Association between mammography timing and measures of screening performance in the United States

Supplemental magnetic resonance imaging plus mammography compared with magnetic resonance imaging or mammography by extent of breast density

BACKGROUND

Examining screening outcomes by breast density for breast magnetic resonance imaging (MRI) with or without mammography could inform discussions about supplemental MRI in women with dense breasts.

METHODS

We evaluated 52 237 women aged 40-79 years who underwent 2611 screening MRIs alone and 6518 supplemental MRI plus mammography pairs propensity score-matched to 65 810 screening mammograms. Rates per 1000 examinations of interval, advanced, and screen-detected early stage invasive cancers and false-positive recall and biopsy recommendation were estimated by breast density (nondense = almost entirely fatty or scattered fibroglandular densities; dense = heterogeneously/extremely dense) adjusting for registry, examination year, age, race and ethnicity, family history of breast cancer, and prior breast biopsy.

RESULTS

Screen-detected early stage cancer rates were statistically higher for MRI plus mammography vs mammography for nondense (9.3 vs 2.9; difference = 6.4, 95% confidence interval [CI] = 2.5 to 10.3) and dense (7.5 vs 3.5; difference = 4.0, 95% CI = 1.4 to 6.7) breasts and for MRI vs MRI plus mammography for dense breasts (19.2 vs 7.5; difference = 11.7, 95% CI = 4.6 to 18.8). Interval rates were not statistically different for MRI plus mammography vs mammography for nondense (0.8 vs 0.5; difference = 0.4, 95% CI = -0.8 to 1.6) or dense breasts (1.5 vs 1.4; difference = 0.0, 95% CI = -1.2 to 1.3), nor were advanced cancer rates. Interval rates were not statistically different for MRI vs MRI plus mammography for nondense (2.6 vs 0.8; difference = 1.8 (95% CI = -2.0 to 5.5) or dense breasts (0.6 vs 1.5; difference = -0.9, 95% CI = -2.5 to 0.7), nor were advanced cancer rates. False-positive recall and biopsy recommendation rates were statistically higher for MRI groups than mammography alone.

CONCLUSION

MRI screening with or without mammography increased rates of screen-detected early stage cancer and false-positives for women with dense breasts without a concomitant decrease in advanced or interval cancers.

Feasibility of predicting a screening digital breast tomosynthesis recall using features extracted from the electronic medical record

PURPOSE

Tools to predict a screening mammogram recall at the time of scheduling could improve patient care. We extracted patient demographic and breast care history information within the electronic medical record (EMR) for women undergoing digital breast tomosynthesis (DBT) to identify which factors were associated with a screening recall recommendation.

METHOD

In 2018, 21,543 women aged 40 years or greater who underwent screening DBT at our institution were identified. Demographic information and breast care factors were extracted automatically from the EMR. The primary outcome was a screening recall recommendation of BI-RADS 0. A multivariable logistic regression model was built and included age, race, ethnicity groups, family breast cancer history, personal breast cancer history, surgical breast cancer history, recall history, and days since last available screening mammogram.

RESULTS

Multiple factors were associated with a recall on the multivariable model: history of breast cancer surgery (OR: 2.298, 95% CI: 1.854, 2.836); prior recall within the last five years (vs no prior, OR: 0.768, 95% CI: 0.687, 0.858); prior screening mammogram within 0-18 months (vs no prior, OR: 0.601, 95% CI: 0.520, 0.691), prior screening mammogram within 18-30 months (vs no prior, OR: 0.676, 95% CI: 0.520, 0.691); and age (normalized OR: 0.723, 95% CI: 0.690, 0.758).

CONCLUSIONS

It is feasible to predict a DBT screening recall recommendation using patient demographics and breast care factors that can be extracted automatically from the EMR.

Prioritizing Screening Mammograms for Immediate Interpretation and Diagnostic Evaluation on the Basis of Risk for Recall

PURPOSE

The aim of this study was to develop a prioritization strategy for scheduling immediate screening mammographic interpretation and possible diagnostic evaluation.

METHODS

A population-based cohort with screening mammograms performed from 2012 to 2020 at 126 radiology facilities from 7 Breast Cancer Surveillance Consortium registries was identified. Classification trees identified combinations of clinical history (age, BI-RADS® density, time since prior mammogram, history of false-positive recall or biopsy result), screening modality (digital mammography, digital breast tomosynthesis), and facility characteristics (profit status, location, screening volume, practice type, academic affiliation) that grouped screening mammograms by recall rate, with ≥12/100 considered high and ≥16/100 very high. An efficiency ratio was estimated as the percentage of recalls divided by the percentage of mammograms.

RESULTS

The study cohort included 2,674,051 screening mammograms in 925,777 women, with 235,569 recalls. The most important predictor of recall was time since prior mammogram, followed by age, history of false-positive recall, breast density, history of benign biopsy, and screening modality. Recall rates were very high for baseline mammograms (21.3/100; 95% confidence interval, 19.7-23.0) and high for women with ≥5 years since prior mammogram (15.1/100; 95% confidence interval, 14.3-16.1). The 9.2% of mammograms in subgroups with very high and high recall rates accounted for 19.2% of recalls, an efficiency ratio of 2.1 compared with a random approach. Adding women <50 years of age with dense breasts accounted for 20.3% of mammograms and 33.9% of recalls (efficiency ratio = 1.7). Results including facility-level characteristics were similar.

CONCLUSIONS

Prioritizing women with baseline mammograms or ≥5 years since prior mammogram for immediate interpretation and possible diagnostic evaluation could considerably reduce the number of women needing to return for diagnostic imaging at another visit.

Association of Screening With Digital Breast Tomosynthesis vs Digital Mammography With Risk of Interval Invasive and Advanced Breast Cancer

Importance

Digital breast tomosynthesis (DBT) was developed with the expectation of improving cancer detection in women with dense breasts. Studies are needed to evaluate interval invasive and advanced breast cancer rates, intermediary outcomes related to breast cancer mortality, by breast density and breast cancer risk.

Objective

To evaluate whether DBT screening is associated with a lower likelihood of interval invasive cancer and advanced breast cancer compared with digital mammography by extent of breast density and breast cancer risk.

Design, Setting, and Participants

Cohort study of 504 427 women aged 40 to 79 years who underwent 1 003 900 screening digital mammography and 375 189 screening DBT examinations from 2011 through 2018 at 44 US Breast Cancer Surveillance Consortium (BCSC) facilities with follow-up for cancer diagnoses through 2019 by linkage to state or regional cancer registries.

Exposures

Breast Imaging Reporting and Data System (BI-RADS) breast density; BCSC 5-year breast cancer risk.

Main Outcomes and Measures

Rates per 1000 examinations of interval invasive cancer within 12 months of screening mammography and advanced breast cancer (prognostic pathologic stage II or higher) within 12 months of screening mammography, both estimated with inverse probability weighting.

Results

Among 504 427 women in the study population, the median age at time of mammography was 58 years (IQR, 50-65 years). Interval invasive cancer rates per 1000 examinations were not significantly different for DBT vs digital mammography (overall, 0.57 vs 0.61, respectively; difference, -0.04; 95% CI, -0.14 to 0.06; P = .43) or among all the 836 250 examinations with BCSC 5-year risk less than 1.67% (low to average-risk) or all the 413 061 examinations with BCSC 5-year risk of 1.67% or higher (high risk) across breast density categories. Advanced cancer rates were not significantly different for DBT vs digital mammography among women at low to average risk or at high risk with almost entirely fatty, scattered fibroglandular densities, or heterogeneously dense breasts. Advanced cancer rates per 1000 examinations were significantly lower for DBT vs digital mammography for the 3.6% of women with extremely dense breasts and at high risk of breast cancer (13 291 examinations in the DBT group and 31 300 in the digital mammography group; 0.27 vs 0.80 per 1000 examinations; difference, -0.53; 95% CI, -0.97 to -0.10) but not for women at low to average risk (10 611 examinations in the DBT group and 37 796 in the digital mammography group; 0.54 vs 0.42 per 1000 examinations; difference, 0.12; 95% CI, -0.09 to 0.32).

Conclusions and Relevance

Screening with DBT vs digital mammography was not associated with a significant difference in risk of interval invasive cancer and was associated with a significantly lower risk of advanced breast cancer among the 3.6% of women with extremely dense breasts and at high risk of breast cancer. No significant difference was observed in the 96.4% of women with nondense breasts, heterogeneously dense breasts, or with extremely dense breasts not at high risk.

Characterizing Breast Lesions Using Quantitative Parametric 3D Subharmonic Imaging: A Multicenter Study

RATIONALE AND OBJECTIVES

Breast cancer is the leading type of cancer among women. Visualization and characterization of breast lesions based on vascularity kinetics was evaluated using three-dimensional (3D) contrast-enhanced ultrasound imaging in a clinical study.

MATERIALS AND METHODS

Breast lesions (n = 219) were imaged using power Doppler imaging (PDI), 3D contrast-enhanced harmonic imaging (HI), and 3D contrast-enhanced subharmonic imaging (SHI) with a modified Logiq 9 ultrasound scanner using a 4D10L transducer. Quantitative metrics of vascularity derived from 3D parametric volumes (based on contrast perfusion; PER and area under the curve; AUC) were generated by off-line processing of contrast wash-in and wash-out. Diagnostic accuracy of these quantitative vascular parameters was assessed with biopsy results as the reference standard.

RESULTS

Vascularity was observed with PDI in 93 lesions (69 benign and 24 malignant), 3D HI in 8 lesions (5 benign and 3 malignant), and 3D SHI in 83 lesions (58 benign and 25 malignant). Diagnostic accuracy for vascular heterogeneity, PER, and AUC ranged from 0.52 to 0.75, while the best logistical regression model (vascular heterogeneity ratio, central PER, and central AUC) reached 0.90.

CONCLUSION

3D SHI successfully detects contrast agent flow in breast lesions and characterization of these lesions based on quantitative measures of vascular heterogeneity and 3D parametric volumes is promising.

Risk-Based Screening Mammography for Women Aged <40: Outcomes From the National Mammography Database

OBJECTIVE

There is insufficient large-scale evidence for screening mammography in women <40 years at elevated risk. This study compares risk-based screening of women aged 30 to 39 with risk factors versus women aged 40 to 49 without risk factors in the National Mammography Database (NMD).

METHODS

This retrospective, HIPAA-compliant, institutional review board-exempt study analyzed data from 150 NMD mammography facilities in 31 states. Patients were stratified by 5-year age intervals, availability of prior mammograms, and specific risk factors for breast cancer: family history of breast cancer, personal history of breast cancer, and dense breasts. Four screening performance metrics were calculated for each age and risk group: recall rate (RR), cancer detection rate (CDR), and positive predictive values for biopsy recommended (PPV₂) and biopsy performed (PPV₃).

RESULTS

Data from 5,986,131 screening mammograms performed between January 2008 and December 2015 in 2,647,315 women were evaluated. Overall, mean CDR was 3.69 of 1,000 (95% confidence interval: 3.64-3.74), RR was 9.89% (9.87%-9.92%), PPV₂ was 20.1% (19.9%-20.4%), and PPV₃ was 28.2% (27.0%-28.5%). Women aged 30 to 34 and 35 to 39 had similar CDR, RR, and PPVs, with the presence of the three evaluated risk factors associated with significantly higher CDR. Moreover, compared with a population currently recommended for screening mammography in the United States (aged 40-49 at average risk), incidence screening (at least one prior screening examination) of women aged 30 to 39 with the three evaluated risk factors has similar cancer detection rates and recall rates.

DISCUSSION

Women with one or more of these three specific risk factors likely benefit from screening commencing at age 30 instead of age 40.

Strategies to Identify Women at High Risk of Advanced Breast Cancer During Routine Screening for Discussion of Supplemental Imaging

IMPORTANCE

Federal legislation proposes requiring that screening mammography reports to practitioners and women incorporate breast density information and that women with dense breasts discuss supplemental imaging with their practitioner given their increased risk of interval breast cancer. Instead of discussing supplemental imaging with all women with dense breasts, it may be more efficient to identify women at high risk of advanced breast cancer who may benefit most from supplemental imaging.

OBJECTIVE

To identify women at high risk of advanced breast cancer to target woman-practitioner discussions about the need for supplemental imaging.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study assessed 638 856 women aged 40 to 74 years who had 1 693 163 screening digital mammograms taken at Breast Cancer Surveillance Consortium (BCSC) imaging facilities from January 3, 2005, to December 31, 2014. Data analysis was performed from October 10, 2018, to March 20, 2019.

EXPOSURES

Breast Imaging Reporting and Data System (BI-RADS) breast density and BCSC 5-year breast cancer risk.

MAIN OUTCOMES AND MEASURES

Advanced breast cancer (stage IIB or higher) within 12 months of screening mammography; high advanced cancer rates (≥0.61 cases per 1000 mammograms) defined as the top 25th percentile of advanced cancer rates, and discussions per potential advanced cancer prevented.

RESULTS

A total of 638 856 women (mean [SD] age, 56.5 [8.9] years) were included in the study. Women with dense breasts (heterogeneously or extremely dense) accounted for 47.0% of screened women and 60.0% of advanced cancers. Low advanced cancer rates (<0.61 per 1000 mammograms) occurred in 34.5% of screened women with dense breasts. High advanced breast cancer rates occurred in women with heterogeneously dense breasts and a 5-year risk of 2.5% or higher (6.0% of screened women) and those with extremely dense breasts and a 5-year risk of 1.0% or higher (6.5% of screened women). Density-risk subgroups at high advanced cancer risk comprised 12.5% of screened women and 27.1% of advanced cancers. Density-risk subgroups had the fewest supplemental imaging discussions per potential advanced cancer prevented compared with a strategy based on dense breasts (1097 vs 1866 discussions). Women with heterogeneously dense breasts and a 5-year risk less than 1.67% (21.7% of screened women) had high rates of false-positive short-interval follow-up recommendation without undergoing supplemental imaging.

CONCLUSIONS AND RELEVANCE

The findings suggest that breast density notification should be combined with breast cancer risk so women at highest risk for advanced cancer are targeted for supplemental imaging discussions and women at low risk are not. BI-RADS breast density combined with BCSC 5-year risk may offer a more efficient strategy for supplemental imaging discussions than targeting all women with dense breasts.

Performance of Screening Ultrasonography as an Adjunct to Screening Mammography in Women Across the Spectrum of Breast Cancer Risk

IMPORTANCE

Whole-breast ultrasonography has been advocated to supplement screening mammography to improve outcomes in women with dense breasts.

OBJECTIVE

To determine the performance of screening mammography plus screening ultrasonography compared with screening mammography alone in community practice.

DESIGN, SETTING, AND PARTICIPANTS

Observational cohort study. Two Breast Cancer Surveillance Consortium registries provided prospectively collected data on screening mammography with vs without same-day breast ultrasonography from January 1, 2000, to December 31, 2013. The dates of analysis were March 2014 to December 2018. A total of 6081 screening mammography plus same-day screening ultrasonography examinations in 3386 women were propensity score matched 1:5 to 30 062 screening mammograms without screening ultrasonography in 15 176 women from a sample of 113 293 mammograms. Exclusion criteria included a personal history of breast cancer and self-reported breast symptoms.

EXPOSURES

Screening mammography with vs without screening ultrasonography.

MAIN OUTCOMES AND MEASURES

Cancer detection rate and rates of interval cancer, false-positive biopsy recommendation, short-interval follow-up, and positive predictive value of biopsy recommendation were estimated and compared using log binomial regression.

RESULTS

Screening mammography with vs without ultrasonography examinations was performed more often in women with dense breasts (74.3% [n = 4317 of 5810] vs 35.9% [n = 39 928 of 111 306] in the overall sample), in women who were younger than 50 years (49.7% [n = 3022 of 6081] vs 31.7% [n = 16 897 of 112 462]), and in women with a family history of breast cancer (42.9% [n = 2595 of 6055] vs 15.0% [n = 16 897 of 112 462]). While 21.4% (n = 1154 of 5392) of screening ultrasonography examinations were performed in women with high or very high (≥2.50%) Breast Cancer Surveillance Consortium 5-year risk scores, 53.6% (n = 2889 of 5392) had low or average (<1.67%) risk. Comparing mammography plus ultrasonography with mammography alone, the cancer detection rate was similar at 5.4 vs 5.5 per 1000 screens (adjusted relative risk [RR], 1.14; 95% CI, 0.76-1.68), as were interval cancer rates at 1.5 vs 1.9 per 1000 screens (RR, 0.67; 95% CI, 0.33-1.37). The false-positive biopsy rates were significantly higher at 52.0 vs 22.2 per 1000 screens (RR, 2.23; 95% CI, 1.93-2.58), as was short-interval follow-up at 3.9% vs 1.1% (RR, 3.10; 95% CI, 2.60-3.70). The positive predictive value of biopsy recommendation was significantly lower at 9.5% vs 21.4% (RR, 0.50; 95% CI, 0.35-0.71).

CONCLUSIONS AND RELEVANCE

In a relatively young population of women at low, intermediate, and high breast cancer risk, these results suggest that the benefits of supplemental ultrasonography screening may not outweigh associated harms.

iCAP: An Individualized Model Combining Gaze Parameters and Image-Based Features to Predict Radiologists' Decisions While Reading Mammograms

This study introduces an individualized tool for identifying mammogram interpretation errors, called eye-Computer Assisted Perception (iCAP). iCAP consists of two modules, one which processes areas marked by radiologists as suspicious for cancer and classifies these as False Positive (FP) or True Positive (TP) decisions, while the second module classifies fixated but not marked locations as False Negative (FN) or True-Negative (TN) decisions. iCAP relies on both radiologists' gaze-related parameters, extracted from eye tracking data, and image-based features. In order to evaluate iCAP, eye tracking data from eight breast radiologists reading 120 two-view digital mammograms were collected. Fifty-nine cases had biopsy proven cancer. For each radiologist, a user-specific support vector machine model was built to classify the radiologist' s reported areas as TPs or FPs and fixated locations as TNs or FNs. The performances of the classifiers were evaluated by utilizing leave-one-out cross validation. iCAP was tested retrospectively in a simulated scenario in which it was assumed that the radiologists would accept all iCAP decisions. Using iCAP led to an average increase of 12%±6% in the number of correctly localized cancer and an average decrease of 44.5%±22.7% in the number of FPs per image.

Accuracy assessment and characterization of x-ray coded aperture coherent scatter spectral imaging for breast cancer classification

Although transmission-based x-ray imaging is the most commonly used imaging approach for breast cancer detection, it exhibits false negative rates higher than 15%. To improve cancer detection accuracy, x-ray coherent scatter computed tomography (CSCT) has been explored to potentially detect cancer with greater consistency. However, the 10-min scan duration of CSCT limits its possible clinical applications. The coded aperture coherent scatter spectral imaging (CACSSI) technique has been shown to reduce scan time through enabling single-angle imaging while providing high detection accuracy. Here, we use Monte Carlo simulations to test analytical optimization studies of the CACSSI technique, specifically for detecting cancer in ex vivo breast samples. An anthropomorphic breast tissue phantom was modeled, a CACSSI imaging system was virtually simulated to image the phantom, a diagnostic voxel classification algorithm was applied to all reconstructed voxels in the phantom, and receiver-operator characteristics analysis of the voxel classification was used to evaluate and characterize the imaging system for a range of parameters that have been optimized in a prior analytical study. The results indicate that CACSSI is able to identify the distribution of cancerous and healthy tissues (i.e., fibroglandular, adipose, or a mix of the two) in tissue samples with a cancerous voxel identification area-under-the-curve of 0.94 through a scan lasting less than 10 s per slice. These results show that coded aperture scatter imaging has the potential to provide scatter images that automatically differentiate cancerous and healthy tissue within ex vivo samples. Furthermore, the results indicate potential CACSSI imaging system configurations for implementation in subsequent imaging development studies.

Circulating microRNA-based screening tool for breast cancer

Circulating microRNAs (miRNAs) are increasingly recognized as powerful biomarkers in several pathologies, including breast cancer. Here, their plasmatic levels were measured to be used as an alternative screening procedure to mammography for breast cancer diagnosis.

A plasma miRNA profile was determined by RT-qPCR in a cohort of 378 women. A diagnostic model was designed based on the expression of 8 miRNAs measured first in a profiling cohort composed of 41 primary breast cancers and 45 controls, and further validated in diverse cohorts composed of 108 primary breast cancers, 88 controls, 35 breast cancers in remission, 31 metastatic breast cancers and 30 gynecologic tumors.

A receiver operating characteristic curve derived from the 8-miRNA random forest based diagnostic tool exhibited an area under the curve of 0.81. The accuracy of the diagnostic tool remained unchanged considering age and tumor stage. The miRNA signature correctly identified patients with metastatic breast cancer. The use of the classification model on cohorts of patients with breast cancers in remission and with gynecologic cancers yielded prediction distributions similar to that of the control group.

Using a multivariate supervised learning method and a set of 8 circulating miRNAs, we designed an accurate, minimally invasive screening tool for breast cancer.

Replacing single-view mediolateral oblique (MLO) digital mammography (DM) with synthesized mammography (SM) with digital breast tomosynthesis (DBT) images: Comparison of the diagnostic performance and radiation dose with two-view DM with or without MLO-DBT

OBJECTIVES

To evaluate the diagnostic performance and radiation dose of single view cranio-caudal (CC) digital mammography (DM) plus mediolateral oblique (MLO) digital breast tomosynthesis (DBT) combined with synthesized mammography (SM) in comparison with two-view DM with or without DBT.

MATERIAL AND METHODS

This study was approved by our institutional review board, and informed consent was obtained from 130 women. Paired two-view DM and single MLO-DBT with SM images were acquired, and four independent retrospective reading sessions of different combinations of DM, SM and DBT were performed for the presence of malignant tumors using jackknife alternative free-response receiver operator curve (JAFROC) methods. The diagnostic performances and average glandular dose (AGD) were compared between different combinations of DM, SM and DBT.

RESULTS

Of 159 lesions in 130 patients, 27 were malignant. When using MLO-DBT with SM instead of MLO-DM, a significantly higher sensitivity (P=0.016) and specificity (P=0.012) were noted than with two-view DM, and comparable figure of merit (FOM), sensitivity, and specificity to two-view DM with DBT were noted. The mean AGD of CC-DM plus MLO-DBT with SM was 5.78mGy±1.06 per patient, which was significantly lower than that with two-view DM with MLO-DBT (8.45mGy±1.32; P <0.001) and slightly higher than that with two-view DM (5.30mGy±0.63).

CONCLUSIONS

The combined use of CC-DM plus MLO-DBT with SM showed higher sensitivity and specificity to two-view DM with a smaller AGD increment and comparable diagnostic performance to that of two-view DM with MLO-DBT with a significantly lower mean AGD.

Improving Screening Mammography Outcomes Through Comparison With Multiple Prior Mammograms

OBJECTIVE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Integrating Customer Intimacy Into Radiology to Improve the Patient Perspective: The Case of Breast Cancer Screening

OBJECTIVE

The customer intimacy business model has emerged as a key operational approach for health care organizations as they move toward patient-centered care. The question arises how the customer intimacy approach can be implemented in the clinical setting and whether it can help practitioners address problems and improve quality of care.

CONCLUSION

Breast cancer screening and its emphasis on the patient perspective provides an interesting case study for understanding how the customer intimacy approach can be integrated into radiologic practice to improve the patient experience.

Influences of Radiology Trainees on Screening Mammography Interpretation

PURPOSE

Participation of radiology trainees in screening mammographic interpretation is a critical component of radiology residency and fellowship training. The aim of this study was to investigate and quantify the effects of trainee involvement on screening mammographic interpretation and diagnostic outcomes.

METHODS

Screening mammograms interpreted at an academic medical center by six dedicated breast imagers over a three-year period were identified, with cases interpreted by an attending radiologist alone or in conjunction with a trainee. Trainees included radiology residents, breast imaging fellows, and fellows from other radiology subspecialties during breast imaging rotations. Trainee participation, patient variables, results of diagnostic evaluations, and pathology were recorded.

RESULTS

A total of 47,914 mammograms from 34,867 patients were included, with an overall recall rate for attending radiologists reading alone of 14.7% compared with 18.0% when involving a trainee (P < .0001). Overall cancer detection rate for attending radiologists reading alone was 5.7 per 1,000 compared with 5.2 per 1,000 when reading with a trainee (P = .517). When reading with a trainee, dense breasts represented a greater portion of recalls (P = .0001), and more frequently, greater than one abnormality was described in the breast (P = .013). Detection of ductal carcinoma in situ versus invasive carcinoma or invasive cancer type was not significantly different. The mean size of cancers in patients recalled by attending radiologists alone was smaller, and nodal involvement was less frequent, though not statistically significantly.

CONCLUSIONS

These results demonstrate a significant overall increase in recall rate when interpreting screening mammograms with radiology trainees, with no change in cancer detection rate. Radiology faculty members should be aware of this potentiality and mitigate tendencies toward greater false positives.

Disparities in the use of screening magnetic resonance imaging of the breast in community practice by race, ethnicity, and socioeconomic status

BACKGROUND

Uptake of breast magnetic resonance imaging (MRI) coupled with breast cancer risk assessment offers the opportunity to tailor the benefits and harms of screening strategies for women with differing cancer risks. Despite the potential benefits, there is also concern for worsening population-based health disparities.

METHODS

Among 316,172 women aged 35 to 69 years from 5 Breast Cancer Surveillance Consortium registries (2007-2012), the authors examined 617,723 negative screening mammograms and 1047 screening MRIs. They examined the relative risks (RRs) of MRI use by women with a <20% lifetime breast cancer risk and RR in the absence of MRI use by women with a ≥20% lifetime risk.

RESULTS

Among women with a <20% lifetime risk of breast cancer, non-Hispanic white women were found to be 62% more likely than nonwhite women to undergo an MRI (95% confidence interval, 1.32-1.98). Of these women, those with an educational level of some college or technical school were 43% more likely and those who had at least a college degree were 132% more likely to receive an MRI compared with those with a high school education or less. Among women with a ≥20% lifetime risk, there was no statistically significant difference noted with regard to the use of screening MRI by race or ethnicity, but high-risk women with a high school education or less were less likely to undergo screening MRI than women who had graduated from college (RR, 0.40; 95% confidence interval, 0.25-0.63).

CONCLUSIONS

Uptake of screening MRI of the breast into clinical practice has the potential to worsen population-based health disparities. Policies beyond health insurance coverage should ensure that the use of this screening modality reflects evidence-based guidelines.

Diagnostic Accuracy of Digital Screening Mammography With and Without Computer-Aided Detection

IMPORTANCE

After the US Food and Drug Administration (FDA) approved computer-aided detection (CAD) for mammography in 1998, and the Centers for Medicare and Medicaid Services (CMS) provided increased payment in 2002, CAD technology disseminated rapidly. Despite sparse evidence that CAD improves accuracy of mammographic interpretations and costs over $400 million a year, CAD is currently used for most screening mammograms in the United States.

OBJECTIVE

To measure performance of digital screening mammography with and without CAD in US community practice.

DESIGN, SETTING, AND PARTICIPANTS

We compared the accuracy of digital screening mammography interpreted with (n = 495 818) vs without (n = 129 807) CAD from 2003 through 2009 in 323 973 women. Mammograms were interpreted by 271 radiologists from 66 facilities in the Breast Cancer Surveillance Consortium. Linkage with tumor registries identified 3159 breast cancers in 323 973 women within 1 year of the screening.

MAIN OUTCOMES AND MEASURES

Mammography performance (sensitivity, specificity, and screen-detected and interval cancers per 1000 women) was modeled using logistic regression with radiologist-specific random effects to account for correlation among examinations interpreted by the same radiologist, adjusting for patient age, race/ethnicity, time since prior mammogram, examination year, and registry. Conditional logistic regression was used to compare performance among 107 radiologists who interpreted mammograms both with and without CAD.

RESULTS

Screening performance was not improved with CAD on any metric assessed. Mammography sensitivity was 85.3% (95% CI, 83.6%-86.9%) with and 87.3% (95% CI, 84.5%-89.7%) without CAD. Specificity was 91.6% (95% CI, 91.0%-92.2%) with and 91.4% (95% CI, 90.6%-92.0%) without CAD. There was no difference in cancer detection rate (4.1 in 1000 women screened with and without CAD). Computer-aided detection did not improve intraradiologist performance. Sensitivity was significantly decreased for mammograms interpreted with vs without CAD in the subset of radiologists who interpreted both with and without CAD (odds ratio, 0.53; 95% CI, 0.29-0.97).

CONCLUSIONS AND RELEVANCE

Computer-aided detection does not improve diagnostic accuracy of mammography. These results suggest that insurers pay more for CAD with no established benefit to women.

Performance of digital screening mammography in a population-based cohort of black and white women

PURPOSE

There is scarce information on whether digital screening mammography performance differs between black and white women.

METHODS

We examined 256,470 digital screening mammograms performed from 2005 to 2010 among 31,654 black and 133,152 white Carolina Mammography Registry participants aged ≥40 years. We compared recall rate, sensitivity, specificity, and positive predictive value (PPV1) between black and white women, adjusting for potential confounders using random effects logistic regression.

RESULTS

Breast cancer was diagnosed in 276 black and 1,095 white women. Recall rates were similar for blacks and whites (8.6 vs. 8.5 %), as were sensitivity (83.7 vs. 82.4 %), specificity (91.8 vs. 91.9 %), and PPV1 (4.8 vs. 5.3 %) (all p values >0.05). Stratified and adjusted models showed similar results. Despite comparable mammography performance, tumors diagnosed in black women were more commonly poorly differentiated and hormone receptor negative.

CONCLUSION

Equivalent performance of digital screening mammography by race suggests that efforts to understand tumor disparities should focus on etiologic factors that influence tumor biology.

National Breast Cancer Screening Programme, Singapore: evaluation of participation and performance indicators

OBJECTIVE

To evaluate participation rates and performance indicators in the National Breast Cancer Screening Programme, BreastScreen Singapore (BSS).

METHODS

Data on women aged 40-69 screened in the period 2002-2009 was obtained from BSS and from the Singapore Cancer Registry. Participation rates and performance indicators (including screen detection rates, small tumour detection rates, recall rates, accuracy and interval cancer rates) were examined.

RESULTS

BSS participation rate has remained above 10% since 2005. Based on health surveys, national mammography rates have increased from 29.7% before BSS to 39.6% in 2010 after BSS. Performance indicators, with the exception of recall rates, specificity, and interval cancer rate (for first screen), generally improved from 2002-2006 to 2007-2009 and are comparable with organized breast screening programmes in other developed countries.

CONCLUSION

BSS breast cancer screening coverage and rescreen rates in Singapore could be improved. Mechanisms to monitor recall rates are in place, and training opportunities are provided to aid the professional development of radiologists.

Comparing sensitivity and specificity of screening mammography in the United States and Denmark

Delivery of screening mammography differs substantially between the United States (US) and Denmark. We evaluated whether there are differences in screening sensitivity and specificity. We included screens from women screened at age 50-69 years during 1996-2008/2009 in the US Breast Cancer Surveillance Consortium (BCSC) (n = 2,872,791), and from two population-based mammography screening programs in Denmark (Copenhagen, n = 148,156 and Funen, n = 275,553). Women were followed-up for 1 year. For initial screens, recall rate was significantly higher in BCSC (17.6%) than in Copenhagen (4.3%) and Funen (3.1%). Sensitivity was fairly similar in BCSC (91.8%) and Copenhagen (90.5%) and Funen (92.5%). At subsequent screens, recall rates were 8.8%, 1.8% and 1.4% in BCSC, Copenhagen and Funen, respectively. The BCSC sensitivity (82.3%) was lower compared with that in Copenhagen (88.9%) and Funen (86.9%), but when stratified by time since last screen, the sensitivity was similar. For both initial and subsequent screenings, the specificity of screening in BCSC (83.2% and 91.6%) was significantly lower than that in Copenhagen (96.6% and 98.8%) and Funen (97.9% and 99.2%). By taking time since last screen into account, it was found that American and Danish women had the same probability of having their asymptomatic cancers detected at screening. However, the majority of women free of asymptomatic cancers experienced more harms in terms of false-positive findings in the US than in Denmark.

Criteria for identifying radiologists with acceptable screening mammography interpretive performance on basis of multiple performance measures

OBJECTIVE

Using a combination of performance measures, we updated previously proposed criteria for identifying physicians whose performance interpreting screening mammography may indicate suboptimal interpretation skills.

MATERIALS AND METHODS

In this study, six expert breast imagers used a method based on the Angoff approach to update criteria for acceptable mammography performance on the basis of two sets of combined performance measures: set 1, sensitivity and specificity for facilities with complete capture of false-negative cancers; and set 2, cancer detection rate (CDR), recall rate, and positive predictive value of a recall (PPV1) for facilities that cannot capture false-negative cancers but have reliable cancer follow-up information for positive mammography results. Decisions were informed by normative data from the Breast Cancer Surveillance Consortium (BCSC).

RESULTS

Updated combined ranges for acceptable sensitivity and specificity of screening mammography are sensitivity≥80% and specificity≥85% or sensitivity 75-79% and specificity 88-97%. Updated ranges for CDR, recall rate, and PPV1 are: CDR≥6 per 1000, recall rate 3-20%, and any PPV1; CDR 4-6 per 1000, recall rate 3-15%, and PPV1≥3%; or CDR 2.5-4.0 per 1000, recall rate 5-12%, and PPV1 3-8%. Using the original criteria, 51% of BCSC radiologists had acceptable sensitivity and specificity; 40% had acceptable CDR, recall rate, and PPV1. Using the combined criteria, 69% had acceptable sensitivity and specificity and 62% had acceptable CDR, recall rate, and PPV1.

CONCLUSION

The combined criteria improve previous criteria by considering the interrelationships of multiple performance measures and broaden the acceptable performance ranges compared with previous criteria based on individual measures.

Identifying women with dense breasts at high risk for interval cancer: a cohort study

BACKGROUND

Twenty-one states have laws requiring that women be notified if they have dense breasts and that they be advised to discuss supplemental imaging with their provider.

OBJECTIVE

To better direct discussions of supplemental imaging by determining which combinations of breast cancer risk and Breast Imaging Reporting and Data System (BI-RADS) breast density categories are associated with high interval cancer rates.

DESIGN

Prospective cohort.

SETTING

Breast Cancer Surveillance Consortium (BCSC) breast imaging facilities.

PATIENTS

365,426 women aged 40 to 74 years who had 831,455 digital screening mammography examinations.

MEASUREMENTS

BI-RADS breast density, BCSC 5-year breast cancer risk, and interval cancer rate (invasive cancer ≤12 months after a normal mammography result) per 1000 mammography examinations. High interval cancer rate was defined as more than 1 case per 1000 examinations.

RESULTS

High interval cancer rates were observed for women with 5-year risk of 1.67% or greater and extremely dense breasts or 5-year risk of 2.50% or greater and heterogeneously dense breasts (24% of all women with dense breasts). The interval rate of advanced-stage disease was highest (>0.4 case per 1000 examinations) among women with 5-year risk of 2.50% or greater and heterogeneously or extremely dense breasts (21% of all women with dense breasts). Five-year risk was low to average (0% to 1.66%) for 51.0% of women with heterogeneously dense breasts and 52.5% with extremely dense breasts, with interval cancer rates of 0.58 to 0.63 and 0.72 to 0.89 case per 1000 examinations, respectively.

LIMITATION

The benefit of supplemental imaging was not assessed.

CONCLUSION

Breast density should not be the sole criterion for deciding whether supplemental imaging is justified because not all women with dense breasts have high interval cancer rates. BCSC 5-year risk combined with BI-RADS breast density can identify women at high risk for interval cancer to inform patient-provider discussions about alternative screening strategies.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Accuracy of screening mammography in women with a history of lobular carcinoma in situ or atypical hyperplasia of the breast

Women with lobular carcinoma in situ (LCIS), atypical lobular hyperplasia (ALH), atypical ductal hyperplasia (ADH), or atypical hyperplasia (AH) are at increased breast cancer (BC) risk. We investigated the accuracy and outcomes of mammography screening in women with histology-proven LCIS, ALH, ADH, or AH history who had screening through Breast Cancer Surveillance Consortium-affiliated mammography facilities. Screens from two cohorts, defined by LCIS/ALH or ADH/AH history, were compared to two cohorts without such history mammogram-matched for age-group, breast density, family history, screen-year, and mammography registry. Overall 359 BCs (277 invasive BC) occurred within 1 year from screening among 52,380 screens. In the LCIS/ALH cohort [versus comparator screens] cancer incidence rates, cancer detection rates (CDR), and interval cancer rates (ICR) were significantly higher (all P < 0.001); although ICR was 4.4/1,000 screens [versus 0.9/1,000; P < 0.001] the proportion that were interval cancers did not differ between compared cohorts (P = 0.43); screening sensitivity was 76.1 % [versus 82.3 %; P = 0.43], however, specificity was significantly lower at 85.1 % [versus 90.7 %; P < 0.0001]. In the ADH/AH cohort [versus comparator] cancer rates and CDR were significantly higher (P < 0.001); although ICR was 2.6/1,000 screens [versus 0.9/1,000; P = 0.002] the proportion that were interval cancers did not differ between cohorts (P = 0.74); screening sensitivity was 81.0 % [versus 82.6 %; P = 0.74] and specificity was lower at 86.2 % [versus 90.2 %; P < 0.0001]. Mammography screening sensitivity in LCIS/ALH and ADH/AH cohorts did not significantly differ from that of matched screens, however, specificity was lower, and ICRs were higher (reflecting underlying cancer rates). Adjunct screening may be of value in these women if it reduces ICR without substantially reducing specificity.

Is it safe to discharge treated proliferative diabetic retinopathy patients from the hospital eye service to a community screening programme?

PURPOSE

To investigate the distribution of new vessels (NV) in patients treated with pan-retinal photocoagulation for proliferative diabetic retinopathy (PDR). To assess whether it is safe to discharge treated PDR patients to the NHS Diabetic Eye Screening Programme (DESP) which uses two mydriatic 45° fields of each eye.

METHODS

Consecutive treated PDR patients undergoing fundus fluorescein angiography between July 2010 and October 2011 for the purpose of looking for NV were included. The distribution of NV was mapped. In particular it was noted whether NV occurred in the area covered by the DESP standard screening images.

RESULTS

A total of 76 patients (108 eyes) met the inclusion criteria for the study. Leaking NV were found inside the DESP fields in 89% of study patients. In 108 eyes with leaking NV, there were a total of 35 NVD and 336 NVE. NV were found within DESP fields in 83% of eyes. Of the 336 NVE, 54% occurred within and 46% outside DESP standard fields. There was no statistically significant difference in the retinal quadrant distribution of NVE.

CONCLUSIONS

If these findings apply to the whole treated PDR population, NVE would be identified in 89% of patients undergoing DESP screening. This would support stable treated PDR patients being monitored within the DESP. We found no preferential clustering of NV within quadrants or between posterior and less posterior retina suggesting that there would be no benefit to the DESP of taking an additional field or graders concentrating on one particular quadrant more than another.

Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment

Purpose

To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC) for colorectal cancer screening.

Materials and Methods

Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between “standard” CTC and “enhanced” CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses.

Results

Data from 122 participants were analysed. There were 30 (25%) non-traders for the cancer scenario and 20 (16%) for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to >85) drop in specificity, equating to 2250 (IQR 1250 to >4250) additional false-positives per additional true-positive cancer, at 0.2% prevalence. For polyps, the figure was 15% (IQR 7.5 to 55), equating to 6 (IQR 3 to 22) additional false-positives per additional true-positive polyp, at 25% prevalence. Tipping points were significantly higher for patients than professionals for both cancer (85 vs 25, p<0.001) and polyps (55 vs 15, p<0.001). Patients were willing to pay significantly more for increased sensitivity for cancer (p = 0.021).

Conclusion

When screening for colorectal cancer, patients and professionals believe gains in true-positive diagnoses are worth much more than the negative consequences of a corresponding rise in false-positives. Evaluation of screening tests should account for this.

Inference based on diagnostic measures from studies of new imaging devices

RATIONALE AND OBJECTIVES

Before using a new diagnostic imaging device regularly in a clinic, it should be studied using patients and radiologists. Often such studies report diagnostic performance in terms of sensitivity, specificity, area under the receiver operating characteristic curve (AUC), or differences thereof. In this report we look at how these studies differ from actual future clinical practice and how those differences may affect reported performance measures.

MATERIALS AND METHODS

We review signal detection (receiver operating characteristic) theory and decision theory. We compare diagnostic measures from several published studies in medical imaging and examine how they relate to theory and each other.

RESULTS

We see that clinical decisions can be modeled using signal detection and decision theories. Sensitivity and specificity are inextricably linked with clinical factors, such as prevalence and costs. Imaging devices are used in many different ways in clinical practice, so that sensitivities, specificities, and AUCs measured in studies of new diagnostic imaging devices will differ from those in actual future clinical use.

CONCLUSIONS

Measured sensitivities, specificities, and the directions of changes thereof are not necessarily consistent or reproducible across studies of new diagnostic devices. A change in the AUC, which should be independent of clinical costs or prevalence, is a consistent measure across similar studies, and a positive change in AUC is indicative of additional diagnostic information that will be available to radiologists in a future clinical environment.

Short-term outcomes of screening mammography using computer-aided detection: a population-based study of medicare enrollees

BACKGROUND

Computer-aided detection (CAD) has rapidly diffused into screening mammography practice despite limited and conflicting data on its clinical effect.

OBJECTIVE

To determine associations between CAD use during screening mammography and the incidence of ductal carcinoma in situ (DCIS) and invasive breast cancer, invasive cancer stage, and diagnostic testing.

DESIGN

Retrospective cohort study.

SETTING

Medicare program.

PARTICIPANTS

Women aged 67 to 89 years having screening mammography between 2001 and 2006 in U.S. SEER (Surveillance, Epidemiology and End Results) regions (409 459 mammograms from 163 099 women).

MEASUREMENTS

Incident DCIS and invasive breast cancer within 1 year after mammography, invasive cancer stage, and diagnostic testing within 90 days after screening among women without breast cancer.

RESULTS

From 2001 to 2006, CAD prevalence increased from 3.6% to 60.5%. Use of CAD was associated with greater DCIS incidence (adjusted odds ratio [OR], 1.17 [95% CI, 1.11 to 1.23]) but no difference in invasive breast cancer incidence (adjusted OR, 1.00 [CI, 0.97 to 1.03]). Among women with invasive cancer, CAD was associated with greater likelihood of stage I to II versus III to IV cancer (adjusted OR, 1.27 [CI, 1.14 to 1.41]). In women without breast cancer, CAD was associated with increased odds of diagnostic mammography (adjusted OR, 1.28 [CI, 1.27 to 1.29]), breast ultrasonography (adjusted OR, 1.07 [CI, 1.06 to 1.09]), and breast biopsy (adjusted OR, 1.10 [CI, 1.08 to 1.12]).

LIMITATION

Short follow-up for cancer stage, potential unmeasured confounding, and uncertain generalizability to younger women.

CONCLUSION

Use of CAD during screening mammography among Medicare enrollees is associated with increased DCIS incidence, the diagnosis of invasive breast cancer at earlier stages, and increased diagnostic testing among women without breast cancer.

PRIMARY FUNDING SOURCE

Center for Healthcare Policy and Research, University of California, Davis.

A semiparametric censoring bias model for estimating the cumulative risk of a false-positive screening test under dependent censoring

False-positive test results are among the most common harms of screening tests and may lead to more invasive and expensive diagnostic testing procedures. Estimating the cumulative risk of a false-positive screening test result after repeat screening rounds is, therefore, important for evaluating potential screening regimens. Existing estimators of the cumulative false-positive risk are limited by strong assumptions about censoring mechanisms and parametric assumptions about variation in risk across screening rounds. To address these limitations, we propose a semiparametric censoring bias model for cumulative false-positive risk that allows for dependent censoring without specifying a fixed functional form for variation in risk across screening rounds. Simulation studies demonstrated that the censoring bias model performs similarly to existing models under independent censoring and can largely eliminate bias under dependent censoring. We used the existing and newly proposed models to estimate the cumulative false-positive risk and variation in risk as a function of baseline age and family history of breast cancer after 10 years of annual screening mammography using data from the Breast Cancer Surveillance Consortium. Ignoring potential dependent censoring in this context leads to underestimation of the cumulative risk of false-positive results. Models that provide accurate estimates under dependent censoring are critical for providing appropriate information for evaluating screening tests.

Comparative effectiveness of digital versus film-screen mammography in community practice in the United States: a cohort study

BACKGROUND

Few studies have examined the comparative effectiveness of digital versus film-screen mammography in U.S. community practice.

OBJECTIVE

To determine whether the interpretive performance of digital and film-screen mammography differs.

DESIGN

Prospective cohort study.

SETTING

Mammography facilities in the Breast Cancer Surveillance Consortium.

PARTICIPANTS

329,261 women aged 40 to 79 years underwent 869 286 mammograms (231 034 digital; 638 252 film-screen).

MEASUREMENTS

Invasive cancer or ductal carcinoma in situ diagnosed within 12 months of a digital or film-screen examination and calculation of mammography sensitivity, specificity, cancer detection rates, and tumor outcomes.

RESULTS

Overall, cancer detection rates and tumor characteristics were similar for digital and film-screen mammography, but the sensitivity and specificity of each modality varied by age, tumor characteristics, breast density, and menopausal status. Compared with film-screen mammography, the sensitivity of digital mammography was significantly higher for women aged 60 to 69 years (89.9% vs. 83.0%; P = 0.014) and those with estrogen receptor-negative cancer (78.5% vs. 65.8%; P = 0.016); borderline significantly higher for women aged 40 to 49 years (82.4% vs. 75.6%; P = 0.071), those with extremely dense breasts (83.6% vs. 68.1%; P = 0.051), and pre- or perimenopausal women (87.1% vs. 81.7%; P = 0.057); and borderline significantly lower for women aged 50 to 59 years (80.5% vs. 85.1%; P = 0.097). The specificity of digital and film-screen mammography was similar by decade of age, except for women aged 40 to 49 years (88.0% vs. 89.7%; P < 0.001).

LIMITATION

Statistical power for subgroup analyses was limited.

CONCLUSION

Overall, cancer detection with digital or film-screen mammography is similar in U.S. women aged 50 to 79 years undergoing screening mammography. Women aged 40 to 49 years are more likely to have extremely dense breasts and estrogen receptor-negative tumors; if they are offered mammography screening, they may choose to undergo digital mammography to optimize cancer detection.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Timeliness of follow-up after abnormal screening mammogram: variability of facilities

PURPOSE

To describe the timeliness of follow-up care in community-based settings among women who receive a recommendation for immediate follow-up during the screening mammography process and how follow-up timeliness varies according to facility and facility-level characteristics.

MATERIALS AND METHODS

This was an institutional review board-approved and HIPAA-compliant study. Screening mammograms obtained from 1996 to 2007 in women 40-80 years old in the Breast Cancer Surveillance Consortium were examined. Inclusion criteria were a recommendation for immediate follow-up at screening, or subsequent imaging, and observed follow-up within 180 days of the recommendation. Recommendations for additional imaging (AI) and biopsy or surgical consultation (BSC) were analyzed separately. The distribution of time to follow-up care was estimated by using the Kaplan-Meier estimator.

RESULTS

Data were available on 214,897 AI recommendations from 118 facilities and 35,622 BSC recommendations from 101 facilities. The median time to subsequent follow-up care after recommendation was 14 days for AI and 16 days for BSC. Approximately 90% of AI follow-up and 81% of BSC follow-up occurred within 30 days. Facilities with higher recall rates tended to have longer AI follow-up times (P < .001). Over the study period, BSC follow-up rates at 15 and 30 days improved (P < .001). Follow-up times varied substantially across facilities. Timely follow-up was associated with larger volumes of the recommended procedures but not notably associated with facility type nor observed facility-level characteristics.

CONCLUSION

Most patients with follow-up returned within 3 weeks of the recommendation.

Effectiveness of computer-aided detection in community mammography practice

BACKGROUND

Computer-aided detection (CAD) is applied during screening mammography for millions of US women annually, although it is uncertain whether CAD improves breast cancer detection when used by community radiologists.

METHODS

We investigated the association between CAD use during film-screen screening mammography and specificity, sensitivity, positive predictive value, cancer detection rates, and prognostic characteristics of breast cancers (stage, size, and node involvement). Records from 684 956 women who received more than 1.6 million film-screen mammograms at Breast Cancer Surveillance Consortium facilities in seven states in the United States from 1998 to 2006 were analyzed. We used random-effects logistic regression to estimate associations between CAD and specificity (true-negative examinations among women without breast cancer), sensitivity (true-positive examinations among women with breast cancer diagnosed within 1 year of mammography), and positive predictive value (breast cancer diagnosed after positive mammograms) while adjusting for mammography registry, patient age, time since previous mammography, breast density, use of hormone replacement therapy, and year of examination (1998-2002 vs 2003-2006). All statistical tests were two-sided.

RESULTS

Of 90 total facilities, 25 (27.8%) adopted CAD and used it for an average of 27.5 study months. In adjusted analyses, CAD use was associated with statistically significantly lower specificity (OR = 0.87, 95% confidence interval [CI] = 0.85 to 0.89, P < .001) and positive predictive value (OR = 0.89, 95% CI = 0.80 to 0.99, P = .03). A non-statistically significant increase in overall sensitivity with CAD (OR = 1.06, 95% CI = 0.84 to 1.33, P = .62) was attributed to increased sensitivity for ductal carcinoma in situ (OR = 1.55, 95% CI = 0.83 to 2.91; P = .17), although sensitivity for invasive cancer was similar with or without CAD (OR = 0.96, 95% CI = 0.75 to 1.24; P = .77). CAD was not associated with higher breast cancer detection rates or more favorable stage, size, or lymph node status of invasive breast cancer.

CONCLUSION

CAD use during film-screen screening mammography in the United States is associated with decreased specificity but not with improvement in the detection rate or prognostic characteristics of invasive breast cancer.

Accuracy of screening mammography varies by week of menstrual cycle

PURPOSE

To investigate sensitivity, specificity, and cancer detection rate of screening mammography according to week of menstrual cycle among premenopausal women.

MATERIALS AND METHODS

In this institutional review board-approved HIPAA-compliant study, sensitivity, specificity, and cancer detection rate of 387,218 screening mammograms linked to 1283 breast cancers in premenopausal women according to week of menstrual cycle were studied by using prospectively collected information from the Breast Cancer Surveillance Consortium. Logistic regression analysis was used to test for differences in mammography performance according to week of menstrual cycle, adjusting for age and registry.

RESULTS

Overall, screening mammography performance did not differ according to week of menstrual cycle. However, when analyses were subdivided according to prior mammography, different patterns emerged. For the 66.6% of women who had undergone regular screening (mammography had been performed within the past 2 years), sensitivity was higher in week 1 (79.5%) than in subsequent weeks (week 2, 70.3%; week 3, 67.4%; week 4, 73.0%; P = .041). In the 17.8% of women who underwent mammography for the first time in this study, sensitivity tended to be lower during the follicular phase (week 1, 72.1%; week 2, 80.4%; week 3, 84.6%; week 4, 93.8%; P = .051). Sensitivity did not vary significantly by week in menstrual cycle in women who had undergone mammography more than 3 years earlier. There were no clinically meaningful differences in specificity or cancer detection rate.

CONCLUSION

Premenopausal women who undergo regular screening may benefit from higher sensitivity of mammography if they schedule screening mammography during the 1st week of their menstrual cycle.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100974/-/DC1.

Screening for breast cancer: an update for the U.S. Preventive Services Task Force

BACKGROUND

This systematic review is an update of evidence since the 2002 U.S. Preventive Services Task Force recommendation on breast cancer screening.

PURPOSE

To determine the effectiveness of mammography screening in decreasing breast cancer mortality among average-risk women aged 40 to 49 years and 70 years or older, the effectiveness of clinical breast examination and breast self-examination, and the harms of screening.

DATA SOURCES

Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (through the fourth quarter of 2008), MEDLINE (January 2001 to December 2008), reference lists, and Web of Science searches for published studies and Breast Cancer Surveillance Consortium for screening mammography data.

STUDY SELECTION

Randomized, controlled trials with breast cancer mortality outcomes for screening effectiveness, and studies of various designs and multiple data sources for harms.

DATA EXTRACTION

Relevant data were abstracted, and study quality was rated by using established criteria.

DATA SYNTHESIS

Mammography screening reduces breast cancer mortality by 15% for women aged 39 to 49 years (relative risk, 0.85 [95% credible interval, 0.75 to 0.96]; 8 trials). Data are lacking for women aged 70 years or older. Radiation exposure from mammography is low. Patient adverse experiences are common and transient and do not affect screening practices. Estimates of overdiagnosis vary from 1% to 10%. Younger women have more false-positive mammography results and additional imaging but fewer biopsies than older women. Trials of clinical breast examination are ongoing; trials for breast self-examination showed no reductions in mortality but increases in benign biopsy results.

LIMITATION

Studies of older women, digital mammography, and magnetic resonance imaging are lacking.

CONCLUSION

Mammography screening reduces breast cancer mortality for women aged 39 to 69 years; data are insufficient for older women. False-positive mammography results and additional imaging are common. No benefit has been shown for clinical breast examination or breast self-examination.

Changes in invasive breast cancer and ductal carcinoma in situ rates in relation to the decline in hormone therapy use

PURPOSE

To assess trends in invasive breast cancer and ductal carcinoma in situ (DCIS) incidence in association with changes in hormone therapy (HT) use in regular mammography screeners.

METHODS

We included 2,071,814 screening mammography examinations performed between January 1997 and December 2006 on 696,385 women age 40 to 79 years; 9,586 breast cancers were diagnosed within 12 months of a screening examination. We calculated adjusted annual rates (mammogram level) for prevalent HT use, incident invasive breast cancer (overall and by tumor histology and estrogen receptor [ER] status), and incident DCIS.

RESULTS

After a precipitous decrease in HT use in 2002, the incidence of invasive breast cancer decreased significantly in 2002 to 2006 among women age 50 to 69 years (P(trend(2002-2006)) = .005) and 70 to 79 years (P(trend(2002-2006)) = .003) but not in women age 40 to 49 years (P(trend(2002-2006)) = .45). DCIS rates significantly decreased in women age 50 to 69 years after 2002 (P(trend(2002-2006)) = .02). Invasive ductal tumors significantly declined in women age 50 to 69 years and 70 to 79 years in 2002 to 2006. In women age 50 to 69 years, invasive lobular and ER-positive cancer rates declined steadily in 2002 to 2005 (P(trend(2002-2005)) = .02 and .03, respectively), but an elevated rate in 2006 rendered the overall trend nonsignificant (P(trend(2002-2006)) = .89 and .91, respectively).

CONCLUSION

In parallel to the sharp decline in HT use in women undergoing regular mammography screening, invasive breast cancer rates decreased in women age 50 to 69 and 70 to 79 years after 2002, and DCIS rates decreased in women age 50 to 69 years, consistent with evidence that HT cessation reduces breast cancer risk. However, the decrease in incidence may have started to level off in 2006; this finding has not been uniformly reported in other populations, warranting further investigation.

Diagnosis of second breast cancer events after initial diagnosis of early stage breast cancer

To examine whether there are any characteristics of women or their initial tumors that might be useful for tailoring surveillance recommendations to optimize outcomes. We followed 17,286 women for up to 5 years after an initial diagnosis of ductal carcinoma in situ (DCIS) or early stage (I/II) invasive breast cancer diagnosed between 1996 and 2006. We calculated rates per 1,000 women years of recurrences and second breast primaries relative to demographics, risk factors, and characteristics of initial diagnosis: stage, treatment, mode of initial diagnosis. Nearly 4% had a second breast cancer event (314 recurrences and 344 second breast primaries). Women who used adjuvant hormonal therapy or were ≥ 80 years had the lowest rates of second events. Factors associated with higher recurrence and second primary rates included: initial DCIS or stage IIB, estrogen/progesterone receptor-negative, younger women (<50 years). Women with a family history or greater breast density had higher second primary rates, and women who received breast conserving surgery without radiation had higher recurrence rates. Roughly one-third of recurrences (37.6%) and second primaries (36.3%) were not screen-detected. Initial mode of diagnosis was a predictor of second events after adjusting for age, stage, primary treatment, and breast density. A recent negative mammogram should not falsely reassure physicians or women with new breast symptoms or changes because one-third of second cancers were interval cancers. This study does not provide any evidence in support of changing surveillance intervals for different subgroups.

Effect of previous benign breast biopsy on the interpretive performance of subsequent screening mammography

BACKGROUND

Most breast biopsies will be negative for cancer. Benign breast biopsy can cause changes in the breast tissue, but whether such changes affect the interpretive performance of future screening mammography is not known.

METHODS

We prospectively evaluated whether self-reported benign breast biopsy was associated with reduced subsequent screening mammography performance using examination data from the mammography registries of the Breast Cancer Surveillance Consortium from January 2, 1996, through December 31, 2005. A positive interpretation was defined as a recommendation for any additional evaluation. Cancer was defined as any invasive breast cancer or ductal carcinoma in situ diagnosed within 1 year of mammography screening. Measures of mammography performance (sensitivity, specificity, and positive predictive value 1 [PPV1]) were compared both at woman level and breast level in the presence and absence of self-reported benign biopsy history. Referral to biopsy was considered a positive interpretation to calculate positive predictive value 2 (PPV2). Multivariable analysis of a correct interpretation on each performance measure was conducted after adjusting for registry, year of examination, patient characteristics, months since last mammogram, and availability of comparison film. Accuracy of the mammogram interpretation was measured using area under the receiver operating characteristic curve (AUC). All statistical tests were two-sided.

RESULTS

A total of 2,007,381 screening mammograms were identified among 799,613 women, of which 14.6% mammograms were associated with self-reported previous breast biopsy. Multivariable adjusted models for mammography performance showed reduced specificity (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.73 to 0.75, P < .001), PPV2 (OR = 0.85, 95% CI = 0.79 to 0.92, P < .001), and AUC (AUC 0.892 vs 0.925, P < .001) among women with self-reported benign biopsy. There was no difference in sensitivity or PPV1 in the same adjusted models, although unadjusted differences in both were found. Specificity was lowest among women with documented fine needle aspiration-the least invasive biopsy technique (OR = 0.58, 95% CI = 0.55 to 0.61, P < .001). Repeating the analysis among women with documented biopsy history, unilateral biopsy history, or restricted to invasive cancers did not change the results.

CONCLUSIONS

Self-reported benign breast biopsy history was associated with statistically significantly reduced mammography performance. The difference in performance was likely because of tissue characteristics rather than the biopsy itself.

Breast cancer risk by breast density, menopause, and postmenopausal hormone therapy use

PURPOSE

We determined whether the association between breast density and breast cancer risk and cancer severity differs according to menopausal status and postmenopausal hormone therapy (HT) use.

METHODS

We collected data on 587,369 women who underwent 1,349,027 screening mammography examinations; 14,090 women were diagnosed with breast cancer. We calculated 5-year breast cancer risk from a survival model for subgroups of women classified by their Breast Imaging Reporting and Data System (BIRADS) breast density, age, menopausal status, and current HT use, assuming a body mass index of 25 kg/m(2). Odds of advanced (ie, IIb, III, IV) versus early (ie, I, IIa) stage invasive cancer was calculated according to BIRADS density.

RESULTS

Breast cancer risk was low among women with low density (BIRADS-1): women age 55 to 59 years, 5-year risk was 0.8% (95% CI, 0.6 to 0.9%) for non-HT users and 0.9% (95% CI, 0.7% to 1.1%) for estrogen and estrogen plus progestin users. Breast cancer risk was high among women with very high density (BIRADS-4), particularly estrogen plus progestin users: women age 55 to 59 years, 5-year risk was 2.4% (95% CI, 2.0% to 2.8%) for non-HT users, 3.0% (95% CI, 2.6% to 3.5%) for estrogen users, and 4.2% (95% CI, 3.7% to 4.6%) for estrogen plus progestin users. Advanced-stage breast cancer risk was increased 1.7-fold for postmenopausal HT users who had very high density (BIRADS-4) compared to those with average density (BIRADS-2).

CONCLUSION

Postmenopausal women with high breast density are at increased risk of breast cancer and should be aware of the added risk of taking HT, especially estrogen plus progestin.

Time trends in radiologists' interpretive performance at screening mammography from the community-based Breast Cancer Surveillance Consortium, 1996-2004

PURPOSE

To examine time trends in radiologists' interpretive performance at screening mammography between 1996 and 2004.

MATERIALS AND METHODS

All study procedures were institutional review board approved and HIPAA compliant. Data were collected on subsequent screening mammograms obtained from 1996 to 2004 in women aged 40-79 years who were followed up for 1 year for breast cancer. Recall rate, sensitivity, and specificity were examined annually. Generalized estimating equation (GEE) and random-effects models were used to test for linear trend. The area under the receiver operating characteristic curve (AUC), tumor histologic findings, and size of the largest dimension or diameter of the tumor were also examined.

RESULTS

Data on 2,542,049 subsequent screening mammograms and 12,498 cancers diagnosed in the follow-up period were included in this study. Recall rate increased from 6.7% to 8.6%, sensitivity increased from 71.4% to 83.8%, and specificity decreased from 93.6% to 91.7%. In GEE models, adjusted odds ratios per calendar year were 1.04 (95% confidence interval [CI]: 1.02, 1.05) for recall rate, 1.09 (95% CI: 1.07. 1.12) for sensitivity, and 0.96 (95% CI: 0.95, 0.98) for specificity (P < .001 for all). Random-effects model results were similar. The AUC increased over time: 0.869 (95% CI: 0.861, 0.877) for 1996-1998, 0.884 (95% CI: 0.879, 0.890) for 1999-2001, and 0.891 (95% CI: 0.885, 0.896) for 2002-2004 (P < .001). Tumor histologic findings and size remained constant.

CONCLUSION

Recall rate and sensitivity for screening mammograms increased, whereas specificity decreased from 1996 to 2004 among women with a prior mammogram. This trend remained after accounting for risk factors. The net effect was an improvement in overall discrimination, a measure of the probability that a mammogram with cancer in the follow-up period has a higher Breast Imaging Reporting and Data System assessment category than does a mammogram without cancer in the follow-up period.

Performance of first mammography examination in women younger than 40 years

BACKGROUND

Few data have been published on mammography performance in women who are younger than 40 years.

METHODS

We pooled data from six mammography registries across the United States from the Breast Cancer Surveillance Consortium. We included 117 738 women who were aged 18-39 years when they had their first screening or diagnostic mammogram during 1995-2005 and followed them for 1 year to determine accuracy of mammography assessment. We measured the recall rate for screening examinations and the sensitivity, specificity, positive predictive value, and cancer detection rate for all mammograms.

RESULTS

For screening mammograms, no cancers were detected in 637 mammograms for women aged 18-24 years. For women aged 35-39 years who had the largest number of screening mammograms (n = 73 335) in this study, the recall rate was 12.7% (95% confidence interval [CI] = 12.4% to 12.9%), sensitivity was 76.1% (95% CI = 69.2% to 82.6%), specificity was 87.5% (95% CI = 87.2% to 87.7%), positive predictive value was 1.3% (95% CI = 1.1% to 1.5%), and cancer detection rate was 1.6 cancers per 1000 mammograms (95% CI = 1.3 to 1.9 cancers per 1000 mammograms). Most (67 468 [77.7%]) of the 86 871 women screened reported no family history of breast cancer. For diagnostic mammograms, the age-adjusted rates across all age groups were: sensitivity of 85.7% (95% CI = 82.7% to 88.7%), specificity of 88.8% (95% CI = 88.4% to 89.1%), positive predictive value of 14.6% (95% CI = 13.3% to 15.8%), and cancer detection rate of 14.3 cancers per 1000 mammograms (95% CI = 13.0 to 15.7 cancers per 1000 mammograms). Mammography performance, except for specificity, improved in the presence of a breast lump.

CONCLUSIONS

Younger women have very low breast cancer rates but after mammography experience high recall rates, high rates of additional imaging, and low cancer detection rates. We found no cancers in women younger than 25 years and poor performance for the large group of women aged 35-39 years. In a theoretical population of 10 000 women aged 35-39 years, 1266 women who are screened will receive further workup, with 16 cancers detected and 1250 women receiving a false-positive result.

Modelling the cumulative risk of a false-positive screening test

The goal of a screening test is to reduce morbidity and mortality through the early detection of disease; but the benefits of screening must be weighed against potential harms, such as false-positive (FP) results, which may lead to increased healthcare costs, patient anxiety, and other adverse outcomes associated with diagnostic follow-up procedures. Accurate estimation of the cumulative risk of an FP test after multiple screening rounds is important for program evaluation and goal setting, as well as informing individuals undergoing screening what they should expect from testing over time. Estimation of the cumulative FP risk is complicated by the existence of censoring and possible dependence of the censoring time on the event history. Current statistical methods for estimating the cumulative FP risk from censored data follow two distinct approaches, either conditioning on the number of screening tests observed or marginalizing over this random variable. We review these current methods, identify their limitations and possibly unrealistic assumptions, and propose simple extensions to address some of these limitations. We discuss areas where additional extensions may be useful. We illustrate methods for estimating the cumulative FP recall risk of screening mammography and investigate the appropriateness of modelling assumptions using 13 years of data collected by the Breast Cancer Surveillance Consortium (BCSC). In the BCSC data we found evidence of violations of modelling assumptions of both classes of statistical methods. The estimated risk of an FP recall after 10 screening mammograms varied between 58% and 77% depending on the approach used, with an estimate of 63% based on what we feel are the most reasonable modelling assumptions.

Screening for breast cancer: an update for the U.S. Preventive Services Task Force

BACKGROUND

This systematic review is an update of evidence since the 2002 U.S. Preventive Services Task Force recommendation on breast cancer screening.

PURPOSE

To determine the effectiveness of mammography screening in decreasing breast cancer mortality among average-risk women aged 40 to 49 years and 70 years or older, the effectiveness of clinical breast examination and breast self-examination, and the harms of screening.

DATA SOURCES

Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (through the fourth quarter of 2008), MEDLINE (January 2001 to December 2008), reference lists, and Web of Science searches for published studies and Breast Cancer Surveillance Consortium for screening mammography data.

STUDY SELECTION

Randomized, controlled trials with breast cancer mortality outcomes for screening effectiveness, and studies of various designs and multiple data sources for harms.

DATA EXTRACTION

Relevant data were abstracted, and study quality was rated by using established criteria.

DATA SYNTHESIS

Mammography screening reduces breast cancer mortality by 15% for women aged 39 to 49 years (relative risk, 0.85 [95% credible interval, 0.75 to 0.96]; 8 trials). Data are lacking for women aged 70 years or older. Radiation exposure from mammography is low. Patient adverse experiences are common and transient and do not affect screening practices. Estimates of overdiagnosis vary from 1% to 10%. Younger women have more false-positive mammography results and additional imaging but fewer biopsies than older women. Trials of clinical breast examination are ongoing; trials for breast self-examination showed no reductions in mortality but increases in benign biopsy results.

LIMITATION

Studies of older women, digital mammography, and magnetic resonance imaging are lacking.

CONCLUSION

Mammography screening reduces breast cancer mortality for women aged 39 to 69 years; data are insufficient for older women. False-positive mammography results and additional imaging are common. No benefit has been shown for clinical breast examination or breast self-examination.

Variability in interpretive performance at screening mammography and radiologists' characteristics associated with accuracy

PURPOSE

To identify radiologists' characteristics associated with interpretive performance in screening mammography.

MATERIALS AND METHODS

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.

RESULTS

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).

CONCLUSION

Fellowship training in breast imaging may lead to improved cancer detection, but it is associated with higher false-positive rates.

Comparing Interval Breast Cancer Rates in Norway and North Carolina: Results and Challenges

Objective

To compare interval breast cancer rates (ICR) between a biennial organized screening programme in Norway and annual opportunistic screening in North Carolina (NC) for different conceptualizations of interval cancer.

Setting

Two regions with different screening practices and performance.

Methods

620,145 subsequent screens (1996–2002) performed in women aged 50–69 and 1280 interval cancers were analysed. Various definitions and quantification methods for interval cancers were compared.

Results

ICR for one year follow-up were lower in Norway compared with NC both when the rate was based on all screens (0.54 versus 1.29 per 1000 screens), negative final assessments (0.54 versus 1.29 per 1000 screens), and negative screening assessments (0.53 versus 1.28 per 1000 screens). The rate of ductal carcinoma in situ was significantly lower in Norway than in NC for cases diagnosed in both the first and second year after screening. The distributions of histopathological tumour size and lymph node involvement in invasive cases did not differ between the two regions for interval cancers diagnosed during the first year after screening. In contrast, in the second year after screening, tumour characteristics remained stable in Norway but became prognostically more favorable in NC.

Conclusion

Even when applying a common set of definitions of interval cancer, the ICR was lower in Norway than in NC. Different definitions of interval cancer did not influence the ICR within Norway or NC. Organization of screening and screening performance might be major contributors to the differences in ICR between Norway and NC.

Screening-detected breast cancers: discordant independent double reading in a population-based screening program

PURPOSE

To analyze discordant and concordant screening-detected breast cancers in a nationwide population-based screening program by using independent double reading with consensus.

MATERIALS AND METHODS

The study is a part of the evaluation of the Norwegian Breast Cancer Screening Program and is covered by the Cancer Registry regulation. Analyses were based on prospective initial interpretation scores of 1 033 870 screenings that included 5611 breast cancers. A five-point scale for probability of cancer was used in the initial interpretation. Screening mammograms with a score of 2 or higher by either radiologist were discussed at consensus meetings where the decision whether to recall was made. A score of 1 by one reader and 2 or higher by the other was defined as a discordant interpretation and discordant cancer, whereas a score of 2 or higher by both readers was defined as a concordant recall and cancer.

RESULTS

Discordant interpretation was present in 5.3% (54 447 of 1 033 870) of the screenings, whereas 2.1% (21 928 of 1 033 870) were concordant positive interpretations. Of the screening-detected cancers, 23.6% (1326 of 5611) were diagnosed in women who were recalled because of screenings with discordant interpretation. One hundred seventeen interval breast cancers were diagnosed among the 40 312 screenings that were dismissed at consensus; these were 6.5% of all interval cancers. A significantly higher proportion of microcalcifications alone was present in discordant cancers (24.9% [304 of 1219]) compared with concordant cancers (17.7% [704 of 3972]) (P < .001).

CONCLUSION

Independent double reading with consensus at mammography screening has the potential to increase the cancer detection rate compared with single reading. Mammograms with microcalcifications alone are significantly more common among discordant cancers.

Decreased accuracy in interpretation of community-based screening mammography for women with multiple clinical risk factors

OBJECTIVE

To assess the impact of women's breast cancer risk factors (use of hormone therapy, family history of breast cancer, previous breast biopsy) on radiologists' mammographic interpretive performance and whether the influence of risk factors varies according to radiologist characteristics.

STUDY DESIGN AND SETTING

Screening mammograms (n=638,947) performed from 1996 to 2005 by 134 radiologists from three Breast Cancer Surveillance Consortium registries was linked to cancer outcomes, radiologist surveys, and patient questionnaires. Interpretive performance measures were modeled using marginal and conditional logistic regression.

RESULTS

Having one or more clinical risk factors was associated with higher recall rates (1 vs. 0 risk factors: odds ratio [OR]=1.17, 95% confidence interval [CI]=1.15-1.19; > or = 2 vs. 0: OR=1.43, 95% CI=1.40-1.47) and lower specificity (1 vs. 0: OR=0.86 [95% CI=0.84-0.88]; > or = 2 vs. 0: OR=0.70 [95% CI=0.68-0.72]) without a corresponding improvement in sensitivity and only a small increase in positive predictive value (1 vs. 0: OR=1.08 [95% CI=0.99-1.19]; > or = 2 vs. 0: OR=1.12 [95% CI=0.99-1.26]). There was no indication that influence of risk factors varied by radiologist characteristics.

CONCLUSION

Women with clinical risk factors who undergo screening mammography are more likely recalled for false-positive evaluation without an associated increase in cancer detection. Radiologists and patients with risk factors should be aware of this increased risk of adverse screening events.