Vulvar Lichen Sclerosus and Neoplastic Transformation: A Retrospective Study of 976 Cases.

OBJECTIVE: The aim of the study was to estimate the neoplastic potential of vulvar lichen sclerosus (VLS). MATERIALS AND METHODS: This was a retrospective study of 976 women with VLS. We recorded age at diagnosis of VLS, length of follow-up, and type of neoplasia, categorized as the following: (1) vulvar intraepithelial neoplasia (VIN), further subdivided in differentiated VIN (dVIN) and high-grade squamous intraepithelial lesion; (2) superficially invasive squamous cell carcinoma; and (3) frankly invasive squamous cell carcinoma. Neoplasia incidence risk, neoplasia incidence rate, and cumulative probability of progression to neoplasia according to the Kaplan-Meier method were estimated. Log-rank test was used to compare the progression-free survival curves by age at diagnosis of VLS. RESULTS: The mean age at diagnosis of VLS was 60 (median = 60; range = 8-91) years. The mean length of follow-up was 52 (median = 21; range = 1-331) months. The following 34 patients developed a neoplasia: 8 VIN (4 dVIN, 4 high-grade squamous intraepithelial lesions), 6 keratinizing superficially invasive squamous cell carcinoma (5 with adjacent dVIN), and 20 keratinizing invasive squamous cell carcinoma (1 with adjacent dVIN). The neoplasia incidence risk was 3.5%. The neoplasia incidence rate was 8.1 per 1,000 person-years. The cumulative probability of progression to neoplasia increased from 1.2% at 24 months to 36.8% at 300 months. The median progression-free survival was significantly shorter in older women (≥70 years) when compared with that in younger women (p = .003). CONCLUSIONS: Vulvar lichen sclerosus has a nonnegligible risk of neoplastic transformation and requires a careful and lifelong follow-up in all patients, particularly in elderly women. Early clinical and histological detection of preinvasive lesions is essential to reduce the risk of vulvar cancer.

Prognostic value of p16-INK4A protein in women with negative or CIN1 histology result: a follow-up study.

P16-INK4A overexpression has been proposed as a prognostic marker to manage the follow up of women with positive cytology and/or HPV test but without high-grade cervical intraepithelial neoplasia (CIN2+). This study measures the relative risk (RR) of CIN2+ of p16 positive versus negative in these women. All the women referred to colposcopy from October 2008 to September 2010 with negative or CIN1 colposcopy-guided biopsy were included in the study; women surgically treated or having a CIN2-3 were excluded. All baseline biopsies were dyed with hematoxylin and eosin and p16. Women were followed up according to screening protocols, with cytology or colposcopy at 6 or 12 months. CIN2/3 RRs and 95% confidence intervals (95%CI) were computed. Of 442 eligible women, 369 (83.5%) had at least one follow-up episode. At baseline, 113 (30.6%) were CIN1, 248 (67.2%) negative, and 8 (2.2%) inadequate histology; 293 (79.4%) were p16-negative, 64 (17.3%) p16 positive and 12 (3.2%) not valid. During follow up, we found ten CIN2 and three CIN3; of these, six were p16 positive (sensitivity 46%, 95% CI 19-75). The absolute risk among p16 positives was 9.4/100 compared to 1.7/100 of the p16 negatives (RR 5.5; 95% CI 1.7-17.4). The risk was also higher for CIN1 than for histologically negative women (RR 4.4; 95% CI 1.3-14.3). The RR for p16 in CIN1 did not change (RR 5.2; 95% CI 0.6-47.5). P16 overexpression is a good candidate for modulating follow-up intensity after a negative colposcopy but is limited by its low prospective sensitivity.

Factors predicting the outcome of conservatively treated adenocarcinoma in situ of the uterine cervix: an analysis of 166 cases.

OBJECTIVE: The present study assessed the clinical outcome of patients conservatively treated for cervical adenocarcinoma in situ (AIS) and their predictive factors using univariate and multivariate population averaged (PA) generalized estimating equation (GEE) model in a longitudinal setting. METHODS: A series of 166 consecutive women (mean age 39.8 yrs; range 23-63 yrs) underwent conservative treatment of AIS as the primary treatment and were followed-up (mean 40.9 mo) using colposcopy, PAP-smear, biopsy and HPV-testing with Hybrid Capture 2. RESULTS: Hysterectomy was performed as part of the primary management in 47 patients, who were excluded from the follow-up (FU) analysis. Out of 119 women closely followed-up, additional therapeutic procedures were performed in 69. At study conclusion, 7 patients (5.9%) showed persistent disease, while 8 (6.7%) had progressed to invasive adenocarcinoma (AC). Positive HR-HPV test was the only independent predictor of disease recurrence (adjusted OR=2.72; 95%CI 1.08-6.87), and together with free cone margins (OR=0.20; 95%CI 0.04-0.92), HR-HPV positivity was also the single most powerful predictor of disease progression to AC, with OR=3.74; 95%CI 1.84-7.61 (p=0.0001) in multivariate PA-GEE. CONCLUSIONS: These results suggest that testing HR-HPV positive at any time point during FU is the most significant independent predictor of progressive disease, while showing free margins in cone has a significant protective effect against progression to AC. Furthermore, because 4.3% women with persistent, recurrent or progressive disease experienced a late (5th and 6th FU) diagnosis of HG-CGIN or microinvasive AC, a close surveillance should be scheduled for at least three years in conservatively treated AIS patients.

Efficacy of human papillomavirus testing for the detection of invasive cervical cancers and cervical intraepithelial neoplasia: a randomised controlled trial.

BACKGROUND: Human papillomavirus (HPV) testing is known to be more sensitive, but less specific than cytology for detecting cervical intraepithelial neoplasia (CIN). We assessed the efficacy of cervical-cancer screening policies that are based on HPV testing. METHODS: Between March, 2004, and December, 2004, in two separate recruitment phases, women aged 25-60 years were randomly assigned to conventional cytology or to HPV testing in combination with liquid-based cytology (first phase) or alone (second phase). Randomisation was done by computer in two screening centres and by sequential opening of numbered sealed envelopes in the remaining seven centres. During phase one, women who were HPV-positive and aged 35-60 years were referred to colposcopy, whereas women aged 25-34 years were referred to colposcopy only if cytology was also abnormal or HPV testing was persistently positive. During phase two, women in the HPV group were referred for colposcopy if the HPV test was positive. Two rounds of screening occurred in each phase, and all women had cytology testing only at the second round. The primary endpoint was the detection of grade 2 and 3 CIN, and of invasive cervical cancers during the first and second screening rounds. Analysis was done by intention to screen. This trial is registered, number ISRCTN81678807. FINDINGS: In total for both phases, 47,001 women were randomly assigned to the cytology group and 47,369 to HPV testing. 33,851 women from the cytology group and 32,998 from the HPV-testing group had a second round of screening. We also retrieved the histological diagnoses from screening done elsewhere. The detection of invasive cervical cancers was similar for the two groups in the first round of screening (nine in the cytology group vs seven in the HPV group, p=0.62); no cases were detected in the HPV group during round two, compared with nine in the cytology group (p=0.004). Overall, in the two rounds of screening, 18 invasive cancers were detected in the cytology group versus seven in the HPV group (p=0.028). Among women aged 35-60 years, at round one the relative detection (HPV vs cytology) was 2.00 (95% CI 1.44-2.77) for CIN2, 2.08 (1.47-2.95) for CIN3, and 2.03 (1.60-2.57) for CIN2 and 3 together. At round two the relative detection was 0.54 (0.23-1.28) for CIN2, 0.48 (0.21-1.11) for CIN3, and 0.51 (0.28-0.93) for CIN2 and 3 together. Among women aged 25-34 years, there was significant heterogeneity between phases in the relative detection of CIN3. At round one the relative detection was 0.93 (0.52-1.64) in phase one and 3.91 (2.02-7.57) in phase two. At round two the relative detection was 1.34 (0.46-3.84) in phase one and 0.20 (0.04-0.93) in phase two. Pooling both phases, the detection ratio of CIN2 for women aged 25-34 years was 4.09 (2.24-7.48) at round one and 0.64 (0.23-1.27) at round two. INTERPRETATION: HPV-based screening is more effective than cytology in preventing invasive cervical cancer, by detecting persistent high-grade lesions earlier and providing a longer low-risk period. However, in younger women, HPV screening leads to over-diagnosis of regressive CIN2. FUNDING: European Union, Italian Ministry of Health, Regional Health Administrations of Piemonte, Tuscany, Veneto and Emilia-Romagna, and Public Health Agency of Lazio.

The risk of false-positive histology according to the reason for colposcopy referral in cervical cancer screening: a blind revision of all histologic lesions found in the NTCC trial.

All cervical intraepithelial neoplasia (CIN) diagnoses identified during the New Technologies for Cervical Cancer trial (ISRCTN81678807) were blindly reviewed by 2 pathologists. Original diagnoses based on colposcopy-guided biopsies were compared with those made by the reviewers who had access to all clinical histologic samples (including postsurgical). Cases downgraded from CIN 2+ by the reviewers were considered indicative of unnecessary treatments. The analyses are presented according to the molecular (high-risk human papillomavirus [HPV]) and/or cytologic diagnosis used to refer the women for colposcopy. We reviewed 812 CIN 1 and 364 CIN 2 + diagnoses. The specificity of colposcopy-guided biopsy was 98% and the sensitivity, 84%. The probability of unnecessary treatment was 27% for women with atypical squamous cells of undetermined significance cytologic findings and 8% for women with low-grade squamous intraepithelial lesion or worse, 10% for HPV+ and positive cytologic findings, and 16% for HPV+ alone. The positive predictive value of the first-level screening test was inversely associated with probability of a histologic false-positive result (P = .015). In screening, a low positive predictive value of the colposcopy-referring test may result in unnecessary treatments.

Risk factors for unrecognized invasive carcinoma in patients with vulvar high-grade squamous intraepithelial lesion at vulvoscopy-directed biopsy.

OBJECTIVE: To evaluate the prevalence and risk factors for unrecognized invasive carcinoma in a series of patients undergoing surgical excision after an office biopsy of vulvar high-grade squamous intraepithelial lesion (VHSIL). METHODS: Two hundred and sixteen consecutive patients treated in a tertiary-level referral center for vulvar disease in north-western Italy were recruited. Patients' records were reviewed by trained personnel. Factors showing a statistically significant (p<0.05) association with detection of stromal invasion at excisional surgery in univariate analysis were further examined in a backward stepwise multiple logistic regression model. RESULTS: The median patient age was 50 years (range, 19-88). More than 25% patients with VHSIL at biopsy had associated cervical/vaginal intraepithelial neoplasia, and more than 35% had a multifocal lesion. Invasive carcinoma was detected in surgical specimens from 24 patients (11%). The depth of stromal invasion varied between 0.1 mm and 3.0 mm with a median of 0.5 mm. In multivariate analysis, the risk of invasive carcinoma detection was greater for patients in the highest tertile of age (p=0.008), for patients with a lesion ≥20 mm in size (p=0.013) and with clitoral involvement (p<0.001), and for patients presenting with a nodular lesion (p=0.078). CONCLUSION: Our study suggests that patient age, lesion size, clitoral involvement and nodular appearance in patients with VHSIL at vulvoscopy-directed biopsy are independently associated with the risk of unrecognized invasive carcinoma.

Interobserver reproducibility of cytologic p16INK4a /Ki-67 dual immunostaining in human papillomavirus-positive women.

BACKGROUND: The accumulation of cyclin-dependent kinase inhibitor 2A (p16ink4a ) protein in a cell is associated with neoplastic progression in precancerous cervical lesions. Dual staining for p16ink4a and Ki-67 has been proposed as a triage test in cervical cancer screening for women who test positive for human papillomavirus DNA. In this study, interobserver reproducibility of the interpretation of this test was assessed. METHODS: Forty-two immunostained, liquid-based cytology slides were divided into 2 sets and were interpreted by 17 to 21 readers from 9 different laboratories, yielding a total of 816 reports. Immunostaining results were classified as positive, negative, inconclusive, or inadequate. After evaluation of the first set of slides and before circulation of the second set, the results were discussed in a plenary meeting. The 10 slides with the most discordant results were evaluated again by selected expert cytopathologists. RESULTS: The overall κ value was 0.612 (95% confidence interval [CI], 0.523-0.701), it was higher for the positive and negative categories (κ = 0.692 and κ = 0.641, respectively), and it was almost null for the inconclusive category (κ = 0.058). Considering only readers from laboratories with documented experience, the κ value was higher (κ = 0.747; 95% CI, 0.643-0.839) compared with nonexperienced centers (κ = 0.498; 95% CI, 0.388-0.616). The results were similar in both sets of slides (κ = 0.505 [95% CI, 0.358-0.642] and κ = 0.521 [95% CI, 0.240-0.698] for the first and second sets, respectively). Reinterpretation of the slides with the most discordant results did not provide any improvement (first evaluation, κ = 0.616 [95% CI, 0.384-0.866]; second evaluation, κ = 0.403 [95% CI, 0.182-0.643]). CONCLUSIONS: Dual staining for p16 ink4a and Ki-67 demonstrated good reproducibility, confirming its robustness, which is a necessary prerequisite for its adoption as a triage test in cervical cancer screening programs that use human papillomavirus DNA as a primary test. Cancer Cytopathol 2017;125:212-220. © 2016 American Cancer Society.

IL-3 affects endothelial cell-mediated smooth muscle cell recruitment by increasing TGF beta activity: potential role in tumor vessel stabilization.

Interleukin-3 (IL-3) expression by tumor-infiltrating lymphocytes (TILs) and its effects on vessel assembly were evaluated. TILs from 'in situ' human breast cancers expressed CD4/CD25 antigens and IL-3. An injection of Matrigel containing SMC and IL-3 or basic-fibroblast growth factor (bFGF) into SCID mice confirmed the neoangiogenetic effect of both factors. However, in response to IL-3, but not to bFGF, only few SMC became incorporated into the nascent vessels. To evaluate the possibility that signals emanated by the nascent vasculature in the presence of IL-3 may negatively regulate SMC recruitment, conditioned media (CM) from IL-3-treated endothelial cells (EC) or SMC were tested for their biological effects on SMC and EC. CM from IL-3-treated SMC stimulated the migration of EC. In contrast, the migration of SMC was not affected by CM from IL-3-stimulated EC; however, it was greatly enhanced by blocking transforming growth factor beta (TGF beta) activity. TGF beta immunoenzymatic assay demonstrated the following: (i) the absence of TGF beta activity in CM from IL-3-stimulated EC; (ii) a barely detectable TGF beta activity in CM from IL-3-stimulated SMC; and (iii) the presence of TGF beta activity in the supernatants of SMC stimulated with CM from IL-3-, but not from bFGF-stimulated EC. Increased TGF beta mRNA expression was only detected in SMC stimulated with CM from IL-3-treated EC. Finally, the inhibitory signals induced by IL-3 in vivo were abrogated by the addition of the neutralizing TGF beta antibody. Thus, the positive immunostaining for IL-3 by TILs in 'in situ' breast cancers sustains the possibility that early in tumor development, IL-3 can contribute to the chronic immaturity of these vessels.

Informed cytology for triaging HPV-positive women: substudy nested in the NTCC randomized controlled trial.

BACKGROUND: Human papillomavirus (HPV)-based screening needs triage. In most randomized controlled trials (RCTs) on HPV testing with cytological triage, cytology interpretation has been blind to HPV status. METHODS: Women age 25 to 60 years enrolled in the New Technology in Cervical Cancer (NTCC) RCT comparing HPV testing with cytology were referred to colposcopy if HPV positive and, if no cervical intraepithelial neoplasia (CIN) was detected, followed up until HPV negativity. Cytological slides taken at the first colposcopy were retrieved and independently interpreted by an external laboratory, which was only aware of patients' HPV positivity. Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were computed for histologically proven CIN2+ with HPV status-informed cytology for women with a determination of atypical squamous cells of undetermined significance (ASCUS) or more severe. All statistical tests were two-sided. RESULTS: Among HPV-positive women, informed cytology had cross-sectional sensitivity, specificity, PPV and 1-NPV for CIN2+ of 85.6% (95% confidence interval [CI] = 76.6 to 92.1), 65.9% (95% CI = 63.1 to 68.6), 16.2% (95% CI = 13.0 to 19.8), and 1.7 (95% CI = 0.9 to 2.8), respectively. Cytology was also associated with subsequent risk of newly diagnosed CIN2+ and CIN3+. The cross-sectional relative sensitivity for CIN2+ vs blind cytology obtained by referring to colposcopy and following up only HPV positive women who had HPV status-informed cytology greater than or equal to ASCUS was 1.58 (95% CI = 1.22 to 2.01), while the corresponding relative referral to colposcopy was 0.95 (95% CI = 0.86 to 1.04). CONCLUSIONS: Cytology informed of HPV positivity is more sensitive than blind cytology and could allow longer intervals before retesting HPV-positive, cytology-negative women.

Interpretation of p16(INK4a) /Ki-67 dual immunostaining for the triage of human papillomavirus-positive women by experts and nonexperts in cervical cytology.

BACKGROUND: The triage of human papillomavirus (HPV)-positive women is needed to avoid overreferral to colposcopy. p16(INK4a) immunostaining is an efficient triage method. p16(INK4a) /Ki-67 dual staining was introduced mainly to increase reproducibility and specificity compared with stand-alone p16(INK4a) staining. METHODS: Within a pilot project, HPV-positive women were referred to colposcopy if cytology was abnormal or unsatisfactory or HPV testing was still positive after 1 year. For 500 consecutive women, a slide obtained during colposcopy was immunostained for p16(INK4a) /Ki-67 and independently interpreted by 7 readers without previous experience with dual staining. Four of these readers were experts in cervical pathology and 3 were not. Kappa values for multiple raters, sensitivity, and specificity for cervical intraepithelial neoplasia type 2-positive histology were computed. Because women with normal cytology were underrepresented, estimates for all HPV-positive women were obtained as weighted means of cytology-specific estimates. RESULTS: The overall kappa for HPV-positive women was 0.70 (95% confidence interval [95% CI], 0.60-0.77). Kappa values were not found to be significantly different between expert and nonexpert readers with regard to cervical cytology but were significantly increased (P =. 0066) after consensus discussion. The overall specificity estimate for HPV-positive women was 64.0% (95% CI, 57.4%-70.2%): 66.7% (95% CI, 59.8%-73.0%) for experts and 60.5% (95% CI, 59.8%-73.0%) for nonexperts. Among women with abnormal cytology, the sensitivity was 85.5% (95% CI, 77.9%-90.8%): 85.8% (95% CI, 77.9%-91.2%) for experts and 85.1% (95% CI, 76.6%-90.9%) for nonexperts. CONCLUSIONS: p16(INK4a) /Ki-67 immunostaining demonstrated good reproducibility and specificity when triaging HPV-positive women. Dual-staining interpretation can be performed, after short training, even by staff who are not experts in cervical cytology. This allows HPV-based screening with triage to be performed in settings in which such expert staff is not available.

Surgical approach and long-term clinical outcome in women with microinvasive cervical cancer.

AIM: To assess the efficacy and safety of conservative surgical approach for microinvasive cervical cancer with regards to cone margins status and lymph vascular space invasion (LVSI). PATIENTS AND METHODS: This was a multicentre retrospective cohort study of 153 women diagnosed with microinvasive cervical cancer over a 10 years period (1993-2003). RESULTS: In conservatively-treated women (n=80), neither cancer mortality nor disease relapse after 184.5 ± 20.5 months of follow-up was detected. Residual disease in women who underwent secondary surgery was significantly related to positive margins on the primary cone excision (p=0.005) while no correlation with LVSI emerged. CONCLUSION: Conization can represent the definitive treatment for stage IA1, if surgical margins are cancer-free, independently of LVSI. A conservative surgical approach could also be considered in women with IA2 cervical cancer when preservation of fertility is strongly requested. A close long-term surveillance should be scheduled for conservatively-treated women.

Impact of p16(INK4a) immunohistochemistry staining on interobserver agreement on the diagnosis of cervical intraepithelial neoplasia.

OBJECTIVES: This study aimed to compare the interobserver Cohen κ on H&E staining and on H&E plus p16(INK4a) staining of all cervical biopsy specimens in a population-based screening program. METHODS: All the colposcopy-guided biopsies generated by the routine screening of 23,258 women aged 25 to 64 years were stained with H&E and H&E plus p16. Biopsy specimens were reviewed by six external experts. RESULTS: The four diagnoses were available in 441 cases. The interobserver κ values were 0.52 (95% confidence interval [CI], 0.45-0.58) and 0.48 (95% CI, 0.42-0.56) with H&E and H&E + p16, respectively, when using a five-group classification (normal, CIN 1, CIN 2, CIN 3, and cancer); adopting a two-group classification (≤CIN 1 and ≥CIN 2), the values were 0.75 (95% CI, 0.66-0.82) and 0.70 (95% CI, 0.61-0.79), respectively. CONCLUSIONS: The use of p16 on all cervical biopsy specimens in a screening program showed virtually no effect on reproducibility of the histologic diagnosis.

HPV testing is an efficient management choice for women with inadequate liquid-based cytology in cervical cancer screening.

This study compares colposcopy referrals of 2 management strategies: oncogenic human papillomavirus (HPV)-DNA testing (Hybrid Capture 2 assay, Qiagen, Germantown, MD) and repeat cytology. In the New Technology in Cervical Cancer Trial, 22,708 subjects were randomly assigned to undergo both HPV and liquid-based cytologic testing. Women aged 35 to 60 years old with unsatisfactory cytologic findings were directly referred for colposcopy if the HPV test result was positive, and were referred for repeat cytologic examination if the HPV test result was negative; women aged 25 to 35 years old were referred for repeat cytologic examination independent of HPV test results. A positive or a second unsatisfactory cytologic examination referred women for colposcopy. Five hundred sixty women had unsatisfactory cytologic findings. Colposcopy referral was not significant and slightly higher with HPV testing than repeat cytologic test (9.8% vs 6.8%, P = .11). When cytologic testing was repeated 36.8% were unavailable for follow-up and most of the colposcopies were performed in HPV-negative women. For unsatisfactory cytologic findings, HPV triage is a more logical and efficient management strategy than a repeat cytologic test.

The reproducibility of CIN diagnoses among different pathologists: data from histology reviews from a multicenter randomized study.

The reproducibility of cervical histology diagnoses is critical for efficient screening and to evaluate the effectiveness of new technologies. The vast majority of cervical intraepithelial neoplasia (CIN) diagnoses reported in the New Technologies for Cervical Cancer study were blindly reviewed by 2 independent pathologists. Only H&E-stained slides were used for the review. The reviewers were asked to reclassify cases using the following categories: normal CIN 1, CIN 2, CIN 3, and squamous and glandular invasive cancer. We reviewed 1,003 cases. The interobserver agreement was 0.36 (95% confidence interval [CI], 0.32-0.40) with an unweighted kappa and 0.54 with a weighted kappa (95% CI, 0.50-0.58). The kappa values from dichotomous classifications with the threshold at CIN 2 were 0.69 (95% CI, 0.64-0.73) and 0.57 (95% CI, 0.51-0.63) with the threshold at CIN 3. The CIN 2 diagnosis had the lowest class-specific agreement, with fewer than 50% of cases confirmed by the panel members, which supports the fact that CIN 2 is not a well-defined stage in the pathogenesis of cervical neoplasia.

Accuracy of liquid based versus conventional cytology: overall results of new technologies for cervical cancer screening: randomised controlled trial.

OBJECTIVE: To compare the accuracy of conventional cytology with liquid based cytology for primary screening of cervical cancer. DESIGN: Randomised controlled trial. SETTING: Nine screening programmes in Italy. PARTICIPANTS: Women aged 25-60 attending for a new screening round: 22 466 were assigned to the conventional arm and 22 708 were assigned to the experimental arm. INTERVENTIONS: Conventional cytology compared with liquid based cytology and testing for human papillomavirus. MAIN OUTCOME MEASURE: Relative sensitivity for cervical intraepithelial neoplasia of grade 2 or more at blindly reviewed histology, with atypical cells of undetermined significance or more severe cytology considered a positive result. RESULTS: In an intention to screen analysis liquid based cytology showed no significant increase in sensitivity for cervical intraepithelial neoplasia of grade 2 or more (relative sensitivity 1.17, 95% confidence interval 0.87 to 1.56) whereas the positive predictive value was reduced (relative positive predictive value v conventional cytology 0.58, 0.44 to 0.77). Liquid based cytology detected more lesions of grade 1 or more (relative sensitivity 1.68, 1.40 to 2.02), with a larger increase among women aged 25-34 (P for heterogeneity 0.0006), but did not detect more lesions of grade 3 or more (relative sensitivity 0.84, 0.56 to 1.25). Results were similar when only low grade intraepithelial lesions or more severe cytology were considered a positive result. No evidence was found of heterogeneity between centres or of improvement with increasing time from start of the study. The relative frequency of women with at least one unsatisfactory result was lower with liquid based cytology (0.62, 0.56 to 0.69). CONCLUSION: Liquid based cytology showed no statistically significant difference in sensitivity to conventional cytology for detection of cervical intraepithelial neoplasia of grade 2 or more. More positive results were found, however, leading to a lower positive predictive value. A large reduction in unsatisfactory smears was evident. TRIAL REGISTRATION: Current Controlled Trials ISRCTN81678807 [controlled-trials.com].