Digital breast tomosynthesis and breast cancer detection in older women: Smaller tumors and more invasive lobular carcinomas.

To review the imaging features of invasive lobular carcinoma (ILC) seen on digital breast tomosynthesis (DBT) in comparison with invasive ductal carcinoma (IDC), and to evaluate whether DBT could improve conspicuity and tumour size assessment of ILC in comparison with digital mammography (DM). Institutional review board with waiver of informed consent was obtained for this retrospective study. Patients with ILC or IDC who underwent DBT and DM at the time of diagnosis were included. DM and DBT images were reviewed in consensus by two breast radiologists in order to assess imaging features, conspicuity and maximum tumour diameter of ILC and IDC. Pathology on the surgical specimen was considered the standard of reference for assessment of tumour size. 43 patients (20 patients with ILC and 23 patients with IDC) were included. On DBT, compared with IDC, ILC presented less frequently as masses (40% vs 78%) (p = 0.01) and more frequently as isolated distortion (20% vs 0%) (p = 0.03). ILC presented more often as asymmetries (60%) than masses (20%) on DM (p = 0.02) but not on DBT (35% vs 40%; p = 1.00). Conspicuity of ILC was significantly higher on DBT than on DM (p = 0.002), while the difference between the two techniques was not significant for IDC (p = 0.2). Regarding ILC, concordance in tumour size measurement between DBT and pathology was fair (intraclass correlation coefficient = 0.24). ILC rarely presented as dense masses but frequently demonstrated architectural distortion on DBT. DBT increased lesion conspicuity but failed to accurately assess tumour size of ILC. Advances in knowledge: (1) This study describes specific features of ILC on DBT. (2) It shows that DBT can improve conspicuity of ILC.

Invasive lobular carcinoma (ILC) is a distinct histological subtype of breast cancer that can make early detection with mammography challenging. We compared imaging performance of digital breast tomosynthesis (DBT) to digital mammography (DM) for diagnoses of ILC, invasive ductal carcinoma (IDC), and invasive mixed carcinoma (IMC) in a screening population. We included screening exams (DM; n = 1,715,249 or DBT; n = 414,793) from 2011 to 2018 among 839,801 women in the Breast Cancer Surveillance Consortium. Examinations were followed for one year to ascertain incident ILC, IDC, or IMC. We measured cancer detection rate (CDR) and interval invasive cancer rate/1000 screening examinations for each histological subtype and stratified by breast density and modality. We calculated relative risk (RR) for DM vs. DBT using log-binomial models to adjust for the propensity of receiving DBT vs. DM. Unadjusted CDR per 1000 mammograms of ILC overall was 0.33 (95%CI: 0.30-0.36) for DM; 0.45 (95%CI: 0.39-0.52) for DBT, and for women with dense breasts- 0.33 (95%CI: 0.29-0.37) for DM and 0.54 (95%CI: 0.43-0.66) for DBT. Similar results were noted for IDC and IMC. Adjusted models showed a significantly increased RR for cancer detection with DBT compared to DM among women with dense breasts for all three histologies (RR; 95%CI: ILC 1.53; 1.09-2.14, IDC 1.21; 1.02-1.44, IMC 1.76; 1.30-2.38), but no significant increase among women with non-dense breasts. DBT was associated with higher CDR for ILC, IDC, and IMC for women with dense breasts. Early detection of ILC with DBT may improve outcomes for this distinct clinical entity.

Looking for a Needle in a Haystack: The Importance of Having Optimal Display Luminance Level for Breast Cancer Detection on Digital Breast Tomosynthesis

Digital breast tomosynthesis as an adjunct to digital mammography for detecting and characterising invasive lobular cancers: a multi-reader study

A decade has passed since the first prospective trials showed that the mammography technology, digital breast tomosynthesis, increased the rate of cancer detection compared with digital mammography. 1 Ciatto S Houssami N Bernardi D et al. Integration of 3D digital mammography with tomosynthesis for population breast-cancer screening (STORM): a prospective comparison study. Lancet Oncol. 2013; 14: 583-589 Summary Full Text Full Text PDF PubMed Scopus (608) Google Scholar , 2 Skaane P Bandos AI Gullien R et al. Prospective trial comparing full-field digital mammography (FFDM) versus combined FFDM and tomosynthesis in a population-based screening programme using independent double reading with arbitration. Eur Radiol. 2013; 23: 2061-2071 Crossref PubMed Scopus (170) Google Scholar A large body of evidence, comprising prospective non-randomised studies and retrospective studies, 3 Marinovich ML Hunter KE Macaskill P Houssami N Breast cancer screening using tomosynthesis or mammography: a meta-analysis of cancer detection and recall. J Natl Cancer Inst. 2018; 110: 942-949 Crossref PubMed Scopus (108) Google Scholar has since accumulated; however, evidence from randomised controlled trials is scarce. In The Lancet Oncology, Walter Heindel and colleagues report the results of the TOmosynthesis plus SYnthesised MAmmography Study (TOSYMA), 4 Heindel W Weigel W Gerß J et al. Digital breast tomosynthesis plus synthesised mammography versus digital screening mammography for the detection of invasive breast cancer (TOSYMA): a multicentre, open-label, randomised, controlled, superiority trial. Lancet Oncol. 2022; (published online April 12.)https://doi.org/10.1016/S1470-2045(22)00194-2 Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar a multicentre trial embedded in the German population-wide mammography screening programme. TOSYMA is the largest of three randomised controlled trials providing evidence on breast tomosynthesis versus mammography screening. 4 Heindel W Weigel W Gerß J et al. Digital breast tomosynthesis plus synthesised mammography versus digital screening mammography for the detection of invasive breast cancer (TOSYMA): a multicentre, open-label, randomised, controlled, superiority trial. Lancet Oncol. 2022; (published online April 12.)https://doi.org/10.1016/S1470-2045(22)00194-2 Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar , 5 Hofvind S Holen AS Aase HS et al. Two-view digital breast tomosynthesis versus digital mammography in a population-based breast cancer screening programme (To-Be): a randomised, controlled trial. Lancet Oncol. 2019; 20: 795-805 Summary Full Text Full Text PDF PubMed Scopus (38) Google Scholar , 6 Pattacini P Nitrosi A Giorgi RP et al. A randomized trial comparing breast cancer incidence and interval cancers after tomosynthesis plus mammography versus mammography alone. Radiology. 2022; (published online Feb 1.)https://doi.org/10.1148/radiol.211132 Crossref PubMed Scopus (3) Google Scholar Heindel and colleagues persevered with TOSYMA despite the COVID-19 pandemic stalling recruitment, resulting in a marginally lower sample size than planned in their adaptive design. 4 Heindel W Weigel W Gerß J et al. Digital breast tomosynthesis plus synthesised mammography versus digital screening mammography for the detection of invasive breast cancer (TOSYMA): a multicentre, open-label, randomised, controlled, superiority trial. Lancet Oncol. 2022; (published online April 12.)https://doi.org/10.1016/S1470-2045(22)00194-2 Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar Digital breast tomosynthesis plus synthesised mammography versus digital screening mammography for the detection of invasive breast cancer (TOSYMA): a multicentre, open-label, randomised, controlled, superiority trialThe results from this study indicate that the detection rate for invasive breast cancer was significantly higher with digital breast tomosynthesis plus s2D mammography than digital mammography alone. Evaluation of interval cancer rates in the follow-up study will further help to investigate incremental long-term benefits of digital breast tomosynthesis screening. Full-Text PDF

Digital breast tomosynthesis plus synthesised mammography versus digital screening mammography for the detection of invasive breast cancer (TOSYMA): a multicentre, open-label, randomised, controlled, superiority trial.

Background: In invasive breast cancer patients being treated with neoadjuvant chemotherapy (NACT), achieving pathological complete response (pCR) is a useful goal of treatment. Monitoring response to NACT and predicting pCR is helpful in planning further therapy and providing robust prognostic information. Digital mammography (DM) and additional digital breast tomosynthesis (DBT) features are important tell-tales of tumor characteristics and behaviour. Following NACT, the mammographic features- both DM and DBT- of responding tumors can vary considerably. In this prospective study, we correlated the DM and DBT features of pre-NACT and post-NACT mammograms to investigate if these can reliably predict pCR to NACT. Methods: Following approval by institutional ethics committee, starting January 2016, 200 consecutive invasive breast carcinoma patients (mean age 51.2 years, all palpable breast masses) undergoing diagnostic breast imaging had their DM and DBT reviewed by two radiologists independently, who were blinded of the cyto/histology and the original DM and DBT reporting. Of these, 47 patients who were treated with NACT and had pre- and post-NACT DM and DBT were recruited. After a core-biopsy, radio-opaque marker(s) were placed in tumor core/margin. The pre- and post-NACT DM and DBT findings were compared and correlated with the extent of response of the primary breast tumor to NACT. DM and DBT characteristics predictive of (in-breast) pCR of index breast lesion were identified. Results: Of the 47 patients who underwent NACT, 44 received both anthracycline and taxane, and 3 received only an anthracycline based combination chemotherapy. Twelve patients underwent breast conservative surgery and the remaining underwent mastectomy. pCR was seen in 17 (36.2%) patients based on the surgical specimen histology. On clinical examination, 19 (40.4%) patients had clinical complete response (cCR) of the breast tumor, 11 (64.7%) of whom had pCR as well. Five patients had radiological complete response (rCR, no breast lesion visualised on post-NACT imaging)- 2 patients on DM alone, 2 patients on DBT alone, and one patient on both DM and DBT. Radio-opaque clips had some obscuring effects in 3 of these 5 patients, especially on DBT, in form of reduced visibility of breast lesion on DBT, c.w. corresponding DM images. All 5 patients with rCR had pCR (sensitivity=29.4%, specificity=100%), in contrast to only 11 (57.9%) patients with cCR having pCR. Patients with pCR had benign appearing (forced Bi-RADS 2 and 3) lesions on mammography more commonly on DM (p<0.001) than on DBT (p=0.042) (41.2% vs 23.5%). Post NACT lesion morphology varied significantly between patients with and without pCR on DM (p=0.038) but not on DBT (p=0.182). Pre-NACT forced Bi-RADS score, lesion morphology or margin characteristics on DM and DBT did not vary significantly amongst patients with and without pCR. Conclusions: Post-NACT DM and DBT features can predict pCR with high specificity but with low sensitivity. Pre-NACT DM and DBT features did not reliably predict response to NACT, and pCR in this study. DM may be better than DBT for assessing response to NACT in the presence of radio-opaque markers/clips. Citation Format: Agarwal G, Sonthineni C, Mohindra N, Jain N, Neyaz Z, Agrawal V, Krishnani N, Maylivahnan S, Mishra A, Lal P. Predicting pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) based on pre- and post-NACT digital mammography and digital breast tomosynthesis findings [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-11.

The objectives are To to compare the diagnostic performance of combined digital breast tomosynthesis (DBT) and digital mammography (DM) with that of DM alone, as a function of radiologists' experience with DBT. Ethical committee approval was obtained. Fifty cases (27 cancer, 23 normal), each containing both digital mammography (DM) and digital breast tomosynthesis (DBT) images, were reviewed by 26 radiologists, divided into three groups according to level of experience with DBT (none, workshop experience, and clinical experience). The radiologists' diagnostic performance using DM was compared with that using DM + DBT, and evaluated by area under receiver-operating characteristic curve (AUC), jackknife free-response receiver-operator characteristics figure of metric (JAFROC FOM), sensitivity, location sensitivity, and specificity. For all readers combined, performance using DM + DBT was significantly higher than for DM alone by both AUC (0.788 vs 0.681, p < 0.001) and JAFROC FOM (0.745 vs 0.621, p < 0.001). Similar results were obtained for readers with no DBT experience (AUC 0.775 vs 0.682, p = 0.004; JAFROC FOM 0.695 vs 0.603, p = 0.016) and with clinical DBT experience (AUC 0.789 vs 0.681, p = 0.042; and JAFROC FOM 0.764 vs 0.632, p = 0.031). Addition of DBT to DM significantly improves radiologists' diagnostic performance whether or not they have prior DBT experience. • Adding DBT to DM increased the number of detected cancers • DBT + DM led to more accurate localization of breast cancers than DM • Addition of DBT improved radiologists' performance regardless of prior DBT experience • High-volume radiologists with different DBT experience levels performed similarly on DM + DBT.

Breast cancer screening examinations using digital breast tomosynthesis (DBT) has been shown to be associated with decreased false-positive test results and increased breast cancer detection compared with digital mammography (DM). Little is known regarding the size and stage of breast cancer types detected and their association with age and breast density. To determine whether screening examinations using DBT detect breast cancers that are associated with an improved prognosis and to compare the detection rates by patient age and breast density. This retrospective analysis of prospective cohort data from 3 research centers in the Population-based Research Optimizing Screening Through Personalized Regimens (PROSPR) consortium included data of women aged 40 to 74 years who underwent screening examinations using DM and DBT from January 1, 2011, through September 30, 2014. Statistical analysis was performed from November 8, 2017, to August 14, 2018. Use of DBT as a supplement to DM at breast cancer screening examination. Recall rate, cancer detection rate, positive predictive value, biopsy rate, and distribution of invasive cancer subtypes. Among 96 269 women (mean [SD] patient age for all examinations, 55.9 [9.0] years), patient age was 56.4 (9.0) years for DM and 54.6 (8.9) years for DBT. Of 180 340 breast cancer screening examinations, 129 369 examinations (71.7%) used DM and 50 971 examinations (28.3%) used DBT. Screening examination with DBT (73 of 99 women [73.7%]) was associated with the detection of smaller, more often node-negative, HER2-negative, invasive cancers compared with DM (276 of 422 women [65.4%]). Screening examination with DBT was also associated with lower recall (odds ratio, 0.64; 95% CI, 0.57-0.72; P < .001) and higher cancer detection (odds ratio, 1.41; 95% CI, 1.05-1.89; P = .02) compared with DM for all age groups even when stratified by breast density. The largest increase in cancer detection rate and the greatest shift toward smaller, node-negative invasive cancers detected with DBT was for women aged 40 to 49 years. For women aged 40 to 49 years with nondense breasts, the cancer detection rate for examinations using DBT was 1.70 per 1000 women higher compared with the rate using DM; for women with dense breasts, the cancer detection rate was 2.27 per 1000 women higher for DBT. For these younger women, screening with DBT was associated with only 7 of 28 breast cancers (25.0%) categorized as poor prognosis compared with 19 of 47 breast cancers (40.4%) when screening with DM. The findings suggest that screening with DBT is associated with increased specificity and an increased proportion of breast cancers detected with better prognosis compared with DM. In the subgroup of women aged 40 to 49 years, routine DBT screening may have a favorable risk-benefit ratio.

INTRODUCTION: Breast Tomosynthesis (DBT) is a procedure developed from digital mammography unit to enable the acquisition of a three-dimensional (3D) volume of thinsection data. The slice examination of breasts can reduce or even eliminate tissue overlap. The purpose of this study was to evaluate if breast tomosynthesis can help to differentiate the assymetries from the overlapping tissues. MATERIALS AND METHODS: A total of 48 cases of asymmetries were referred to perform stereotactic guided core needle biopsy or vacuum assisted biopsy. Each case was analyzed with full field digital mammography(FFDM) and with digital breast tomosynthesis (DBT) previously to the procedure. The study included 47 women (age range 34-78 years, mean age 44, 3 years;) and all the lesions were sampled. The histopathologic results were compared with those obtained with FFDM and DBT. RESULTS: of the 48 cases of asymmetries, 19 (39, 58%) did not change with DBT and 27 (60, 41%) attenuated or disappeared. Among the 19 lesions, the stereotactic guided biopsy diagnosed 8 cases of breast cancer (4 invasive ductal carcinoma, 3 invasive lobular carcinoma, 1 ductal carcinoma in situ), 1 of lobular neoplasia, 1 atypical ductal hyperplasia, 6 of fibroadenoma and 3 cases of normal breast tissue. There were no cases of breast cancer or atypical hyperplasia in those images that attenuated or disappeared with DBT. In this study the biopsy could be avoided in 60, 41% of the cases of asymmetries with the performance of the DBT. DISCUSSION: These results indicate that DBT can be useful in the differentiation between the asymmetries and the overlapping tissues, allowing a decrease in the number of unnecessary biopsies in these cases.

Background Digital breast tomosynthesis (DBT) has been shown to help increase cancer detection compared with two-dimensional digital mammography (DM). However, it is unclear whether additional tumor detection will improve outcomes or lead to overdiagnosis of breast cancer. Purpose This study aimed to compare cancer types and stages over 3 years of DM screening and 10 years of DBT screening to determine the effect of DBT. Materials and Methods A retrospective search identified breast cancers detected by using screening mammography from August 2008 through July 2021. Data collected included demographic, imaging, and pathologic information. Invasive cancers 2 cm or larger, human epidermal growth factor 2-positive or triple-negative tumors greater than 10 mm, axillary nodes positive for cancer, and distant organ spread were considered advanced cancers. The DBT and DM cohorts were compared and further analyzed by prevalent versus incident examinations. False-negative findings were also assessed. Results A total of 1407 breast cancers were analyzed (142 with DM, 1265 with DBT). DBT showed a higher rate of cancer depiction than DM (5.3 vs four cancers per 1000, respectively; P = .001), with a similar ratio of invasive cancers to ductal carcinomas in situ (76.5%:23.5% [968 and 297 of 1265, respectively] vs 71.1%:28.9% [101 and 41 of 142, respectively]). Mean invasive cancer size did not differ between DM and DBT (1.44 cm ± 0.93 [SD] vs 1.36 cm ± 1.14, respectively; P = .49), but incident DBT cases were smaller than prevalent cases (1.2 cm ± 1.0 vs 1.6 cm ± 1.4, respectively; P < .001). DBT and DM had similar rates of invasive cancer subtypes: low grade (26.5% [243 of 912] vs 29% [28 of 96], respectively), moderate grade (57.2% [522 of 912] vs 51% [49 of 96], respectively), and high grade (16.1% [147 of 912] vs 20% [19 of 96], respectively) (P = .65). The proportion of advanced cancers was lower with DBT than DM (32.6% [316 of 968] vs 43.6% [44 of 101], respectively; P = .04) and between DBT prevalent and incident screening (39.1% [133 of 340] vs 29.1% [183 of 628], respectively; P = .003). There was no difference in interval cancer rates (0.14 per 1000 with DM and 0.2 per 1000 with DBT; P = .42) for both groups. Conclusion DBT helped to increase breast cancer detection rate and depicted invasive cancers with a lower rate of advanced cancers compared with DM, with further improvement observed at incident rounds of screening. © RSNA, 2024 See also the editorial by Kim and Woo in this issue.

Diagnostic Management Pathways for Workup of Abnormal Screening With Digital Mammography Versus Digital Breast Tomosynthesis.

Objectives: Mammographic density (MD) is the amount of fibroglandular breast tissue, which appears relatively radiopaque on mammography when compared with fat that appears radiolucent. It may obscure an underlying breast cancer (BC), thus decreases mammographic sensitivity. MD is also an independent BC risk factor. MD is most commonly classified by the Breast Imaging Reporting and Data System (BI-RADS), fifth edition, 2012, where breast density is determined by radiologists using visual assessment that is subject to inter-rater variability. The term “dense breasts” refers to either heterogeneously dense or extremely dense breasts (category C or D), accounting for approximately 47%–50% of women. Supplemental screening modalities, such as digital breast tomosynthesis (DBT), MRI, and ultrasound, when combined with digital mammography (DM) have shown to be effective in the identification of mammographically occult breast lesions in high breast density patients. In this study, we examined the potential value of available screening modalities and their importance in patients with increased MD. Methodology: We conducted a systematic review of the literature via MEDLINE assessing the clinical importance of MD and its role in supplemental screening protocols. Results: Reduced mammographic sensitivity — Mammographic sensitivity rate is adversely proportional to MD. Breast stromal component and hence stromal stiffening promote an increase in MD. Another important factor is that extracellular matrix stiffness has been found to be tumorigenic and is significantly associated with BC. As a consequence, the combined relative BC risk is increased exponentially in levels A, B, C, and D BI-RADS categories, respectively. Supplemental screening modalities — To overcome the limitations of digital mammography in higher MD categories, the introduction of DBT has significantly improved BC detection and reduced recall rates when added to mammography. Both STORM-1 and STORM-2 trials showed the significant improvement in BC detection rate when DBT was combined with DM. On the other hand, MBTST trial revealed an increase of false-positive rates when BC screening was carried out with DBT alone. In another multicenter study, the ACRIN Protocol 6666 established that the addition of ultrasound (US) to DM in women within BI-RADS C and D groups will identify an additional 1.1–7.2 cancers per 1,000 high-risk women, but substantially increase the number of false positive results. Breast MRI may be offered as supplemental screening modality in women with heterogeneous or extremely dense breast tissue. The combination of MRI with DM and US in screening of heterogeneous or extremely dense breasts with at least one risk factor for BC produces a 100% sensitivity rate. Also, supplemental MRI screening in women with extremely dense breasts can reduce the incidence of undetected interval BC. On the contrary, the addition of MRI possesses low specificity rates and increased cost. Conclusions: Increased BD is a common mammographic finding in women. Although very common, its association with reduced mammographic sensitivity and consequently BC detection masking is of high clinical significance. Additionally, BD alone is a risk factor for BC, despite the fact that the exact mechanisms of tumorigenesis associated to it are yet to be fully understood. Supplemental screening modalities, such as DBT, MRI, and US, when combined with DM have been shown to be effective in the identification of mammographically occult BC in high BD patients. The increased number of unnecessary biopsies as a result of increased false positivity rates may increase the physical and psychological patient burden. Since there is no consensus for routine use of DBT or MRI in screening of women with increased BD, the decision for supplemental screening should be personalized.

Invasive lobular carcinoma (ILC) is the second-most common histologic subtype of breast cancer, constituting 5% to 15% of all breast cancers. It is characterized by an infiltrating growth pattern that may decrease detectability on mammography and US. The use of digital breast tomosynthesis (DBT) improves conspicuity of ILC, and sensitivity is 80% to 88% for ILC. Sensitivity of mammography is lower in dense breasts, and breast tomosynthesis has better sensitivity for ILC in dense breasts compared with digital mammography (DM). Screening US identifies additional ILCs even after DBT, with a supplemental cancer detection rate of 0 to 1.2 ILC per 1000 examinations. Thirteen percent of incremental cancers found by screening US are ILCs. Breast MRI has a sensitivity of 93% for ILC. Abbreviated breast MRI also has high sensitivity but may be limited due to delayed enhancement in ILC. Contrast-enhanced mammography has improved sensitivity for ILC compared with DM, with higher specificity than breast MRI. In summary, supplemental screening modalities increase detection of ILC, with MRI demonstrating the highest sensitivity.

No consensus exists on digital breast tomosynthesis (DBT) utilization for breast cancer detection. We performed a diagnostic test accuracy systematic review and meta-analysis comparing DBT, combined DBT and digital mammography (DM), and DM alone for breast cancer detection in average-risk women. MEDLINE and EMBASE were searched until September 2018. Comparative design studies reporting on the diagnostic accuracy of DBT and/or DM for breast cancer detection were included. Demographic, methodologic, and diagnostic accuracy data were extracted. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. Accuracy metrics were pooled using bivariate random-effects meta-analysis. The impact of multiple covariates was assessed using meta-regression. CRD 42018111287. Thirty-eight studies reporting on 488,099 patients (13,923 with breast cancer) were included. Eleven studies were at low risk of bias. DBT alone, combined DBT and DM, and DM alone demonstrated sensitivities of 88% (95% confidence interval [CI] 83-92), 88% (CI 83-92), and 79% (CI 75-82), as well as specificities of 84% (CI 76-89), 81% (CI 73-88), and 79% (CI 71-85), respectively. The greater sensitivities of DBT alone and combined DBT and DM compared to DM alone were preserved in the combined meta-regression models accounting for other covariates (p = 0.003-0.006). No significant difference in diagnostic accuracy between DBT alone and combined DBT and DM was identified (p = 0.175-0.581). DBT is more sensitive than DM, while the addition of DM to DBT provides no additional diagnostic benefit. Consideration of these findings in breast cancer imaging guidelines is recommended. • Digital breast tomosynthesis with or without additional digital mammography is more sensitive in detecting breast cancer than digital mammography alone in women at average risk for breast cancer. • The addition of digital mammography to digital breast tomosynthesis provides no additional diagnostic benefit in detecting breast cancer compared to digital breast tomosynthesis alone. • The specificity of digital breast tomosynthesis with or without additional digital mammography is no different than digital mammography alone in the detection of breast cancer.