Table 1.

Descriptive characteristics of female breast cancer patients, ages 20–84 years at breast cancer diagnosis, in the National Cancer Registry of Ireland (NCRI), 2004–2013, with 15,878,592 woman-years in the general population at risk.

ASR per 100,000	Total (n=24,845) 163.1		ER-positive (n=19,264) 126.1		ER-negative (n=4,161) 27.4		ER-unknown (n=1,420) 9.5		P value for heterogeneity*
	n	%	n	%	n	%	n	%
Age									<0.001
<50 years	6,429	26	4,859	25	1,262	30	308	22
50–64 years	10,596	43	8,438	44	1,657	40	501	35
≥65 years	7,820	34	5,967	31	1,242	30	611	43
Mean (Std Dev)	58 (12.7)		58 (12.5)		57 (13.1)		61.53 (13.9)
Median (Range)	58 (20–84)		58 (21–84)		57 (21–84)		62 (27–84)
Year of Diagnosis									<0.001
2004–2005	4,212	17	2,968	15	831	20	413	29
2006–2009	9,835	40	7,517	39	1,728	42	590	42
2010–2013	10,798	43	8,779	46	1,602	39	417	29
HER2 status									0.362
Negative	17,412	70	14,782	77	2,353	57	277	20
Positive	3,926	16	2,390	12	1,439	35	97	7
Unknown	3507	14	2,092	11	369	9	1,046	74
Stage									<0.001
Stage 0*	114	0	34	0	35	1	45	3
Stage 1	7,949	32	3,580	34	988	24	381	27
Stage 2	11,074	45	8,688	45	1,926	46	460	32
Stage 3	3,032	12	2,228	12	678	16	126	9
Stage 4	1,715	7	1,162	6	355	9	198	14
TNM unavailable	84	0	14	0	12	0	58	4
Unknown	877	4	558	3	167	4	152	11
Grade									<0.001
Grade 1	2,613	11	2,432	13	42	1	139	10
Grade 2	12,426	50	11,056	57	899	22	471	33
Grade 3	8,374	34	5,007	26	2,991	72	376	26
Grade 4	26	0	11	0	12	0	3	0
Unknown	1,406	6	758	4	217	5	431	30

ASR; age-standardized incidence rate per 100,000 woman-years; Stage 0, including invasive Paget disease

^*P value for ER-positive vs. ER-negative comparison