Positive Predictive Value Of Recall Research Articles

Does the availability of prior mammograms improve radiologists' observer performance?-a scoping review.

The objective of this review was to examine the impact of previous mammogram availability on radiologists' performance from screening populations and experimental studies. A search of the literature was conducted using five databases: MEDLINE, PubMed, Web of Science, ScienceDirect, and CINAHL as well as Google and reference lists of articles. Keywords were combined with "AND" or "OR" or "WITH" and included "prior mammograms, diagnostic performance, initial images, diagnostic efficacy, subsequent images, previous imaging, and radiologist's performance". Studies that assessed the impact of previous mammogram availability on radiologists' performance were reviewed. The Standard for Reporting Diagnostic Accuracy guidelines was used to critically appraise individual sources of evidence. A total of 15 articles were reviewed. The sample of mammogram cases used across these studies varied from 36 to 1,208,051. Prior mammograms did not affect sensitivity [with priors: 62-86% (mean = 73.3%); without priors: 69.4-87.4% (mean = 75.8%)] and cancer detection rate, but increased specificity [with priors: 72-96% (mean = 87.5%); without priors: 63-87% (mean = 80.5%)] and reduced false-positive rates [with priors: 3.7 to 36% (mean = 19.9%); without priors 13.3-49% (mean = 31.4%)], recall rates [with priors: 3.8-57% (mean = 26.6%); without priors: [4.9%-67.5% (mean = 37.9%)], and abnormal interpretation rate decreased by 4% with priors. Evidence for the associations between the availability of prior mammograms and positive-predictive value, area under the curve (AUC) from the receiver operating characteristic curve (ROC) and localisation ROC AUC, and positive-predictive value of recall is limited and unclear. Availability of prior mammograms reduces recall rates, false-positive rates, abnormal interpretation rates, and increases specificity without affecting sensitivity and cancer detection rate.

Mammographic Screening in Routine Practice: Multisite Study of Digital Breast Tomosynthesis and Digital Mammography Screenings.

Background The use of digital breast tomosynthesis (DBT) is increasing over digital mammography (DM) following studies demonstrating lower recall rates (RRs) and higher cancer detection rates (CDRs). However, inconsistent interpretation of evidence on the risks and benefits of mammography has resulted in varying screening mammography recommendations. Purpose To evaluate screening outcomes among women in the United States who underwent routine DM or DBT mammographic screening. Materials and Methods This retrospective cohort study included women aged 40-79 years who underwent DM or DBT screening mammograms between January 2014 and December 2020. Outcomes of RR, CDR, positive predictive value of recall (PPV1), biopsy rate, and positive predictive value of biopsy (PPV3) were compared between DM and DBT with use of adjusted multivariable logistic regression models. Results A total of 2 528 063 screening mammograms from 1 100 447 women (mean age, 57 years ± 10 [SD]) were included. In crude analyses, DBT (1 693 727 screening mammograms vs 834 336 DM screening mammograms) demonstrated lower RR (10.3% [95% CI: 10.3, 10.4] for DM vs 8.9% [95% CI: 8.9, 9.0] for DBT; P < .001) and higher CDR (4.5 of 1000 screening mammograms [95% CI: 4.3, 4.6] vs 5.3 of 1000 [95% CI: 5.2, 5.5]; P < .001), PPV1 (4.3% [95% CI: 4.2, 4.5] vs 5.9% [95% CI: 5.7, 6.0]; P < .001), and biopsy rates (14.5 of 1000 screening mammograms [95% CI: 14.2, 14.7] vs 17.6 of 1000 [95% CI: 17.4, 17.8]; P < .001). PPV3 was similar between cohorts (30.0% [95% CI: 29.2, 30.9] for DM vs 29.3% [95% CI: 28.7, 29.9] for DBT; P = .16). After adjustment for age, breast density, site, and index year, associations remained stable with respect to statistical significance. Conclusion Women undergoing digital breast tomosynthesis had improved screening mammography outcomes compared with women who underwent digital mammography. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Bae and Seo in this issue.

Supplemental Breast Cancer Screening in Women with Dense Breasts and Negative Mammography: A Systematic Review and Meta-Analysis.

Background The best supplemental breast cancer screening modality in women at average risk or intermediate risk for breast cancer with dense breast and negative mammogram remains to be determined. Purpose To conduct systematic review and meta-analysis comparing clinical outcomes of the most common available supplemental screening modalities in women at average risk or intermediate risk for breast cancer in patients with dense breasts and mammography with negative findings. Materials and Methods A comprehensive search was conducted until March 12, 2020, in Medline, Epub Ahead of Print and In-Process and Other Non-Indexed Citations; Embase Classic and Embase; Cochrane Central Register of Controlled Trials; and Cochrane Database of Systematic Reviews, for Randomized Controlled Trials and Prospective Observational Studies. Incremental cancer detection rate (CDR); positive predictive value of recall (PPV1); positive predictive value of biopsies performed (PPV3); and interval CDRs of supplemental imaging modalities, digital breast tomosynthesis, handheld US, automated breast US, and MRI in non-high-risk patients with dense breasts and mammography negative for cancer were reviewed. Data metrics and risk of bias were assessed. Random-effects meta-analysis and two-sided metaregression analyses comparing each imaging modality metrics were performed (PROSPERO; CRD42018080402). Results Twenty-two studies reporting 261 233 screened patients were included. Of 132 166 screened patients with dense breast and mammography negative for cancer who met inclusion criteria, a total of 541 cancers missed at mammography were detected with these supplemental modalities. Metaregression models showed that MRI was superior to other supplemental modalities in CDR (incremental CDR, 1.52 per 1000 screenings; 95% CI: 0.74, 2.33; P < .001), including invasive CDR (invasive CDR, 1.31 per 1000 screenings; 95% CI: 0.57, 2.06; P < .001), and in situ disease (rate of ductal carcinoma in situ, 1.91 per 1000 screenings; 95% CI: 0.10, 3.72; P < .04). No differences in PPV1 and PPV3 were identified. The limited number of studies prevented assessment of interval cancer metrics. Excluding MRI, no statistically significant difference in any metrics were identified among the remaining imaging modalities. Conclusion The pooled data showed that MRI was the best supplemental imaging modality in women at average risk or intermediate risk for breast cancer with dense breasts and mammography negative for cancer. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Hooley and Butler in this issue.

Added Value of Prereading Screening Mammograms for Breast Cancer by Radiologic Technologists on Early Screening Outcomes.

Background In the Dutch breast cancer screening program, mammograms are preread by technologists to identify possible abnormalities, leading to "warning signals" (an audible and visual alert if the technologist observed an abnormality suspicious for cancer) for radiologists. The best moment to present these warning signals is unknown. Purpose To determine the effect that blinding of technologists' warning signals has on radiologists' early screening outcome measures during interpretation of mammograms. Materials and Methods In this prospective study from September 2017 to May 2019, on alternating months, radiologists were either blinded or nonblinded to the warning signals of the technologist when interpreting screening mammograms for breast cancer. All discrepancies between radiologists and technologists were reviewed during quality assurance sessions every 6 weeks, which could result in secondary recalls. The outcome measures of this study were recall rate, cancer detection rate, and positive predictive value of recall. A χ2 test was used to test for differences between the two groups. Results During the study period, 109 596 women (mean age, 62 years ± 7 [standard deviation]), including 53 291 in the blinded and 56 305 in the nonblinded groups, participated. The overall recall rate (including secondary recalls) was lower for women in the blinded group than in the nonblinded group (blinded: 1140 of 53 291 women [2.1%], nonblinded: 1372 of 56 305 women [2.4%]; P = .001). There was no evidence of cancer detection rate differences between the groups (blinded: 349 of 53 291 women [6.5 per 1000 screening examinations], nonblinded: 360 of 56 305 women [6.4 per 1000 screening examinations]; P = .75). The blinded group thus had a higher positive predictive value of recall (blinded: 349 of 1140 women [30.6%], nonblinded: 360 of 1372 women [26.2%]; P = .02). Conclusion While interpreting screening mammograms for breast cancer, radiologists blinded to technologists' warning signals had lower recall rates with higher positive predictive values than nonblinded radiologists, yet cancer detection rates seemed to remain unchanged. See also the editorial by Hofvind and Lee in this issue. © RSNA, 2021.

Using deep learning to assist readers during the arbitration process: a lesion-based retrospective evaluation of breast cancer screening performance

ObjectivesTo evaluate if artificial intelligence (AI) can discriminate recalled benign from recalled malignant mammographic screening abnormalities to improve screening performance.MethodsA total of 2257 full-field digital mammography screening examinations, obtained 2011–2013, of women aged 50–69 years which were recalled for further assessment of 295 malignant out of 305 truly malignant lesions and 2289 benign lesions after independent double-reading with arbitration, were included in this retrospective study. A deep learning AI system was used to obtain a score (0–95) for each recalled lesion, representing the likelihood of breast cancer. The sensitivity on the lesion level and the proportion of women without false-positive ratings (non-FPR) resulting under AI were estimated as a function of the classification cutoff and compared to that of human readers.ResultsUsing a cutoff of 1, AI decreased the proportion of women with false-positives from 89.9 to 62.0%, non-FPR 11.1% vs. 38.0% (difference 26.9%, 95% confidence interval 25.1–28.8%; p < .001), preventing 30.1% of reader-induced false-positive recalls, while reducing sensitivity from 96.7 to 91.1% (5.6%, 3.1–8.0%) as compared to human reading. The positive predictive value of recall (PPV-1) increased from 12.8 to 16.5% (3.7%, 3.5–4.0%). In women with mass-related lesions (n = 900), the non-FPR was 14.2% for humans vs. 36.7% for AI (22.4%, 19.8–25.3%) at a sensitivity of 98.5% vs. 97.1% (1.5%, 0–3.5%).ConclusionThe application of AI during consensus conference might especially help readers to reduce false-positive recalls of masses at the expense of a small sensitivity reduction. Prospective studies are needed to further evaluate the screening benefit of AI in practice.Key Points• Integrating the use of artificial intelligence in the arbitration process reduces benign recalls and increases the positive predictive value of recall at the expense of some sensitivity loss.• Application of the artificial intelligence system to aid the decision to recall a woman seems particularly beneficial for masses, where the system reaches comparable sensitivity to that of the readers, but with considerably reduced false-positives.• About one-fourth of all recalled malignant lesions are not automatically marked by the system such that their evaluation (AI score) must be retrieved manually by the reader. A thorough reading of screening mammograms by readers to identify suspicious lesions therefore remains mandatory.

Radiologist Characteristics Associated with Interpretive Performance of Screening Mammography: A National Mammography Database (NMD) Study.

Background Factors affecting radiologists' performance in screening mammography interpretation remain poorly understood. Purpose To identify radiologists characteristics that affect screening mammography interpretation performance. Materials and Methods This retrospective study included 1223 radiologists in the National Mammography Database (NMD) from 2008 to 2019 who could be linked to Centers for Medicare & Medicaid Services (CMS) datasets. NMD screening performance metrics were extracted. Acceptable ranges were defined as follows: recall rate (RR) between 5% and 12%; cancer detection rate (CDR) of at least 2.5 per 1000 screening examinations; positive predictive value of recall (PPV1) between 3% and 8%; positive predictive value of biopsies recommended (PPV2) between 20% and 40%; positive predictive value of biopsies performed (PPV3) between the 25th and 75th percentile of study sample; invasive CDR of at least the 25th percentile of the study sample; and percentage of ductal carcinoma in situ (DCIS) of at least the 25th percentile of the study sample. Radiologist characteristics extracted from CMS datasets included demographics, subspecialization, and clinical practice patterns. Multivariable stepwise logistic regression models were performed to identify characteristics independently associated with acceptable performance for the seven metrics. The most influential characteristics were defined as those independently associated with the majority of the metrics (at least four). Results Relative to radiologists practicing in the Northeast, those in the Midwest were more likely to achieve acceptable RR, PPV1, PPV2, and CDR (odds ratio [OR], 1.4-2.5); those practicing in the West were more likely to achieve acceptable RR, PPV2, and PPV3 (OR, 1.7-2.1) but less likely to achieve acceptable invasive CDR (OR, 0.6). Relative to general radiologists, breast imagers were more likely to achieve acceptable PPV1, invasive CDR, percentage DCIS, and CDR (OR, 1.4-4.4). Those performing diagnostic mammography were more likely to achieve acceptable PPV1, PPV2, PPV3, invasive CDR, and CDR (OR, 1.9-2.9). Those performing breast US were less likely to achieve acceptable PPV1, PPV2, percentage DCIS, and CDR (OR, 0.5-0.7). Conclusion The geographic location of the radiology practice, subspecialization in breast imaging, and performance of diagnostic mammography are associated with better screening mammography performance; performance of breast US is associated with lower performance. ©RSNA, 2021 Online supplemental material is available for this article.

Optimum screening mammography reading volumes: evidence from the NHS Breast Screening Programme.

Minimum caseload standards for professionals examining breast screening mammograms vary from 480 (US) to 5000 (Europe). We measured the relationship between the number of women's mammograms examined per year and reader performance. We extracted routine records from the English NHS Breast Screening Programme for readers examining between 1000 and 45,000 mammograms between April 2014 and March 2017. We measured the relationship between the volume of cases read and screening performance (cancer detection rate, recall rate, positive predictive value of recall (PPV) and discrepant cancers) using linear logistic regression. We also examined the effect of reader occupational group on performance. In total, 759 eligible mammography readers (445 consultant radiologists, 235 radiography advanced practitioners, 79 consultant radiographers) examined 6.1 million women's mammograms during the study period. PPV increased from 12.9 to 14.4 to 17.0% for readers examining 2000, 5000 and 10000 cases per year respectively. This was driven by decreases in recall rates from 5.8 to 5.3 to 4.5 with increasing volume read, and no change in cancer detection rate (from 7.6 to 7.6 to 7.7). There was no difference in cancer detection rate with reader occupational group. Consultant radiographers had higher recall rate and lower PPV compared to radiologists (OR 1.105, p = 0.012; OR 0.874, p = 0.002, unadjusted). Positive predictive value of screening increases with the total volume of cases examined per reader, through decreases in numbers of cases recalled with no concurrent change in numbers of cancers detected. • In the English Breast Screening Programme, readers who examined a larger number of cases per year had a higher positive predictive value, because they recalled fewer women for further tests but detected the same number of cancers. • Reader type did not affect cancer detection rate, but consultant radiographers had a higher recall rate and lower positive predictive value than consultant radiologists, although this was not adjusted for length of experience.

Frequency and diagnostic outcome of bilateral recall at screening mammography.

Our study was performed to determine the frequency of recall for bilateral breast lesions at screening mammography and compare its outcome with respect to unilateral recall. We included 329 132 screening mammograms (34 889 initial screens and 294 243 subsequent screens) from a Dutch screening mammography program between January 2013 and January 2018. During a 2‐year follow‐up, we collected radiological data, pathology reports and surgical reports of all recalled women. At bilateral recall, the lesion with the highest Breast Imaging Reporting and Data System score was used as the index lesion when comparing screening mammography characteristics at bilateral vs unilateral recall. A total of 9806 women were recalled at screening (recall rate, 3.0%). Bilateral recall comprised 2.8% (271/9806) of all recalls. Biopsy was more frequently performed after bilateral recall than unilateral recall (54.6% [148/271] vs 44.1% [4201/9535], P < .001), yielding a lower positive predictive value (PPV) of biopsy after bilateral recall (42.6% vs 51.7%, P = .029). The PPV of recall was comparable for both groups (23.2% [63/271] vs 22.8% [2173/9535], P = .85). Invasive cancers after bilateral recall were larger than those diagnosed after unilateral recall (P = .02), but histological subtype, histologic grading, receptor status and proportions of lymph node positive cancers were comparable. Bilateral recall infrequently occurs at screening mammography. Biopsy is more frequently performed following bilateral recall, but the PPV of recall is similar for unilateral and bilateral recall. Invasive cancers of both groups show comparable pathological features except of a larger tumor size after bilateral recall.

Mammographic breast density: How it affects performance indicators in screening programmes?

ObjectivesTo investigate how breast density affects screening performance indicators in a digital mammography context. MethodsWe assessed the effect of breast density over the screen-detected and interval cancers rates, false-positives, specificity, sensitivity, recall rate, positive predictive value of recall (PPV-1), and PPV of invasive tests (PPV-2). Radiologists classified breast density using the BIRADS System. We used generalized estimating equations to account for within-woman correlation by means of the robust Huber-White variance estimator. ResultsWe included 177,164 women aged 50–69 years who underwent 499,251 digital mammograms from 2004 to 2015 in Spain. According to the fibroglandular tissue percentage, 24.7% of mammograms were classified as BI-RADS 1 (<25% glandular), 54.7% as BI-RADS 2 (25–50% glandular), 14.0% as BI-RADS 3 (51–75% glandular) and 6.6% as BI-RADS 4 (>75% glandular). Overall, women with BI-RADS 3 had the highest screen-detected cancer rate (5.9 per 1000) and BI-RADS 4 the highest interval cancer rate (2.4 per 1000). Sensitivity decreased from 89.2% in women with BI-RADS 1 to 67.9% in BI-RADS 4. Both PPV-1 and PPV-2 decreased from 10.4% to 5.7% and from 49.8% to 32.4% in women with BI-RADS 1 and BI-RADS 4, respectively. Women aged 60–69 years with BI-RADS 4 had the lowest sensitivity (54.9%) and the highest interval cancer rate (3.8 per 1000). ConclusionsPerformance screening measures are negatively affected by breast density falling to a lower sensitivity and PPV, and higher interval cancer rate as breast density increases. Particularly women aged 60–69 years with >75% glandular breasts had the worst results and therefore may be candidates for screening using other technologies.

Impact of the second reader on screening outcome at blinded double reading of digital screening mammograms

BackgroundTo determine the impact of the second reader on screening outcome at blinded double reading of digital screening mammograms.MethodsWe included a consecutive series of 99,013 digital screening mammograms, obtained between July 2013 and January 2015 and double read in a blinded fashion. During 2-year follow-up, we collected radiology, surgery and pathology reports of recalled women.ResultsSingle reading resulted in 2928 recalls and 616 screen-detected cancers (SDCs). The second reader recalled another 612 women, resulting in 82 additional SDCs. Addition of the second reader increased the recall rate (3.0% to 3.6%, p < 0.001), cancer detection rate (6.2–7.0 per 1000 screens, p < 0.001) and false positive recall rate (24.4–28.7 per 1000 screens, p < 0.001). Positive predictive value of recall (21.0% vs. 19.7%, p = 0.20) and of biopsy (52.1% vs. 50.9%, p = 0.56) were comparable for single reading and blinded double reading. Tumour characteristics were comparable for cancers detected by the first reader and cancers additionally detected by the second reader, except of a more favourable tumour grade in the latter group.ConclusionsAt blinded double reading, the second reader significantly increases the cancer detection rate, at the expense of an increased recall rate and false positive recall rate.

Digital breast tomosynthesis plus synthesised images versus standard full-field digital mammography in population-based screening (TOSYMA): protocol of a randomised controlled trial

IntroductionDevelopment of digital breast tomosynthesis (DBT) provides a technology that generates three-dimensional data sets, thus reducing the pitfalls of overlapping breast tissue. Observational studies suggest that the combination of two-dimensional...

Is breast compression associated with breast cancer detection and other early performance measures in a population-based breast cancer screening program?

We aimed to investigate early performance measures in a population-based breast cancer screening program stratified by compression force and pressure at the time of mammographic screening examination. Early performance measures included recall rate, rates of screen-detected and interval breast cancers, positive predictive value of recall (PPV), sensitivity, specificity, and histopathologic characteristics of screen-detected and interval breast cancers. Information on 261,641 mammographic examinations from 93,444 subsequently screened women was used for analyses. The study period was 2007-2015. Compression force and pressure were categorized using tertiles as low, medium, or high. χ 2 test, t tests, and test for trend were used to examine differences between early performance measures across categories of compression force and pressure. We applied generalized estimating equations to identify the odds ratios (OR) of screen-detected or interval breast cancer associated with compression force and pressure, adjusting for fibroglandular and/or breast volume and age. The recall rate decreased, while PPV and specificity increased with increasing compression force (p for trend <0.05 for all). The recall rate increased, while rate of screen-detected cancer, PPV, sensitivity, and specificity decreased with increasing compression pressure (p for trend <0.05 for all). High compression pressure was associated with higher odds of interval breast cancer compared with low compression pressure (1.89; 95% CI 1.43-2.48). High compression force and low compression pressure were associated with more favorable early performance measures in the screening program.

Improving Screening Mammography Outcomes Through Comparison With Multiple Prior Mammograms

The objective of the present study is to evaluate the effect of comparison with multiple prior mammograms on the outcomes of screening mammography relative to comparison with a single prior mammogram. We retrospectively analyzed 46,288 consecutive screening mammograms performed at our institution for 22,792 women. We divided these examinations into three groups: those interpreted without comparison with prior mammograms, those interpreted in comparison with one prior examination, and those interpreted in comparison with two or more prior examinations. For each group, we determined the rate of examination recall. We also calculated the positive predictive value of recall (i.e., positive predictive value level 1 [PPV1]) and the cancer detection rate (CDR) for both the group of examinations compared with a single prior mammogram and the group compared with multiple prior mammograms. Generalized estimating equations with the logistic link function were used to determine the relative odds ratio of recall as a function of the number of comparisons, with adjustment made for age as a confounding variable. The Fisher exact test was performed to compare the PPV1 and the CDR in the different cohorts. The recall rate for mammograms interpreted without comparison with prior examinations was 16.6%, whereas that for mammograms compared with one prior examination was 7.8% and that for mammograms compared with two or more prior examinations was 6.3%. After adjustment was made for age, the odds ratio of recall for the group with multiple prior examinations relative to the group with a single prior examination was 0.864 (95% CI, 0.776-0.962; p = 0.0074). Statistically significant increases in the PPV1 of 0.05 (p = 0.0009) and in the CDR of 2.3 cases per 1000 examinations (p = 0.0481) were also noted for mammograms compared with multiple prior examinations relative to those compared with a single prior examination. Comparison with two or more prior mammograms resulted in a statistically significant reduction in the screening mammography recall rate and increases in the CDR and PPV1 relative to comparison with a single prior mammogram.

The cumulative risk of false-positive screening results across screening centres in the Norwegian Breast Cancer Screening Program

BackgroundRecall for assessment in mammographic screening entails an inevitable number of false-positive screening results. This study aimed to investigate the variation in the cumulative risk of a false positive screening result and the positive predictive value across the screening centres in the Norwegian Breast Cancer Screening Program. MethodsWe studied 618,636 women aged 50–69 years who underwent 2,090,575 screening exams (1996–2010. Recall rate, positive predictive value, rate of screen-detected cancer, and the cumulative risk of a false positive screening result, without and with invasive procedures across the screening centres were calculated. Generalized linear models were used to estimate the probability of a false positive screening result and to compute the cumulative false-positive risk for up to ten biennial screening examinations. ResultsThe cumulative risk of a false-positive screening exam varied from 10.7% (95% CI: 9.4–12.0%) to 41.5% (95% CI: 34.1–48.9%) across screening centres, with a highest to lowest ratio of 3.9 (95% CI: 3.7–4.0). The highest to lowest ratio for the cumulative risk of undergoing an invasive procedure with a benign outcome was 4.3 (95% CI: 4.0–4.6). The positive predictive value of recall varied between 12.0% (95% CI: 11.0–12.9%) and 19.9% (95% CI: 18.3–21.5%), with a highest to lowest ratio of 1.7 (95% CI: 1.5–1.9). ConclusionsA substantial variation in the performance measures across the screening centres in the Norwegian Breast Cancer Screening Program was identified, despite of similar administration, procedures, and quality assurance requirements. Differences in the readers’ performance is probably of influence for the variability. This results underscore the importance of continuous surveillance of the screening centres and the radiologists in order to sustain and improve the performance and effectiveness of screening programs.

BreastScreen‐based mammography screening in women with a personal history of breast cancer, Western Australian study

To evaluate mammography screening outcomes in women with a personal history of breast cancer (PHBC), who have an increased risk of recurrent or new breast cancer, relative to women without PHBC. Retrospective study of 713,191 screening mammograms from two groups of women - those with versus those without PHBC - who participated in the BreastScreen WA program in Western Australia between 1997 and 2006. Cancer detection rate (CDR), recall to assessment rate, recall positive predictive value (PPV) for cancer, and distribution of cancer characteristics within and between the two groups. Screening detected 4125 breast cancers: CDR per 10,000 screens was significantly higher in women with PHBC (95.5; 95% CI, 78.3-112.7) than in women without PHBC (57.2; 95% CI, 55.4-58.9). Recall to assessment rate per 10,000 screens was lower in women with PHBC (385.2; 95% CI, 350.6-419.8) than in women without PHBC (504.9; 95% CI, 499.7-510.2). Recall PPV was higher for women with PHBC (24.8%; 95% CI, 21.0%-28.9%) than those without PHBC (11.2%; 95% CI, 10.9%-11.6%). Cancer characteristics were consistent with early detection (most were smaller than 2 cm and node-negative) and were similarly distributed in both groups, except for tumour grade, with PHBC women having fewer low-grade cancers and slightly more high-grade cancers than women without PHBC. The relative rate of cancer detection between women with PHBC and women without PHBC who attended an Australian population-based breast screening program was similar to estimates from international studies. Recall rates were within national standards. Screen-detected cancers had similar characteristics in both groups, except for tumour grade. These data support national integration of mammography screening for women with PHBC into BreastScreen, although evaluation of interval cancers will be necessary.

Optimal screening mammography reading volumes; evidence from real life in the East Midlands region of the NHS Breast Screening Programme

To assess real-life reader performance as a function of both volume of mammograms read and reading experience in a multicentre cohort. Thirty-seven film readers from the East Midlands Breast Screening Programme had 3 years of consecutive screen reading results available for comparison. Markers of screening performance as the first film reader [cancer detection rates, small cancer detection rates, recall rates, positive predictive value of recall (PPV), and missed cancers] were compared with both volume of films read and years of film reading experience. For reading volume, readers were categorized according to film reading volume over the 3 year period: < 15,000 (i.e., on average less than the recommended 5000/year); 15-< 20,000; 20-< 25,000; and ≥ 25,000. For years of experience, readers were categorized into the following groups: < 5 years, 5-< 10 years, 10-< 15 years, and 15-< 20 years. There was no evidence to suggest a relationship between years of film reading experience and film-reading performance. For reading volume, there was a significant difference in the distribution of cancer-detection rate between the four groups (p=0.01); however, there was no difference in small cancer-detection rates, missed cancers or PPV. The median cancer detection rate in the high-volume group (≥ 25,000 mammograms/3 years) was significantly lower than the other groups combined (6.9 per 1000 women screened versus 7.9 per 1000 women screened). The lowest median recall rate was also in the high-volume group, whilst those readers not meeting the NHSBSP minimum requirement had the highest median recall rate; however, there was borderline evidence to suggest a difference in the distribution of recall rates between the four groups. The data from the East Midlands do not provide any evidence for reducing the threshold volume of 5000 cases /year. However, there appears to be an upper limit above which reader performance deteriorates in terms of lower cancer-detection rates. With the imminent expansion of the programme, this has implications for service quality. These higher-volume readers should be encouraged to recall more borderline cases to assessment. Analysis of national data is recommended to further evaluate these findings.

Variability in Interpretive Performance at Screening Mammography and Radiologists’ Characteristics Associated with Accuracy

To identify radiologists' characteristics associated with interpretive performance in screening mammography. The study was approved by institutional review boards of University of Washington (Seattle, Wash) and institutions at seven Breast Cancer Surveillance Consortium sites, informed consent was obtained, and procedures were HIPAA compliant. Radiologists who interpreted mammograms in seven U.S. regions completed a self-administered mailed survey; information on demographics, practice type, and experience in and perceptions of general radiology and breast imaging was collected. Survey data were linked to data on screening mammograms the radiologists interpreted between January 1, 1998, and December 31, 2005, and included patient risk factors, Breast Imaging Reporting and Data System assessment, and follow-up breast cancer data. The survey was returned by 71% (257 of 364) of radiologists; in 56% (205 of 364) of the eligible radiologists, complete data on screening mammograms during the study period were provided; these data were used in the final analysis. An evaluation of whether the radiologists' characteristics were associated with recall rate, false-positive rate, sensitivity, or positive predictive value of recall (PPV(1)) of the screening examinations was performed with logistic regression models that were adjusted for patients' characteristics and radiologist-specific random effects. Study radiologists interpreted 1 036 155 screening mammograms; 4961 breast cancers were detected. Median percentages and interquartile ranges, respectively, were as follows: recall rate, 9.3% and 6.3%-13.2%; false-positive rate, 8.9% and 5.9%-12.8%; sensitivity, 83.8% and 74.5%-92.3%; and PPV(1), 4.0% and 2.6%-5.9%. Wide variability in sensitivity was noted, even among radiologists with similar false-positive rates. In adjusted regression models, female radiologists or fellowship-trained radiologists had significantly higher recall and false-positive rates (P < .05, all). Fellowship training in breast imaging was the only characteristic significantly associated with improved sensitivity (odds ratio, 2.32; 95% confidence interval: 1.42, 3.80; P < .001) and the overall accuracy parameter (odds ratio, 1.61; 95% confidence interval: 1.05, 2.45; P = .028). Fellowship training in breast imaging may lead to improved cancer detection, but it is associated with higher false-positive rates.

Non-consensual Double Reading in the Singapore Breast Screening Project: Benefits and Limitations

Introduction: The aims of this study were to assess the efficacy of non-consensual double reading (against single reading) in the Singapore Breast Screening Project (SBSP) and to compare the benefits (increase in cancer detection) and limitations (increase in recall and biopsy) with published data. Materials and Methods: The data from the SBSP was retrospectively analysed and the recommendations of the first and second readers were evaluated separately with regards to rate of recall, biopsy and cancer detection. The mean second screener contribution (MSSC) was also calculated for double reading. Results: In the SBSP, double reading detected 7 additional cancers (5.2% of cancers detected) compared with single reading and the MSCC was 5.5%. Double reading also resulted in 632 additional recalls, with a decrease in the positive predictive value (PPV) of cancer in the recalled women from 8.2% for single reading to 6.1% for double reading. An additional 30 biopsies were performed with double reading which represented a small decrease in PPV (41% compared to 42.9% for single reading). Conclusion: In the SBSP, non-consensual double reading (compared to single reading) resulted in a modest increase in cancer detection (MSSC, 5.5%) with a modest decrease in PPV of recall (2.1%) and biopsy (1.9%). These findings were consistent with that of published data and non-consensual double reading is thus recommended.