Table 3. Childhood and Adolescent Somatotype and Risk of Breast Cancer According to Molecular Subtype, Nurses’ Health Study and Nurses’ Health Study II.
| Luminal A | Luminal B | HER2-Enriched | Basal-like | Unclassified | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases | HR (95% CI) | Cases | HR (95% CI) | Cases | HR (95% CI) | Cases | HR (95% CI) | Cases | HR (95% CI) | p-het | |
| Childhooda,b | 0.51 | ||||||||||
| 1 | 606 | 1.00 (reference) | 283 | 1.00 (reference) | 66 | 1.00 (reference) | 84 | 1.00 (reference) | 13 | 1.00 (reference) | |
| 1.5-2 | 632 | 1.00 (0.89-1.12) | 284 | 0.93 (0.79-1.10) | 69 | 1.04 (0.73-1.47) | 69 | 0.74 (0.53, 1.02) | 16 | 1.45 (0.68, 3.05) | |
| 2.5-3 | 360 | 0.75 (0.66-0.86) | 206 | 0.89 (0.74-1.07) | 44 | 0.89 (0.60-1.32) | 57 | 0.82 (0.58, 1.16) | 7 | 0.84 (0.33, 2.15) | |
| 3.5-4.5 | 315 | 0.79 (0.69-0.91) | 153 | 0.78 (0.64-0.95) | 23 | 0.55 (0.34-0.90) | 32 | 0.54 (0.35, 0.81) | 7 | 0.88 (0.34, 2.27) | |
| ≥ 5 | 118 | 0.77 (0.63, 0.94) | 45 | 0.60 (0.44-0.83) | 8 | 0.52 (0.26-1.09) | 8 | 0.35 (0.17, 0.74) | 7 | 2.33 (0.90, 6.06) | |
| Per 1 unit increase |
2031 | 0.93 (0.87, 0.96) | 971 | 0.91 (0.86, 0.96) | 210 | 0.84 (0.74, 0.94) | 250 | 0.83 (0.74, 0.92) | 50 | 1.06 (0.86, 1.31) | |
| P trend | <0.0001 | 0.0003 | 0.003 | 0.0007 | 0.57 | ||||||
| Adolescent a,c | 0.046 | ||||||||||
| 1 | 198 | 1.00 (reference) | 90 | 1.00 (reference) | 21 | 1.00 (reference) | 23 | 1.00 (reference) | 8 | 1.00 (reference) | |
| 1.5-2 | 660 | 1.00 (0.85-1.18) | 322 | 1.02 (0.81-1.29) | 84 | 1.21 (0.75, 1.97) | 87 | 1.06 (0.66, 1.68) | 6 | 0.24 (0.08, 0.71) | |
| 2.5-3 | 607 | 0.90 (0.76-1.06) | 299 | 0.91 (0.72-1.16) | 64 | 0.89 (0.54, 1.47) | 80 | 0.93 (0.57, 1.49) | 15 | 0.69 (0.28, 1.67) | |
| 3.5-4.5 | 461 | 0.83 (0.69-0.98) | 220 | 0.80 (0.62-1.03) | 37 | 0.64 (0.67, 1.10) | 53 | 0.73 (0.44, 1.21) | 15 | 0.80 (0.32, 1.96) | |
| ≥ 5 | 105 | 0.80 (0.62-1.01) | 40 | 0.60 (0.41-0.88) | 4 | 0.29 (0.10, 0.85) | 7 | 0.40 (0.17, 0.95) | 6 | 1.08 (0.36, 3.25) | |
| Per 1 unit increase |
2031 | 0.93 (0.89, 0.97) | 971 | 0.88 (0.83, 0.93) | 210 | 0.79 (0.70, 0.90) | 250 | 0.82 (0.73, 0.92) | 50 | 1.12 (0.89, 1.40) | |
| P trend | 0.0002 | <0.0001 | 0.0005 | 0.0008 | 0.33 |
All estimates are adjusted for age (months), time period, cohort, recent alcohol consumption (0, 0.1-1.4, 1.5-4.9, 5.0-9.9, ≥ 10 g/day), age at menarche (<12, 12, 13, 14, >14), age at menopause (years), height (inches), menopausal status and PMH use (premenopausal, postmenopausal-never PMH, postmenopausal-past PMH, postmenopausal-current PMH, postmenopausal –unknown PMH), birth index (cont), oral contraceptive duration (years), history of benign breast disease (yes/no), first degree family history of breast cancer (yes/no), birth weight (< 5.5 lbs, 5.5-6.9 lbs, 7-8.4 lbs, ≥ 8.5 lbs), weight change since age 18 (kg), interaction between menopausal status and weight change since 18, cumulative average physical activity (quintiles).
Average of somatotype at ages 5 and 10;
Average of somatotype at ages 10 and 20;