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Table 1 Main characteristics of study population by case/control status

From: Inflammatory biomarkers and risk of breast cancer among young women in Latin America: a case-control study

 

Controls (n = 453)

Cases (n = 453)

 

Mean (SD) or N (%)

Mean (SD) or N (%)

Age at inclusion (years)

38.67 (5.18)

38.76 (5.08)

Age at menarche (years)

12.52 (1.83)

12.47 (1.67)

Age at first full-term pregnancy (years)a

21.89 (5.16)

23.91 (5.86)

Number of full-term pregnancies (%)

  0

34 (7.5)

82 (18.1)

  1

97 (21.4)

129 (28.5)

  2

189 (41.7)

156 (34.4)

  3 or more

133 (29.4)

86 (19.0)

Total duration of breastfeeding in parous women (months) (%)a

  < 8

109 (26.0)

155 (41.8)

  8–22

143 (34.1)

120 (32.3)

  > 22

167 (39.9)

96 (25.9)

  Use of hormones at blood collection (%)

48 (10.6)

38 (8.4)

  Personal history of benign breast disease (%)

55 (12.1)

165 (36.4)

Level of education

  ≤ Primary school

95 (21.0)

58 (12.8)

  Secondary school

247 (54.5)

227 (50.1)

  > Secondary school

111 (24.5)

168 (37.1)

Never smoker (%)

203 (44.8)

239 (52.8)

Moderate physical activity (hours/day)

3.2 (2.6)

2.4 (2.6)

Body mass index (kg/m2)

29.2 (9.7)

26.4 (5.0)

  < 25 kg/m2 (%)

119 (26.3)

199 (43.9)

  25–29.9 kg/m2 (%)

175 (38.6)

175 (38.6)

  ≥ 30 kg/m2 (%)

159 (35.1)

79 (17.4)

Waist circumference (cm)

94.5 (15.1)

91.0 (12.3)

Hip circumference (cm)

106.5 (12.9)

103.5 (9.9)

Waist/hip ratio

0.89 (0.10)

0.88 (0.08)

Tumor characteristicsb

  ER-positive (irrespective of other receptors)

 

215 (72.1)

  PR-positive (irrespective of other receptors)

 

205 (68.8)

  HER2-positive (irrespective of other receptors)

 

50 (16.8)

  Triple Negative: ER-/PR-/HER2-

 

64 (14.1)

Biomarkers (geometric mean (geometric SD))

  IL-6 (pg/ml)

0.69 (1.92)

0.73 (2.29)

  IL-8 (pg/ml) c

7.74 (2.05)

8.27 (2.04)

  IL-10 (pg/ml)

0.19 (2.27)

0.18 (2.05)

  TNF-α (pg/ml)

1.86 (1.50)

1.90 (1.56)

  IFN-γ (pg/ml)

4.44 (2.32)

4.07 (2.34)

  Leptin (ng/ml) d

14.44 (2.48)

11.19 (2.51)

  Adiponectin (µg/ml)

8.12 (4.47)

8.52 (4.21)

  Leptin/adiponectin ratio

1.74 (5.72)

1.29 (5.85)

  1. Abbreviations: ER Estrogen receptor, HER2 Human epidermal growth factor receptor 2, IFN-γ Interferon γ, IL-6 Interleukin 6, IL-8 Interleukin 8, IL-10 Interleukin 10, PR Progesterone receptor, SD Standard deviation, TNF-α Tumor necrosis factor α.
  2. aIn parous women only
  3. bAvailable on 298 (65.8%) cases
  4. cAvailable on 314 cases and 314 controls
  5. dAvailable on 430 cases and 430 controls