A study of Amplicor human papillomavirus DNA detection in the atypical squamous cells of undetermined significance-low-grade squamous intraepithelial lesion triage study

Lack of association between high-risk human papillomaviruses and oral squamous cell carcinoma in young Japanese patients

BACKGROUND

Human papillomaviruses (HPV) may play an important role as one of the possible etiologies of oral squamous cell carcinoma (OSCC). The present study aimed to investigate the association between HPV and OSCC in young Japanese patients by examining the presence of HPV DNA and surrogate markers in OSCC tissues.

MATERIALS AND METHODS

Forty young patients with OSCC whose surgical specimens were available were analyzed and compared with 40 patients randomly recruited from a pool of patients aged >40 years. HPV DNA was detected using the polymerase chain reaction-based AMPLICOR(®) HPV test, and surrogate markers of HPV infection were analyzed using immunohistochemical techniques to detect p16(INK4a) and p53.

RESULTS

Only two (5%) young patients and one (2.5%) older patient were positive for HPV DNA. p16(INK4a) overexpression was identified in six (15%) young patients. p53 staining levels were not high in tissues of most young patients (27 patients, 67.5%). HPV DNA status did not significantly correlate with p16(INK4a) expression levels. Profiles of increased levels of p16(INK4a) expression with diminished levels of p53 staining were not associated with the presence of HPV DNA. The combined p53 with p16(INK4a) profiles were significantly correlated with alcohol consumption in younger patients (p=0.006).

CONCLUSIONS

RESULTS of the present study indicate that HPV is less likely to cause OSCC in young Japanese patients, and the p16(INK4a) expression level is not an appropriate surrogate marker for HPV infection in OSCC.

Comparison of methods for diagnostics and treatment of clinical manifestations of the papilloma viral infection

The article describes modern methods for diagnostics of clinical, subclinical and latent forms of the papilloma viral infection. The authors reviewed different methods of the destruction of anogenital warts and described their advantages and shortcomings. They provide the results of studies of the efficacy of Imiquimod for the treatment of anogenital warts.

Seroprevalence of 8 oncogenic human papillomavirus genotypes and acquired immunity against reinfection

BACKGROUND

Natural human papillomavirus (HPV) antibody titers have shown protection against subsequent HPV infection, but previous studies were restricted to few HPV genotypes. We examined the association of naturally occurring antibodies against 8 carcinogenic HPV types with subsequent infections.

METHODS

A total of 2302 women enrolled in the Atypical Squamous Cells of Undetermined Significance/Low-Grade Squamous Intraepithelial Lesion Triage Study provided blood samples at baseline. Serum samples were tested for antibodies against 8 carcinogenic HPV genotypes (16, 18, 31, 33, 35, 45, 52, and 58) using a multiplex serology assay. We analyzed the relationship between HPV antibodies and HPV infection during 2 years of follow-up among women negative for the specific HPV type at baseline.

RESULTS

Baseline seroprevalence for HPV16 L1 was associated with decreased risk of DNA positivity for HPV16 (odds ratio, 0.39 [95% confidence interval, .18-.86]) at ≥2 follow-up visits. We observed similar but nonsignificant decreased risks for HPV18 and 31. These findings were restricted to women reporting a new sex partner during follow-up. There was no association between baseline seroprevalence and detection of precancer during follow-up.

CONCLUSIONS

Seroprevalence conferred protection against subsequent HPV infection for HPV16 and indicated possible protection for 2 other genotypes, suggesting that this effect is common to several HPV genotypes.

HPV detection methods and genotyping techniques in screening for cervical cancer

Human papillomaviruses (HPV), double-stranded DNA viruses, are causing many mucocutaneous diseases, benign or malignant, ranging from common warts to malignancies involving the upper aerodigestive tract and the anogenital sphere. The diagnosis of HPV infection is based primarily on the viral genome detection by molecular biological methods, given the difficulty in routine cultivation of these viruses. The current trend in screening against cervical cancer is to improve the sensitivity of screening with new methods and to propose new algorithms for diagnostic and therapeutic decisions. The development of liquid-based cytology facilitates the cytologic diagnosis and molecular assays from the same sample. There are two main types of HPV detection methods used on uterine cervical samples: signal amplification methods (hybridization techniques in liquid phase) and target amplification methods (the techniques of gene amplification or Polymerase Chain Reaction [PCR]). Genotyping techniques are also developed: they are based on an amplification technique followed by hybridization with probe specific types. In addition to the detection, genotyping techniques allow quantitative detection of viral DNA of HPV genotype and so monitor changes in viral load over time. Another approach relies on the detection of messenger RNA (mRNA) of HPV proteins E6 and E7 oncogenes, which would appear to be a relevant marker to identify and monitor women at risk of progression to a precancerous lesion or cervical cancer.

The diagnostic accuracy of two methods for E6&7 mRNA detection in women with minor cytological abnormalities

OBJECTIVE

To examine the diagnostic accuracy of nucleic acid sequence based amplification (NASBA) and flow cytometry for E6&7 human papillomavirus (HPV) mRNA detection in the triage of minor cytological abnormalities.

DESIGN

Prospective diagnostic accuracy study.

SETTING

Gynecology outpatient clinics of a university hospital.

POPULATION

472 women with low-grade squamous intraepithelial lesion (LSIL) or atypical squamous cells of undetermined significance (ASCUS).

METHODS

Residual material of the liquid-based smears was tested by NASBA and by flow cytometry for E6&E7 mRNA expression. Histological diagnosis was used as reference standard.

MAIN OUTCOME MEASURES

Accuracy indices of the two techniques and of type 16-specific NASBA for the detection of cervical intraepithelial neoplasia (CIN) 2+ and CIN3+, accuracy indices at age >35 years, correlation between NASBA and flow, comparison between integrated and episomal high-risk HPV infection for risk of CIN2+.

RESULTS

Both tests showed increased positivity rates with increasing severity of the lesion (p < 0.05, chi-squared test for trend). There was a positive correlation between NASBA and flow results (phi coefficient = 0.325). NASBA-positive cases were more likely to have CIN2+ than were NASBA-negative/DNA-positive for types 16, 18, 31, 33, 45 (25/73 vs. 4/52, p= 0.0004; Fisher's exact test). In the LSIL group the NASBA accuracy indices for CIN3+ were: sensitivity 75%, specificity 78.7% and positivity rate 20.8%, and for flow 77.8%, 64.5% and 35.9%, respectively.

CONCLUSIONS

NASBA has favorable specificity and positivity rates for triaging LSIL prior to colposcopy. A relatively low sensitivity warrants cytological surveillance of the NASBA-negative LSILs. Flow cytometry does not perform as well overall.

Cytology and human papillomavirus testing 6 to 12 months after ASCUS or LSIL cytology in organized screening to predict high-grade cervical neoplasia between screening rounds

We carried out a prospective study comparing the performance of human papillomavirus (HPV) E6/E7 mRNA (PreTect HPV-Proofer; NorChip, Klokkarstua, Norway) and DNA (Amplicor HPV test; Roche Diagnostics, Basel, Switzerland) triage testing of women 6 to 12 months after atypical-squamous-cells-of-undetermined-significance (ASCUS) or low-grade-squamous-intraepithelial-lesion (LSIL) cytology in organized screening to predict high-grade cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) between screening rounds. Between January 2005 and April 2008, 692 study women with screening-detected ASCUS/LSIL cytology 6 to 12 months earlier returned for HPV mRNA and DNA testing and repeat cytology. The median follow-up time was 3 years, using existing health care facilities. Follow-up test results were available for 625 women. Of the 145 CIN2+ cases detected during the study period, 95 (65.5%) were HPV mRNA positive 6 to 12 months after screening-detected ASCUS/LSIL, 44 (30.4%) were HPV mRNA negative, and 6 (4.1%) were invalid. The corresponding HPV DNA results were 139 (95.9%), 5 (3.4%), and 1 (0.7%), respectively. The cumulative incidences of CIN2+ 3 years after a negative HPV mRNA and DNA test were 10.3% (95% confidence interval [CI], 7.2 to 13.3%) and 1.8% (95% CI, 0.0 to 3.6%), respectively. The cumulative incidences of CIN2+ 3 years after positive HPV mRNA and DNA tests were 52.8% (95% CI, 40.1 to 60.1%) and 41.3% (95% CI, 35.5 to 46.6%), respectively. In conclusion, both positive HPV mRNA and DNA test results have a high enough long-term prediction of CIN2+ risk to consider referral to colposcopy as good practice when performed in delayed triage of women with ASCUS/LSIL cytology. In addition, the low CIN2+ risk among women with a negative Amplicor HPV test in our study confirms its safe use in a clinical setting.

Comparative performance of human papillomavirus DNA testing using novel sample collection methods

To explore alternative cervical cancer screening approaches in an underserved population, we compared the performance of human papillomavirus (HPV) DNA assays in combination with different sample collection methods for primary cervical screening in the Mississippi Delta region. Three specimens were collected from women aged 26 to 65 years who were either routinely undergoing screening (n = 252) or not (n = 191): clinician-collected cervical specimens, clinician-collected cervicovaginal specimens, and self-collected cervicovaginal specimens taken at home. A novel collection device and medium were used for cervicovaginal sampling. Specimens were tested by three HPV DNA assays: hybrid capture 2 (HC2; Qiagen Corp., Gaithersburg, MD), Linear Array (LA; Roche Molecular Systems, Pleasanton, CA), and Amplicor (Roche Molecular Systems, Pleasanton, CA). Liquid-based cytology was performed on cervical specimens. We compared the overall positivity (a proxy for clinical specificity) for any carcinogenic HPV genotype and calculated the agreement across assay and specimen type using McNemar's test for differences in test positivity. Across all three assays there were no significant differences between clinician-collected and self-collected cervicovaginal specimens (P > 0.01 for all comparisons). For both cervicovaginal specimens (clinician collected and self-collected), fewer women tested positive by HC2 than by LA or Amplicor (P < 0.01 for all comparisons). HC2 had the best agreement between specimens for all assays. HC2 is likely more clinically specific, although possibly less sensitive, than either PCR test. Thus, use of HC2 on cervicovaginal specimens for screening could result in fewer referrals compared to LA and Amplicor.

Human papillomavirus and cervical cancer: biomarkers for improved prevention efforts

While organized screening programs in industrialized countries have significantly reduced cervical cancer incidence, cytology-based screening has several limitations. Equivocal or mildly abnormal Pap tests require costly retesting or diagnostic work-up by colposcopy and biopsy. In low-resource countries, it has been difficult to establish and sustain cytology-based programs. Advances in understanding human papillomavirus biology and the natural history of human papillomavirus-related precancers and cancers have led to the discovery of a range of novel biomarkers in the past decade. In this article, we will discuss the potential role of new biomarkers for primary screening, triage and diagnosis in high-resource countries and their promise for prevention efforts in resource constrained settings.

[Molecular diagnosis of HPV infections]

Carcinogenic human papillomaviruses (HPV) cause the majority of cervical cancers and other anogenital cancers. Large randomized trials have shown that HPV testing can be efficiently used for primary cervical cancer screening. Other applications include the triage of abnormal cytology results and the follow-up of women after treatment. Many assays have been developed to measure DNA, RNA and proteins of HPV and the various tests can have very different applications. It is important to rigorously validate HPV assays before they are implemented in screening or clinical care.

Human papillomavirus (HPV) DNA triage of women with atypical squamous cells of undetermined significance with Amplicor HPV and Hybrid Capture 2 assays for detection of high-grade lesions of the uterine cervix

Up to 20% of women having a cytology smear showing atypical squamous cells of undetermined significance (ASC-US) and infected with high-risk human papillomavirus (HR HPV) have high-grade cervical intraepithelial neoplasia (CIN 2/3). Results obtained with the Amplicor HPV and Hybrid Capture 2 (HC-2) assays for HR HPV DNA detection in women referred to colposcopy for an ASC-US smear were compared. Cervical samples in PreservCyt were tested for the presence of 13 HR HPV types with HC-2, with Amplicor at three cutoffs for positivity (0.2, 1.0, and 1.5 optical density units), and for 36 genotypes with the Linear Array (LA). Of 396 eligible women, 316 did not have CIN, 47 had CIN 1, 29 had CIN 2/3, and 4 had CIN of unknown grade. HR HPV was detected in 129 (32.6%) and 164 (41.4%) samples with HC-2 and Amplicor HPV (cutoff, 0.2), respectively (P = 0.01). Overall, 112 specimens were positive and 215 were negative with the HC-2 and Amplicor HPV assays (agreement of 82.6%; 95% confidence interval [CI], 78.5 to 86.0). The clinical sensitivity and specificity of Amplicor HPV at cutoffs of 0.2, 1.0 and 1.5 and of HC-2 for detection of CIN 2/3 were 89.7% (95% CI, 72.8 to 97.2) and 62.5% (95% CI, 57.5 to 52.4), 89.7% (95% CI, 72.8 to 97.2) and 64.5% (95% CI, 59.4 to 69.2), 89.7% (95% CI, 72.8 to 97.2) and 64.7% (95% CI, 59.7 to 69.5), and 93.1% (95% CI, 77.0 to 99.2) and 72.2% (95% CI, 67.4 to 76.5), respectively. Both HR HPV detection tests identified women with ASC-US who would benefit the most from colposcopy. Women with persistent HR HPV infection need further investigation despite a first normal colposcopy.

Comparison of measurements of human papillomavirus persistence for postcolposcopic surveillance for cervical precancerous lesions

OBJECTIVE

Following guidelines, women evaluated by colposcopy, but not found to have a precancerous lesion, could be tested again at 12 months for carcinogenic human papillomavirus (HPV). Compared with pooled-probe testing, measuring HPV genotype-specific persistence might better predict subsequent grade 3 cervical intraepithelial neoplasia (CIN3).

METHODS

For women enrolled in the immediate colposcopy arm of the Atypical squamous cells of undetermined significance (ASCUS) and Low-grade squamous intraepithelial lesion (LSIL) Triage Study (ALTS), who underwent enrollment colposcopy but were without prevalently detected CIN2 or worse (CIN2+; n = 671), we compared 1-year HPV persistence, as measured by a pooled HPV genotype test (hybrid capture 2; hc2) versus a research PCR HPV genotyping test (line blot assay; LBA) as predictors of "missed prevalent" or possibly incident CIN3 diagnosed between 12 and 24 months.

RESULTS

Thirty-two (4.8%) women were diagnosed with subsequent CIN3. Testing repeatedly hc2-positive (hc2+) was more common (49.0%) than genotype-specific persistence as detected by LBA (30.3%, P < 0.01). Although absolute risks of CIN3 following repeat hc2+ or genotype-specific persistence were similar (8.8% versus 8.4%, P = 0.86), repeat hc2+ was more sensitive for identifying CIN3 than genotype-specific persistence (90.6% versus 53.1%, P < 0.01). Among 329 women repeatedly hc2+, women with persistent HPV16 were at higher risk of CIN3 than non-HPV16-persistent women (23.1% versus 7.0%, P < 0.01).

CONCLUSIONS

For postcolposcopy management, 1-year HPV persistence as measured by hc2 would recall more women but was more sensitive and similarly predictive for CIN3 in the following year than detection of genotype-specific persistence by LBA.

IMPACT

Although find little utility for measuring type-specific persistence, testing for persistent HPV16 might be clinically useful.

Impact of improved classification on the association of human papillomavirus with cervical precancer

Misclassification of exposure and surrogate endpoints of disease can obscure causal relations. Using data from the Atypical Squamous Cells of Undetermined Significance/Low-Grade Squamous Intraepithelial Lesion Triage Study (ALTS, 1997-2001), the authors explored the impact of exposure (human papillomavirus (HPV) detection) and endpoint (histologic cervical precancer) classification on their mutual association. Women referred into this study with an atypical squamous cells of undetermined significance Papanicolaou test with satisfactory results for all 4 HPV tests were included in this analysis (n = 3,215; 92.2%). HPV testing results were related to different definitions of cervical precancer, based on paired, worst 2-year histologic diagnoses, by calculating clinical sensitivity, specificity, and odds ratios. The authors found that HPV test sensitivity increased and specificity decreased with increasing certainty of cervical precancer, with HPV testing having the highest sensitivity (92%-98%) and lowest specificity (46%-54%) for consensus cervical intraepithelial neoplasia grade 3 (CIN 3). The overall accuracy of each HPV test, as measured by odds ratios, was greatest for consensus CIN-3 diagnoses, from 2- to 4-fold greater than for a less stringent precancer definition of any diagnosis of CIN 2 or more severe. In summary, there was convergence of greater certainty of carcinogenic HPV with greater certainty of a precancerous diagnosis, such that all 4 HPV tests almost always tested positive in women most likely to have cervical precancer. Finding increasingly strong associations when both test and diagnostic misclassification are reduced is a useful sign of "true association" in molecular epidemiology.