Kin-cohort estimates for familial breast cancer risk in relation to variants in DNA base excision repair, BRCA1 interacting and growth factor genes

Table 1 Descriptive characteristics of breast cancer cases (probands) from the US Radiologic Technologist study and their first degree relatives with and without breast cancer.

Characteristic at time of interview (1999–2001)	Radiologic technologists with breast cancer* (n = 748)		First degree female relatives with breast cancer (n = 190)		First degree female relatives without breast cancer (N = 2240)
	N	%	N	%	N	%
Year of birth
<1900	0	0.0	19	10.0	165	7.4
1900–29	155	20.7	110	57.9	702	31.3
1930–39	202	27.0	28	14.7	234	10.5
1940–49	276	36.9	20	10.5	271	12.1
1950–59	115	15.4	10	5.3	304	13.6
≥1960+	0	0.0	3	1.6	564	25.2
Calendar year of breast cancer diagnosis
<1975	43	5.8	56	29.5	NA**	---
1975–79	42	5.6	16	8.4	NA	---
1980–84	98	13.1	20	10.5	NA	---
1985–89	172	23.0	35	18.4	NA	---
1990–94	313	41.8	31	16.3	NA	---
≥1995	80	10.7	32	16.8	NA	---
Age at diagnosis
<40	114	15.2	22	11.6	NA	---
40–49	299	40.0	28	14.7	NA	---
50–59	203	27.1	42	22.1	NA	---
60–69	90	12.0	49	25.8	NA	---
≥70	42	5.6	49	25.8	NA	---
Relationship to the radiologic technologist (index proband)
Mother	NA	---	98	51.6	648	28.9
Sister	NA	---	85	44.7	882	39.4
Daughter	NA	---	7	3.7	710	31.7

* Includes invasive breast cancer and ductal carcinoma in situ **NA is Not applicable

ISSN: 1471-2407