Table 1 Characteristics of breast cancer cases and matched controls
From: Plasma perfluoroalkyl substances and breast cancer risk in Brazilian women: a case–control study
Cases (n = 471) | Controls (n = 471) | Pa | |||||
|---|---|---|---|---|---|---|---|
Missing (n) | Missing (n) | ||||||
Age [years], mean (SD) | 53.3 (10.9) | 0 | 53.3 (10.7) | 0 | - | ||
Ethnicity, n (%) | 0 | 0 | - | ||||
Caucasian | 263 (55.84) | 264 (56.05) | |||||
Mixed | 84 (17.83) | 83 (17.62) | |||||
Black | 42 (8.92) | 42 (8.92) | |||||
Japanese Brazilian | 82 (17.41) | 82 (17.41) | |||||
Age at menarche, n (%) | 0 | 0 | 0.94 | ||||
< 12 years | 84 (17.83) | 82 (17.41) | |||||
12 years | 92 (19.53) | 100 (21.23) | |||||
13 years | 115 (24.42) | 103 (21.87) | |||||
14 years | 83 (17.62) | 94 (19.96) | |||||
≥ 15 years | 97 (20.59) | 92 (19.53) | |||||
Age at first birth, n (%) | 1 | 0 | 0.031 | ||||
Nulliparous women | 236 (50.21) | 263 (55.84) | |||||
< 25 years | 42 (8.94) | 48 (10.19) | |||||
25–26 years | 39 (8.30) | 36 (7.64) | |||||
27–28 years | 91 (19.36) | 71 (15.07) | |||||
≥ 29 years | 62 (13.19) | 53 (11.25) | |||||
Age at menopause, n (%) | 1 | 1 | 0.41 | ||||
Premenopausal women | 187 (39.79) | 173 (36.81) | |||||
< 48 years | 111 (23.62) | 124 (26.38) | |||||
48–50 years | 80 (17.02) | 72 (15.32) | |||||
51–52 years | 39 (8.30) | 46 (9.79) | |||||
≥ 53 years | 53 (11.28) | 55 (11.70) | |||||
Height [cm], meanb | 157.4 | 8 | 157.6 | 10 | 0.81 | ||
Body mass index [kg/m2], n (%) | 11 | 15 | 0.46 | ||||
< 21 | 48 (10.43) | 44 (9.65) | |||||
21 to < 24 | 103 (22.39) | 107 (23.46) | |||||
24 to < 27 | 129 (28.04) | 140 (30.70) | |||||
27 to < 30 | 95 (20.65) | 92 (20.18) | |||||
≥ 30 | 85 (18.48) | 73 (16.01) | |||||
Family history of breast cancer, n (%) | 30 (6.37) | 0 | 28 (5.94) | 0 | 0.79 | ||
History of benign breast disease, n (%) | 37 (7.86) | 0 | 31 (6.58) | 0 | 0.45 | ||
Number of births, n (%) | 0 | 0 | 0.033 | ||||
0 | 62 (13.16) | 53 (11.25) | |||||
1 | 67 (14.23) | 58 (12.31) | |||||
2 | 138 (29.30) | 116 (24.63) | |||||
≥ 3 | 204 (43.31) | 244 (51.80) | |||||
Breastfeeding duration, n (%) | 1 | 0 | 0.01 | ||||
0 months | 110 (23.40) | 93 (19.75) | |||||
1–6 months | 105 (22.34) | 87 (18.47) | |||||
7–15 months | 89 (18.94) | 98 (20.81) | |||||
16–40 months | 101 (21.49) | 97 (20.59) | |||||
≥ 41 months | 65 (13.83) | 96 (20.38) | |||||
Smoking status, n (%) | 0 | 0 | 0.003 | ||||
Never | 284 (60.30) | 320 (67.94) | |||||
Former | 114 (24.20) | 106 (22.51) | |||||
Current | 73 (15.50) | 45 (9.55) | |||||
Vigorous physical activity in the past 5 years, n (%) | 21 (4.46) | 0 | 20 (4.25) | 0 | 0.87 | ||
Moderate physical activity in the past 5 years, n (%) | 0 | 0 | 0.009 | ||||
No | 419 (88.96) | 389 (82.59) | |||||
3 days/month or less | 2 (0.42) | 3 (0.64) | |||||
1–4 days/week | 29 (6.16) | 52 (11.04) | |||||
≥ 5 days/week | 21 (4.46) | 27 (5.73) | |||||
Alcohol intake, n (%) | 0 | 0 | < 0.001 | ||||
Non-drinker | 61 (12.95) | 102 (21.66) | |||||
Drinker | 410 (87.05) | 369 (78.34) | |||||
Education level, n (%) | 0 | 0 | 0.82 | ||||
Primary school diploma or lower | 294 (62.42) | 297 (63.06) | |||||
< 11 years of education | 62 (13.16) | 60 (12.74) | |||||
High school diploma | 70 (14.86) | 71 (15.07) | |||||
University degree | 45 (9.55) | 43 (9.13) | |||||
Calendar year of blood sampling, n (%) | 0 | 0 | < 0.001 | ||||
2001 | 75 (15.92) | 60 (12.74) | |||||
2002 | 255 (54.14) | 222 (47.13) | |||||
2003 | 105 (22.29) | 127 (26.96) | |||||
2004 | 17 (3.61) | 26 (5.52) | |||||
2005 | 19 (4.03) | 34 (7.22) | |||||
2006 | 0 (0.00) | 2 (0.42) | |||||
Total energy intake [kcal/day], meanb, c | 1816 | 12 | 1723 | 12 | 0.21 | ||
Fish and shellfish intake [g/day], meanb, c | 16.1 | 12 | 19.1 | 12 | 0.17 | ||
Isoflavone intake [mg/day], meanb, c | 3.8 | 12 | 7.9 | 12 | 0.006 | ||