Table 2.

Quantitative TDLU measures and breast cancer risk factors among 1,083 controls.

nMedian TDLU span (μm)TDLU counts/mm2Median acini counts/TDLUMedian TDLU area (mm2)
Age at BBD biopsy
 <40 years2440.56 (0.55–0.58)0.48 (0.44–0.52)7.56 (7.11–8.04)0.11 (0.10–0.11)
 40–49 years4310.52 (0.51–0.53)0.49 (0.46–0.51)7.52 (7.18–7.87)0.09 (0.09–0.10)
 50–59 years2720.47 (0.45–0.48)0.43 (0.40–0.46)5.32 (5.02–5.64)0.07 (0.07–0.07)
 ≥60 years1360.46 (0.44–0.47)0.38 (0.34–0.42)4.33 (3.99–4.71)0.07 (0.06–0.07)
P<0.001<0.001<0.001<0.001
BBD histologic subtype
 Nonproliferative3030.49 (0.48–0.51)0.43 (0.40–0.46)6.40 (6.05–6.78)0.08 (0.08–0.09)
 Proliferative without atypia6250.51 (0.50–0.52)0.46 (0.44–0.48)6.36 (6.12–6.62)0.09 (0.08–0.09)
 Atypical hyperplasia1550.51 (0.50–0.53)0.48 (0.44–0.53)6.86 (6.33–7.43)0.09 (0.08–0.10)
P0.060.140.250.04
Body size at ages 5–10 years
 Level 13080.51 (0.50–0.53)0.46 (0.43–0.49)6.58 (6.22–6.97)0.09 (0.08–0.09)
 Level 1.5 to 22760.51 (0.50–0.52)0.45 (0.42–0.48)6.66 (6.27–7.07)0.09 (0.08–0.09)
 Level ≥2.53530.50 (0.49–0.51)0.46 (0.44–0.49)6.12 (5.80–6.45)0.08 (0.08–0.09)
P0.440.840.070.10
BMI (kg/m2)
 <256120.51 (0.50–0.52)0.45 (0.43–0.47)6.52 (6.26–6.78)0.09 (0.08–0.09)
 25 to <302880.50 (0.49–0.52)0.45 (0.42–0.48)6.62 (6.24–7.01)0.08 (0.08–0.09)
 ≥301690.51 (0.49–0.52)0.48 (0.44–0.52)5.90 (5.47–6.36)0.08 (0.08–0.09)
P0.880.440.040.34
Age of menarche
 ≤12 years5150.50 (0.49–0.51)0.46 (0.44–0.49)6.46 (6.19–6.75)0.08 (0.08–0.09)
 13 years3170.51 (0.50–0.52)0.45 (0.42–0.48)6.51 (6.16–6.88)0.09 (0.08–0.09)
 ≥14 years2460.51 (0.50–0.53)0.45 (0.42–0.49)6.29 (5.91–6.70)0.09 (0.08–0.09)
P0.550.790.700.84
Parity
 Nulliparous1010.48 (0.46–0.51)0.33 (0.30–0.38)5.20 (4.71–5.73)0.08 (0.07–0.08)
 Parous9780.51 (0.50–0.52)0.47 (0.45–0.49)6.58 (6.38–6.79)0.09 (0.08–0.09)
P0.03<0.001<0.0010.03
Age at first birth among parous women
 <25 years5350.50 (0.49–0.51)0.46 (0.44–0.49)6.55 (6.28–6.83)0.08 (0.08–0.09)
 25–29 years3470.51 (0.50–0.52)0.49 (0.46–0.52)6.42 (6.10–6.76)0.09 (0.08–0.09)
 ≥30 years990.52 (0.50–0.54)0.44 (0.39–0.50)6.77 (6.14–7.46)0.09 (0.08–0.10)
P0.220.280.630.20
Birth index among parous women
 ≤302260.52 (0.50–0.53)0.47 (0.43–0.51)6.43 (5.99–6.91)0.09 (0.08–0.10)
 31–592750.52 (0.50–0.53)0.48 (0.45–0.52)7.29 (6.86–7.74)0.09 (0.09–0.10)
 ≥602180.52 (0.50–0.53)0.51 (0.47–0.56)7.05 (6.56–7.58)0.09 (0.08–0.09)
P0.970.350.040.82
Breastfeeding among parous women
 Never3900.50 (0.49–0.51)0.46 (0.43–0.49)6.39 (6.09–6.70)0.08 (0.08–0.09)
 <6 months2030.50 (0.49–0.52)0.48 (0.44–0.52)6.85 (6.41–7.32)0.09 (0.08–0.09)
 ≥6 months2920.51 (0.50–0.53)0.47 (0.44–0.51)6.50 (6.15–6.88)0.09 (0.08–0.09)
P0.430.700.250.65
Menopausal status
 Pre6670.52 (0.51–0.53)0.49 (0.46–0.52)7.35 (7.03–7.68)0.09 (0.09–0.09)
 Post3320.49 (0.47–0.50)0.39 (0.36–0.43)4.93 (4.59–5.29)0.08 (0.07–0.08)
P<0.01<0.01<0.001<0.001
% TDLU area (total)% TDLU area (nonadipose)Acini counts/mm2Median acini density
Age at BBD biopsy
 <40 years11.15 (9.95–12.50)13.08 (11.69–14.64)9.27 (8.21–10.46)80.88 (76.82–85.16)
 40–49 years7.87 (7.22–8.57)9.64 (8.86–10.49)7.64 (6.97–8.37)90.92 (87.46–94.51)
 50–59 years4.90 (4.39–5.45)6.19 (5.56–6.88)4.41 (3.93–4.95)83.00 (79.05–87.15)
 ≥60 years3.39 (2.91–3.95)4.45 (3.83–5.17)2.80 (2.38–3.29)73.01 (68.14–78.23)
P<0.001<0.001<0.001<0.001
BBD histologic subtype
 Nonproliferative4.99 (4.52–5.52)6.26 (5.67–6.92)5.01 (4.49–5.58)87.47 (83.44–91.70)
 Proliferative without atypia7.59 (7.09–8.14)9.31 (8.69–9.97)6.52 (6.04–7.03)82.51 (79.86–85.25)
 Atypical hyperplasia7.94 (6.90–9.15)9.71 (8.45–11.17)7.10 (6.09–8.28)84.80 (79.34–90.64)
P<0.001<0.001<0.0010.13
Body size at ages 5–10 years
 Level 17.45 (6.73–8.25)9.16 (8.29–10.13)6.66 (5.97–7.43)84.80 (80.90–88.88)
 Level 1.5–26.97 (6.26–7.75)8.49 (7.64–9.44)6.15 (5.48–6.91)83.78 (79.72–88.03)
 Level ≥2.56.41 (5.83–7.05)7.98 (7.27–8.76)5.82 (5.26–6.45)83.00 (79.44–86.72)
P0.100.140.210.81
BMI (kg/m2)
 <256.84 (6.36–7.35)8.34 (7.77–8.96)6.10 (5.64–6.59)83.86 (81.12–86.69)
 25 to <306.85 (6.17–7.61)8.46 (7.62–9.39)6.36 (5.68–7.13)87.02 (82.89–91.35)
 ≥306.49 (5.66–7.43)8.28 (7.24–9.48)5.73 (4.95–6.64)80.77 (75.84–86.02)
P0.780.960.540.18
Age of menarche
 ≤12 years6.74 (6.24–7.29)8.33 (7.71–9.00)6.13 (5.64–6.67)85.23 (82.21–88.36)
 13 years6.90 (6.25–7.63)8.53 (7.73–9.41)6.24 (5.61–6.95)84.30 (80.51–88.26)
 ≥14 years6.78 (6.06–7.59)8.31 (7.43–9.29)5.94 (5.26–6.71)81.53 (77.39–85.90)
P0.940.920.830.39
Parity
 Nulliparous4.41 (3.70–5.26)5.44 (4.57–6.47)3.52 (2.92–4.25)73.92 (68.11–80.21)
 Parous7.10 (6.71–7.51)8.75 (8.28–9.25)6.48 (6.10–6.88)85.33 (83.14–87.58)
P<0.001<0.001<0.001<0.01
Age at first birth among parous women
 <25 years6.64 (6.15–7.16)8.21 (7.62–8.85)6.15 (5.67–6.66)86.92 (83.92–90.04)
 25–29 years7.51 (6.83–8.24)9.31 (8.48–10.21)6.73 (6.09–7.45)84.03 (80.44–87.79)
 ≥30 years6.89 (5.78–8.22)8.36 (7.03–9.94)6.27 (5.19–7.56)81.34 (74.95–88.28)
P0.130.110.380.24
Birth index among parous women
 ≤307.48 (6.60–8.48)9.20 (8.14–10.41)6.64 (5.79–7.61)80.05 (75.45–84.92)
 31–597.77 (7.00–8.63)9.57 (8.63–10.61)7.24 (6.46–8.12)88.67 (84.38–93.18)
 ≥607.95 (7.01–9.02)9.74 (8.61–11.03)7.70 (6.71–8.84)90.27 (85.04–95.81)
P0.820.830.370.01
Breastfeeding among parous women
 Never6.71 (6.14–7.33)8.33 (7.64–9.09)6.06 (5.51–6.66)84.89 (81.52–88.41)
 <6 months6.88 (6.09–7.78)8.48 (7.51–9.57)6.54 (5.74–7.46)89.52 (84.62–94.69)
 ≥6 months7.38 (6.67–8.18)9.11 (8.23–10.07)6.70 (6.01–7.48)84.58 (80.70–88.64)
P0.370.410.350.25
Menopausal Status
 Pre7.76 (7.16–8.42)9.52 (8.78–10.31)7.49 (6.86–8.17)89.94 (86.64–93.35)
 Post5.40 (4.73–6.15)6.70 (5.89–7.63)4.13 (3.59–4.75)72.15 (67.93–76.63)
P<0.001<0.001<0.001<0.001
  • Note: Data presented for age are means (95% CI). Data for other variables are presented as age-adjusted means (95% CI); age was adjusted as a continuous variable. Bold text represents values of statistical significance (P < 0.05).

  • Abbreviation: BBD, benign breast disease.