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Purpose: To analyse digital breast tomosynthesis (DBT) reading times in the screening setting, compared to 2D full-field digital mammography (FFDM), and investigate the impact of reader experience and professional group on interpretation times., Method: Reading time data were recorded in the PROSPECTS Trial, a prospective randomised trial comparing DBT plus FFDM or synthetic 2D mammography (S2D) to FFDM alone, in the National Health Service (NHS) breast screening programme, from January 2019-February 2023. Time to read DBT+FFDM or DBT+S2D and FFDM alone was calculated per case and reading times were compared between modalities using dependent T-tests. Reading times were compared between readers from different professional groups (radiologists and radiographer readers) and experience levels using independent T-tests. The learning curve effect of using DBT in screening on reading time was investigated using a Kruskal-Wallis test., Results: Forty-eight readers interpreted 1,242 FFDM batches (34,210 FFDM cases) and 973 DBT batches (13,983 DBT cases). DBT reading time was doubled compared to FFDM (2.09 ± 0.64 min vs. 0.98 ± 0.30 min; p < 0.001), and DBT+S2D reading was longer than DBT + FFDM (2.24 ± 0.62 min vs. 2.04 ± 0.46 min; p = 0.006). No difference was identified in reading time between radiologists and radiographers (2.06 ± 0.71 min vs. 2.14 ± 0.46 min, respectively; p = 0.71). Readers with five or more years of experience reading DBT were quicker than those with less experience (1.86 ± 0.56 min vs. 2.37 ± 0.65 min; p = 0.008), and DBT reading time decreased after less than 9 months accrued screening experience (p = 0.01)., Conclusions: DBT reading times were double those of FFDM in the screening setting, but there was a short learning curve effect with readers showing significant improvements in reading times within the first nine months of DBT experience., Clinicaltrials: gov Identifier: NCT03733106., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives: Digital breast tomosynthesis (DBT) can improve diagnostic accuracy compared to 2D mammography, but DBT reporting is time-consuming and potentially more fatiguing. Changes in diagnostic accuracy and subjective and objective fatigue were evaluated over a DBT reporting session, and the impact of taking a reporting break was assessed., Materials and Methods: Forty-five National Health Service (NHS) mammography readers from 6 hospitals read a cancer-enriched set of 40 DBT cases whilst eye tracked in this prospective cohort study, from December 2020 to April 2022. Eye-blink metrics were assessed as objective fatigue measures. Twenty-one readers had a reporting break, 24 did not. Subjective fatigue questionnaires were completed before and after the session. Diagnostic accuracy and subjective and objective fatigue measures were compared between the cohorts using parametric and non-parametric significance testing., Results: Readers had on average 10 years post-training breast screening experience and took just under 2 h (105.8 min) to report all cases. Readers without a break reported greater levels of subjective fatigue (44% vs. 33%, p = 0.04), which related to greater objective fatigue: an increased average blink duration (296 ms vs. 286 ms, p < 0.001) and a reduced eye-opening velocity (76 mm/s vs. 82 mm/s, p < 0.001). Objective fatigue increased as the trial progressed for the no break cohort only (ps < 0.001). No difference was identified in diagnostic accuracy between the groups (accuracy: 87% vs. 87%, p = 0.92)., Conclusions: Implementing a break during a 2-h DBT reporting session resulted in lower levels of subjective and objective fatigue. Breaks did not impact diagnostic accuracy, which may be related to the extensive experience of the readers., Clinical Relevance Statement: DBT is being incorporated into many mammography screening programmes. Recognising that reporting breaks are required when reading large volumes of DBT studies ensures this can be factored in when setting up reading sessions., Trial Registration: Clinical trials registration number: NCT03733106 KEY POINTS: • Use of digital breast tomosynthesis (DBT) in breast screening programmes can cause significant reader fatigue. • The effectiveness of incorporating reading breaks into DBT reporting sessions, to reduce mammography reader fatigue, was investigated using eye tracking. • Integrating breaks into DBT reporting sessions reduced reader fatigue; however, diagnostic accuracy was unaffected., (© 2023. The Author(s).)

Image-based prediction models for disease detection are sensitive to changes in data acquisition such as the replacement of scanner hardware or updates to the image processing software. The resulting differences in image characteristics may lead to drifts in clinically relevant performance metrics which could cause harm in clinical decision making, even for models that generalise in terms of area under the receiver-operating characteristic curve. We propose Unsupervised Prediction Alignment, a generic automatic recalibration method that requires no ground truth annotations and only limited amounts of unlabelled example images from the shifted data distribution. We illustrate the effectiveness of the proposed method to detect and correct performance drift in mammography-based breast cancer screening and on publicly available histopathology data. We show that the proposed method can preserve the expected performance in terms of sensitivity/specificity under various realistic scenarios of image acquisition shift, thus offering an important safeguard for clinical deployment., (© 2023. Springer Nature Limited.)

Background The Personal Performance in Mammographic Screening (PERFORMS) scheme is used to assess reader performance. Whether this scheme can assess the performance of artificial intelligence (AI) algorithms is unknown. Purpose To compare the performance of human readers and a commercially available AI algorithm interpreting PERFORMS test sets. Materials and Methods In this retrospective study, two PERFORMS test sets, each consisting of 60 challenging cases, were evaluated by human readers between May 2018 and March 2021 and were evaluated by an AI algorithm in 2022. AI considered each breast separately, assigning a suspicion of malignancy score to features detected. Performance was assessed using the highest score per breast. Performance metrics, including sensitivity, specificity, and area under the receiver operating characteristic curve (AUC), were calculated for AI and humans. The study was powered to detect a medium-sized effect (odds ratio, 3.5 or 0.29) for sensitivity. Results A total of 552 human readers interpreted both PERFORMS test sets, consisting of 161 normal breasts, 70 malignant breasts, and nine benign breasts. No difference was observed at the breast level between the AUC for AI and the AUC for human readers (0.93% and 0.88%, respectively; P = .15). When using the developer's suggested recall score threshold, no difference was observed for AI versus human reader sensitivity (84% and 90%, respectively; P = .34), but the specificity of AI was higher (89%) than that of the human readers (76%, P = .003). However, it was not possible to demonstrate equivalence due to the size of the test sets. When using recall thresholds to match mean human reader performance (90% sensitivity, 76% specificity), AI showed no differences inperformance, with a sensitivity of 91% ( P =. 73) and a specificity of 77% ( P = .85). Conclusion Diagnostic performance of AI was comparable with that of the average human reader when evaluating cases from two enriched test sets from the PERFORMS scheme. © RSNA, 2023 See also the editorial by Philpotts in this issue.

Aims: The method of diagnosis of ductal carcinoma in situ (DCIS) has changed since the 1980s. The aim of this audit was to assess changes in the preoperative diagnosis of DCIS since the introduction of needle core biopsy, particularly the proportion with a preoperative biopsy diagnosis of DCIS., Methods and Results: The preoperative diagnoses of patients with a final diagnosis of DCIS in the surgical specimen were reviewed (i) in 809 patients who presented through breast screening from 1997 to 2021, and (ii) in all patients in 5 individual years at 5-year intervals from 2000 to 2020 (254 in total). For screening-detected DCIS the proportion with a preoperative diagnosis of DCIS increased from 75% to 98% over the study period. In a detailed analysis of all cases of DCIS in 5 separate years the proportion with a preoperative diagnosis of DCIS increased from 68% in 2000 to 96% in 2020. For high-grade DCIS the proportion increased from 87% to 97%, and for low- or intermediate-grade DCIS from 48% to 93%. The proportion of women who had vacuum-assisted biopsy increased from 7% in 2000 to 58% in 2015. There was a small increase in the number of biopsies that had basal cytokeratin and oestrogen receptor immunohistochemistry to aid diagnosis., Conclusion: There has been an increase in the preoperative diagnosis of DCIS, particularly of low- or intermediate-grade, over the last two decades. The increasing use of vacuum-assisted biopsy is likely to be a major contributory factor to this increase., (© 2023 John Wiley & Sons Ltd.)

Objective: To evaluate the effectiveness of a new strategy for using artificial intelligence (AI) as supporting reader for the detection of breast cancer in mammography-based double reading screening practice., Methods: Large-scale multi-site, multi-vendor data were used to retrospectively evaluate a new paradigm of AI-supported reading. Here, the AI served as the second reader only if it agrees with the recall/no-recall decision of the first human reader. Otherwise, a second human reader made an assessment followed by the standard clinical workflow. The data included 280 594 cases from 180 542 female participants screened for breast cancer at seven screening sites in two countries and using equipment from four hardware vendors. The statistical analysis included non-inferiority and superiority testing of cancer screening performance and evaluation of the reduction in workload, measured as arbitration rate and number of cases requiring second human reading., Results: Artificial intelligence as a supporting reader was found to be superior or noninferior on all screening metrics compared with human double reading while reducing the number of cases requiring second human reading by up to 87% (245 395/280 594). Compared with AI as an independent reader, the number of cases referred to arbitration was reduced from 13% (35 199/280 594) to 2% (5056/280 594)., Conclusion: The simulation indicates that the proposed workflow retains screening performance of human double reading while substantially reducing the workload. Further research should study the impact on the second human reader because they would only assess cases in which the AI prediction and first human reader disagree., (© The Authors 2023.)

Background: Double reading (DR) in screening mammography increases cancer detection and lowers recall rates, but has sustainability challenges due to workforce shortages. Artificial intelligence (AI) as an independent reader (IR) in DR may provide a cost-effective solution with the potential to improve screening performance. Evidence for AI to generalise across different patient populations, screening programmes and equipment vendors, however, is still lacking., Methods: This retrospective study simulated DR with AI as an IR, using data representative of real-world deployments (275,900 cases, 177,882 participants) from four mammography equipment vendors, seven screening sites, and two countries. Non-inferiority and superiority were assessed for relevant screening metrics., Results: DR with AI, compared with human DR, showed at least non-inferior recall rate, cancer detection rate, sensitivity, specificity and positive predictive value (PPV) for each mammography vendor and site, and superior recall rate, specificity, and PPV for some. The simulation indicates that using AI would have increased arbitration rate (3.3% to 12.3%), but could have reduced human workload by 30.0% to 44.8%., Conclusions: AI has potential as an IR in the DR workflow across different screening programmes, mammography equipment and geographies, substantially reducing human reader workload while maintaining or improving standard of care., Trial Registration: ISRCTN18056078 (20/03/2019; retrospectively registered)., (© 2023. The Author(s).)

Objectives: The interpretation of digital breast tomosynthesis (DBT) screening examinations is a complex task for an already overstretched workforce which has the potential to increase pressure on readers leading to fatigue and patient safety issues. Studies in non-medical and medical settings have suggested that changes in blink characteristics can reflect fatigue. The purpose of this study is to investigate the use of blink characteristics as an objective marker of fatigue in readers interpreting DBT breast screening examinations., Methods: Twenty-six DBT readers involved in the UK PROSPECTS trial interpreted a test set of 40 DBT cases while being observed by an eye tracking device from November 2019 to February 2021. Raw data from the eye tracker were collected and automated processing software was used to produce eye blinking characteristics data which were analysed using multiple linear regression statistical models., Results: Of the 26 DBT readers recruited, eye tracking data from 23 participants were analysed due to missing data rendering 3 participants' data uninterpretable. The mean reading time per DBT case was 2.81 min. There was a statistically significant increase in blinking duration of 0.38 ms/case as the reading session progressed ( p < 0.0001). This was the result of a significant decrease in the number of ultra-short blinks lasting ≤50 ms ( p = 0.0005) and a significant increase in longer blinks lasting 51-100 ms ( p = 0.008)., Conclusion: Changes in blinking characteristics could serve as objective measures of reader fatigue and may prove useful in the development of DBT reading protocols., Advances in Knowledge: Blink characteristics can be used as an objective measure of fatigue; however there is limited evidence of their use in radiological settings. Our study suggests that changes in blink duration and frequency could be used to monitor fatigue in DBT reading sessions.

Background Double reading can be used in screening mammography, but it is labor intensive. There is limited evidence on whether trained radiographers (ie, technologists) may be used to provide double reading. Purpose To compare the performance of radiologists and radiographers double reading screening mammograms, considering reader experience level. Materials and Methods In this retrospective study, performance and experience data were obtained for radiologists and radiographer readers of all screening mammograms in England from April 2015 to March 2016. Cancer detection rate (CDR), recall rate (RR), and positive predictive value (PPV) of recall based on biopsy-proven findings were calculated for first readers. Performance metrics were analyzed according to reader professional group and years of reading experience using the analysis of variance test. P values less than .05 were considered to indicate statistically significant difference. Results During the study period, 401 readers (224 radiologists and 177 radiographers) double read 1 404 395 screening digital mammograms. There was no difference in CDR between radiologist and radiographer readers (mean, 7.84 vs 7.53 per 1000 examinations, respectively; P = .08) and no difference for readers with more than 10 years of experience compared with 5 years or fewer years of experience, regardless of professional group (mean, 7.75 vs 7.71 per 1000 examinations respectively, P = .87). No difference in the mean RR was observed between radiologists and radiographer readers (5.0% vs 5.2%, respectively, P = .63). A lower RR was seen for readers with more than 10 years of experience compared with 5 years or fewer, regardless of professional group (mean, 4.8% vs 5.8%, respectively; P = .001). No variation in PPV was observed between them ( P = .42), with PPV values of 17.1% for radiologists versus 16.1% for radiographers. A higher PPV was seen for readers with more than 10 years of experience compared with 5 years or less, regardless of professional group (mean, 17.5% and 14.9%, respectively; P = .02). Conclusion No difference in performance was observed between radiographers and radiologists reading screening mammograms in a program that used double reading. Published under a CC BY 4.0 license Online supplemental material is available for this article. See also the editorial by Hooley and Durand in this issue.

Objective: Contrast-enhanced spectral mammography (CESM) breast biopsy has been recently introduced into clinical practice. This short communication describes the technique and potential as an alternative to MRI-guided biopsy., Methods and Materials: An additional abnormality was detected on a breast MRI examination in a patient with lobular carcinoma. The lesion was occult on conventional mammography, tomosynthesis and ultrasound and required histological diagnosis. Traditionally, this would have necessitated an MRI-guided breast biopsy, but was performed under CESM guidance., Results: A diagnostic CESM study was performed to ensure the lesion visibility with CESM and then targeted under CESM guidance. A limited diagnostic study, CESM scout and paired images for stereotactic targeting were obtained within a 10 min window following a single injection of iodinated contrast agent. The time from positioning in the biopsy device to releasing compression after biopsy and marker clip placement was 15 min. The biopsy confirmed the presence of multifocal breast cancer., Conclusion: CESM-guided breast biopsy is a new technique that can be successfully used as an alternative to MRI-guided breast biopsy., Advances in Knowledge: CESM-guided biopsy can be used to sample breast lesions which remain occult on standard mammography and ultrasound.

Objectives: Traditionally B3 breast lesions are treated surgically, but overtreatment is a concern, as the majority have a final benign diagnosis. A national screening program introduced vacuum-assisted excision (VAE) for managing B3 lesions in late 2016. This retrospective study aimed to assess the outcomes associated with this approach., Methods: All B3 lesions diagnosed between 01/2017 and 12/2019 were identified at two centres. Information was obtained on the initial biopsy and final histology, and method of VAE image guidance, needle size and number of cores. Lesions were excluded if there was cancer elsewhere in the breast at the time of diagnosis; the lesion was not suitable for VAE due to position in the breast or had B3 pathology for which open biopsy was still required. The final decision to offer VAE was always made at a multidisciplinary meeting (MDM). Risk difference was used to test the significance at p ≤ .05., Results: In total, 258 B3 lesions were diagnosed, 105 (40.7%) met the inclusion criteria and underwent VAE. VAE was performed under X-ray (89/105) or ultrasound guidance (16/105), taking an average of 18.5 cores with the 10-G needle or 10.8 cores with the 7-G needle. Nine cases (8.6%) were upgraded to a malignant diagnosis following VAE. Malignancy was found in 15.5% (9/58) of B3 lesions with epithelial atypia, but in none without atypia (0/47) (p = .004). No new lesions or malignancy has occurred at the site of the VAE with an average mammographic follow-up of 2.2 years., Conclusion: Upgrade to malignancy following VAE was uncommon (8.6%) and associated with atypia in the initial biopsy. VAE is an alternative approach to the management of B3 lesions, reducing open surgical procedures., Key Points: • Upgrade to malignancy after a vacuum-assisted excision of a B3 breast lesion is uncommon with an 8.6% upgrade rate. • The risk of a malignant diagnosis after a vacuum-assisted excision was significantly higher for B3 lesions with atypia compared to those without (+15.5% difference, p = .004)., (© 2021. European Society of Radiology.)

Purpose: This retrospective study determined whether a test-set based assessment scheme (PERFORMS) used in a national breast screening programme could be used to predict real-life performance by investigating if the number of cancers missed by mammography readers in real-life related to the number of cancers missed in the PERFORMS test-set and whether real-life reading volumes affected performance., Method: Data was obtained from consenting readers in the screening programme in England (NHSBSP) where double reading is standard. The rate of cancers missed by individual first readers but correctly identified by second readers was compared with the number of cancers missed in the PERFORMS test-set over a 3-year period. NHSBSP readers are required to interpret at least 1500 cases per year as a first reader, so results were compared between readers who exceeded this target and those that did not. Parametric and non-parametric correlations were calculated., Results: Amongst the 536 readers, there was a highly significant positive correlation between the real-life and PERFORMS test-set missed cancer metrics (Pearson Correlation = 0.228, n = 536, p < .0001, Spearman's rho = 0.265, n = 536, p < .0001). There was no significant difference in rates of missed cancers between the 452 readers who exceeded the 1500 first read per year target and those who did not (t(94.2) = -1.87, p = .0643, r = 0.19)., Conclusions: The use of a test-set based assessment scheme accurately reflects real-life mammography reading performance, indicating that it can be a useful tool in identifying poor reader performance., (Crown Copyright © 2021. Published by Elsevier B.V. All rights reserved.)

Purpose: To compare an individual's Personal Performance in Mammographic Screening (PERFORMS) score with their Breast Screening Information System (BSIS) real-life performance data and determine which parameters in the PERFORMS scheme offer the best reflection of BSIS real-life performance metrics., Materials and Methods: In this retrospective study, the BSIS real-life performance metrics of individual readers ( n = 452) in the National Health Service Breast Screening Program (NHSBSP) in England were compared with performance in the test set-based assessment scheme over a 3-year period from 2013 to 2016. Cancer detection rate (CDR), recall rate, and positive predictive value (PPV) were calculated for each reader, for both real-life screening and the PERFORMS test. For each metric, real-life and test set versions were compared using a Pearson correlation. The real-life CDR, recall rate, and PPV of outliers were compared against other readers (nonoutliers) using analysis of variance., Results: BSIS real-life CDRs, recall rates, and PPVs showed positive correlations with the equivalent PERFORMS measures ( P < .001, P = .002, and P < .001, respectively). The mean real-life CDR of PERFORMS outliers was 7.2 per 1000 women screened and was significantly lower than other readers (nonoutliers) where the real-life CDR was 7.9 ( P = .002). The mean real-life screening PPV of PERFORMS outliers was 0.14% and was significantly lower than the nonoutlier group who had a mean PPV of 0.17% ( P = .006)., Conclusion: The use of test set-based assessment schemes in a breast screening program has the potential to predict and identify poor performance in real life.© RSNA, 2020 Keywords: Breast, ScreeningSee also the commentary by Thigpen and Rapelyea in this issue., (2020 by the Radiological Society of North America, Inc.)

Purpose: To evaluate the mammographic features of breast cancer that favor lesion detection with single reading and computer-aided detection (CAD) or with double reading., Materials and Methods: The Computer Aided Detection Evaluation Trial II study was approved by the ethics committee, and all participants provided written informed consent. A total of 31,057 women were recruited from three screening centers between September 2006 and August 2007. They were randomly allocated to the double reading group, the single reading with CAD group, or the double reading and single reading with CAD group at a ratio of 1:1:28, respectively. In this study, cancers in the women whose mammograms were read with both single reading with CAD and double reading were retrospectively reviewed. The original mammograms were obtained for each case and reviewed by two of three experienced breast radiologists in consensus. The method of detection was noted. The size and predominant mammographic feature of the cancer were recorded, as was the breast density. CAD marking data were reviewed to determine if the cancer had been correctly marked., Results: A total of 227 cancers were detected in 28,204 women. A total of 170 cases were recalled with both reading regimens. Lesion types were masses (66%), microcalcifications (25%), parenchymal deformities (6%), and asymmetric densities (3%). The ability of the reading regimens to correctly prompt the reader to recall cases varied significantly by lesion type (P < .001). More parenchymal deformities were recalled with double reading, whereas more asymmetric densities were recalled with single reading with CAD. There was no difference in the ability of either reading regimen to prompt the reader to correctly recall masses or microcalcifications. CAD correctly prompted 100% of microcalcifications, 87% of mass lesions, 80% of asymmetric densities, and 50% of parenchymal deformities. CAD correctly marked 93% of spiculated masses compared with 80% of ill-defined masses (P = .054). There was a significant trend for cancers detected with double reading to occur only in women with a denser mammographic background pattern (P = .02). Size had no effect on lesion detection., Conclusion: Readers using either single reading with CAD or double reading need to be aware of the strengths and weaknesses of reading regimens to avoid missing the more challenging cancer cases.

Background: The sensitivity of screening mammography for the detection of small breast cancers is higher when the mammogram is read by two readers rather than by a single reader. We conducted a trial to determine whether the performance of a single reader using a computer-aided detection system would match the performance achieved by two readers., Methods: The trial was designed as an equivalence trial, with matched-pair comparisons between the cancer-detection rates achieved by single reading with computer-aided detection and those achieved by double reading. We randomly assigned 31,057 women undergoing routine screening by film mammography at three centers in England to double reading, single reading with computer-aided detection, or both double reading and single reading with computer-aided detection, at a ratio of 1:1:28. The primary outcome measures were the proportion of cancers detected according to regimen and the recall rates within the group receiving both reading regimens., Results: The proportion of cancers detected was 199 of 227 (87.7%) for double reading and 198 of 227 (87.2%) for single reading with computer-aided detection (P=0.89). The overall recall rates were 3.4% for double reading and 3.9% for single reading with computer-aided detection; the difference between the rates was small but significant (P<0.001). The estimated sensitivity, specificity, and positive predictive value for single reading with computer-aided detection were 87.2%, 96.9%, and 18.0%, respectively. The corresponding values for double reading were 87.7%, 97.4%, and 21.1%. There were no significant differences between the pathological attributes of tumors detected by single reading with computer-aided detection alone and those of tumors detected by double reading alone., Conclusions: Single reading with computer-aided detection could be an alternative to double reading and could improve the rate of detection of cancer from screening mammograms read by a single reader. (ClinicalTrials.gov number, NCT00450359.), (2008 Massachusetts Medical Society)

Objective: Basal phenotype has been found to be an independent poor prognostic factor for breast cancer. The aim of this study was to assess the mammographic appearance of screening-detected breast carcinoma with the basal phenotype., Materials and Methods: A series of 1,944 consecutively enrolled patients with operable invasive breast cancer underwent immunohistochemical analysis with cytokeratin 5/6 and cytokeratin 14 markers to identify tumors exhibiting basal phenotype characteristics. Among those patients, 356 women with breast cancer were common to a prospectively collected database of screening-detected cases of breast cancer. The predominant mammographic appearance and any associated features were reported by experienced image readers blinded to phenotype status. A chi-square test was used to assess difference between the mammographic appearances of a group of tumors with the basal phenotype and those of a group with the nonbasal phenotype., Results: Forty-one (12%) of the screening-detected tumors had basal phenotypic expression, and these were compared with 309 (88%) nonbasal tumors. Basal-phenotype tumors were significantly more likely to manifest as an ill-defined mass (basal phenotype, 25 [61%] of 41 tumors; nonbasal phenotype, 75 [24%] of 309 tumors; p < 0.001) or with comedo calcification (basal phenotype, nine [22%] of 41 tumors; nonbasal phenotype, 30 [10%] of 309 tumors; p = 0.019). Nonbasal-phenotype tumors were more likely to manifest as a spiculated mass (nonbasal phenotype, 150 [49%] of 309 tumors; basal phenotype, eight [20%] of 41 tumors; p < 0.001). The low rate of spiculation in basal tumors was independent of histologic grade., Conclusion: Screening-detected breast tumors with a basal phenotype have a mammographic appearance different from that of nonbasal tumors. This finding may explain the good prognostic value of mammographic spiculation reported in previous studies.

Objective: The aim of our study was to assess the effect of mammographic parenchymal pattern on patient survival, mammographic features, and pathologic features of breast cancer in a screened population., Materials and Methods: We classified the parenchymal pattern (according to BI-RADS) of 759 screened women who presented with a screening-detected (n = 455) or interval (n = 304) invasive breast cancer. Pathologic details (tumor size, histologic grade, lymph node stage, vascular invasion, and histologic type) and mammographic appearances were recorded. Breast cancer-specific survival was ascertained, with a median follow-up of 9.0 years., Results: An excess of interval cancers was seen in women with dense breasts (p < 0.0001). Screening-detected (but not interval) tumors were significantly smaller in fatty breasts (p = 0.014). Tumor grade, lymph node stage, vascular invasion, and histologic type did not vary significantly with mammographic parenchymal pattern in screening-detected or interval cancers. Screening-detected cancers in fatty breasts were more likely to appear as indistinct (p = 0.003) or spiculated (p = 0.002) masses in contrast to cancers in dense breasts, which more commonly appeared as architectural distortions (p < 0.0001). No significant breast cancer-specific survival difference was seen by mammographic parenchymal pattern for screening-detected cancers (p = 0.75), interval cancers (p = 0.82), or both groups combined (p = 0.12)., Conclusion: The prognosis of screened women presenting with breast cancer is unrelated to dense mammographic parenchymal pattern despite an excess of interval cancers and larger screening-detected tumors in this group. These data support the mammographic screening of women with dense parenchymal patterns.

Objective: The aim of this study was to review the prognostic significance of pathologic and radiologic factors for screening-detected invasive breast cancers of any size., Materials and Methods: The patient group was a consecutive series of 470 screening-detected invasive breast cancers that were diagnosed between 1988 and 1998. Data regarding tumor type, grade, maximum invasive diameter, lymph node status, and the presence or absence of vascular invasion were recorded, as were the mammographic features of the lesion. Survival was ascertained from hospital records and a cancer registry. Differences in survival were assessed using Kaplan-Meier survival curves with a log-rank test for difference. The significance of any correlations was assessed using the chi-square test and the chi-square test for trend. Multivariate analysis used a Cox proportional hazards model., Results: At univariate analysis, large invasive size, the presence of definite vascular invasion, high histologic grade, and nodal involvement were associated with poorer breast-cancer-specific survival. Mammographic spiculation (the presence of either a spiculated mass or distortion) was associated with more prolonged breast-cancer-specific survival. The presence or absence of mammographic comedo calcification did not influence breast-cancer-specific survival. In a Cox multivariate analysis that included those factors significant in univariate analysis, size, grade, nodal stage, and mammographic spiculation maintained their prognostic significance., Conclusion: Mammographic spiculation is an independent, good prognostic factor for screening-detected invasive breast cancer. The mechanism of how mammographic spiculation confers a beneficial prognostic effect is not clear.