Table 1. Model Input Parameters.

Parameter	ATM	PALB2 a	CHEK2 a	Source
Breast cancer risk and subtype
Odds ratio of breast cancer	1.82	3.67	2.36	CARRIERS Consortium5 (age-specific odds ratios available in eTable 1 in Supplement 1)
Subtype distributions, %				CARRIERS Consortium5
ER positive and ERBB2 negative	70	47	67
ER positive and ERBB2 positive	22	13	22
ER negative and ERBB2 positive	4	1	5
ER negative and ERBB2 negative	4	39	7
	MMG	MRI	MMG plus MRI
Screening performance
Sensitivity, %	Overall, 40.8	90.8 (84.7)	96.0 (92.2)	Chiarelli et al,9 with age-specific adjustments for MMGb,c
	At age 30-39 y, 40.0
	At age 40-49 y, 40.4
	At age 50-69 y, 41.9
Specificity, %				Chiarelli et al9
Initial screening	88.0	79.7 (78.8 to 80.6)	72.2 (71.2 to 73.1)
With DBT	89.6	NA	73.8	Conant et al27d
Second or later screening	92.5	90.5 (89.9 to 91.0)	84.5 (83.8 to 85.2)
With DBT	94.1	NA	85.5	Conant et al27d
False-positive screenings with biopsy performed, %				Chiarelli et al9
Initial screening	19	36	28
Second or later screening	13	38	26
AJCC stage (screening-detected cancers), %				Chiarelli et al,9 adjusted for missing stage of cancers treated with NAC28
DCIS	22	22	23
I	48	58	57
II	24	15	15
III	6	4	4
Treatment and mortality
Treatment receipt	Guideline treatment by age, stage, and receptor status			NCCN29
Treatment effectiveness	Estimated from meta-analyses of randomized trials			Peto et al30
Nonbreast cancer mortality	Age-specific and birth cohort–specific all-cause mortality			Gangnon et al31

Abbreviations: AJCC, American Joint Committee on Cancer; BCSC, Breast Cancer Surveillance Consortium; CARRIERS, Cancer Risk Estimates Related to Susceptibility; DBT, digital breast tomosynthesis; DCIS, ductal carcinoma in situ; ER, estrogen receptor; MMG, mammography; MRI, magnetic resonance imaging; NA, not applicable; NAC, neoadjuvant chemotherapy; NCCN, National Comprehensive Cancer Network.

^a Values shown in parentheses were used in sensitivity analyses.

^b In the study by Chiarelli et al,⁹ all women received MMG and MRI performed concurrently, and sensitivity calculations for each modality included cancers detected by the other modality as false-negative screenings. The models were therefore calibrated with MMG and MRI performed concurrently, adjusting the individual performance of each modality until the model output matched the observed data.

^c Age-specific MMG sensitivity was derived from the overall sensitivity reported in the study by Chiarelli et al,⁹ by adjusting for differences in breast density by age based on data from the BCSC.

^d Specificity of MMG and MMG plus MRI were adjusted by decreasing false-positive screenings due to MMG by 15%.