Table 6.

Women at low or high risk of breast cancer and non-BC death in each cohort

	5-year Breast cancer risk (threshold ≥ 3%)a,b	10-year Non-breast cancer death risk (threshold ≥ 50%)a,b	NHS development cohort	NHS validation cohort	BWHS
55–64 years	High	Low	8.1% (939)	7.9% (454)	7.0% (600)
	Low	Low	91.8% (10,586)	92.1% (5317)	93.0% (8031)
	Low	High	0.1% (9)	0.1% (3)	0.1% (5)
	High	High	0.0% (0)	0.0% (0)	0.0% (0)
65–74 years	High	Low	8.3% (1408)	8.2% (694)	5.9% (211)
	Low	Low	90.0% (15,262)	90.1% (7651)	91.6% (3278)
	Low	High	1.5% (257)	1.5% (129)	2.4% (85)
	High	High	0.2% (27)	0.2% (16)	0.2% (6)
75+ years	High	Low	6.6% (603)	6.1% (287)	5.6% (58)
	Low	Low	71.7% (6552)	72.7% (3426)	62.0% (639)
	Low	High	19.8% (1812)	19.5% (920)	30.5% (314)
	High	High	1.9% (173)	1.8% (83)	1.9% (20)

NHS = Nurses’ Health Study, BWHS = Black Women’s Health Study

^aGuidelines: The American Cancer Society recommends biennial screening for women ≥ 55 at average risk and stopping screening when life expectancy is < 10 years. The American College of Physicians recommends not screening any women ≥ 75 at low or average breast cancer risk or any women with < 10 year life expectancy. The United States Preventive Services Task Force recommends biennial screening for women 50–74 years and states the evidence is insufficient to recommend screening to women ≥ 75 but recommends consideration of women’s breast cancer risk and health [7, 8, 11]

^bBased on guidelines, we defined breast cancer risk as high when 5-year risk ≥ 3%; otherwise, we defined breast cancer risk as low. We defined mortality risk as high when 10-year mortality risk was ≥ 50%; otherwise, we defined mortality risk as low [36–39]