Manuel Zorzi

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.

Results at Recruitment From a Randomized Controlled Trial Comparing Human Papillomavirus Testing Alone With Conventional Cytology as the Primary Cervical Cancer Screening Test

BACKGROUND In the first recruitment phase of a randomized trial of cervical cancer screening methods (New Technologies for Cervical Cancer Screening [NTCC] study), we compared screening with conventional cytology with screening by human papillomavirus (HPV) testing in combination with liquid-based cytology. HPV-positive women were directly referred to colposcopy if aged 35 or older; if younger, they were retested after 1 year. METHODS In the second recruitment phase of NTCC, we randomly assigned women to conventional cytology (n = 24,661) with referral to colposcopy if cytology indicated atypical squamous cells of undetermined significance or more severe abnormality or to testing for high-risk HPV DNA alone by Hybrid Capture 2 (n = 24,535) with referral to colposcopy if the test was positive at a concentration of HPV DNA 1 pg/mL or greater. For the main endpoint of the study, histologic detection of cervical intraepithelial neoplasia of grade 2 or more (CIN2+), we calculated and compared sensitivity and positive predictive value (PPV) of the two screening methods using HPV DNA cutoffs of 1 pg/mL and 2 pg/mL. All statistical tests were two-sided. RESULTS For women aged 35-60 years, the relative sensitivity of HPV testing for detection of CIN2+ at a cutoff of 1 pg/mL vs conventional cytology was 1.92 (95% CI = 1.28 to 2.87) and the relative PPV was 0.80 (95% CI = 0.55 to 1.18). At a cutoff of 2 pg/mL HPV DNA, the relative sensitivity was 1.81 (95% CI = 1.20 to 2.72) and the relative PPV was 0.99 (95% CI = 0.67 to 1.46). In this age group, there was no evidence of heterogeneity between study phases. Among women aged 25-34 years, the relative sensitivity for detection of CIN2+ of HPV testing at a cutoff of 1 pg/mL vs cytology was 3.50 (95% CI = 2.11 to 5.82), statistically significantly larger (P = .019) than that observed in phase 1 at this age (1.58; 95% CI = 1.03 to 2.44). CONCLUSIONS For women aged 35-60 years, HPV testing with a cutoff of 2 pg/mL achieves a substantial gain in sensitivity over cytology with only a small reduction in PPV. Among women aged 25-34 years, the large relative sensitivity of HPV testing compared with conventional cytology and the difference between relative sensitivity during phases 1 and 2 suggests that there is frequent regression of CIN2+ that are detected by direct referral of younger HPV-positive women to colposcopy. Thus, triage test or repeat testing is needed if HPV is to be used for primary testing in this context.

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.

Use of p16-INK4A overexpression to increase the specificity of human papillomavirus testing: a nested substudy of the NTCC randomised controlled trial

BACKGROUND Human-papillomavirus (HPV) testing is more sensitive, but less specific, than conventional cytology for detecting high-grade cervical intraepithelial neoplasia (CIN). We assessed whether HPV testing with triage by p16-INK4A overexpression can increase specificity while maintaining sensitivity. METHODS HPV-positive women were enrolled between June 10, 2003, and Dec 31, 2004 in a multicentre randomised controlled trial, which compared stand-alone HPV testing by Hybrid Capture 2 (experimental group) with conventional cytology, were referred for colposcopy. In seven of nine centres, cytospin preparations from these women were tested for p16-INK4A overexpression by immunostaining. The sensitivity and specificity for CIN grade 2 or more, determined at blind review of histology, were calculated for these women. We also estimated the relative sensitivity and relative referral to colposcopy that would have been obtained by HPV testing with p16-INK4A triage compared with conventional cytology. This trial is registered as a Standard Randomised Controlled Trial, number ISRCTN81678807. FINDINGS 24 661 women were randomly assigned to the experimental group. 1137 women (74% of those undergoing colposcopy in relevant centres), including 50 with CIN2 and 42 with CIN3 or cancer, had valid p16-INK4A immunostaining. For the endpoint of CIN2+, sensitivity and specificity of p16-INK4A (deemed positive with any number of stained cells-except endocervical, metaplastic, and atrophic cells if morphologically normal) in HPV-positive women of any age were 88% (81 of 92; 95% CI 80-94) and 61% (633 of 1045; 57-64), respectively. In the 35-60-year age group, the relative sensitivity of HPV testing and p16-INK4A triage versus conventional cytology for CIN2+ was 1.53 (95% CI 1.15-2.02) and relative referral was 1.08 (0.96-1.21). In the 25-34-year age group, relative sensitivity was 3.01 (1.82-5.17) and relative referral was 1.15 (0.96-1.37). In the latter age group, when 5% or more stained cells were deemed positive, the corresponding values were 2.06 (1.20-3.68) and 0.58 (0.46-0.73), respectively. INTERPRETATION HPV testing with p16-INK4A triage produces a significant increase in sensitivity compared with conventional cytology, with no substantial increase in referral to colposcopy.

Risk of high-grade cervical intraepithelial neoplasia during follow-up in HPV-positive women according to baseline p16-INK4A results: a prospective analysis of a nested substudy of the NTCC randomised controlled trial

BACKGROUND Immunostaining for p16-INK4A (henceforth p16) is a sensitive and specific method for detection of high-grade cervical intraepithelial neoplasia (CIN) in women infected with human papillomavirus (HPV), but longitudinal data have not been obtained. We investigated the relation between p16 status and risk of CIN during 3 years of follow-up. METHODS Women aged 25-60 years were enrolled between June 10, 2003, and Dec 31, 2004, in a multicentre randomised trial comparing HPV testing with cytology. HPV-positive women were referred for colposcopy and, in seven of nine centres, were tested for p16 overexpression by immunostaining. If no CIN was detected, these women were followed up at yearly intervals until clearance of HPV infection. The primary endpoint was histologically confirmed CIN of grade 2 or worse (CIN of grade 2 [CIN2], CIN of grade 3 [CIN3], or invasive cervical cancer) at recruitment or during follow-up. We calculated the absolute and relative risks by p16 status at recruitment. We also calculated the longitudinal sensitivity of p16 testing. Additionally, we assessed the relative sensitivity of an alternative strategy (referral to colposcopy and follow-up of only HPV-positive, p16-positive women) versus conventional cytology in two age groups. Percentages were weighted by the inverse of the tested fraction. The trial in which this study is nested is registered, number ISRCTN81678807. FINDINGS Of 1042 HPV-positive women who were tested for p16 with no CIN detected during the first round of screening, 944 (91%) had further HPV tests. 793 (84%) of these 944 were followed up until detection of CIN2 or worse, HPV infection clearance, or for at least 3 years. CIN2 or worse was detected during follow-up in more p16-positive women (31 of 365, 8·8% [95% CI 5·8-11·8]) than in p16-negative women (17 of 579, 3·7% [1·9-5·4]; relative risk [RR] 2·61 [95% CI 1·49-4·59]). RR was higher in women aged 35-60 years at recruitment (3·37 [1·39-8·15]) than in those aged 25-34 years (2·15 [1·00-4·61]), but age was not a significant modifier. CIN3 or worse was detected during follow-up in more p16-positive women (16 of 365, 4·4% [2·3-6·6]) than in p16-negative women (six of 579, 1·3% [0·2-2·3]; RR 3·90 [95% CI 1·57-9·68]). Longitudinal sensitivity of p16 testing for detection of CIN3 or worse during follow-up at all ages was 77·8% (95% CI 63·9-91·6). The relative sensitivity of the alternative strategy compared with conventional cytology was 2·08 (1·13-3·56) in women aged 35-60 years and 2·86 (1·28-5·36) in those aged 25-34 years. HPV-positive, p16-negative women aged 35-60 years had a higher cumulative risk of CIN3 or worse during recruitment or follow-up (2·0%, 95% CI 0·3-3·7) than did HPV-negative women (0·01%, 0-0·04) or those who were cytologically normal (0·04%, 0·02-0·09) at recruitment. INTERPRETATION p16 overexpression is a marker for CIN2 or worse or for development of CIN2 or worse within 3 years in HPV-positive women, especially those aged 35-60 years. HPV-positive, p16-positive women need immediate colposcopy and, if the assessment is negative, annual follow-up. Immediate colposcopy can be avoided in HPV-positive, p16-negative women, who can be safely managed with repeat screening after 2-3 year intervals. FUNDING European Union; Italian Ministry of Health; Regional Health Administrations of Piemonte, Tuscany, Veneto and Emilia Romagna; and Public Health Agency of Lazio Region.

Estimate of overdiagnosis of breast cancer due to mammography after adjustment for lead time. A service screening study in Italy

IntroductionExcess of incidence rates is the expected consequence of service screening. The aim of this paper is to estimate the quota attributable to overdiagnosis in the breast cancer screening programmes in Northern and Central Italy.MethodsAll patients with breast cancer diagnosed between 50 and 74 years who were resident in screening areas in the six years before and five years after the start of the screening programme were included. We calculated a corrected-for-lead-time number of observed cases for each calendar year. The number of observed incident cases was reduced by the number of screen-detected cases in that year and incremented by the estimated number of screen-detected cases that would have arisen clinically in that year.ResultsIn total we included 13,519 and 13,999 breast cancer cases diagnosed in the pre-screening and screening years, respectively. In total, the excess ratio of observed to predicted in situ and invasive cases was 36.2%. After correction for lead time the excess ratio was 4.6% (95% confidence interval 2 to 7%) and for invasive cases only it was 3.2% (95% confidence interval 1 to 6%).ConclusionThe remaining excess of cancers after individual correction for lead time was lower than 5%.

Effectiveness of service screening: a case–control study to assess breast cancer mortality reduction

The aim of this study was the evaluation of the impact of service screening programmes on breast cancer mortality in five regions of Italy. We conducted a matched case–control study with four controls for each case. Cases were defined as breast cancer deaths occurred not later than 31 December 2002. Controls were sampled from the local municipality list and matched by date of birth. Screening histories were assessed by the local, computerised, screening database and subjects were classified as either invited or not-yet-invited and as either screened or unscreened. There were a total of 1750 breast cancer deaths within the 50 to 74-year-old breast cancer cases and a total of 7000 controls. The logistic conditional estimate of the cumulative odds ratios comparing invited with not-yet-invited women was 0.75 (95% CI: 0.62–0.92). Restricting the analyses to invited women, the odds ratio of screened to never-respondent women corrected for self-selection bias was 0.55 (95% CI: 0.36–0.85). The introduction of breast cancer screening programmes in Italy is associated with a reduction in breast cancer mortality attributable to the additional impact of service screening over and above the background access to mammography.

High sensitivity of five colorectal screening programmes with faecal immunochemical test in the Veneto Region, Italy

Objective Although guaiac-based faecal occult blood test screening has been shown to be effective in reducing colorectal cancer (CRC) mortality, it has been criticised mostly for its low sensitivity. Italian CRC screening programmes are based on immunochemical tests (iFOBT). We collected and analysed the interval cancers (ICs) found by five screening programmes to estimate their sensitivity. Methods ICs were identified in subjects who had a negative result in a screening examination from 2002 to 2007 (N=267 789); data were linked with 2002–2008 hospital discharge records. Analysis was based on the follow up of 468 306 person-years. The proportional incidence-based sensitivity was estimated overall and by sex, age class, time since last negative iFOBT result, anatomical site, and history of screening (first or subsequent test). Results Overall, 126 ICs were identified, compared to 572 expected cancers. The proportional incidences were 15.3% and 31.0% in the first and the second interval-years, respectively, with an overall episode sensitivity of 78.0% (95% CI: 73.8 to 81.6). Sensitivity was higher for males than females (80.1% vs 74.8%); no differences were observed by age, anatomical site or between programmes. The test sensitivity of iFOBT was 82.1% (95% CI 78.1% to 85.3%). Conclusions iFOBT-based screening programmes showed a high performance in terms of sensitivity as estimated through the IC rates. The screening schedule utilised in our programmes (single iFOBT, positivity threshold of 100 ng Hb/ml of sample solution, inter-screening interval of 2 years) shows low rates of missed cancers that are diagnosed during the interval. HDR are a convenient and reliable source of data for IC studies.

Colorectal Cancer Screening: Tests, Strategies, and Perspectives

Screening has a central role in colorectal cancer (CRC) control. Different screening tests are effective in reducing CRC-specific mortality. Influence on cancer incidence depends on test sensitivity for pre-malignant lesions, ranging from almost no influence for guaiac-based fecal occult blood testing (gFOBT) to an estimated reduction of 66–90% for colonoscopy. Screening tests detect lesions indirectly in the stool [gFOBT, fecal immunochemical testing (FIT), and fecal DNA] or directly by colonic inspection [flexible sigmoidoscopy, colonoscopy, CT colonography (CTC), and capsule endoscopy]. CRC screening is cost-effective compared to no screening but no screening strategy is clearly better than the others. Stool tests are the most widely used in worldwide screening interventions. FIT will soon replace gFOBT. The use of colonoscopy as a screening test is increasing and this strategy has superseded all alternatives in the US and Germany. Despite its undisputed importance, CRC screening is under-used and participation rarely reaches 70% of target population. Strategies to increase participation include ensuring recommendation by physicians, introducing organized screening and developing new, more acceptable tests. Available evidence for DNA fecal testing, CTC, and capsule endoscopy is reviewed.

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.