Biospectroscopy insights into the multi-stage process of cervical cancer development: probing for spectral biomarkers in cytology to distinguish grades.

Cervical cancer screening programmes have greatly reduced the burden associated with this disease. However, conventional cervical cytology screening still lacks sensitivity and specificity. There is an urgent need for the development of a low-cost robust screening technique. By generating a spectral "biochemical-cell fingerprint", Fourier-transform infrared (FTIR) spectroscopy has been touted as a tool capable of segregating grades of dysplasia. A total of 529 specimens were collected over a period of one year at two colposcopy centres in Dublin, Ireland. Of these, n = 128 were conventionally classed as high-grade, n = 186 as low-grade and n = 215 as normal. Following FTIR spectroscopy, derived spectra were examined for segregation between classes in scores plots generated with subsequent multivariate analysis. A degree of crossover between classes was noted and this could be associated with imperfect conventional screening resulting in an inaccurate diagnosis or an incomplete transition between classes. Maximal crossover associated with n = 102 of 390 specimens analyzed was found between normal and low-grade specimens. However, robust spectral differences (P≤ 0.0001) were still observed at 1512 cm(-1), 1331 cm(-1) and 937 cm(-1). For high-grade vs. low-grade specimens, spectral differences (P≤ 0.0001) were observed at Amide I (1624 cm(-1)), Amide II (1551 cm(-1)) and asymmetric phosphate stretching vibrations (νasPO2(-); 1215 cm(-1)). Least crossover (n = 50 of 343 specimens analyzed) was seen when comparing high-grade vs. normal specimens; significant inter-class spectral differences (P≤ 0.0001) were noted at Amide II (1547 cm(-1)), 1400 cm(-1) and 995 cm(-1). Deeper understanding of the underlying changes in the transition between cervical cytology classes (normal vs. low-grade vs. high-grade) is required in order to develop biospectroscopy tools as a screening approach. This will then allow for the development of blind classification algorithms.

Evaluation of type-specific HPV persistence and high-risk HPV viral load quantitation in HPV positive women under 30 with normal cervical cytology.

The persistence of high-risk HPV (HR-HPV) infection is necessary for the development of cervical intraepithelial neoplasia. The aim of this study was to evaluate if HR-HPV typing and HPV16, 18, 31, and 33 quantitation are predictive for type-specific infection persistence and/or the development of CIN in women under 30 with normal cervical cytology. Young women (under 30) attending a family planning clinic who were HPV positive with normal cervical cytology were included. HPV genotyping was assessed by MY09/MY11 PCR, sequencing, phylogenetic analysis, and cloning when necessary. HR-HPV viral load was quantified using duplex real-time PCR. Study patients were offered for a second smear and HR-HPV detection and quantitation after 12 months. HR-HPV was identified in 43 (21.9%) of the 199 included women. Of these, 39 patients had a second cervical sample taken within a mean interval of 11.7 months (8.8-18.3 months). The mean HR-HPV 16, 18, 31, and 33 initial viral load was 1.9 × 10(6) copies/million cells. The level of viral load did not reveal any significant association with type-specific HR-HPV persistence or the subsequent development of cervical intraepithelial neoplasia. Only HPV16 infection was significantly more likely to persist (91.7% vs. 33.1%, P=0.001) and to develop CIN (33.3% vs. 3.7%, P=0.025). In women under 30 with normal cytology, HR-HPV viral load is common and is not predictive of HPV persistence or the development of cervical intraepithelial neoplasia. HPV16 positive women are significantly more likely to have persistent infection and to develop cervical intraepithelial neoplasia.

Comparison of HPV detection technologies: Hybrid capture 2, PreTect HPV-Proofer and analysis of HPV DNA viral load in HPV16, HPV18 and HPV33 E6/E7 mRNA positive specimens.

Human papillomavirus (HPV) testing using molecular methods in liquid based cytology (LBC) specimens may be useful as an adjunct to cervical screening by cytology. We compared the positivity rate of the commercially available HPV DNA method hybrid capture 2 (hc2) and the commercially available E6/E7 mRNA method PreTect HPV-Proofer in cytological specimens (n=299). LBC specimens collected (n=299) represented the following cervical cytological disease categories: Normal (n=60), borderline nuclear abnormalities (BNA) (n=34), CIN1 (n=121), CIN2 (n=60), CIN3 (n=24). Overall, 69% (205/299) of the cases were positive by hc2 and 38% (112/299) of the cases were positive by PreTect HPV-Proofer. Concordance rates between the two tests were highest in the high-grade cytology cases (CIN2: 67% and CIN3: 83%) and the normal cytology cases (88%) and lowest in the BNA and CIN1 categories (56% and 52%). HPV DNA viral load analyses were carried out on HPV16 (n=55), HPV18 (n=9) and HPV33 (n=13) samples that were positive by PreTect HPV-Proofer. The sensitivity and specificity of PreTect HPV-Proofer and the hc2 DNA test for the detection of high-grade cytology (i.e. CIN2+) were 71.4% and 75.8% vs 100% and 43.7%, respectively. The relatively low detection rate observed by PreTect HPV-Proofer in the whole range of cytological positive cases, combined with a relatively higher specificity and PPV, suggests that PreTect HPV-Proofer may be more useful than hc2 for triage and in predicting high-grade disease.

Implementation and evaluation of a new automated interactive image analysis system.

OBJECTIVE: To compare automated interactive screening using the ThinPrep Imaging System with independent manual primary screening of 12,000 routine ThinPrep slides. STUDY DESIGN: With the first 6,000 cases, the Review Scopes (RS) screening results from the 22 fields of view (FOV) only were compared to independent manual primary screening. In the next 6,000 cases, any abnormality detected in the 22 FOV resulted in full manual screening on the cytotechnologist's own microscope. Sensitivity and specificity together with their 95% CIs were calculatedfor each method. RESULTS: In the first set of 6, 000 cases, diagnostic sensitivity and specificity of the imager were 85.19% and 96.67%, respectively. The diagnostic sensitivity and specificity of manual primary screening were 89.38% and 98.42%. This highersensitivity and specificity of manual primary screening were found to be statistically significant. The second set of 6,000 cases demonstrated no significant statistical difference in sensitivity or specificity between the sets of data. CONCLUSION: The results from our study show that the sensitivity and specificity of the imager technology are equivalent to those of manual primary screening. The system is ideally suited to the rapid screening of negative cases, allowing increased laboratory productivity and greater throughput of cases on a daily basis.

Human papillomavirus detection and genotyping, by HC2, full-spectrum HPV and molecular beacon real-time HPV assay in an Irish colposcopy clinic.

Cervical screening programmes are moving towards HPV testing as part of the screening process and as a triage for colposcopy. Three HPV detection methods were evaluated using cervical cytology specimens from colposcopy patients. PreservCyt™ liquid based cytology specimens from 241 women attending colposcopy clinics with greater than 2 persistently abnormal smears were recruited through the Coombe Women and Infants University Hospital, Dublin. HPV DNA was detected by Hybrid Capture (HC2) for 13 high-risk HPV types, Full-Spectrum HPV (FS-HPV) for 49 high and low-risk types and Molecular Beacon Real-Time HPV assay (MBRT-HPV) for 16 high and low-risk types. HPV genotyping was performed using Linear Array HPV Assay (LA-HPV). HPV was detected in 83.3% (195/234), 91.9% (217/236) and 80.1% (169/211) of cytology specimens by HC2, FS-HPV and MBRT-HPV, HPV DNA detection assays. The sensitivity of the assays for the detection of high-risk HPV in cytology specimens that had a Cervical Intraepithelial Neoplasia Grade 2+ result by histology were, 98%, 97% and 94% for HC2, FS-HPV and MBRT-HPV assays with positive predictive values of 94.1%, 94.1% and 97.3%. The most common HPV genotypes were HPV 16, 31, 33, 58, 42, 61 and 53, and the most common high-risk HPV genotypes were HPV 16, 31, 33, 58, 18, 45, 59, 51, 56 and 39, with detection of multiple infections in 57.7% of all cases. FS-HPV and MBRT-HPV are highly sensitive and have a similarly high PPV as the HC2 assay for detection of HPV in patients with Cervical Intraepithelial Neoplasia Grade 2+ disease. HPV genotyping of women with persistent abnormalities is warranted prior to the introduction of HPV DNA testing in a colposcopy setting.