Table 1. the characteristics of the cohort studies about the BMI and BC risk included in the meta-analysis.
| First author | Published year | Country | Ethnicity | Follow-up (mean years) | No. of BC cases | Sample size, no. | Person-years | Menopausal status | Adjustmenta |
|---|---|---|---|---|---|---|---|---|---|
| van den Brandt PA[24] | 1997 | Netherlands | White | 4.3 | 553 | 1716 | 6284 | Postmenopausal | 1,5,6,7,8 |
| Galanis DJ[15] | 1998 | US | White, Asian | 14.9 | 86 | 11460 | 170754 | Premenopausal | 1,8,11,20 |
| White, Asian | 292 | 11344 | 169025.60 | Postmenopausal | |||||
| Kaaks R[11] | 1998 | Netherlands | White | 10.6 | 147 | 5891 | 56646 | Premenopausal | 1,5,6, |
| Netherlands | White | 10.6 | 76 | 3521 | 34362 | Postmenopausal | 7,12,33 | ||
| Netherlands | White | 10.6 | 52 | 2068 | 19870 | Postmenopausal(hysterectomy/ovariectomy) | |||
| Sonnenschein E[16] | 1999 | US | White | 6.6 | 109 | 4475 | 29535 | Premenopausal | 1,2,5,6, 22,21 |
| White | 150 | 3941 | 26010.60 | Postmenopausal | |||||
| Manjer J[17] | 2001 | Sweden | White | 13.1 | 112 | 3873 | 58079 | Premenopausal | 1,4,5,7,8,10, |
| White | 157 | 5865 | 60845 | Pere/Postmenopausal | 13,23,31 | ||||
| Weiderpass E[18] | 2004 | Sweden and Norway | White | 6.7 | 716 | 96986 | 775888 | Premenopausal | 1,2,4,5,6,7,10,19,26,27,28 |
| Sweeney C[8] | 2004 | US | White | 16 | 428 | NA | 124202 | Postmenopausal (55–64) | 1,2,4,5, 6,7,11 |
| White | 1297 | NA | 282749 | Postmenopausal (65–74) | |||||
| White | 561 | NA | 101319 | Postmenopausal (75–84) | |||||
| Michels KB[9] | 2006 | US | White | 10.8 | 1398 | 113130 | 1225520 | Premenopausal | 1,2,3,4,5,6,7,8,9,10 |
| Suzuki R[6] | 2006 | Sweden | White | 8.3 | 1284 | 51823 | 430331 | Postmenopausal | 1,2,3,4,5,6,7,8,10,11,13,14,15,16,17 |
| Mellemkjaer L[25] | 2006 | Denmark | White | 6.7 | 217 | 11796 | 78120 | Postmenopausal (HRT user) | 3,6,7,8, 11,13 |
| White | 416 | 11992 | 78690 | Postmenopausal (HRT no-user) | |||||
| Li HL[20] | 2006 | China | Asian | 5.66 | 221 | 37827 | 214164 | Premenopausal | 1,2,3,6,11, |
| Asian | 211 | 35583 | 201638 | Postmenopausal | 12,15,27 | ||||
| Tehard B[10] | 2006 | France | White | 3.6 | 212 | 20000 | 72000 | Premenopausal | 2,3,5,6,7, |
| White | 4.7 | 1037 | 41857 | 196728 | Postmenopausal | 8,9,11,34 | |||
| Palmer JR[21] | 2007 | US | Black | 10 | 495 | 42538 | 316637 | Premenopausal | 1,2,5,6,7,9 |
| US | Black | 10 | 454 | 9542 | 112263 | Postmenopausal | 11,12,13,19 | ||
| Song YM[26] | 2008 | Korea | Asian | 8.75 | 713 | 154693 | 1491465 | Postmenopausal | 1,4,8,9,15,23 |
| Kerlikowske K[27] | 2008 | US | White, Asian and Black | 2.14 | 4446 | 287115 | 614562 | Postmenopausal | 1,18,20,30, |
| Lacey Jr JV[28] | 2009 | US | Asian, Black | 4.98 | 2063 | 69756 | 384968 | Postmenopausal | 1,2,3,4,5,6,7,13,18,20,31 |
| Phipps AI[29] | 2011 | US | White, Asian and Black | 7.9 | 2898 | 152126 | 1201795.4 | Postmenopausal | 1,2,9,11,20,29,30 |
| Manders P[22] | 2011 | Netherlands | White | 10 | 155 | 609 | 3013 | Premenopausal | 9 |
| Opdahl S[30] | 2011 | Norway | White | 24.1 | 2178 | 44952 | 1002895 | Postmenopausal | 1,5,24,26,34,35 |
| Cecchini RS[23] | 2012 | North American | White | 4.1 | 126 | 5850 | 23985 | Premenopausal | 10,13,23,3236,37, |
| White | 4.1 | 126 | 6352 | 26043.2 | Postmenopausal | ||||
| White | 6.4 | 555 | 19357 | 123884.8 | Postmenopausal | ||||
| Canchola AJ[31] | 2012 | US | White, non-white, Missing | 12.1 | 1938 | 52642 | 636968.20 | Postmenopausal | 2,5,6,7,8,9,13,20,22 |
| Gaudet MM[32] | 2014 | US | White | 11.58 | 1088 | 28965 | 279665 | Postmenopausal | 2,3,4,6,7,8,9,10,11,12,13, |
| 20,23,30,32 | |||||||||
| Wada K[19] | 2014 | Japan | Asian | 11.93 | 721 | 62689 | 789388 | Premenopausal | 1,5,6,7,8,18,23 |
| 11.93 | 996 | 111446 | 1301876 | Postmenopausal | 1,5,6,7,8,12,18,23 |
Abbreviation: US, United States; NA, unkown; UK, United kingdom; HRT, hormone replacement therapy; BC, breast cancer.
a: 1 = age; 2 = family history of BC; 3 = history of benign breast disease; 4 = height; 5 = age at menarche; 6 = age at first birth; 7 = parity; 8 = alcohol consumption; 9 = physical activity; 10 = current and past oral contraceptive use; 11 = education; 12 = age at menopause; 13 = use of postmenopausal hormones (duration); 14 = the reason of menopause; 15 = energy intake; 16 = dietary fiber; 17 = total fat intake; 18 = area (study centers); 19 = BMI at 18 yr; 20 = ethnicity; 21 = weight/height ratio; 22 = history of breast biopsy; 23 = smoking; 24 = occupation; 25 = BMI at 20 yr; 26 = country of residence; 27 = total duration of breast-feeding; 28 = body shape at age 7; 29 = income; 30 = history of mammography; 31 = weight; 32 = history of diabetes; 33 = menopausal status; 34 = marital status; 35 = urban or rural community; 36 = treatment; 37 = Gail score; 38 = waist circumference.