Search

In this study, we investigate the potential of near-infrared Raman spectroscopy to differentiate cervical precancers from normal tissues, inflammation and metaplasia and to differentially diagnose low-grade and high-grade precancers. Near infrared Raman spectra were measured from 36 biopsies from 18 patients in vitro. Detection algorithms were developed and evaluated relative to histopathologic examination. Algorithms based on empirically selected peak intensities, ratios of peak intensities and a combination of principal component analysis for data reduction and Fisher discriminant analysis for classification were investigated. Spectral peaks were tentatively identified from measured spectra of potential chromophores. Empirically selected normalized intensities can differentiate precancers from other tissues with an average sensitivity and specificity of 88 +/- 4% and 92 +/- 4%. Ratios of unnormalized intensities can differentiate precancers from other tissues with a sensitivity and specificity of 82% and 88% and high-grade from low-grade lesions with a sensitivity and specificity of 100%. Using multivariate methods, intensities at eight frequencies can be used to differentiate precancers from all other tissues with a sensitivity and specificity of 82% and 92% in an unbiased test. Raman algorithms can potentially separate benign abnormalities such as inflammation and metaplasia from precancers. Comparison of tissue spectra to published and measured chromophore spectra indicate that the most likely primary contributors to the tissue spectra are collagen, nucleic acids, phospholipids and glucose 1-phosphate. These results suggest that near-infrared Raman spectroscopy can be used for cervical precancer diagnosis and may be able to accurately separate samples with inflammation and metaplasia from precancer.

Current cervical cancer screening programs are changing due to the development of tests that detect the presence of human papillomavirus (HPV), the cause of cervical cancer. These tests are more sensitive than cytology-based methods for detecting cervical precancer and a negative test offers long-term assurance that cervical cancer will not develop and therefore longer screening intervals can be achieved. In screening programs, HPV-based tests have been approved to triage women with equivocal cytology results and as a primary testing method in conjunction with cytology. HPV-based tests also have a role in determining risk of recurrence after treatment for cervical precancer as well as in surveillance for vaccine-related changes in HPV genotype prevalence.

Raman spectroscopy is a vibrational spectroscopic technique capable of optically probing the compositional, conformational, and structural changes in the tissue associated with disease progression. The main goal of this work is to develop an integrated fingerprint (FP) and high wavenumber (HW) in vivo confocal Raman spectroscopy for simultaneous FP/HW tissue Raman spectral measurements. This work further explores the potential of integrated FP/HW Raman spectroscopy developed as a diagnostic tool for in vivo detection of cervical precancer. A total of 473 in vivo integrated FP/HW Raman spectra (340 normal and 133 precancer) were acquired from 35 patients within 1 s during clinical colposcopy. The major tissue Raman peaks are noticed around 854, 937, 1001, 1095, 1253, 1313, 1445, 1654, 2946 and 3400 cm -1 , related to the molecular changes (e.g., proteins, lipids, glycogen, nucleic acids, water, etc.) that accompany the dysplastic transformation of tissue. The FP (800 - 1800 cm -1 ), HW (2800 - 3800 cm -1 ) and the integrated FP/HW Raman spectra were analyzed using partial least squares-discriminant analysis (PLS-DA) together with the leave-one patient-out, cross-validation. The developed PLS-DA classification models and receiver operating characteristics (ROC) curves for the FP, HW and integrated FP/HW spectroscopy further discloses that the performance of integrated FP/HW Raman spectroscopy is superior to that of all others in discriminating the dysplastic cervix. The results of this work indicate that the co-contributions of underlying rich biochemical information revealed by the complementary spectral modalities (FP and HW Raman) can improve the in vivo early diagnosis of cervical precancer at clinical colposcopy

Clinical, Investigative, Postoperative Status in Cervical Precancer and Cancer Early diagnosis and accurate staging are essential for appropriate management of cervical cancer, one of the most common cancers and leading cause of cancer deaths worldwide. The objective of present study was to know the correlation between clinical,investigative, surgical and histopathological diagnosis in suspicious and staging in obvious cancer cases. Study subjects were of 20-64 years, diagnosed over 2 years with aid of visual inspection (VI), vaginal and cervical cytology, visual inspection after application of acetic acid (VIA), VI after application of Lugol’s iodine (VILI), followed by colposcope guided cervical biopsy, intraoperative and postoperative staging after histopathology of specimen in clinically suspicious and obvious cancer cases.

Abstract 74 PATH is a nonprofit organization involved in the development of new technologies for screening and treatment of precancerous lesions of the uterine cervix for the last 25 years. PATH had private-public partnerships with four private companies for the design, development, improvement, and/or field validation of two new technologies for screening (careHPV and OncoE6 Cervical Test) and two devices for treatment (CryoPen and the Liger Thermal Coagulator). This experience allows us to identify some commonalities among those companies: they all had the technical or scientific background for developing or improving the technologies needed, they were committed to creating technologies suitable for emerging economies, and their knowledge or presence in low-resource countries was limited. The characteristics of our collaboration with the private companies varied depending on the initial status of the technology. Two of the companies already had marketed technologies that required adaptation for suitability in low-resource settings, and the role of PATH was to support the planning and modification of the technology, bench and field testing of the prototypes, and/or clinical validation of the product. Meanwhile, the other two companies had the technological capacity and expertise for developing the required technologies, but they did not have a working prototype; therefore, the role of PATH involved supporting the design and development of the new technology, as well as the required bench testing and validations. The financial support required was variable; in some cases PATH provided technical support for developing a “proof of concept” prototype, which later extended to financial support from PATH or other organizations. In other cases, the complexity of the initial work required financial support to start the development of that “proof of concept.” In conclusion, public-private partnerships are very effective for the development of new, affordable, and suitable technologies for screening and treatment of cervical precancer in emerging economies. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST: Francesca Holme Travel, Accommodations, Expenses: Qiagen Rose Slavkovsky No relationship to disclose Jose Jeronimo No relationship to disclose

Fluorescence microscopy has been widely used in characterizing the pathological states of tissues because intensity and spectra arise from fluorescence emission can reveal structural and biochemical information of biological samples and the fluorescence excited state lifetime has been verified to identify tissue pathology due to its sensitivity to the fluorophore microenvironment. In this study, we have demonstrated that early cervical cancer can be quantitatively diagnosed using intensity and lifetime derived from the stroma fluorescence in conjunction with extreme learning machine (ELM) classifier which can result in a concurrently high sensitivity of 99.1% and specificity of 99.6%. The results suggest that the proposed technique can be used to aid and supplement the traditional histopathological examination of cervical precancer.

Objective: Nucleolar organizer region (NOR) associated proteins are argyrophilic and visualized by silver stains. AgNOR pleomorphic dots increase in cancer and most researchers have done a common count of single dots. Pleomorphic dots are few and perhaps indicate a more severe prognosis. The present study was aimed at investigating the relative preponderance and diagnostic value of both pleomorphic and single AgNOR dots in cervical carcinogenesis. Study design: Silver nitrate staining was performed in 50 cervical smears each of cytologically diagnosed normal, inflammatory, low grade squamous intraepithelial lesion (LSIL), High-grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma cases registered at C.S.M. Medical University, Lucknow, India. Results: The accumulated data revealed a positive and significant correlation of cell counts of both pleomorphic (r = 0.94; p < 0.01) and single dots (r = 0.95; p < 0.01) with disease severity. The rate of increase in cell counts of pleomorphic dots (β = 2.61) was 1.1 times higher than the rate of increase in cell counts of single dots (β = 2.29). Conclusion: This study indicates the diagnostic potential of pleomorphic dots in the process of cervical carcinogenesis. The number of pleomorphic dots also varies significantly in different types of SIL, which may help in discriminating precancerous lesions of the cervix.

Raman spectroscopy is a vibrational spectroscopic technique capable of nondestructively probing endogenous biomolecules and their changes associated with dysplastic transformation in the tissue. The main objectives of this study are (i) to develop a simultaneous fingerprint (FP) and high-wavenumber (HW) confocal Raman spectroscopy and (ii) to investigate its diagnostic utility for improving in vivo diagnosis of cervical precancer (dysplasia). We have successfully developed an integrated FP/HW confocal Raman diagnostic system with a ball-lens Raman probe for simultaneous acquistion of FP/HW Raman signals of the cervix in vivo within 1 s. A total of 476 in vivo FP/HW Raman spectra (356 normal and 120 precancer) are acquired from 44 patients at clinical colposcopy. The distinctive Raman spectral differences between normal and dysplastic cervical tissue are observed at ~854, 937, 1001, 1095, 1253, 1313, 1445, 1654, 2946, and 3400 cm(-1) mainly related to proteins, lipids, glycogen, nucleic acids and water content in tissue. Multivariate diagnostic algorithms developed based on partial least-squares-discriminant analysis (PLS-DA) together with the leave-one-patient-out, cross-validation yield the diagnostic sensitivities of 84.2%, 76.7%, and 85.0%, respectively; specificities of 78.9%, 73.3%, and 81.7%, respectively; and overall diagnostic accuracies of 80.3%, 74.2%, and 82.6%, respectively, using FP, HW, and integrated FP/HW Raman spectroscopic techniques for in vivo diagnosis of cervical precancer. Receiver operating characteristic (ROC) analysis further confirms the best performance of the integrated FP/HW confocal Raman technique, compared to FP or HW Raman spectroscopy alone. This work demonstrates, for the first time, that the simultaneous FP/HW confocal Raman spectroscopy has the potential to be a clinically powerful tool for improving early diagnosis and detection of cervical precancer in vivo during clinical colposcopic examination.

Raman spectroscopy is a unique analytical probe for molecular vibration and is capable of providing specific spectroscopic fingerprints of molecular compositions and structures of biological tissues. The aim of this study is to improve the classification accuracy of cervical precancer by characterizing the variations in the normal high wavenumber (HW - 2800-3700cm -1 ) Raman spectra arising from the menopausal status of the cervix. A rapidacquisition near-infrared (NIR) Raman spectroscopic system was used for in vivo tissue Raman measurements at 785 nm excitation. Individual HW Raman spectrum was measured with a 5s exposure time from both normal and precancer tissue sites of 15 patients recruited. The acquired Raman spectra were stratified based on the menopausal status of the cervix before the data analysis. Significant differences were noticed in Raman intensities of prominent band at 2924 cm -1 (CH 3 stretching of proteins) and the broad water Raman band (in the 3100-3700 cm -1 range) with a peak at 3390 cm -1 in normal and dysplasia cervical tissue sites. Multivariate diagnostic decision algorithm based on principal component analysis (PCA) and linear discriminant analysis (LDA) was utilized to successfully differentiate the normal and precancer cervical tissue sites. By considering the variations in the Raman spectra of normal cervix due to the hormonal or menopausal status of women, the diagnostic accuracy was improved from 71 to 91%. By incorporating these variations prior to tissue classification, we can significantly improve the accuracy of cervical precancer detection using HW Raman spectroscopy.

We report clinical imaging results for an MDC that has been applied to more than 50 patients with suspected cervical precancer and analyze against matched histopathology results. For high grade dysplasia: sensitivity ~90%, specificity ~55%.

Cervical cancer develops over a long time through precursor lesions that can be detected by cytological screening. Majority of these lesions regress spontaneously. Therefore, the challenge of cervical cancer screening is to detect the lesions that have a high risk of progression. Several promising biomarkers have been described that may improve screening of cervical cancer, but to date, new biomarkers have not been thoroughly validated in high-quality studies. The knowledge about human papillomavirus as a causative agent of cervical cancer has accumulated over the last decades has opened the possibility to improve the existing prevention strategies and screening practices. p16 has amply been applied on cytologic samples and has been shown to be a promising marker especially in identification of high-grade dysplasia. ProEx C, a replication marker, has also been recently shown to be a good marker for identification of high-grade dysplasia and has been used on cytologic samples. Proliferation markers such as MYC, Ki67, telomerase, MCM, topoisomerase 2A and 3q amplification by in situ hybridization technique are other methods being employed in identification of high-grade dysplasia. However, currently available data on most of the biomarkers does not warrant their routine use yet. This review highlights the major findings of previous studies on cervical cancer biomarkers.

The major cause of cervical cancer and its pre-invasive lesions is persistent infections with oncogenic human papillomavirus (HPV). Viral replication and integration in the cervix depends on the ordered expression of viral gene products, which can lead to overexpression of multiple molecular proteins or biomarkers. These novel biomarkers allow the monitoring of essential molecular events in histological or cytological specimens and are likely to improve the detection of lesions that have a high risk of progression in both primary screening and triage settings. This review focuses on these molecular markers and their role in the diagnosis and management of cervical dysplasia and cancer.

The purpose of this study is to explore the feasibility of utilizing near-infrared (NIR) autofluorescence spectroscopy for in vivo diagnosis of precancer (i.e., dysplasia) in the cervix. A rapid NIR spectroscopy system in combination with a fiber-optic probe was developed for the in vivo NIR fluorescence measurements under the 785 nm laser excitation. Multivariate statistical techniques including principal component analysis (PCA) and linear discriminant analysis (LDA) were employed to develop the diagnostic algorithms for spectra classification. Classification result obtained from the PCA-LDA model based on tissue NIR autofluorescence data yielded a diagnostic sensitivity of 84.8% and specificity of 85.1% for discrimination of precancer from normal cervical sites. The results demonstrate that NIR autofluorescence technique has the capacity for the noninvasive, in vivo diagnosis of precancer in the cervix.

To estimate the accuracy of colposcopy to identify cervical precancer in screening and diagnostic settings.As part of a larger clinical trial to evaluate the diagnostic accuracy of optical spectroscopy, we recruited 1,850 patients into a diagnostic or a screening group depending on their history of abnormal findings on Papanicolaou tests. Colposcopic examinations were performed and biopsies specimens obtained from abnormal and normal colposcopic sites for all patients. The criterion standard of test accuracy was the histologic report of biopsies. We calculated sensitivities, specificities, likelihood ratios, receiver operating characteristic curves, and areas under the receiver operating characteristic curves.The prevalence of high-grade squamous intraepithelial lesions (HSIL) or cancer was 29.0% for the diagnostic group and 2.2% for the screening group. Using a disease threshold of HSIL, colposcopy had a sensitivity of 0.983 and a specificity of 0.451 in the diagnostic group when the test threshold was low-grade squamous intraepithelial lesions (LSIL), and a sensitivity of 0.714 and a specificity of 0.813 when the test threshold was HSIL. Using the same HSIL disease threshold, in the screening group, colposcopy had a sensitivity of 0.286 and a specificity of 0.877 when the test threshold was LSIL, and a sensitivity of 0.191 and a specificity of 0.961 when the threshold was HSIL. The colposcopy area under the receiver operating characteristic curve was 0.821 (95% confidence interval 0.79-0.85) in the diagnostic setting compared with 0.587 (95% confidence interval 0.56-0.62) in the screening setting. Changing the disease threshold to LSIL demonstrated similar patterns in the tradeoff of sensitivity and specificity and measure of accuracy.Colposcopy performs well in the diagnostic setting and poorly in the screening setting. Colposcopy should not be used to screen for cervical intraepithelial neoplasia.II.

Near-infrared (NIR) Raman spectroscopy has shown promise to detect cancer and precancer in human through measuring the biomolecular and biochemical changes of tissue associated with diseases transformation. Most of studies of NIR Raman spectroscopy on tissue diagnosis are concentrated on the so-called fingerprint region (800-1800 cm-1), there are only very limited work for tissue diagnosis using the high wavenumber (2800-3700 cm-1) spectral features. The purpose of this study is to explore the ability of NIR Raman spectroscopy in high wavenumber region for the in vivo detection of cervical precancer. A rapid NIR Raman spectroscopy system associated with a fiber-optic Raman probe was used for the in vivo spectroscopic measurements. Multivariate statistical techniques including principal components analysis (PCA) and linear discriminant analysis (LDA) were employed to develop the diagnostic algorithm based on the spectral data from 2800-3700 cm-1. Classification result based on PCA-LDA showed that high wavenumber NIR Raman spectroscopy can achieve the diagnostic sensitivity of 93.5% and specificity of 95.7% for precancer classification.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Background: Investigation of the potential association of single nucleotide polymorphisms (SNPs) at –308 G/A and –238 G/A of Tumor necrosis factor α (TNFα) with susceptibility to HPV-16 associated cervical cancer in Indian women. Methods: The study included 165 histologically confirmed cases with 45 precancer and 120 cancer patients and an equal number (165) of healthy controls with normal cervical cytology. PCR-RFLP was employed to analyze TNFα promoter polymorphisms, which were confirmed by direct sequencing. Both patients and controls were screened for Human Papillomavirus (HPV) infection. Results: The frequency of –308 A allele in TNFα was significantly higher in cases compared with control subjects (21% in cases vs. 9% in controls; p < 0.01), with an odds ratio of 2.7 (95% CI = 1.41–5.15). Also, women carrying A allele for this locus presented 3 times increased susceptibility to HPV 16 infection as evident from carrier genotype distribution between HPV positive cases and control subjects (24% in HPV positive cases vs. 9% in controls; p < 0.01; OR = 3.1; 95% CI = 1.60–6.03). No such association was found for TNFα–238 (G/A) polymorphism with the risk of development of cervical cancer. Conclusion: It suggests that SNP at –308 (G/A) of TNFα promoter may represent an increased risk for HPV infection and development of cervical cancer in Indian women.

Context and Aim: Screening programs using conventional cytology conventional Pap smear (CPS) have successfully reduced cervical cancer, but newer tests like liquid-based cytology (LBC) and human papillomavirus testing might enhance screening. The main aim of the present study was to assess the diagnostic accuracy of LBC versus CPS using "split samples." Materials and Methods: This was a prospective study comprising of 1000 consecutive cervical "split samples" over a period of 1 year. Split sample was obtained using cervex-brush. CPS was prepared from the brush and the brush head was suspended in the LBC vial and processed by SurePath™ LBC. Results: There were 4.3% unsatisfactory (U/S) cases in CPS and 1.7% in LBC; the main cause is insufficient cells, and excess of blood in CPS. About 25/100 (2.5%) split samples had epithelial abnormalities both in CPS and LBC (1.2%-atypical squamous cells of undetermined significance; 0.4%-low grade squamous intraepithelial lesion; 0.2%-high grade squamous intraepithelial lesion; 0.5%-squamous cell carcinoma; 0.1%-atypical glandular cells favouring neoplasia; 0.2%-adenocarcinoma). Inflammatory organisms were almost equally identified in both techniques but were better seen in LBC samples. Conclusions: LBC technique leads to significant reduction of U/S rate. LBC samples offered better clarity, uniform spread of smears, less time for screening and better handling of hemorrhagic and inflammatory samples. LBC had equivalent sensitivity and specificity to CPS.

This study assesses one possible cause of inter-patient varia- tion in fluorescence spectroscopy of the cervix: the menstrual cycle. Ten patients with no history of an abnormal Pap smear were seen daily throughout 30 consecutive days of their cycle. Fluorescence excitation-emission matrices were measured from three cervical sites on each patient. Principal component analysis was used to determine which spectral regions varied with the day of the cycle. Classification was performed to assess the influence of menstrual cycle on precan- cer diagnosis. Variations in the principal component scores and the redox ratio values show that the fluorescence emission spectra at 340-380 nm excitation appear to correlate with the cell metabolism of the cervical epithelium throughout the menstrual cycle; these changes do not affect diagnostic classification. The menstrual cycle affects intra-patient variation but does not appear to cause a signifi- cant level of inter-patient variation. It does not need to be controlled for in optical detection strategies based on fluorescence spectroscopy.

This study aimed to evaluate the clinical utility of applying near-infrared (NIR) Raman spectroscopy and genetic algorithm-partial least squares-discriminant analysis (GA-PLS-DA) to identify biomolecular changes of cervical tissues associated with dysplastic transformation during colposcopic examination. A total of 105 in vivo Raman spectra were measured from 57 cervical sites (35 normal and 22 precancer sites) of 29 patients recruited, in which 65 spectra were from normal sites, while 40 spectra were from cervical precancerous lesions (i.e., 7 low-grade CIN and 33 high-grade CIN). The GA feature selection technique incorporated with PLS was utilized to study the significant biochemical Raman bands for differentiation between normal and precancer cervical tissues. The GA-PLS-DA algorithm with double cross-validation (dCV) identified seven diagnostically significant Raman bands in the ranges of 925-935, 979-999, 1080-1090, 1240-1260, 1320-1340, 1400-1420, and 1625-1645 cm(-1) related to proteins, nucleic acids and lipids in tissue, and yielded a diagnostic accuracy of 82.9% (sensitivity of 72.5% (29/40) and specificity of 89.2% (58/65)) for precancer detection. The results of this exploratory study suggest that Raman spectroscopy in conjunction with GA-PLS-DA and dCV methods has the potential to provide clinically significant discrimination between normal and precancer cervical tissues at the molecular level.

A series of 103 cervical biopsies derived from 103 women during July 1958 to September 1963 from Beijing, China were investigated with in situ hybridization for the presence of HPV6, 11, 16, 18, 31 and 33 DNA. The mean age of the patients was 46.1 + 10.6 years with a range of 24-74 years. Morphological features of HPV infection were found in 80 (77.7%) biopsies. Invasive cervical cancer was diagnosed in 43 biopsies and cervical intraepithelial neoplasia CIN I, CIN II and CIN III in 9, 9, and 27 cases, respectively. A total of 63.1% (65/103) of the lesions had morphological features of HPV infections associated with CIN or invasive carcinomas. Altogether, 31.1% (32/103) of the biopsies were shown to contain HPV DNA. Of the cases showing HPV morphology, 43.1% were HPV DNA positive. HPV16 (30/32) was the most frequent type, followed by HPV11 and 18, whereas no lesions with HPV6, 31 or 33 were found. A total of 19/43 (44.2%) of the invasive carcinomas contained HPV DNA. HPV DNA positivity and the grade of CIN showed a statistically significant correlation (P = 0.0011). Our study demonstrated the presence of HPV in cervical lesions among Chinese women in the late 1950's and early 1960's when a single sexual partner was the rule and also supports the concept that HPV has as an important etiological role in cervical cancer, the highest risk being associated with HPV type 16. The applicability of in situ hybridization in retrospective assessment is emphasized.

Background Cryotherapy is often used to treat cervical precancer in developing countries. There are different methods and cryogen gases used for cryotherapy, including the freeze-flush-freeze (cough) technique employed to minimize gas blockage. However, there is limited information to compare their effectiveness. Methods Using a tissue model, we compared temperature-time curves for four cryotherapy methods: uninterrupted freezing with nitrous oxide (N2O) and carbon dioxide (CO2), and two methods using a standard and extended version of the cough technique with CO2. Results Uninterrupted freezing with both N2O and CO2 produced tissue temperatures less than -20°C (-40°C and -30°C respectively). CO2 cryotherapy procedures using the two cough techniques produced temperatures greater than -20°C in the model tissue. Conclusion CO2 cryotherapy using the cough technique may not achieve sufficiently low temperatures to produce the desired therapeutic effect. Other alternatives to the prevention of gas blockage should be developed.

1545 Background: We sought to determine the accuracy of colposcopy to diagnose cervical precancer in screening and diagnostic settings. Methods: As part of a larger clinical trial, 1850 patients were recruited into a diagnostic group or a screening group depending on their history of abnormal Papanicolaou smear results. For all patients, colposcopic examination was performed and biopsies were obtained from abnormal and normal colposcopic sites. The gold standard of test result accuracy was the histologic report of biopsies. Results: The diagnostic group had a 29.0% prevalence of high-grade squamous intraepithelial lesions (HGSIL) or cancer, and the screening group had a 2.2% prevalence of HGSIL or cancer. Using a disease threshold of HGSIL or worse, the diagnostic group had a sensitivity of 71.4% and a specificity of 81.3%, and the screening group had a sensitivity of 19.1% and a specificity of 96.1%. The areas under the receiver operating characteristic (ROC) curves for the diagnostic and screening groups at the same disease threshold were 0.854 and 0.511, respectively. Conclusions: We demonstrated that colposcopy performs well in the diagnostic setting and poorly in the screening setting. Colposcopy should not be used for the screening of cervical intraepithelial neoplasia. No significant financial relationships to disclose.

Optical technologies, in particular fluorescence spectros- copy, have shown the potential to provide improved detection meth- ods for cervical neoplasia that are sensitive and cost effective through accurate, objective, instantaneous point-of-care diagnostic tools. The specific goals of this study were to analyze reflectance spectra of nor- mal and neoplastic cervical tissue in vivo and to evaluate the data for use in diagnostic algorithm development. Spectroscopic measure- ments were obtained at four distinct source-detector separations from 324 sites in 161 patients. As the source-detector separation increases, greater tissue depth is probed. The average spectra of each diagnostic class differed at all source-detector separations, with the greatest dif- ferences occurring at the smallest source-detector separations. Algo- rithms, based on principal-component analysis and Mahalanobis dis- tance classification, were developed and evaluated for all combinations of source-detector separations relative to the gold stan- dard of colposcopically directed biopsy. The diagnostic combination of squamous normal versus high-grade squamous intraepithelial le- sions gave good discrimination with a sensitivity of 72% and a speci- ficity of 81%; discrimination of columnar normal versus high-grade squamous intraepithelial lesions also was good, with sensitivity of 72% and specificity of 83%. Thus, reflectance spectroscopy appears promising for in vivo detection of cervical precancer. Strategies that combine fluorescence and reflectance spectroscopy may enhance the discrimination capabilities. © 2002 Society of Photo-Optical Instrumentation Engi

In the field of viral pathology, conventional light and electron microscopy and in particular immunocytochemistry represent interesting tools for the recognition of productive virus infections (Almeida 1980; Chernesky and Mahony 1984).

218 women treated by cone biopsy or hysterectomy for severe cervical dysplasia or carcinoma-in-situ were followed up for 4 to 20 years by cytological surveillance. When the first two postoperative cervical smears were negative, only 2 of 106 patients treated by cone biopsy, and followed-up for 725 women-years, showed recurrence of abnormal cytology, found later on histology of biopsy specimens to be due to mild dysplasia. The incidence of mild dysplasia after cone biopsy for severe dysplasia or carcinoma-in-situ is thus 2·76 per 1000 women-years, which is not more than that expected in the general population. There was no evidence of recurrence in 112 patients treated by hysterectomy in 861 women-years of follow-up. These results support the hypothesis that lesions remaining after treatment are detected by the first two postoperative smears; thereafter new lesions do not arise more frequently than in the general population. A less intensive follow-up regimen than that commonly practised is suggested, not only to encourage long-term patient compliance but also to reduce the pressure on hospital outpatient and cytopathological facilities.

Evidence suggests the vaginal microbiota (VM) may influence risk of persistent Human Papillomavirus (HPV) infection and cervical carcinogenesis. Established cytology biobanks, typically collected with a cytobrush, constitute a unique resource to study such associations longitudinally. It is plausible that compared to rayon swabs; the most commonly used sampling devices, cytobrushes may disrupt biofilms leading to variation in VM composition. Cervico-vaginal samples were collected with cytobrush and rayon swabs from 30 women with high-grade cervical precancer. Quantitative PCR was used to compare bacterial load and Illumina MiSeq sequencing of the V1-V3 regions of the 16S rRNA gene used to compare VM composition. Cytobrushes collected a higher total bacterial load. Relative abundance of bacterial species was highly comparable between sampling devices (R2 = 0.993). However, in women with a Lactobacillus-depleted, high-diversity VM, significantly less correlation in relative species abundance was observed between devices when compared to those with a Lactobacillus species-dominant VM (p = 0.0049). Cytobrush and swab sampling provide a comparable VM composition. In a small proportion of cases the cytobrush was able to detect underlying high-diversity community structure, not realized with swab sampling. This study highlights the need to consider sampling devices as potential confounders when comparing multiple studies and datasets.

The continuing morbidity and mortality rate related to cervical cancer necessitates an improvement in current screening and diagnostic programs that target early detection of its curable precursor, cervical squamous intraepithelial lesion (SIL). Optical spectroscopy is a technique that has the capability to improve the accuracy and efficacy of current techniques for the detection of SILs. We have utilized fluorescence spectroscopy for the differential detection of SILs, in vivo and we have also evaluated the utility of near infrared (IR) Raman spectroscopy for the characterization of SILs in vitro.