Table 1. Descriptive characteristics of 28 765 women diagnosed with primary invasive breast cancer below the age of 70 years in Denmark, 1983–1999.

	Low-risk breast cancer (N=5809)		High-risk breast cancer (N=22 956)
Characteristic	N	%	N	%
Age at diagnosis
<44 years	903	16	4350	19
45–49 years	996	17	3620	16
50–54 years	970	17	3884	17
55–59 years	967	17	3717	16
60–64 years	1010	17	3751	16
65–69 years	963	17	3634	16
Year of diagnosis
1983–1987	1314	19	5569	81
1988–1992	1662	20	6561	80
1993–1997	1936	20	7513	80
1998–1999	897	21	3312	79
Menopausal status
Premenopausal	2274	39	9411	41
Postmenopausal	3535	61	13 545	59
Highest attained education
Basic school/high school	2565	44	10 905	48
Vocational training	1742	30	6621	29
Higher education	1123	19	3991	17
Unknown	379	7	1439	6
Occupation
Higher functionary	1072	18	4071	18
Lower functionary	1014	17	4047	18
Skilled worker	378	7	1575	7
Unskilled worker	677	12	2907	13
Unemployed or housewife	869	15	3459	15
Pensioner	1799	31	6897	30
Disposable household income a
–99 999 DKK	1369	24	6099	27
100 000–129 999 DKK	1482	26	6022	26
130 000–164 999 DKK	1309	23	5203	23
165 000–DKK	1649	28	5632	25
Cohabiting
Living with partner	4128	71	16 571	72
Single	1681	29	6385	28
Children living at home b
0	4735	82	18126	79
1	659	11	2641	11
2–5	415	7	2189	10
Housing status
Owner-occupied	3719	64	15 250	66
Rental	2090	36	7706	34
Size of dwelling
0–99 m2	2193	38	8474	37
100–124 m2	1168	20	4814	21
125–149 m2	1003	17	4083	18
⩾150 m2	1445	25	5585	24
Degree of urbanicity
Capital areas	944	16	2901	13
Suburbs	916	16	3175	14
Provincial cities	2197	38	8930	39
Rural areas	1752	30	7950	35
Mammography screening
Availablec	5087	88	21 322	93
Not available	722	12	1634	7
Comorbidity d
0	5324	92	21 132	92
1	384	6	1384	6
2+	101	2	440	2

Low-risk breast cancer: tumour size <2.0 cm, negative axillary lymph nodes, low histologic grade and oestrogen receptor positive; High-risk breast cancer: tumour size >2.0 cm, positive axillary lymph nodes, high histologic grade and oestrogen receptor negative.

^aHousehold disposable income in Danish crowns (DKK) after taxation and interest adjusted for number of persons in household.

^bChildren aged 0–17 years.

^cMammography screening was offered to all women aged 50–69 years living in Copenhagen municipality from 1991, Frederiksberg municipality from 1992 and Funen County from 1994.

^dPresence of these disorders as defined in Charlson index was defined as an in- or outpatient contact with one of the below diagnosis from 1978 to half a year prior to the diagnosis of breast cancer; Score 1: myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, ulcer disease, mild liver disease, diabetes type1, diabetes type2; Score 2: hemiplegia, moderate to severe renal disease, diabetes with end organ damage type1, diabetes with end organ damage type2; Score 3: moderate to severe liver disease; Score 6: AIDS; All cancer related diagnoses were excluded since first primary cancers only are in DBCG.