Subsequent Screening Examinations Research Articles

Prevalent vs Incident Screen: Why Does It Matter?

There are important differences in the performance and outcomes of breast cancer screening in the prevalent compared to the incident screening rounds. The prevalent screen is the first screening examination using a particular imaging technique and identifies pre-existing, undiagnosed cancers in the population. The incident screen is any subsequent screening examination using that technique. It is expected to identify fewer cancers than the prevalent screen because it captures only those cancers that have become detectable since the prior screening examination. The higher cancer detection rate at prevalent relative to incident screening should be taken into account when analyzing the medical audit and effectiveness of new screening technologies.

Utilization of Diagnostic Procedures After Lung Cancer Screening in the National Lung Screening Trial

ObjectiveTo examine utilization patterns of diagnostic procedures after lung cancer screening among participants enrolled in the National Lung Screening Trial. MethodsUsing a sample of National Lung Screening Trial participants with abstracted medical records, we assessed utilization of imaging, invasive, and surgical procedures after lung cancer screening. Missing data were imputed using multiple imputation by chained equations. For each procedure type, we examined utilization within a year after the screening or until the next screen, whichever came first, across arms (low-dose CT [LDCT] versus chest X-ray [CXR]) and by screening results. We also explored factors associated with having these procedures using multivariable negative binomial regressions. ResultsAfter baseline screening, our sample had 176.5 and 46.7 procedures per 100 person-years for those with a false-positive and negative result, respectively. Invasive and surgical procedures were relatively infrequent. Among those who screened positive, follow-up imaging and invasive procedures were 25% and 34% less frequent in those screened with LDCT, compared with CXR. Postscreening utilization of invasive and surgical procedures was 37% and 34% lower at the first incidence screen compared with baseline. Participants with positive results at baseline were six times more likely to undergo additional imaging than those with normal findings. DiscussionUse of imaging and invasive procedures to evaluate abnormal findings varied by screening modality, with a lower rate for LDCT than CXR. Invasive and surgical workup were less prevalent after subsequent screening examinations compared with baseline screening. Utilization was associated with older age but not gender, race or ethnicity, insurance status, or income.

Cumulative risks of false positive recall and screen-detected breast cancer after multiple screening examinations.

Women tend to make a decision about participation in breast cancer screening and adhere to this for future invitations. Therefore, our study aimed to provide high-quality information on cumulative risks of false-positive (FP) recall and screen-detected breast cancer over multiple screening examinations. Individual Dutch screening registry data (2005-2018) were gathered on subsequent screening examinations of 92 902 women age 49 to 51 years in 2005. Survival analyses were used to calculate cumulative risks of a FP and a true-positive (TP) result after seven examinations. Data from 66 472 women age 58 to 59 years were used to extrapolate to 11 examinations. Participation, detection and additional FP rates were calculated for women who previously received FP results compared to women with true negative (TN) results. After 7 examinations, the cumulative risk of a TP result was 3.7% and the cumulative risk of a FP result was 9.1%. After 11 examinations, this increased to 7.1% and 13.5%, respectively. Following a FP result, participation was lower (71%-81%) than following a TN result (>90%). In women with a FP result, more TP results (factor 1.59 [95% CI: 1.44-1.72]), more interval cancers (factor 1.66 [95% CI: 1.41-1.91]) and more FP results (factor 1.96 [95% CI: 1.87-2.05]) were found than in women with TN results. In conclusion, due to a low recall rate in the Netherlands, the cumulative risk of a FP recall is relatively low, while the cumulative risk of a TP result is comparable. Breast cancer diagnoses and FP results were more common in women with FP results than in women with TN results, while participation was lower.

Stratification of Breast Cancer Risk in Terms of the Influence of Age and Mammographic density.

Analysis of the influence of the singular risk factors age and breast density on the 2-year incidence of breast cancer among participants in the German mammography screening program. The multicenter study includes 111 456 subsequent round digital mammographic screening examinations from four screening units with prospective visual categorization of breast density. Based on detection in screening and during the 2-year interval after negative screening participation (interval cancers), 2-year breast cancer incidences (2YBCI) (‰) were calculated in the 5-year age groups (5 YAG) of the target group 50-69 years and in the BI-RADS density categories ACR 1-4. Multivariate statistical evaluations were carried out using logistic regression models. With an increase in the 5 YAG, the 2 YBCI increased by 5.0 ‰, 6.7 ‰, 8.5 ‰ to 9.7 ‰, and was significantly different among 55-59, 60-64 and 65-69-year-old women compared to the youngest reference group 50-54 years (odds ratio (OR): 1.34; 1.68; and 1.93; p-value < 0.0001). With an increase in density categories 1-4, the 2 YBCI increased from 2.6 ‰, to 5.8 ‰, 9.6 ‰, and 9.7 ‰. The 2 YBCI differed significantly in breast density categories 2, 3, 4 from reference group 1 (OR: 2.17; 3.65; and 3.76; p-value < 0.0001). Only within the two main breast density groups 2 (frequency 44.3 %) and 3 (44.7 %), a significant increase in the 2 YBCI was observed across the 5 YAG (category 2: 3.7-8.9 ‰; category 3: 5.8-11.7 ‰; p-value < 0.001 each). The 2 YBCI was above the median of 7.5 ‰ in women with breast density category 2 and aged 65-69 years, as well as in women with breast density categories 3 and 4 aged 55-69 years. A 2 YBCI below the median was seen in women between 50-54 years regardless of breast density, as well as women in category 1 in all age groups. Within the main breast density categories 2 and 3 (almost 90 % of participants), incidences increase with age to double. A consistently low incidence is found regardless of breast density at a young screening age and in women with the lowest breast density. · The risk of breast cancer is modified by age in density categories.. · Women aged 50-54 years have a low risk in all density categories.. · Women in category ACR 1 of any age group have a low risk.. · Weigel S, Heindel W, Dietz C et al. Stratifizierung des Brustkrebsrisikos hinsichtlich der Einflüsse von Alter und mammografischer Dichte. Fortschr Röntgenstr 2020; 192: 678 - 685.

Annual Cervical Cancer Screening Revealed Early Stage Clear Cell Adenocarcinoma of the Uterine Cervix: A Case Report

Clear cell adenocarcinoma of the uterine cervix (CCAC) is rare. We describe a case of CCAC, which was treated with complete resection without adjuvant therapy. The patient was a 42-year-old woman, who had no chief complaint. She had undergone annual cervical cancer screening, and no abnormalities had been detected in previous examinations. However, in a subsequent screening examination, cervical cytology produced negative results, but cervicovaginal erosion was observed at the uterine cervix. A detailed examination led to adenocarcinoma being suspected, and so conization was performed, resulting in a diagnosis of CCAC. A microscopic examination revealed atypical cells with clear-slightly basophilic cytoplasm, and immunohistochemical studies showed that they were positive for napsin A, p16, and AE1/3. Radical hysterectomy, pelvic lymph node dissection, and bilateral salpingo-oophorectomy were performed. Complete resection was achieved, and the postoperative diagnosis was CCAC, pT1b1N0M0, ly(-), v(-). The patient did not undergo adjuvant treatment. She is still alive and recurrence-free. J Clin Gynecol Obstet. 2019;8(1):21-24 doi: https://doi.org/10.14740/jcgo530

Time trend in programme sensitivity within the German mammography screening programme in North Rhine-Westphalia and Lower Saxony

The programme sensitivity is aperformance indicator for evaluating the quality of the mammography screening programme (MSP). We analysed the development of the programme sensitivity over time in two federal states of Germany, North Rhine-Westphalia (NRW) and Lower Saxony (NDS). Data from 2,717,801 (NRW) and 1,197,660 (NDS) screening examinations between 2006 and 2011 were linked with data of the State Cancer Registry NRW and the Epidemiological Cancer Registry NDS, respectively. Breast cancers (invasive and in situ) were either detected at screening or diagnosed within the 24-month interval after an inconspicuous screening result outside the programme. The crude and age-standardized programme sensitivity was calculated per calendar year. The German mammography screening office provided aggregated recall rates. The age-standardized programme sensitivity increased markedly for initial screening examinations from 2006 to 2011 from 75.0% (95% CI: 72.1-77.9) to 80.5% (95% CI: 78.5-82.5) in NRW, and from 74.9% (95% CI: 71.4-78.5) to 84.7% (95% CI: 81.1-88.3) in NDS. Concurrently, recall rates increased as well. For subsequent screening examinations, the programme sensitivity increased from 2008 to 2011 from 68.1% (95% CI: 63.1-73.1) to 71.9% (95% CI: 70.2-73.6) in NRW, and from 69.8% (95% CI: 64.2-75.4) to 74.9% (95% CI: 72.3-77.5) in NDS, whereas the recall rates remained relatively constant. In both federal states, the programme sensitivity increased over time. This increase, possibly indicating an improved quality of diagnosis within the MSP as alearning system, is discussed under consideration of the age distribution of screening participants and the recall rates.

Clinical performance of digital mammography systems in a breast screening programme – An update

The purpose of this research was to compare the clinical performance of three individual digital mammography (DM) systems utilised within a population based screening program. The results presented here expand on previously published data from a 3 to a 9 year period. 28 DM systems from three different vendors were involved in the study. The retrospective analysis included 971612 screening examinations of females aged between 50 and 64 years. All images were double read and assigned a result according to a 5 point rating scale to indicate the probability of cancer. Women with a positive result were recalled for further assessment imaging and biopsy if necessary. Clinical performance in terms of cancer detection rate was analysed and the results presented A total of 5262 cancers were diagnosed. No statistically significant difference was found between the three individual mammography systems in terms of overall cancer detection rate or in the detection of invasive cancer and ductal carcinoma in situ. This was shown in both prevalent and subsequent screening examination categories. The results demonstrate comparable cancer detection performance for the three imaging system types. The study expansion from a 3 to a 9 year period provided sufficient numbers of cancers, 5262 (n = 971612) compared to 1632 (n = 238182) in the original study, to prove statistical significance. Overall the results provide a reassuring audit measure, suggesting that technical differences evident from routine quality assurance measurements do not appear to be reflected clinically in terms of overall cancer detection.

What is an acceptable false negative rate in the detection of prostate cancer?

BackgroundIn prostate cancer (PCa) screening men and their physicians aim to rule out the presence of potentially life threatening PCa. To date, prostate specific antigen (PSA) testing and systematic prostate biopsy (Bx)—in case of an elevated PSA—are still the main modes of PCa detection. Often uncertainty remains when a PSA-test is <3.0 ng/mL or a Bx shows a benign result, leading to the continuous repeating of procedures. Here we assess the potential consequences of false negatives by studying follow-up data of a purely PSA-based approach with applying sextant Bx, an approach considered to have a high risk of missing PCa diagnosis.MethodsOur study population consisted of 19,970 men from the ERSPC project section Rotterdam, initially screened in 1993–1999. We assessed clinically significant Gleason ≥3+4 PCa (csPCa) diagnosis within the 4-year screening interval and subsequent screening round 4 years later in men having a PSA <3.0 ng/mL at initial screening (no Bx) and men with Bx (PSA >3.0 ng/mL), but no PCa detected at that time. In addition, we addressed PCa mortality and PCa diagnosis for men with a negative PSA test and negative Bx, who were retested every 4 years covering a 15-year follow-up.ResultsA total of 14,935 men had PSA <3.0 ng/mL in the initial screening round, of whom 75 (0.5%) were diagnosed with csPCa at a subsequent screening examination and 2 (<0.1%) in the 4-year screening interval. For 2,260 men with a previously negative Bx at first screening, the figures were 17 (0.8%) and 2 (0.1%) respectively. Indolent PCa (Gleason ≤3+3) was diagnosed in 312 (2%) men with PSA <3.0 ng/mL initially and 115 (5%) men with initial negative Bx. After a 15-year follow-up, 45 (0.3%) PCa deaths occurred in men with initially low PSA, and 29 men (0.2%) had metastasis. For men with negative Bx, 11 (0.5%) PCa deaths occurred and 4 (0.2%) experienced metastasis.ConclusionsThe false negative rates for men with PSA <3.0 ng/mL and negative sextant Bx are extremely low but not negligible. Proper risk stratification before deciding to biopsy is expected to hardly miss any clinical significant PCa diagnosis. This is especially relevant with the increased use of the relatively expensive multi-parametric magnetic resonance imaging (mpMRI) guided targeted Bx procedures.

A new near-term breast cancer risk prediction scheme based on the quantitative analysis of ipsilateral view mammograms

PurposeTo help improve efficacy of screening mammography and eventually establish an optimal personalized screening paradigm, this study aimed to develop and test a new near-term breast cancer risk prediction scheme based on the quantitative analysis of ipsilateral view of the negative screening mammograms. MethodsThe dataset includes digital mammograms acquired from 392 women with two sequential full-field digital mammography examinations. All the first (“prior”) sets of mammograms were interpreted as negative during the original reading. In the sequential (“current”) screening, 202 were proved positive and 190 remained negative/benign. For each pair of the “prior” ipsilateral mammograms, we adaptively fused the image features computed from two views. Using four different types of image features, we built four elastic net support vector machine (EnSVM) based classifiers. Then, the initial prediction scores form the 4 EnSVMs were combined to build a final artificial neural network (ANN) classifier that produces the final risk prediction score. The performance of the new scheme was evaluated by using a 10-fold cross-validation method and an assessment index of the area under the receiver operating characteristic curve (AUC). ResultsA total number of 466 features were initially extracted from each pair of ipsilateral mammograms. Among them, 51 were selected to build the EnSVM based prediction scheme. The AUC = 0.737 ± 0.052 was yielded using the new scheme. Applying an optimal operating threshold, the prediction sensitivity was 60.4% (122 of 202) and the specificity was 79.0% (150 of 190). ConclusionThe study results showed moderately high positive association between computed risk scores using the “prior” negative mammograms and the actual outcome of the image-detectable breast cancers in the next subsequent screening examinations. The study also demonstrated that quantitative analysis of the ipsilateral views of the mammograms enabled to provide useful information in predicting near-term breast cancer risk.

Association between Computed Tissue Density Asymmetry in Bilateral Mammograms and Near-term Breast Cancer Risk

This study investigated association between bilateral mammographic density asymmetry and near-term breast cancer risk. A data base of digital mammograms acquired from 690 women was retrospectively collected. All images were originally interpreted as negative by radiologists. During the next subsequent screening examinations (between 12 and 36months later), 230 women were diagnosed positive for cancer, 230 were recalled for additional diagnostic workups and proved to be benign, and 230 remained negative (not recalled). We applied a computerized scheme to compute the differences of five image features between the left and right mammograms, and trained an artificial neural network (ANN) to compute a bilateral mammographic density asymmetry score. Odds ratios (ORs) were used to assess associations between the ANN-generated scores and risk of women having detectable cancers during the next screening examinations. A logistic regression method was applied to test for trend as a function of the increase in ANN-generated scores. The results were also compared with ORs computed using other existing cancer risk factors. The ORs showed an increasing risk trend with the increase in ANN-generated scores (from 1.00 to 9.07 between positive and negative case groups). The regression analysis also showed a significant increase trend in slope (p<0.05). No significant increase trends of the ORs were found when using woman's age, subjectively rated breast density, or family history of breast cancer. This study demonstrated that the computed bilateral mammographic density asymmetry had potential to be used as a new risk factor to improve discriminatory power in predicting near-term risk of women developing breast cancer.

Glossary of essential terms used in cancer screening

Asymptomatic cancer: see preclinical cancer. Attendance rate: see participation rate. Background incidence rate: the incidence rate of invasive cancer that would be expected in the absence of screening. Clinical cancer: a cancer that causes symptom(s) or clinical sign(s). Coverage (screening coverage): proportion of subjects eligible for screening who have had a test in the time period corresponding to the recommended screening schedule. For instance, for a biennial screening schedule, the coverage will be computed considering subjects who had a test during a twoyear period. Delay time: the time between when a cancer could be screen-detected and when it is actually detected (Fig. 3). Detection rate: number of cancer detected per 1000 screened subjects. This rate will differ for initial (prevalent) versus subsequent (incident) screening examinations. Efficacy (of screening): ability of screening to decrease deaths due to cancer under ideal conditions (e.g., in randomised trials). Effectiveness (of screening): ability of screening to decrease deaths due to cancer in the general population, under real world conditions. Efficiency (of screening): it is the balance between health benefits versus the side effects and the costs of implementation of screening. False negative (FN) result: subjects having a cancer that is not detected by the screening test (Fig. 1). False positive (FP) result: subjects without cancer that have a positive test (Fig. 1). Incidence rate: the rate at which new cancer cases occur in a population. The incidence rate is usually expressed as the number of new cases per 100,000 per year, i.e., per 100,000 person-years or PYs. The numerator is the number of persons living in an area newly developing the disease during a year. The denominator is the number of persons at risk of developing the cancer resident in the area at the middle of the year. Incidence rate of advanced cancer (IAC): the rate at which new cases of advanced cancer cases occur in a population. This rate is calculated as the incidence rate but the numerator includes numbers of advanced cancer only. Because screening aims at detecting cancers before they have progressed to advanced stage (through detection of precursor lesions or through detection of early cancer), the IAC should decrease before one would observe reductions in cancer mortality attributable to screening. Incident cancer: cancer found at a subsequent screening rounds, i.e., cancers deemed to have progressed to a screen-detectable tumour after a previous negative screening round. Initial (or prevalent) screening: the first time subjects are screened. The initial screening will find cancers sometimes present since a long time (i.e., cancers with long sojourn time). Therefore, the detection rate at initial screening round will generally be higher than the detection rate at subsequent screening rounds. Interval cancer (IC): a cancer diagnosed in subjects who had a negative screening test within a period equal to the time interval between two screening rounds. If the interval between two screening rounds is 2 years, statistics may report interval cancers diagnosed within 1 and within 2 years after the test. Broadly, ICs are of two types: cancers present at screening but missed by the screening test, and cancers that became detectable after the last screening test. In practice, it proves difficult to distinguish between the two types of IC. Interval cancer rate (ICR): the number of interval cancer found within a defined period of time after the last screening test divided by the number of

Evaluation of reader variability in the interpretation of follow-up CT scans at lung cancer screening.

To measure reader agreement in determining whether lung nodules detected at baseline screening computed tomography (CT) had changed at subsequent screening examinations and to evaluate the variability in recommendations for further follow-up. All subjects were enrolled in the National Lung Screening Trial (NLST), and each participant consented to the use of their de-identified images for research purposes. The authors randomly selected 100 cases of nodules measuring at least 4.0 mm at 1-year screening CT that were considered by the original screening CT reader to be present on baseline CT scans; nodules considered by the original reader to have changed were oversampled. Selected images from each case showing the entire nodule at both examinations were preloaded on a picture archiving and communication system workstation. Nine radiologists served as readers, and they evaluated whether the nodule was present at baseline and recorded the bidimensional measurements and nodule characteristics at each examination, presence or absence of change, results of screening CT, and follow-up recommendations (high-level follow-up, low-level follow-up, no follow-up). On the basis of reviews during case selection, five nodules seen at follow-up were judged not to have been present at baseline; for 19 of the remaining 95 cases, at least one reader judged the nodule not to have been present at baseline. For the 76 nodules that were unanimously considered to have been present at baseline, 21%-47% (mean ± standard deviation, 30% ± 9) were judged to have grown. The κ values were similar for growth (κ = 0.55) and a positive screening result (κ = 0.51) and were lower for a change in margins and attenuation (κ = 0.27-0.31). The κ value in the recommendation of high- versus low-level follow-up was high (κ = 0.66). Reader agreement on nodule growth and screening result was moderate to substantial. Agreement on follow-up recommendations was lower.

Estimating screening test sensitivity and tumour progression using tumour size and time since previous screening

As mammography screening aims to improve the prognosis through earlier detection/treatment, tumour progression and screening test sensitivity (STS) represent key parameters in the evaluation of screening programs. We will here study some methods for estimation of tumour progression and STS, and show how previously used methods can be combined and developed to utilise more of the data available in modern screening programs. Weedon-Fekjaer et al. recently suggested a study design using interview data about time since previous screening to estimate tumour progression and STS in a stepwise Markov model. While useful, the approach does not utilise tumour size measurements, nor link tumour progression to tumour size. Hence, we will here propose formulas for estimating tumour progression and STS using a continuous tumour growth model. To estimate tumour progression and STS, tumour growth curves are followed from one screening to the next, and probabilities for all combinations of tumour sizes at repeated screening examinations calculated. Based on the probabilities for screening detection on subsequent screening examinations, maximum likelihood estimates are calculated. Applied to Norwegian data, the new approach gives similar results to previously published results based on interval data, confirming the earlier estimated large variation in tumour growth rates.

Cancers inBRCA1andBRCA2Carriers and in Women at High Risk for Breast Cancer: MR Imaging and Mammographic Features

To review imaging features of screening-detected cancers on images from diagnostic and prior examinations to identify specific abnormalities to aid earlier detection of or facilitate differentiation of cancers in BRCA1 and BRCA2 carriers and in women with a high risk for breast cancer. Informed consent and multicenter and local research ethics committee approval were obtained. Women (mean age, 40.1 years; range, 27-55 years) who had at least a 50% risk of being a BRCA1, BRCA2, or TP53 gene mutation carrier were recruited from August 1997 to March 2003 into the United Kingdom Magnetic Resonance Imaging in Breast Screening Study Group trial and were offered annual magnetic resonance (MR) imaging and two-view mammography (total number of screenings, 2065 and 1973; mean, 2.38 and 2.36, respectively). Images in all 39 cancer cases were reread in consensus to document the morphologic and enhancement imaging features on MR and mammographic images in screening and prior examinations. Cases were grouped into genetic subtypes. With MR imaging, there was no difference in morphologic or enhancement characteristics between the genetic subgroups. Cancers on images from prior examinations were of smaller size, showed less enhancement, and were more likely to have a type 1 enhancement curve compared with those cancers in the subsequent diagnostic screening examinations. The tumor sizes detected by using MR imaging and mammography were not significantly different (P = .46). The cancers in BRCA1 carriers found by using MR imaging tended to be smaller than those detected by using mammography (median, 17 mm vs 30 mm; P = .37), whereas the opposite was true for cancers found in BRCA2 carriers (MR imaging median size = 12.5 mm vs mammographic median size = 6 mm; P = .067); the difference was not significant. Tumors with prior MR imaging abnormalities grew at an average of 5.1 mm/y. When undertaking MR imaging surveillance in high-risk women, small enhancing lesions should be regarded with suspicion and biopsied or patients should be followed up at 6 months.

Breast Cancer Screening Results 5 Years after Introduction of Digital Mammography in a Population-based Screening Program

To compare full-field digital mammography (FFDM) using computer-aided diagnosis (CAD) with screen-film mammography (SFM) in a population-based breast cancer screening program for initial and subsequent screening examinations. The study was approved by the regional medical ethics review board. Informed consent was not required. In a breast cancer screening facility, two of seven conventional mammography units were replaced with FFDM units. Digital mammograms were interpreted by using soft-copy reading with CAD. The same team of radiologists was involved in the double reading of FFDM and SFM images, with differences of opinion resolved in consensus. After 5 years, screening outcomes obtained with both modalities were compared for initial and subsequent screening examination findings. A total of 367,600 screening examinations were performed, of which 56,518 were digital. Breast cancer was detected in 1927 women (317 with FFDM). At initial screenings, the cancer detection rate was .77% with FFDM and .62% with SFM. At subsequent screenings, detection rates were .55% and .49%, respectively. Differences were not statistically significant. Recalls based on microcalcifications alone doubled with FFDM. A significant increase in the detection of ductal carcinoma in situ was found with FFDM (P < .01). The fraction of invasive cancers with microcalcifications as the only sign of malignancy increased significantly, from 8.1% to 15.8% (P < .001). Recall rates were significantly higher with FFDM in the initial round (4.4% vs 2.3%, P < .001) and in the subsequent round (1.7% vs 1.2%, P < .001). With the FFDM-CAD combination, detection performance is at least as good as that with SFM. The detection of ductal carcinoma in situ and microcalcification clusters improved with FFDM using CAD, while the recall rate increased.

Human Papillomavirus and Papanicolaou Tests to Screen for Cervical Cancer

Screening for cervical cancer based on testing for human papillomavirus (HPV) increases the sensitivity of detection of high-grade (grade 2 or 3) cervical intraepithelial neoplasia, but whether this gain represents overdiagnosis or protection against future high-grade cervical epithelial neoplasia or cervical cancer is unknown. In a population-based screening program in Sweden, 12,527 women 32 to 38 years of age were randomly assigned at a 1:1 ratio to have an HPV test plus a Papanicolaou (Pap) test (intervention group) or a Pap test alone (control group). Women with a positive HPV test and a normal Pap test result were offered a second HPV test at least 1 year later, and those who were found to be persistently infected with the same high-risk type of HPV were then offered colposcopy with cervical biopsy. A similar number of double-blinded Pap smears and colposcopies with biopsy were performed in randomly selected women in the control group. Comprehensive registry data were used to follow the women for a mean of 4.1 years. The relative rates of grade 2 or 3 cervical intraepithelial neoplasia or cancer detected at enrollment and at subsequent screening examinations were calculated. At enrollment, the proportion of women in the intervention group who were found to have lesions of grade 2 or 3 cervical intraepithelial neoplasia or cancer was 51% greater (95% confidence interval [CI], 13 to 102) than the proportion of women in the control group who were found to have such lesions. At subsequent screening examinations, the proportion of women in the intervention group who were found to have grade 2 or 3 lesions or cancer was 42% less (95% CI, 4 to 64) and the proportion with grade 3 lesions or cancer was 47% less (95% CI, 2 to 71) than the proportions of control women who were found to have such lesions. Women with persistent HPV infection remained at high risk for grade 2 or 3 lesions or cancer after referral for colposcopy. The addition of an HPV test to the Pap test to screen women in their mid-30s for cervical cancer reduces the incidence of grade 2 or 3 cervical intraepithelial neoplasia or cancer detected by subsequent screening examinations. (ClinicalTrials.gov number, NCT00479375 [ClinicalTrials.gov].).

Can selenium supplementation prevent colorectal cancer?

Can selenium supplementation prevent colorectal cancer?

Organized Breast Screening Programs in Canada: Effect of Radiologist Reading Volumes on Outcomes

To examine retrospectively the relationship between radiologist screening program reading volumes and interpretation results. This research project was reviewed by the University of British Columbia Research Ethics Board. Informed patient consent was not required. Data were requested from Canadian provincial screening programs for the period 1988-2000. Cancer detection rates, abnormal interpretation rates, and positive predictive values (PPVs) were calculated for individual radiologists in those programs. Multivariate Poisson mixed regression models were used to examine the effect of patient age, screening examination sequence (first or subsequent screening examination), province, radiologist reading volume, and interradiologist differences on cancer detection rate, abnormal interpretation rate, and PPV. The results of the interpretation of 1406678 screening mammograms by 304 radiologists from seven provincial programs were analyzed. Cancer detection rate, abnormal interpretation rate, and PPV all varied according to age of woman screened and screening sequence and across the sample of radiologists. None of the rates varied by province. Neither the cancer detection rate nor the abnormal interpretation rate varied by reading volume, but the average PPV was increased by 34% for volumes over 2000 mammograms versus volumes of 480-699 mammograms per year. There was no evidence that the magnitude of variability around the average, for radiologists reading the same volume of mammograms, varied across different volume groups for any of the outcome measures. Cancer detection did not vary with reading volume. The average PPV for individual radiologists increased as reading volume rose up to 2000 mammograms per year; it stabilized at higher volumes.

Comparison of early performance indicators for screening projects within the European Breast Cancer Network: 1989–2000

In 1989 the European Breast Cancer Network (EBCN) was established by the first pilot projects for breast cancer screening, co-funded by the Europe Against Cancer programme. We report early performance indicators for these EBCN projects while taking into account their organizational setting. Out of 17 projects in the network, 10 projects from six European countries contributed aggregated data on number of invitations, screening examinations, and breast cancers detected over the period 1989-2000. Results were summarized separately for projects in centralized versus decentralized health care environments. The European Guidelines for quality assurance in mammography screening provided reference values for the performance indicators. The most prominent finding in this study was the higher participation rate in centralized versus decentralized projects (average participation in 1998: 74 versus 33%; P<0.001), whereas the invitation system and screening policy in these projects were similar. Detection rates and characteristics of cancers detected at initial and subsequent screening examinations showed no significant differences between centralized and decentralized projects. Even though early performance indicators for centralized versus decentralized projects were similar, the impact of breast screening on mortality from this disease at the population level will differ since the decentralized projects reach only part of the target population.

Evaluation of The Netherlands breast cancer screening programme

The Netherlands breast cancer screening programme for women aged 50–75 years was gradually implemented during 1989–1997. Short-term indicators for this mammography screening are 80% attendance (800000 examinations yearly), and for the subsequent screening examinations 7.4 referrals for clinical assessment per 1000 women screened, 4.7 biopsies and 3.6 breast cancers detected. Breast cancer mortality in The Netherlands has been decreasing since 1997 after having been stable for decades. The challenge now is to disentangle the relative contributions of mammographic screening, earlier clinical diagnosis, less aggressive tumours, treatment advances and risk factors towards this decline.