Table 3 Overview of studies on association between breast density and breast cancer-specific survival
From: Breast density and breast cancer-specific survival by detection mode
Study | Country | Setting | Study design | Breast cancer deaths (N) | Density measurement | Outcome (univariable or minimally adjusted) | Outcome (multivariable) |
|---|---|---|---|---|---|---|---|
Olsen [20] | Denmark | Screening interval 2y, age 50-69y, 1991–2001 | Cohort. Inclusion of interval and screen-detected cancer deaths. | Fatty: 37 Mixed/dense: 53 | Dichotomized measure with Fatty breasts and Mixed/Dense breasts | Dense vs. Fatty Case fatality RR 0.53 (0.34–0.82)a, Mortality: RR 1.78 (95%CI 1.17–2.72) | |
Olsson [21] | Sweden | Screening interval 18 to 24 m, age 50-69y, 1991–1996 | Cohort. Inclusion of non-symptomatic and symptomatic cancer deaths. | Fatty: 7 Moderate: 37 Dense: 32 | Modification of the BI-RADS classification with Fatty, Moderate, and Dense breasts | Dense vs. Fatty All: HR 1.92 (0.85–4.35) Non-symptomatic: HR 1.47 (0.41–5.27) Symptomatic: HR 2.33 (0.80–6.80) | Dense vs. Fatty All: HR 2.63 (1.10–6.30)b Non-symptomatic: HR 2.04 (0.49–8.49) Symptomatic: HR 3.40 (1.06–10.90) |
Porter [22] | England | Screening interval 3y, age 50-64y, since 1987 | Cohort. Inclusion of interval and screen-detected cancer deaths. | BI-RADS 1: 186 BI-RADS 2: 126 BI-RADS 3: 373 BI-RADS 4: 74 | BI-RADS breast density | Dense vs. Fatty No significant difference all cancer deaths (p = 0.12), screen-detected (p = 0.75), or interval (p = 0.82) | |
van Gils [23] | The Netherlands | Screening interval 2y, age 50-69y, 1977–1994 | Cohort. Inclusion of screen-detected cancer deaths. | 26 | Visual assessment fatty (≤ 25%) and dense (> 25%) | Dense vs. Fatty 10-year survival dense 73% vs. fatty 83% (survival p = 0.07) in first rounds, later rounds 10-year survival dense 89% vs. fatty 96% (no significant difference, p = 0.48) | |
Eriksson [24] | Sweden | Screening interval 24 m, age 50-74y, 1993–1995 | Cohort. Inclusion of interval and screen-detected cancer deaths. | Dense: 345 Nondense: 1055 | Cumulus dichotomized into nondense (< 25%) and dense (≥ 25%) | Interval vs. Screen-detected All: HR 3.50 (2.25–5.44)c Dense: HR 3.00 (1.26–7.17) Nondense: HR 3.62 (2.17–6.06) | Interval vs. Screen-detected All: HR 1.69 (1.03–2.76)d Dense: HR 1.26 (0.47–3.38) Nondense: HR 1.76 (1.01–3.09) |
Gierach [25] | US | Age > 30y, 1996–2005 | Cohort. Inclusion of screen-detected, interval, other screen-detected, clinically detected, and other cancer deaths. | BI-RADS 1: 72 BI-RADS 2: 346 BI-RADS 3: 387 BI-RADS 4: 84 | BI-RADS breast density | Extremely dense vs. Scattered All: HR 0.83 (0.65–1.07)e | Extremely dense vs. Scattered All: HR 0.92 (0.71–1.19)f |
Maskarinec [26] | US | 1993–1996 | Case-control. | Low density: 12 High density: 15 | Cumulus dichotomized into low (< 35%) and high (> 35%) | High vs. Low percent density All: HR 0.83 (0.36–1.92)g | |
Chiu [27] | Sweden | Age 45-59y, 1977–2004 | Cohort. Mammographically detected, interval cancer, and refuser cases. | Dense: 28 Nondense: 99 | Tabár dichotomized into dense (IV and V) and nondense (I-III) | Dense vs. Fatty All: HR 1.41 (0.92–2.14) | Dense vs. Fatty All: HR 1.75 (0.99–3.10)h |
Zhang [28] | US | 1994–2008 | Cohort. | BI-RADS breast density dichotomized into dense (3 and 4) and fatty (1 and 2) | Dense vs. Fatty All: HR 0.91 (p-value = 0.1242)i |