Skip to main content

Table 1 Relative risk of breast cancer in women with family history of in situ and invasive breast cancer in first-degree and second-degree relatives

From: Risk of invasive breast cancer in relatives of patients with breast carcinoma in situ: a prospective cohort study

Family history of breast tumor

Age at invasive breast cancer diagnosis in index woman (years)

All ages

< 50

≥ 50

Obs

SIR

95% CI

Obs

SIR

95% CI

Obs

SIR

95% CI

No family history of in situ or invasive

102,177

Reference

31,693

Reference

70,484

Reference

1 FDR in situ

575

1.5

1.4–1.7

126

1.6

1.3–1.9

449

1.5

1.4–1.7

1 FDR invasive

11,990

1.7

1.7–1.8

2874

2.0

1.9–2.1

9116

1.7

1.6–1.7

1 SDR in situ

132

1.2§

1.0–1.4

67

1.1

0.9–1.4

65

1.3

1.0–1.7

1 SDR invasive

2309

1.3§

1.3–1.4

1478

1.3

1.3–1.4

831

1.3

1.2–1.4

1 SDR invasive + 1 SDR in situ

44

2.4

1.7–3.2

32

2.4

1.6–3.4

12

2.3

1.2–4.1

2 SDRs invasive

223

1.6

1.4–1.8

180

1.7

1.5–2.0

43

1.2

0.9–1.6

1 FDR in situ + 1 SDR invasive

33

2.2

1.5–3.1

24

2.8

1.8–4.2

9

1.3

0.6–2.6

1 FDR invasive + 1 SDR invasive

453

2.3

2.1–2.5

248

2.6

2.3–2.9

205

2.0

1.8–2.3

1 FDR invasive + 1 FDR in situ

89

2.6

2.1–3.2

9

3.5

1.6–6.6

80

2.5

2.0–3.1

2 FDRs invasive

689

2.7

2.5–2.9

86

4.6

3.7–5.7

603

2.6

2.4–2.8

  1. All SIRs were adjusted for age, socio-economic status, period, and region. Bold values are statistically significant
  2. Obs observed number of breast cancer cases, SIR standardized incidence ratio, FDR first-degree relative, SDR second-degree relative, CI confidence interval
  3. §Example: Having one second-degree relative with breast carcinoma in situ was associated with a 20% increased risk of invasive breast cancer, which was comparable to 30% increase in risk associated with having a second-degree relative with invasive breast cancer