Use of a liquid-based, thin-layer Pap test in a community hospital. Impact on cytology performance and productivity

OBJECTIVE: To evaluate the direct-to-vial efficacy of the SurePath Pap test (TriPath Imaging, Burlington, North Carolina, U.S.A.) in a community hospital laboratory and to assess its impact on productivity, as measured by Pap test turnaround times (TATs). STUDY DESIGN: A total of 8,771 SurePath Pap tests were compared to 5,055 conventional Pap smears collected and processed over the same 12-month period. SurePath histologic correlation rates were compared to historical correlation rates for conventional Pap smears. Pap test TATs for 3 months prior to implementing SurePath were compared to TATs for the last 3 months of the study, which included an approximate 70:30 ratio of SurePath to conventional Pap tests. Laboratory staffing was unchanged, and mean monthly accessions were relatively constant. RESULTS: SurePath showed statistically significant improvements in the detection of low grade (LSIL) (196%) and high grade (HSIL) (243%) squamous intraepithelial lesions (SILs) relative to conventional Pap smears. The atypical cells of undetermined significance (ASCUS) rate remained nearly constant with SurePath, while the ASCUS/SIL ratio decreased by 68%. Unsatisfactory rates declined 81%. Histologic correlation rates with SurePath increased over those of conventional Pap smears. Pap test mean TATs improved 73% with SurePath. CONCLUSION: Sure-Path detected significantly more cases of LSIL and HSIL than conventional smears without compromising specificity. The ASCUS/SIL ratio and unsatisfactory rate declined dramatically. Pap test TATs also improved markedly with SurePath.     

Utility of the in situ detection of HPV in Pap smears diagnosed as within normal limits.

OBJECTIVE: To determine the clinical significance in normal Pap smears of HPV detection as determined by Hybrid Capture (HC) and in situ hybridization analyses. STUDY DESIGN: We studied 135 consecutive Pap smears as well as 46 other smears from high-risk patients each initially diagnosed as within normal limits. RESULTS: The 135 "normal" Pap smears were rescreened, and 6 (4%) where found to be either ASCUS or SIL. In the remaining 129 cases, HPV DNA was detected in 0% and 9%, respectively, using in situ hybridization and HC I. Upon rescreening the high-risk patients, nine (20%) were reclassified as having SIL/ASCUS; each was in situ hybridization positive, and eight were HC positive; six (67%) of these women developed SIL on follow-up. In the 37 Pap smears in high-risk women still within normal limits after manual rescreening, HPV was detected in 2% by in situ hybridization and 46% by HC; 6% of the HC-positive women developed SIL on follow-up. CONCLUSION: In situ hybridization rarely detects HPV in Pap smears diagnosed as within normal limits after manual rescreening. In situ hybridization is very effective in detecting rare, atypical cells in Pap smears diagnosed as within normal limits and, in a high-risk population, is predictive of SIL on clinical follow-up.     

Effectiveness of liquid-based cytology and papanicolaou tests in a low risk population

OBJECTIVE: To compare sensitivity an effectiveness of ThinPrep vs. Pap Test and determine whether the Hybrid Capture System II (HCII) for detection of human papillomavirus (HPV) could increase the sensitivity and effectiveness of cervical screening in a low risk population. STUDY DESIGN: We present a comparative observer, blind, "split sample" study of ThinPrep and Papanicolaou staining in a population of 2026 consecutive women. RESULTS: Conventional Papanicolaou stain detected lesions in 62 cases (3.06%), including 1 atypical glandular cell of undetermined significance (AGUS), 34 atypical squamous cells of undetermined significance (ASCUS) (1.73% of atypias), 20 (0.99%) low grade squamous intraepithelial lesions (LSIL), and 7 (0.35%) high grade squamous intraepithelial lesions (HSIL). ThinPrep detected lesions in 63 cases (3.11%), including 26 (1.28%) ASCUS, 27 (1.33%) LSIL and 10 (0.49%) HSIL. Despite this overall similarity, only 35 had a coincident cytopathologic result by both methods. The kappa concordance index between ThinPrep and Pap was 0.546. Sensitivity and specificity were 74.6 and 45.0 in ThinPrep and 69.5 and 25.0 in Papanicolaou-stained smears. High risk HPV (HR-HP 17) was positive in 13 of ZOASCUS and in 21 of 22 SIL. CONCLUSION: Technologies now widely available such as Thin Prep and viral detection aim to improve accuracy of screening.     

Opportunistic testing of medically underserved women for cervical cancer in South Africa

OBJECTIVE: To determine the yield of opportunistic Pap smears taken in an unscreened and medically underserved population in the Transkei Region of South Africa. STUDY DESIGN: Cross-sectional study of 22,160 cervical cytology specimens from an unscreened population attending gynecologic outpatient clinics between January 1990 and December 1996. RESULTS: The overall prevalence of atypical squamous cells of uncertain significance (ASCUS), low grade squamous intraepithelial lesions (LSIL) and high grade squamous intraepithelial lesions (HSIL) was, respectively, 34.7%, 8.3% and 2.4%. The ASCUS: SIL ratio was 3:1. The prevalence of invasive squamous cell carcinoma was 1.6%. The yield of opportunistic Pap smears was 10.7% including only LSIL and HSIL. CONCLUSION: The pathologic process of precursor lesions of cervical cancer appears to start at an early age since > 20% of cases are diagnosed before the age of 30 years. In the absence of a national screening program, opportunistic testing of medically underserved women needs to be maintained and encouraged.     

Clinical impact of atypical squamous cells of undetermined significance. A cytohistologic comparison

OBJECTIVE: To assess the percentage of squamous intraepithelial lesions (SILs) in the atypical squamous cells of undetermined significance (ASCUS) cytologic diagnosis. STUDY DESIGN: From January 1994 to December 1995, 421 cervical Pap smears with a diagnosis of ASCUS were followed with cervical biopsies within three months. The ASCUS cytologic diagnosis was correlated with the histologic findings and stratified according to age group, previous abnormal history and cell type of ASCUS (squamoid vs. metaplastic). RESULTS: Histologic diagnosis showed that of ASCUS diagnoses, 13% were normal, 34% were reactive, 4.8% were atypical, 43% were low grade SIL, 4% were high grade SIL, 1% were carcinoma in situ, and none were invasive lesions. The patients in the youngest group, up to 25 years, demonstrated the highest percentage of SIL. Patients with a previous abnormal gynecologic history showed a higher percentage of SIL than those without an abnormal history. SILs were observed in 51.5% of squamoid ASCUS and 36.5% of metaplastic ASCUS. CONCLUSION: Forty-eight percent of females having an ASCUS diagnosis on Pap smears had SIL and thus a preneoplastic lesion. The highest percentage of SIL was found in females 25 years and younger. Our findings suggest that an ASCUS diagnosis warrants ongoing follow-up.     

Hospital-based prevalence and sensitivity of high-risk human papillomavirus in Thai urban population

Background: To study the prevalence of high-risk human papillomavirus (HPV) types 16, 18, 31 and 33 in healthy Thai women using polymerase chain reaction (PCR) technique. Material and method: Two hundred and sixty three healthy urban women in Pathumthani, Thailand were recruited. Cervical cancer screening was performed and residual specimen from Pap smears was subjected to PCR to identify the presence of HPV types 16, 18, 31 and 33. Individuals’ demographic, health-specific and sexual behavior data were also collected. Results: Colposcopic biopsy revealed cases with high-grade squamous intraepithelial lesions (HSIL) and low-grade squamous intraepithelial lesions (LSIL). HPV 16 and 18 positive results were associated with abnormal Pap smears. Genotyping gave a 6.1%, 11.8%, 12.1%, and 14.1%, prevalence for HPV types 16, 18, 31 and 33, while 25% were infected with multiple HPV types. Discussion: High-risk HPV screening, used with abnormal pathology of HSIL gives 100% sensitivity and negative predictive value. Data from patient showed not significant correlation with neither different religion level of education, marital status, age of first sexual experience nor the number of sexual partners. Thus high-risk HPV screening is a recommended procedure with excellent sensitivity for detecting HSIL.     

Variables associated with squamous intraepithelial lesions among women with a cytologic diagnosis of atypical squamous cells of undetermined significance.

OBJECTIVE: To identify factors among women with atypical squamous cells of undetermined significance (ASCUS) cytologic diagnosis that are associated with either low grade squamous intraepithelial lesions (LSILs) or high grade squamous intraepithelial lesions (HSILs). STUDY DESIGN: From January 1992 to June 1995, 1,660 women with a diagnosis of ASCUS were followed until the next follow-up appointment after the ASCUS diagnosis. Logistic regression analysis with either LSIL or HSIL at follow-up examination as a dependent variable was done with the following independent variables: patient age, method of follow-up, follow-up time, type of health care coverage and household income. RESULTS: In multivariate analyses, there was a 2.7-fold increase in the odds of LSIL (OR = 2.7, 95% CI = 1.3-5.8) for young women (< or = 25 years), a 2-fold decrease in the odds of LSIL (OR = .5, 95% CI .3-.9) for long time to follow-up (> 18 weeks after ASCUS diagnosis) and an 7.8-fold increase in the odds of LSIL (OR = 7.8, 95% CI = 5.1-11.9) for follow-up by colposcopic biopsy. For the odds of HSIL, there was a 6.8-fold increase (95% CI = 3.2-14.5) for follow-up by colposcopic biopsy as compared to Pap smears and a 3-fold decrease in the odds of HSIL (OR = 3, 95% CI = .1-.7) for high-income women (> $34,857). CONCLUSION: Our findings suggest that among ASCUS patients, younger women and those with shorter follow-up time are more likely to be diagnosed with LSIL. Women with a high income showed a protective association for HSIL. Colposcopic biopsy identified more LSIL and HSIL as compared to repeat Pap smear.     

Conventional Pap smear and liquid-based cytology as screening tools in low-resource settings in Latin America: experience of the Latin American screening study

OBJECTIVE: To evaluate the performance of the conventional Pap test and liquid-based cytology (LBC) in an ongoing multicenter trial testing optional screening tools (cytology, screening colposcopy, visual inspection with acetic acid, visual inspection with Lugol's Iodine, cervicography and Hybrid Capture II [HCII] (Digene Brazil, S?o Paulo, Brazil) conventional and self-sampling), for cervical cancer in Brazil and Argentina. STUDY DESIGN: A cohort of 12,107 women attending four clinics (Campinas, S?o Paulo, Porto Alegre, Buenos Aires) were randomized into the 8 diagnostic arms. Women testing positive with any of the tests were referred for colposcopy, and cervical biopsies were used as the gold standard to assess performance characteristics of the diagnostic tests. Conventional Pap smears were sampled by all clinics (n = 10,240), and LBC (Autocyte PREP, [TriPath Imaging, Burlington, North Carolina, U.S.A.], n=320, and DNA-Citoliq [Digene Brazil], n =1,346) was performed by 1 of the clinics. RESULTS: Conventional Pap smears showed no squamous intraepithelial lesions (normal) in 8,946 (87.4%) and LBC in 1,373 (82.4%). Using high grade squamous intraepithelial lesions (HSIL) as the cutoff, Pap smears predicted high grade (cervical intraepithelial neoplasia [CIN] 3) with OR 63.0 (95% CI, 36.90-107.70), standard error (SE) 59%, SP 97.8%, positive predictive value (PPV) 68.1% and negative predictive value (NPV) 96.7%. The same figures for Autocyte PREP were: OR 9.0 (95% CI, 2.43-33.24), sensitivity (SE) 33.3%, specificity (SP) 100%, PPV 100% and negative PV (NPV) 88.8%. DNA-Citoliq detected CIN 3 as follows: OR 11.8 (95% CI 2.60-53.26), SE 40.0%, SP 94.6%, PPV 40.0% and NPV 94.6%. Lowering the cutoff to low grade squamous intraepithelial lesions increased SE and NPV but compromised SP and PPV. The detection rates for high grade lesions after an atypical squamous cells of undetermined significance diagnosis were similar with the 3 techniques. In our settings, the 3 methods of cervical cytology were slightly different in performance. The conventional Pap smear had the highest SE, while Autocyte PREP had 100% SP and PPV in detecting CIN3 with the HSIL cutoff. All 3 tests had lower SE but higher SP as compared to HCII.     

Significance of high-risk human papillomavirus DNA-positive atypical squamous cells of undetermined significance pap smears in perimenopausal and postmenopausal women

OBJECTIVE: To determine the risk of high-grade squamous intraepithelial lesion (HSIL)/cervical intraepithelial neoplasia (CIN) 2 or 3 in perimenopausal and postmenopausal women with high-risk human papillomavirus (HPV) DNA-positive atypical squamous cells of undetermined significance (ASCUS) on Pap tests. STUDY DESIGN: A total of 752 perimenopausal and postmenopausal women (patients 45 years) with an ASCUS interpretation on ThinPrep Pap tests were identified in 2002 and 2003. High risk HPVDNA was detected in 191 (25.4%) women. The follow-up results in these 136 women were compared with those of women <45 years. RESULTS: Of the 136 perimenopausal and postmenopausal women, 64.7% became negative on cytology or biopsy and 30.9% revealed persistent low-grade SIL (LSIL)/CIN 1. Furthermore, 5 women (3.68%) were diagnosed with HSIL/CIN 2 or 3, and 1 patient had squamous cell carcinoma (0.74%). The rate of HSIL/CIN 2 or 3 or worse detected in perimenopausal and postmenopausal women was significant lower than 10.6% in women <45 years (p = 0.028). CONCLUSION: Our study showed that perimenopausal and postmenopausal women with high-risk HPV positivity and an ASCUS interpretation have a significantly lower risk of HSIL/CIN 2 or 3 detected. Nonetheless, the risk of a significant finding on workup, including invasive carcinoma, indicates the need for colposcopic evaluation of these women.     

A human papillomavirus testing system in women with abnormal Pap results: a comparison study with follow-up biopsies

OBJECTIVE: To evaluate the efficacy of INFORM HPV using the SurePath collection method in women whose Pap tests indicated abnormal results. STUDY DESIGN: Ninety-two women from the gynecology clinics at The University of Texas M.D. Anderson Cancer Center who had Pap tests and underwent follow-up biopsies were selected for the study. This included 51 women with atypical squamous cells of undetermined significance (ASCUS), 23 women with low-grade squamous intraepithelial lesion (LSIL), 15 women with high-grade squamous intraepithelial lesion (HSIL) and 3 women with negative Pap results. The INFORM HPV, an in situ hybridization assay, testing for oncogenic types of HPV was performed, and the results were compared with follow-up biopsies. RESULTS: The positive rate of the INFORM HPV increased with higher grades of cytology diagnoses. The sensitivity of the INFORM HPV testing for predicting high-grade cervical intraepithelial neoplasia (CIN 2/3) also increased with higher grades of cytology diagnoses. A negative predictive value (NPV) of 94.9% and a specificity of 80.4% for predicting CIN 2/3 were observed in the ASCUS group. CONCLUSION: Using SurePath Pap specimens, the INFORM HPV lacks sufficient sensitivity and NPV for predicting CIN 2/3 in women with ASCUS. Therefore, use of the test as a triage tool is limited.     

P16(INK4a) immunocytochemistry in liquid-based cytology samples in equivocal Pap smears: added value in management of women with equivocal Pap smear

OBJECTIVE: To test whether p1l6(INK4a) immunocytochemistry (ICC) in liquid-based cytology (LBC) is useful with colposcopy in abnormal Pap smears. STUDY DESIGN: A series of 248 women with abnormal Pap smear were analyzed for oncogenic (HR) human papillomavirus (HPV) types using the Hybrid Capture II assay and for p16(INK4a) expression using ICC on cervical samples in PreservCyt liquid media. Colposcopic and loop electrosurgical excision procedure (LEEP) cone biopsy were the gold standard. RESULTS: p16(INK4a) ICC did best as predictor of high-grade squamous intraepithelial lesion, with OR 12.18 (2.72-54.57) (p = 0.0001), showing 88.2% sensitivity (SE), 61.9% specificity (SP), 14.6% positive predictive value (PPV) and 98.6% negative predictive value (NPV). In sorting discrepant cases, p16(INK4a) ICC results in 100% SE and 100% NPV in detecting cervical intraepithelial neoplasia (CIN) 2 lesions among Pap+/biopsy- women. In atypical squamous cells undetermined significance (ASCUS) cytology, adding p16(INK4a) ICC improves specificity of colposcopy from 27.3% to 81.8% and PPV from 42.8% to 71.4%. Best performance is obtained with p16(INK4a) ICC and colposcopy: 83.3% SE, 81.8% SP, 71.4% PPV and 90.0% NPV. CONCLUSION p16(INK4a) is useful in sorting clinically relevant discrepant cases, and p16(INK4a) ICC significantly improves SP and PPV of colposcopy in management of ASCUS cytology.     

Diagnostic and prognostic significance of image cytometric DNA ploidy measurement in cytological samples of cervical squamous intraepithelial lesions

D. Demirel, N. Akyürek and I. Ramzy
Diagnostic and prognostic significance of image cytometric DNA ploidy measurement in cytological samples of cervical squamous intraepithelial lesions Objective: To study the DNA ploidy pattern of uterine cervical squamous intraepithelial lesions (SILs) and its diagnostic and prognostic significance. Methods: The study included 31 cases of SIL: 11 low‐grade (LSIL) and 20 high‐grade (HSIL). Feulgen–pararosaniline staining was performed on previously Papanicolaou‐stained smears and a DNA image cytometric study was performed. An internal reference was used to calibrate the samples. Results: All 31 cases of SIL, either LSIL or HSIL, were non‐diploid. Of the 11 cases of LSIL, four were tetraploid and seven were aneuploid, whereas, of the 20 cases of HSIL, four were tetraploid and 16 were aneuploid. Stemline aneuploidy was not a significant discriminator between LSIL and HSIL (P = 0.32). Based on single‐cell analysis, HSIL cases had significantly higher DNA content than LSIL cases (P < 0.01). When a mean of 30% or more was used for the 6c‐exceeding event (6cEE) value, the sensitivity and specificity to indicate HSIL were 83% and 64%, respectively, with a positive predictive value (PPV) of 81% and negative predictive value (NPV) of 65%. All HSIL cases were cervical intraepithelial neoplasia grade 2 or worse (CIN2+) on biopsy. In addition, cases which showed recurrence had more DNA content by single‐cell analysis than those with an indolent clinical behaviour: P = 0.04 and P = 0.03 for LSIL and HSIL, respectively. Conclusions: Image cytometric DNA analysis is a useful technique for diagnostic and prognostic purposes in uterine cervical SIL when appropriate ‘c’ values are used in single‐cell analysis. We propose that a >6c DNA content of 30% is useful as a cut‐off level for predicting cases with CIN2+ in DNA image cytometry of cervical smears.     

Do qualifiers of ASCUS distinguish between low- and high-risk patients?

OBJECTIVE: To evaluate the qualification of a Pap smear classified as atypical squamous cells of undetermined significance (ASCUS) favor reactive or neoplasia as recommended by the Bethesda System. STUDY DESIGN: The smears from 105 concurrent patients with a cytologic diagnosis of ASCUS not otherwise qualified were reviewed and subclassified as ASCUS favor reactive, low grade squamous intraepithelial lesion (LSIL) or high grade squamous intraepithelial lesion (HSIL) based on the Bethesda System criteria. The cervical biopsy diagnoses were correlated. RESULTS: Of the 105 cases classified as ASCUS, 37 were subclassified as favor reactive, 51 as favor LSIL and 17 as favor HSIL on cytologic review. In the ASCUS favor reactive group, 19 (51%) had reactive changes on biopsy, 17 (46%) had cervical intraepithelial neoplasia (CIN) 1, and 1 (2%) had CIN 3. A total of 48% patients had CIN. In the favor LSIL group, there was CIN 1 in 28 cases (55%), CIN 2 or 3 in 12 (23%) and benign changes in 11 (22%) on biopsy. Seventy-eight percent had CIN. In the 17 cases classified as ASCUS favor HSIL group, all had CIN. CONCLUSION: Of the total 105 cases of ASCUS, 71% had CIN, 29% had reactive changes on follow-up biopsies, and 48% of patients in the ASCUS favor reactive group had CIN. Qualifiers of ASCUS have questionable utility in patient management.     

Cervicovaginal smear abnormalities in sexually active adolescents. Implications for management

OBJECTIVE: To assess the prevalence and spectrum of Pap smear (PS) abnormalities in sexually active adolescents in comparison to adult women in order to determine whether management of adolescents should differ from that of adults. STUDY DESIGN: Five hundred twenty-four adolescents who had an initial PS at our institution from January to September 1997 were followed for 36 months with repeat PS and/or cervical biopsy. Initial PS results were compared with those of adult women. The chi 2 test was used to calculate the statistical significance of differences between the two groups. The qualified atypical squamous cells of undetermined significance (ASCUS) cytologic diagnosis in adolescents was correlated with follow-up data. RESULTS: The overall prevalence of squamous intraepithelial lesions (SILs) in adolescents was 29% as compared to 23% in adults. Almost all initial squamous lesions were ASCUS and low grade squamous intraepithelial lesion (LSIL); only one case of high grade squamous intraepithelial lesion (HSIL) was detected. On follow-up 18% and 2.4% of adolescents developed LSIL and HSIL, with a LSIL/HSIL ratio of 8/1 as compared to 5/1 in adults. The average time from initial PS to detection of HSIL was 20 months. All patients with HSIL except one had had one or more previous abnormal PSs. The positive predictive values (PPVs) for subsequent dysplasia for ASCUS favor reactive (ASCUS.R), ASCUS not otherwise specified (ASCUS.NOS) and ASCUS favor dysplasia (ASCUS.D) in adolescents were .13, .17 and .31, respectively. ASCUS.NOS (P = .01) and ASCUS.D (P = .007) were strong indicators of dysplasia as compared to ASCUS.R. CONCLUSION: PS abnormalities are more common in sexually active adolescents, with a significantly higher prevalence of LSIL over HSIL as compared to adult women. Given the natural history of HPV infection, we recommend follow-up with cytology rather than colposcopy/biopsy for adolescents with ASCUS and LSIL PSs. Qualification of ASCUS is useful in determining which adolescents are at the highest risk of cervical dysplasia.     

The ASCUS : SIL ratio and the reference laboratory pathologist

The atypical squamous cells of undetermined significance (ASCUS) : squamous intraepithelial lesion (SIL) ratio was proposed to monitor laboratory use of the ASCUS diagnosis. This study addresses problems associated with comparing pathologists by this means. An intuitive example showed the ASCUS : SIL ratio depends on the prevalence of smears from patients who actually have SIL. In this study of 2000 cervical smears, each of five pathologists made 400 diagnoses. Differences among proportions of SIL diagnoses were statistically significant; differences among proportions of ASCUS diagnoses were not. Had an ASCUS : SIL ratio upper limit of 3.0 been used, two pathologists would have been misidentified as having high ASCUS diagnosis rates. Unlike the situation for laboratories, potential variability in SIL prevalence requires caution in the use of this ratio in assessing pathologists. An alternative measure that is independent of prevalence, the ASCUS : SIL odds ratio, is posited.     

Performance of an imaging system vs. manual screening in the detection of squamous intraepithelial lesions of the uterine cervix

OBJECTIVE: To compare the ThinPrep Imaging System (Cytyc Corp., Boxborough Massachusetts, U.S.A) to manual screening in the detection of cervical squamous epithelial lesion (SIL). STUDY DESIGN: A total of 27,525 manually screened ThinPrep Pap tests were compared with 27,725 imaged ThinPrep Pap tests for: (1) diagnostic rates of atypical squamous cells of undetermined significance; atypical squamous cells of undetermined significance, cannot rule out high grade SIL (ASC-H); low grade SIL and high grade SIL (HSIL); (2) ASC/SIL ratio; (3) high-risk HPV positivity for ASC; and (4) biopsy follow-up for ASC-H and HSIL. RESULTS: There were significant increases in the percentage of cytologic diagnoses in all categories with the imager. The ASC/SIL ratios of both groups were comparable. There was a significant decrease in HPV positivity in the imager group of ASC. Biopsy results confirmed a significant increase in the detection of HSIL in both the ASC-H and HSIL groups of the imaged cohort. CONCLUSION: The ThinPrep Imaging System is significantly better than manual screening in the detection of cervical SIL.     

Significance of high-risk human papillomavirus detection by polymerase chain reaction in primary cervical cancer screening

The purposes of this study were to evaluate the incidence of high-risk human papillomavirus (HPV) infection by polymerase chain reaction (PCR) and to assess its diagnostic usefulness in primary cervical screening. PCR testing for HPV type 16, 18, 31 and 33 was performed on 1305 specimens obtained during routine cervical cancer screening. We analysed the concurrent cervical smears and biopsy, and correlated them with the HPV infection status. We also evaluated histologically-proven cases with ASCUS smears according to HPV infection. HPV DNA was identified in eight (0.7%) of 1144 cytologically normal patients; nine (10.5%) of 86 ASCUS; seven (25.0%) of 28 LSIL; 26 (78.8%) of 33 HSIL; and in all of three squamous cell carcinomas (SCC). HPV positivity was significantly associated with cytohistological diagnosis for HSIL of more. In addition, HPV-positive ASCUS cases were found to be associated with histological abnormality rather than HPV-negative. The results indicate that high-risk HPV testing by PCR could be a useful adjunct tool for Pap smear in primary cervical screening. The combination of Pap smear and high-risk HPV testing by PCR might reduce unnecessary colposcopy-guided biopsy of women with cytological diagnosis of ASCUS.     

Detection of HPV DNA in cervical specimens collected in cytologic solution by ligation-dependent PCR

OBJECTIVE: To determine the feasibility and sensitivity of detecting human papillomavirus (HPV) in specimens collected in Cytyc PreservCyt fluid (Boxborough, Massachusetts, U.S.A.) using ligation-dependent polymerase chain reaction (LD-PCR) and to demonstrate the diagnostic value of HPV DNA testing as an adjunct to cytology in the detection of cervical squamous intraepithelial lesions (SIL), especially in cases of atypical squamous cells of undetermined significance (ASCUS). STUDY DESIGN: LD-PCR is a recently invented DNA amplification technology that utilizes a capture probe for target isolation and 2 hemiprobes for target detection. The hemiprobes are designed in such a way that when they hybridize to their target, the 5' end of one probe and the 3' end of the other probe are brought together. Two hemiprobes can then be ligated into a full probe that can serve as a template for PCR amplification. A total of 94 cervical specimens were collected in cytologic fluid and tested with LD-PCR. The results were compared with those of the Digene Hybrid Capture II assay (HC II) (Beltville, Maryland, U.S.A.) and consensus PCR. RESULTS: The overall sensitivity for detecting HPV was 41.5% (39/94) by LD-PCR, 50% (47/94) by consensus PCR and 37.2% (35/94) by HC II. The prevalence of HPV by HC II, consensus PCR and LD-PCR were 87.5%, 100% and 87.5% in the high grade SIL group; 100%, 90.9% and 90.9% in the low grade SIL group; 30%, 52.5% and 40% in the ASCUS group; and 14.2%, 22.8% and 17.1% in women with normal cytology. These results indicate that all 3 methods have similar sensitivity in patients with SIL. However, there is greater variation in detection rates in the ASCUS and normal cytology groups. CONCLUSION: LD-PCR is a useful method of detecting HPV in liquid-based gynecologic cytologic preservatives, and HPV testing as a method adjunct to the liquid-based Pap test could be useful in detecting SILs, especially for the management of patients with ASCUS.     

Experience with a thin-layer,liquid-based cervical cytologic screening method

OBJECTIVE: To assess the utility of a thin-layer cytology system for cervicovaginal screening in clinical practice. STUDY DESIGN: Twenty-five hundred cervicovaginal split samples were processed with the traditional direct smearing method and with the ThinPrep Pap Test (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) method and evaluated according to the Bethesda system, focusing mainly on the cytomorphologic features. RESULTS: The ThinPrep Pap Test yielded improved specimen adequacy and an increased detection rate of squamous abnormalities, which resulted in a decrease in the ASCUS/SIL ratio. Moreover, the thin-layer system provided adequate material for concomitant HPV testing, mainly in the LSIL and the ASCUS favor SIL cases, with satisfactory results, as well as for cell block preparations in a few selected cases that presented diagnostic difficulties. Furthermore, the morphologic features of the LSIL cases were virtually identical on both preparations, while in the HSIL cases, distinct features were noted on ThinPrep. CONCLUSION: The ThinPrep Pap Test is significantly more effective than the conventional smear in clinical practice. However, training and experience are necessary to take full advantage of this promising new technology.     

Comparative analysis of a liquid-based Pap test and concurrent HPV DNA assay of residual samples. A study of 608 cases

OBJECTIVE: To retrospectively study the HPV DNA assay of residual samples from the ThinPrep Pap Test (Cytyc Corporation, Boxborough, Massachusetts, U.S.A.) PreserveCyt (Cytyc) vial as a quality improvement (QI) indicator for management of patients with abnormal cervical cytology. STUDY DESIGN: Six hundred eight residual sample vials of liquid-based Pap-Test specimens were selected for the study based on Pap-test results from October 1998 to March 2001. The specimen vials were forwarded to the reference laboratory (American Medical Laboratories, Chantilly, Virginia, U.S.A.) for HPV DNA assay using the Hybrid Capture System method (Digene Corporation, Gaithersburg, Maryland, U.S.A.). At the time of HPV DNA assay, the residual samples were between 8 days to 10 months old, and each vial contained 4 mL. Of the 608 study cases, 76 were WNL, 115 contained BCC, 172 contained ASCUS, 179 were LSIL and 66 were HSIL. In this study, the 191 WNL and BCC cases were designated as the disease-free control group. The HPV DNA typing results were reported as low-risk, high/intermediate-risk or HPV DNA "not detected" HPV types. The HPV DNA testing results were compared to the Pap-Test diagnoses and statistical analysis performed. RESULTS: The following information reflects the percentage of HPV DNA-positive cases based on the Pap-Test diagnoses: 16.2% in WNL and BCC, 51.1% in ASCUS, 94.4% in LSIL and 98.4% in HSIL. Sensitivity (95.5%), specificity (83.7%), false negative value (4.4%), false positive value (16.2%) and predictive value of a positive (88.3%) and negative (93.5%) Pap-Test were calculated on the basis of HPV DNA testing results for 436 cases that were diagnosed as either SIL or negative (WNL and BCC). ASCUS (172) Pap-Test cases were considered borderline--disease positive and excluded from statistical analysis. CONCLUSION: The HPV DNA assay of residual samples from ThinPrep Pap-Test liquid-based specimens is an objective adjunct to the gynecologic cytology QI protocol and is the gold standard reference test for triaging women with equivocal cytologic diagnoses. The great value of HPV DNA testing is its high sensitivity (95.5%), specificity (83.7%) and negative predictive value (93.5%). HPV DNA testing results can be used as a tool to better determine the need for referrals for colposcopic biopsy, especially for patients with an ASCUS diagnosis. The residual Pap-Test specimens are stable and reproducible for HPV DNA typing. A working flow chart for our gynecologic cytology QI program was produced from the Pap-Test and HPV DNA assay results. This offer presents the added benefit of minimizing the problem of sample variation. The prevalence of HPV infection was 16.2% in this study.