Table 2 Standardized incidence ratio (SIR) of a second breast event (contralateral in situ or ipsilateral or contralateral invasive breast cancer) after diagnosis of first in situ breast cancer and its 95 % CI, by type of second breast event and family history

(95 % CI)

(95 % CI)

(95 % CI)

(95 % CI)

Second breast cancer^a

886

5.1 (4.8–5.4)

781

5.0 (4.6 − 5.3)

105

6.3 (5.1–7.6)

1.2 (1.0–1.4)

Second contralateral in situ ^a

118

16.0 (13.2–19.1)

104

15.8 (12.9–19.2)

14

17.4 (9.5– 29.3)

1.1 (0.6–1.9)

Second invasive^b

768

4.6 (4.2–4.9)

677

4.4 (4.1–4.7)

91

5.6 (4.5–6.9)

1.2 (1.0–1.5)

Second ipsilateral invasive^c

376

4.3 (3.8–4.7)

334

4.2 (3.8–4.7)

42

5.0 (3.6–6.7)

1.00 (0.7– 1.4)

Second contralateral invasive^c

303

3.4 (3.1–3.8)

262

3.3 (2.9–3.7)

41

4.8 (3.5–6.5)

1.5 (1.0–2.0)