The effect of length of birth interval on the risk of breast cancer by subtype in grand multiparous women

BMC Cancer

Table 1 Number (N) and percentage (%) of women with first breast cancer diagnosed after 5th birth (1974–2014) among 47,479 women in Finland born after 1935 and registered to have at least five biological children, by histology, stage of cancer, number of children (parity) and age at breast cancer diagnosis

Variable	Age at breast cancer diagnosis						Percentage of breast cancers diagnosed in age 50+ out of all breast cancers
	All ages		< 50 years		50+ years
	N	%	N	%	N	%
All	1354	100	312	100	1042	100	77
Histology & stage
Ductal	1037	77	252	81	785	75	76
Localized	537	52	95	38	442	56	82
Advanced	434	42	142	56	292	37	67
Unknown	66	6	15	6	51	7	77
Lobular	207	15	32	10	175	17	86
Localized	79	38	8	25	71	41	90
Advanced	108	52	23	72	85	49	79
Unknown	20	10	1	3	19	10	95
Other/unknown	110	8	28	9	82	8	75
Parity
5	857	63	179	58	678	65	79
6	264	20	60	19	204	20	77
7	93	7	29	9	64	6	69
8+	140	10	44	14	96	9	69

ISSN: 1471-2407