TABLE 2:
Summary of Results of Studies of Supplemental Breast MRI for Screening Women With Dense Breasts
| Study Finding or Feature | ACRIN 6666 Trial [54] | Kuhl et al. 2017 [81] | DENSE Trial [82] | ECOG-ACRIN 1141 Trial [87] | |
|---|---|---|---|---|---|
| Breast density | Density C or Da | All densities; 1282 (60.5%) of women had density C or D | Density D | Density C or D | |
| Cancer risk | ≥ 2.5% 5-y risk by Claus or Gail model OR ≥ 1.7% 5-y risk if patient had extremely dense breasts, or PHBC | Average risk (< 15% lifetime risk by Gail model) | Risk level not specified | Median 5-year BCSC risk 1.6% (range, 0.3–7.8%) | |
| Type of conventional imaging performed | Film mammography or 2D DM plus US | 2D DM; 1335 (63%) underwent screening US | 2D DM | Tomosynthesis | |
| Total no. of women and MRI examinations | 612 | 3861 MRI examinations in 1021 women | 4783 | 1444 | |
| No. of women with PHBC | 275 | 0 | NR | 8 | |
| Breast imaging modality | Full-protocol MRI | Full-protocol MRI | Full-protocol MRI | DBT | |
| Incremental CDR per 1000 women screened (no. of women with cancer/total no. of women screened) | 14.7 (9/612) | Overall, 15.5 (60/3861) | 16.5 (79/4783) | 0.7 (1/1444)b | |
| Prevalence screening, 22.6 (48/2120); incidence screening, 6.9 (12/1741) | |||||
| Prevalence screening of dense breasts only, 20.3 (26/1282) | |||||
| Incremental invasive CDR per 1000 women screened (no. of women with cancer/total no. of women) | 13.1 (8/612) | Prevalence screening, 14.2 (30/2120); incidence screening, 5.7 (10/1741) | 13.4 (64/4783) | 0 | |
| Median size of invasive cancer (mm) | 8.5 | 8 | 9.5 | NR | |
| Staged, node-negative invasive cancers, % (of those staged, no. of node-negative invasive cancer/total no. of women with invasive cancer) | 100 (7/7) | 90 (37/41) | 86 (55/64) | NR | |
| Recall rate, % (no. of recalls/total no. of examinations)c | 25.9 (159/612) | 16.3 (346/2120) | 9.5 (454/4783) | 10.1 (146/1444) | |
| PPV3, malignancies as % of of biopsies performed | 23.1 (12/52) | 35.7 (61/174) | 26.3 (79/300) | 31.0 (9/29) | |
| Sensitivity, %d (n/N) | 87.5 (14/16) | 100 (61/61) | 95.2 (79/83) | 39.1 (9/23) | |
| Specificity, %e | 75.7 (451/596) | Prevalence screening, 95.8 (1986/2072); incidence screening, 98.4 (1701/1728) | 92.1 (4329/4700)f | 97.4 (1371/1407) | |
| Interval cancer rate per 1000 screening examinations | NR | 0 | 0.8 (4/4783) | NA | |
Note—ACRIN = American College of Radiologic Imaging Network, ECOG = Eastern Cooperative Oncology Group, PHBC = personal history of breast cancer, BCSC = Breast Cancer Surveillance Consortium, DM = digital mammography, NR = not reported, DBT = digital breast tomosynthesis, CDR = cancer detection rate, PPV3 = positive predictive value 3, NA = not applicable.
BI-RADS breast density category C denotes heterogeneously dense breasts and category D denotes extremely dense breasts.
Of 17 invasive cancers, 10 were seen on abbreviated MRI only. Of six ductal carcinomas in situ, four were seen on abbreviated MRI only, one was seen on DBT only, and one was seen on both abbreviated MRI and DBT.
Abnormal interpretation rate.
Values in parentheses denote number of cancers detected by supplemental MRI/cancers diagnosed within screening interval.
Values in parentheses denote number of true-negative MRI examinations/women without a cancer diagnosis within the screening interval.
The published study reported 92.0%; however, it appears that four interval cancers were erroneously included in the denominator when the percentage was calculated.