Table 4.
Breast cancer incidence in pre-, peri/postmenopausal and all women in relation to serum TSH levels
| Group | TSH (quartile) |
Individuals (n) |
Breast cancer cases (n) |
Person-years | Incidence/100,000 | All cases | Cases >3 years following Baseline examination |
||
|---|---|---|---|---|---|---|---|---|---|
| RR (CI: 95%) |
RR** (CI: 95%) |
RR (CI: 95%) |
RR** (CI: 95%) |
||||||
| All | 1 | 647 | 40 | 11,764 | 340 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 528 | 42 | 9,517 | 441 | 1.05 (0.70 to 1.58) | 1.07 (0.71 to 1.62) | 1.28 (0.81 to 2.01) | 1.26 (0.80 to 1.97) | |
| 3 | 793 | 55 | 15,829 | 347 | 0.93 (0.62 to 1.41) | 0.94 (0.62 to 1.42) | 1.20 (0.77 to 1.87) | 1.19 (0.76 to 1.85) | |
| 4 | 710 | 36 | 14,521 | 248 | 0.87 (0.55 to 1.37) | 0.80 (0.50 to 1.27) | 0.95 (0.57 to 1.57) | 1.03 (0.62 to 1.69) | |
| P-trend | 0.46 | 0.29 | 0.82 | 0.94 | |||||
| Premenopausal | 1 | 155 | 10 | 3,170 | 315 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 221 | 18 | 4,669 | 386 | 1.48 (0.76 to 2.90) | 1.38 (0.69 to 2.77) | 1.91(0.90 to 4.08) | 2.02 (0.97 to 4.23) | |
| 3 | 329 | 28 | 6,869 | 408 | 0.95 (0.48 to 1.87) | 0.94 (0.47 to 1.87) | 1.31(0.62 to 2.79) | 1.30 (0.62 to 2.72) | |
| 4 | 194 | 7 | 4,213 | 166 | 0.81 (0.36 to 1.86) | 0.62 (0.26 to 1.46) | 0.88 (0.35 to 2.21) | 1.11 (0.46 to 2.67) | |
| P-trend | 0.42 | 0.20 | 0.64 | 0.91 | |||||
| Peri/post-menopausal | 1 | 492 | 30 | 8,593 | 349 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 307 | 24 | 4,848 | 495 | 0.86 (0.51 to 1.45) | 0.87 (0.51 to 1.47) | 0.93 (0.52 to 1.67) | 0.94 (0.53 to 1.67) | |
| 3 | 464 | 27 | 8,960 | 301 | 0.93 (0.56 to 1.56) | 0.94 (0.56 to 1.58) | 1.13 (0.65 to 1.98) | 1.14 (0.66 to 1.99) | |
| 4 | 516 | 29 | 10,308 | 281 | 0.88 (0.51 to 1.53) | 0.82 (0.47 to 1.43) | 0.89 (0.48 to 1.65) | 0.97 (0.53 to 1.78) | |
| P-trend | 0.73 | 0.57 | 0.94 | 0.87 | |||||
Abbreviations: TSH, thyrotropin; RR, relative risk; RR**, relative risk adjusted for age (continuous), menopausal status (in analysis of all women), use of HRT, nulliparity, use of oral contraception, age at menarche, smoking status, alcohol consumption, BMI, height, educational level and marital status. * P < 0.05.