Table 1.

Descriptive characteristics for study participants at birth, menarche, first birth, and overall study: Western New York exposures and breast cancer study (WEB study)

Premenopausal Women
Birth
Menarche
First birth
Overall study

Cases (n = 164)
Controls (n = 283)
Cases (n = 204)
Controls (n = 386)
Cases (n = 181)
Controls (n = 371)
Cases (n = 325)
Controls (n = 610)
Age [y, mean (SD)]44.3 (4.5)43.8 (4.5)44.5 (4.5)43.8 (4.6)44.5 (4.7)44.2 (4.6)44.9 (4.6)44.1 (4.6)
Education [y, mean (SD)]13.7 (2.6)14.2 (2.2)13.9 (2.0)14.1 (2.2)13.9 (2.0)14.1 (2.1)14.0 (2.3)14.2 (2.2)
Age at menarche [y, mean (SD)]12.5 (1.5)12.6 (1.6)12.5 (1.6)12.6 (1.6)12.5 (1.4)12.7 (1.6)12.5 (1.6)12.6 (1.6)
Age at first birth [y, mean (SD)]25.1 (4.8)26.1 (4.5)25.4 (4.9)25.7 (4.8)25.7 (7.2)26.1 (4.9)25.0 (5.1)25.8 (4.8)
Body mass index [mean (SD)]27.4 (7.2)27.3 (6.3)27.0 (6.9)27.6 (6.8)27.2 (7.2)27.3 (6.6)27.2 (6.8)27.6 (6.7)
TSP [μg/m3,mean (SD)]135.7 (27.1)138.2 (33.4)122.4 (34.4)124.0 (37.2)65.6 (32.0)69.2 (36.7)
Benign breast disease (yes)34%22%35%20%35%22%37%21%
First-degree relative with breast cancer (yes)
23%
10%
23%
10%
21%
9%
21%
10%
Postmenopausal women
Birth
Menarche
First birth
Overall study
Cases (n = 357)Controls (n = 524)Cases (n = 469)Controls (n = 757)Cases (n = 435)Controls (n = 782)Cases (n = 841)Controls (n = 1,495)
Age [y, mean (SD)]62.3 (7.9)62.1 (9.1)61.9 (8.1)62.2 (9.1)62.8 (8.3)63.0 (8.9)63.0 (8.5)63.4 (8.9)
Education [y, mean (SD)]13.4 (2.5)13.0 (2.1)13.4 (2.5)13.0 (2.1)13.2 (2.4)13.0 (2.2)13.3 (2.6)13.0 (2.3)
Age at menarche [y, mean (SD)12.4 (1.5)12.8 (1.7)12.5 (1.5)12.8 (2.1)12.6 (1.6)12.8 (1.7)12.6 (1.6)12.8 (1.7)
Age at first birth [y, mean (SD)]23.9 (4.5)23.7 (3.9)23.9 (4.5)23.7 (6.3)24.3 (4.8)24.1 (4.4)23.8 (4.7)23.5 (4.3)
Body mass index [mean (SD)]28.6 (5.9)28.4 (6.1)28.6 (5.8)26.7 (6.3)28.9 (5.8)28.5 (5.9)28.9 (6.0)28.5 (6.1)
Age at menopause [y, mean (SD)]48.3 (5.0)47.4 (6.0)48.0 (5.3)47.6 (6.0)45.9 (5.6)47.6 (6.0)48.3 (5.4)47.4 (6.3)
TSP [μg/m3,mean (SD)]141.4 (31.2)137.7 (28.9)139.1 (31.6)138.1 (31.2)126.7 (36.8)127.9 (36.6)
Benign breast disease (yes)36%22%34%23%34%21%33%22%
First-degree relative with breast cancer (yes)20%14%19%15%21%13%20%14%