prospective studies are required to determine whether these regressions are sustained.

Understanding HPV tests and their appropriate applications

Greater understanding of the role played by human papillomavirus (HPV) in the causation of disease has led to the development of an increasing number of HPV tests with different characteristics. The bewildering choice facing healthcare professionals and providers is daunting. Clearly, HPV testing is no longer simply of research interest, but can provide information that can be used for individual patient management and at the population level for cervical screening and vaccine surveillance. This review aims to provide the background to the development of HPV tests, to explain the different technologies and to discuss the challenges of the application of these optimally in the varied contexts of disease management. Few HPV tests are approved for clinical use and it is important that clinicians understand which test can be utilized, in what circumstances, with what specimens and the meaning of the report issued. HPV testing is no longer applicable only to cervical disease, and we have suggested additional areas, such as the oropharynx, in which HPV testing services might be implemented in the near future. New tests will continue to emerge and we have identified some of the indirect measures of HPV activity, or biomarkers, that could help in the risk stratification of HPV infection and associated disease. The challenges relating to the optimal application of the various HPV technologies are compounded by the lack of evidence regarding their performance in vaccinated populations. Currently published work, including modelling studies, has been undertaken in non-immunized populations. We therefore end by addressing the issues regarding appropriate strategies and tests for immunized populations.

Screening guidelines for non-AIDS defining cancers in HIV-infected individuals

PURPOSE OF REVIEW

The growing burden of non-AIDS defining malignancies (non-ADMs) among people living with HIV/AIDS (PLWHA) highlights the need for cancer prevention and early detection. In this article, we propose screening guidelines for non-ADMs in PLWHA.

RECENT FINDINGS

A number of recent findings may help direct cancer screening guidelines in PLWHA. Screening for lung cancer with low-dose helical chest computerized tomography (LDCT) in the National Lung Screening Trial data demonstrated a decrease in lung cancer and all-cause mortality. Recent studies have demonstrated a favorable experience among PLWHA with liver transplantation. Overdiagnosis is common with breast and prostate cancer screening. Anal cancer rates were substantially higher for HIV-infected MSM, other men and women than for HIV-uninfected individuals.

SUMMARY

Screening recommendations for the general population can be applied to PLWHA patients for breast, colon and prostate cancer. Screening for lung cancer with LDCT could be considered in PLWHA at risk. American Association for the Study of Liver Diseases screening recommendations with biennial ultrasonography may be applied to at-risk PLWHA for hepatocellular carcinoma. All HIV-infected adults should be offered anal cancer screening as part of clinical care at specialized centres.

Risk factors for anal HPV infection and anal precancer in HIV-infected men who have sex with men

BACKGROUND

Carcinogenic human papillomaviruses (HPVs) cause a large proportion of anal cancers. Human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) are at increased risk of HPV infection and anal cancer compared with HIV-negative men. We evaluated risk factors for HPV infection and anal precancer in a population of HIV-infected MSM.

METHODS

Our study included 305 MSM at an HIV/AIDS clinic in the Kaiser Permanente Northern California Health Maintenance Organization. Logistic regression was used to estimate associations of risk factors comparing men without anal HPV infection; men with anal HPV infection, but no precancer; and men with anal precancer.

RESULTS

Low CD4 count (<350 cells/mm(3)) and previous chlamydia infection were associated with an increased risk of carcinogenic HPV infection (odds ratio [OR], 3.65; 95% confidence interval [CI], 1.28-10.40 and OR, 4.24; 95% CI, 1.16-15.51, respectively). History of smoking (OR, 2.71 95% CI, 1.43-5.14), duration, recency, and dose of smoking increased the risk of anal precancer among carcinogenic HPV-positive men but had no association with HPV infection.

CONCLUSIONS

We found distinct risk factors for anal HPV infection and anal precancer. Risk factors for HPV infection and anal precancer are similar to established risk factors for cervical cancer progression.

A comparison of human papillomavirus genotype-specific DNA and E6/E7 mRNA detection to identify anal precancer among HIV-infected men who have sex with men

BACKGROUND

Human papillomavirus (HPV) RNA detection is reportedly more specific for the detection of anogenital precancer than HPV DNA but it is unknown whether this is due to detection of RNA or due to HPV genotype restriction.

METHODS

A total of 363 human immunodeficiency virus (HIV)-positive men who have sex with men had two anal cytology samples taken and were evaluated using high-resolution anoscopy and biopsies of visible lesions. Anal specimens were tested for E6/E7 RNA for five carcinogenic HPV genotypes (HPV16, 18, 31, 33, and 45) and tested for the DNA of 13 carcinogenic HPV genotypes.

RESULTS

DNA testing was more likely to be positive than RNA testing (53% vs. 48%; P = 0.02) for the same five HPV genotypes in aggregate. When restricted to five HPV genotypes targeted by the RNA test, the sensitivity to detect anal precancer was the same for DNA and RNA (81%), whereas RNA was more specific than DNA (65% vs. 58%; P = 0.007). In comparison, DNA detection of all 13 carcinogenic HPV genotypes was more sensitive (96% vs. 81%; P = 0.001) but much less specific (65% vs. 33%; P < 0.001) as compared with RNA detection of the five HPV genotypes.

CONCLUSION

After controlling for HPV genotypes, RNA was only slightly more specific than DNA detection for anal precancer.

IMPACT

DNA or RNA testing for a subset of the most carcinogenic HPV genotypes may be useful for distinguishing between those HPV-positive men at higher and lower risk of anal precancer and cancer.