The impact of in situ breast cancer and family history on risk of subsequent breast cancer events and mortality - a population-based study from Sweden

Table 4 Standardized mortality ratio (SMR) with second breast events (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

	All		No family history		Family history		<50		>50
	Deaths (n)	SMR	Deaths (n)	SMR	Deaths (n)	SMR	Deaths (n)	SMR	Deaths (n)	SMR
	(95 % CI)		(95 % CI)		(95 % CI)		(95 % CI)		(95 % CI)
Overall	1343	1.28	1258	1.2	85	1.44	122	2.19	1221	1.24
Overall	(1.2–1.2)		(1.2–1.4)		(1.2–1.8)		(1.8–2.6)		(1.2–1.3)
No event + 2^nd contralateral in situ	927	1.01	875	1.0	52	1.02	58	1.17	869	1.00
No event + 2^nd contralateral in situ	(1.0–1.1)		(0.9–1.1)		(0.8–1.3)		(0.8–1.5)		(0.9–1.1)
Second invasive^a	132	2.06	122	2.03	10	2.54	29	8.03	103	1.7
Second invasive^a	(1.7–2.4)		(1.7–2.4)		(1.2–4.7)		(5.4–11.5)		(1.4–2.1)
Second ipsilateral invasive	63	2.16	58	2.12	5^b	2.75	17	12.89	46	1.65
Second ipsilateral invasive	(1.7–2.8)		(1.6–2.7)		(0.9–6.4)		(7.5–20.6)		(1.2–2.2)
Second contralateral invasive	55	1.99	49	1.92	6^b	2.82	10	7.85	45	1.71
Second contralateral invasive	(1.5–2.6)		(1.4–2.5)		(1.0–6.2)		(3.8–14.4)		(1.2–2.3)

^aIncludes ipsilateral, contralateral and missing side. ^bOne subject had both ipsilateral and contralateral invasive breast cancer, which is why the total is 6 + 5 = 11 > 10

ISSN: 1465-542X