Table 2.
Quantitative terminal duct lobular unit (TDLU) measures and breast cancer risk factors among 1083 controls. Data presented for age are means (95% confidence interval). Data for other variables are presented as age-adjusted means (95% confidence interval); age was adjusted as a continuous variable.
| n | Median TDLU span (μm) | TDLU counts/mm2 | Median acini counts/TDLU | Median TDLU area (mm2) | |
|---|---|---|---|---|---|
| Age at benign breast disease (BBD) biopsy | |||||
| <40 years | 244 | 0.56 (0.55,0.58) | 0.48 (0.44,0.52) | 7.56 (7.11,8.04) | 0.11 (0.10,0.11) |
| 40-49 years | 431 | 0.52 (0.51,0.53) | 0.49 (0.46,0.51) | 7.52 (7.18,7.87) | 0.09 (0.09,0.10) |
| 50-59 years | 272 | 0.47 (0.45,0.48) | 0.43 (0.40,0.46) | 5.32 (5.02,5.64) | 0.07 (0.07,0.07) |
| ≥60 years | 136 | 0.46 (0.44,0.47) | 0.38 (0.34,0.42) | 4.33 (3.99,4.71) | 0.07 (0.06,0.07) |
| p-value | <0.001 | <0.001 | <0.001 | <0.001 | |
| BBD histological subtype | |||||
| Non-proliferative | 303 | 0.49 (0.48,0.51) | 0.43 (0.40,0.46) | 6.40 (6.05,6.78) | 0.08 (0.08,0.09) |
| Proliferative without atypia | 625 | 0.51 (0.50,0.52) | 0.46 (0.44,0.48) | 6.36 (6.12,6.62) | 0.09 (0.08,0.09) |
| Atypical hyperplasia | 155 | 0.51 (0.50,0.53) | 0.48 (0.44,0.53) | 6.86 (6.33,7.43) | 0.09 (0.08,0.10) |
| p-value | 0.06 | 0.14 | 0.25 | 0.04 | |
| Body size at ages 5-10 years | |||||
| Level 1 | 308 | 0.51 (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 2 | 276 | 0.51 (0.50,0.52) | 0.45 (0.42,0.48) | 6.66 (6.27,7.07) | 0.09 (0.08,0.09) |
| Level ≥2.5 | 353 | 0.50 (0.49,0.51) | 0.46 (0.44,0.49) | 6.12 (5.80,6.45) | 0.08 (0.08,0.09) |
| p-value | 0.44 | 0.84 | 0.07 | 0.10 | |
| Body mass index (kg/m2) | |||||
| <25 | 612 | 0.51 (0.50,0.52) | 0.45 (0.43,0.47) | 6.52 (6.26,6.78) | 0.09 (0.08,0.09) |
| 25 to <30 | 288 | 0.50 (0.49,0.52) | 0.45 (0.42,0.48) | 6.62 (6.24,7.01) | 0.08 (0.08,0.09) |
| ≥30 | 169 | 0.51 (0.49,0.52) | 0.48 (0.44,0.52) | 5.90 (5.47,6.36) | 0.08 (0.08,0.09) |
| p-value | 0.88 | 0.44 | 0.04 | 0.34 | |
| Age of menarche | |||||
| ≤12 years | 515 | 0.50 (0.49,0.51) | 0.46 (0.44,0.49) | 6.46 (6.19,6.75) | 0.08 (0.08,0.09) |
| 13 years | 317 | 0.51 (0.50,0.52) | 0.45 (0.42,0.48) | 6.51 (6.16,6.88) | 0.09 (0.08,0.09) |
| ≥14 years | 246 | 0.51 (0.50,0.53) | 0.45 (0.42,0.49) | 6.29 (5.91,6.70) | 0.09 (0.08,0.09) |
| p-value | 0.55 | 0.79 | 0.70 | 0.84 | |
| Parity | |||||
| Nulliparous | 101 | 0.48 (0.46,0.51) | 0.33 (0.30,0.38) | 5.20 (4.71,5.73) | 0.08 (0.07,0.08) |
| Parous | 978 | 0.51 (0.50,0.52) | 0.47 (0.45,0.49) | 6.58 (6.38,6.79) | 0.09 (0.08,0.09) |
| p-value | 0.03 | <0.001 | <0.001 | 0.03 | |
| Age at first birth among parous women | |||||
| <25 years | 535 | 0.50 (0.49,0.51) | 0.46 (0.44,0.49) | 6.55 (6.28,6.83) | 0.08 (0.08,0.09) |
| 25 to 29 years | 347 | 0.51 (0.50,0.52) | 0.49 (0.46,0.52) | 6.42 (6.10,6.76) | 0.09 (0.08,0.09) |
| ≥30 years | 99 | 0.52 (0.50,0.54) | 0.44 (0.39,0.50) | 6.77 (6.14,7.46) | 0.09 (0.08,0.10) |
| p-value | 0.22 | 0.28 | 0.63 | 0.20 | |
| Birth index among parous women | |||||
| ≤30 | 226 | 0.52 (0.50,0.53) | 0.47 (0.43,0.51) | 6.43 (5.99,6.91) | 0.09 (0.08,0.10) |
| 31 to 59 | 275 | 0.52 (0.50,0.53) | 0.48 (0.45,0.52) | 7.29 (6.86,7.74) | 0.09 (0.09,0.10) |
| ≥60 | 218 | 0.52 (0.50,0.53) | 0.51 (0.47,0.56) | 7.05 (6.56,7.58) | 0.09 (0.08,0.09) |
| p-value | 0.97 | 0.35 | 0.04 | 0.82 | |
| Breastfeeding among parous women | |||||
| Never | 390 | 0.50 (0.49,0.51) | 0.46 (0.43,0.49) | 6.39 (6.09,6.70) | 0.08 (0.08,0.09) |
| <6 months | 203 | 0.50 (0.49,0.52) | 0.48 (0.44,0.52) | 6.85 (6.41,7.32) | 0.09 (0.08,0.09) |
| ≥6 months | 292 | 0.51 (0.50,0.53) | 0.47 (0.44,0.51) | 6.50 (6.15,6.88) | 0.09 (0.08,0.09) |
| p-value | 0.43 | 0.70 | 0.25 | 0.65 | |
| Menopausal Status | |||||
| Pre | 667 | 0.52 (0.51,0.53) | 0.49 (0.46,0.52) | 7.35 (7.03,7.68) | 0.09 (0.09,0.09) |
| Post | 332 | 0.49 (0.47,0.50) | 0.39 (0.36,0.43) | 4.93 (4.59,5.29) | 0.08 (0.07,0.08) |
| p-value | <0.01 | <0.01 | <0.001 | <0.001 | |
| % TDLU area (total) | % TDLU area (non-adipose) | Acini counts/mm2 | Median acini density | ||
| Age at benign breast disease (BBD) biopsy | |||||
| <40 years | 11.15 (9.95,12.50) | 13.08 (11.69,14.64) | 9.27 (8.21,10.46) | 80.88 (76.82,85.16) | |
| 40-49 years | 7.87 (7.22,8.57) | 9.64 (8.86,10.49) | 7.64 (6.97,8.37) | 90.92 (87.46,94.51) | |
| 50-59 years | 4.90 (4.39,5.45) | 6.19 (5.56,6.88) | 4.41 (3.93,4.95) | 83.00 (79.05,87.15) | |
| ≥60 years | 3.39 (2.91,3.95) | 4.45 (3.83,5.17) | 2.80 (2.38,3.29) | 73.01 (68.14,78.23) | |
| p-value | <0.001 | <0.001 | <0.001 | <0.001 | |
| BBD histological subtype | |||||
| Non-proliferative | 4.99 (4.52,5.52) | 6.26 (5.67,6.92) | 5.01 (4.49,5.58) | 87.47 (83.44,91.70) | |
| Proliferative without atypia | 7.59 (7.09,8.14) | 9.31 (8.69,9.97) | 6.52 (6.04,7.03) | 82.51 (79.86,85.25) | |
| Atypical hyperplasia | 7.94 (6.90,9.15) | 9.71 (8.45,11.17) | 7.10 (6.09,8.28) | 84.80 (79.34,90.64) | |
| p-value | <0.001 | <0.001 | <0.001 | 0.13 | |
| Body size at ages 5-10 years | |||||
| Level 1 | 7.45 (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 to 2 | 6.97 (6.26,7.75) | 8.49 (7.64,9.44) | 6.15 (5.48,6.91) | 83.78 (79.72,88.03) | |
| Level ≥2.5 | 6.41 (5.83,7.05) | 7.98 (7.27,8.76) | 5.82 (5.26,6.45) | 83.00 (79.44,86.72) | |
| p-value | 0.10 | 0.14 | 0.21 | 0.81 | |
| Body mass index (kg/m2) | |||||
| <25 | 6.84 (6.36,7.35) | 8.34 (7.77,8.96) | 6.10 (5.64,6.59) | 83.86 (81.12,86.69) | |
| 25 to <30 | 6.85 (6.17,7.61) | 8.46 (7.62,9.39) | 6.36 (5.68,7.13) | 87.02 (82.89,91.35) | |
| ≥30 | 6.49 (5.66,7.43) | 8.28 (7.24,9.48) | 5.73 (4.95,6.64) | 80.77 (75.84,86.02) | |
| p-value | 0.78 | 0.96 | 0.54 | 0.18 | |
| Age of menarche | |||||
| ≤12 years | 6.74 (6.24,7.29) | 8.33 (7.71,9.00) | 6.13 (5.64,6.67) | 85.23 (82.21,88.36) | |
| 13 years | 6.90 (6.25,7.63) | 8.53 (7.73,9.41) | 6.24 (5.61,6.95) | 84.30 (80.51,88.26) | |
| ≥14 years | 6.78 (6.06,7.59) | 8.31 (7.43,9.29) | 5.94 (5.26,6.71) | 81.53 (77.39,85.90) | |
| p-value | 0.94 | 0.92 | 0.83 | 0.39 | |
| Parity | |||||
| Nulliparous | 4.41 (3.70,5.26) | 5.44 (4.57,6.47) | 3.52 (2.92,4.25) | 73.92 (68.11,80.21) | |
| Parous | 7.10 (6.71,7.51) | 8.75 (8.28,9.25) | 6.48 (6.10,6.88) | 85.33 (83.14,87.58) | |
| p-value | <0.001 | <0.001 | <0.001 | <0.01 | |
| Age at first birth among parous women | |||||
| <25 years | 6.64 (6.15,7.16) | 8.21 (7.62,8.85) | 6.15 (5.67,6.66) | 86.92 (83.92,90.04) | |
| 25 to 29 years | 7.51 (6.83,8.24) | 9.31 (8.48,10.21) | 6.73 (6.09,7.45) | 84.03 (80.44,87.79) | |
| ≥30 years | 6.89 (5.78,8.22) | 8.36 (7.03,9.94) | 6.27 (5.19,7.56) | 81.34 (74.95,88.28) | |
| p-value | 0.13 | 0.11 | 0.38 | 0.24 | |
| Birth index among parous women | |||||
| ≤30 | 7.48 (6.60,8.48) | 9.20 (8.14,10.41) | 6.64 (5.79,7.61) | 80.05 (75.45,84.92) | |
| 31 to 59 | 7.77 (7.00,8.63) | 9.57 (8.63,10.61) | 7.24 (6.46,8.12) | 88.67 (84.38,93.18) | |
| ≥60 | 7.95 (7.01,9.02) | 9.74 (8.61,11.03) | 7.70 (6.71,8.84) | 90.27 (85.04,95.81) | |
| p-value | 0.82 | 0.83 | 0.37 | 0.01 | |
| Breastfeeding among parous women | |||||
| Never | 6.71 (6.14,7.33) | 8.33 (7.64,9.09) | 6.06 (5.51,6.66) | 84.89 (81.52,88.41) | |
| <6 months | 6.88 (6.09,7.78) | 8.48 (7.51,9.57) | 6.54 (5.74,7.46) | 89.52 (84.62,94.69) | |
| ≥6 months | 7.38 (6.67,8.18) | 9.11 (8.23,10.07) | 6.70 (6.01,7.48) | 84.58 (80.70,88.64) | |
| p-value | 0.37 | 0.41 | 0.35 | 0.25 | |
| Menopausal Status | |||||
| Pre | 7.76 (7.16,8.42) | 9.52 (8.78,10.31) | 7.49 (6.86,8.17) | 89.94 (86.64,93.35) | |
| Post | 5.40 (4.73,6.15) | 6.70 (5.89,7.63) | 4.13 (3.59,4.75) | 72.15 (67.93,76.63) | |
| p-value | <0.001 | <0.001 | <0.001 | <0.001 | |