Table 1 Study characteristics of papers included in the systematic review.
| First author, year (Reference No.) | Study type | Country | Age range | Period of enrolment | No. of cases | Immunohistochemical markers | BMI measurement | Anthropometric measurements |
|---|---|---|---|---|---|---|---|---|
| BMI: Body mass index, HC: Hip circumference, WC: Waist circumference, WHR: Waist-to-hip ratio | ||||||||
| John EM, 2011 17 | Case–control | USA (San Francisco Bay Area Breast Cancer study) | 35 – 79 | 1995 – 2004 | 672 | ER, PR | Self-reported | BMI, WHR, WC, HC |
| Berstad P, 2010 18 | Case–control | USA (Woman Contraceptive and Reproductive Experiences Study [CARE]) | 35 – 64 | 1994 – 1998 | 2097 | ER, PR | Self-reported | BMI |
| Bandera EV, 2013 19 | Case–control | USA (Womanʼs Circle of Health Study) | 20 – 75 | 2002 – 2008 | 469 | ER, PR | Trained personnel | BMI, WHR, WC, HC |
| Kawai M, 2013 20 | Case–control | Japan | Mean 56.8 (ER+/PR+), 58.6 (ER+/PR−), 56.8 (ER−/PR−) | 1997 – 2009 | 389 | ER, PR | Self-reported | BMI |
| Wang F, 2017 21 | Case–control | China | 25 – 70 | 2012 – 2013 | 828 | ER, PR | Self-reported | BMI, WC, HC, WHR |
| White AJ, 2015 22 | Cohort | Sister Study, USA | 35 – 74 | 2003 – 2009 | 413 | ER, PR | Trained personnel | BMI, WC, WHR |
| Fagherazzi G, 2012 23 | Cohort | France (E3N) | 40 – 65 | 1990 – 1991 | 277 | ER, PR | Self-reported | BMI, WC, HC, WHR, |
| Nagrani R, 2016 24 | Case–control | India | 20 – 69 | 2009 – 2013 | 818 | ER, PR, HER2 | Self-reported | BMI, WHR, WC |
| Sahin S, 2017 25 | Single cohort | Turkey | Median 48.6 | 1994 – 2015 | 1834 | ER, PR, HER2 | Unknown | BMI |
| Biglia N, 2012 11 | Single cohort | Italy | Mean 45 | 1999 – 2009 | 592 | ER, PR, HER2, Ki67 | Unknown | BMI |
| Yanai A, 2014 13 | Single cohort | Japan | Mean 44.5 | 2005 – 2012 | 187 | ER, PR, HER2, Ki67 | Unknown | BMI |
| Nattenmüller CJ, 2018 26 | Cohort | Germany (EPIC-Germany-study) | 35.2 – 65.2 | 1994 – 2010 | 308 | ER, PR, HER2, Ki67, Bcl-2, p53 | Trained personnel | BMI |
| Yang XR, 2007 27 | Case–control | Poland | 20 – 74 | 2000 – 2003 | 217 | ER, PR, HER2, HER1, CK5 | Self-reported | BMI |
| Chen FY, 2013 28 | Single cohort | China | Median 54.1 (obese), 45.1 (underweight) | 2001 – 2011 | 1277 | ER, PR, HER2, Ki67 | Unknown | BMI |
| Chen L, 2016 29 | Single cohort | USA (Seattle-Puget Sound, Washington) | 20 – 69 | 2004 – 2012 | 1217 | ER, PR, HER2 | Self-reported, medical records | BMI |
| Milikan RC, 2008 30 | Case–control | USA (Carolina Breast Cancer Study [CBCS]) | 20 – 74 | 1993 – 2001 | 638 | ER, PR, HER2 | Trained personnel | BMI |
| Agresti R, 2016 31 | Cross-sectional | Italy | Median age 45.2 | 2011 – 2015 | 596 | ER, PR, HER2, Ki67 | Unknown | BMI, WC |
| Lara-Medina F, 2011 32 | Single cohort | Mexico | Mean age 50 | 1998 – 2008 | 269 | ER, PR, HER2 | Self-reported | BMI |
| Lin NU, 2012 33 | Single cohort | USA | Mean age 55 | 2000 – 2006 | 6175 | ER, PR, HER2 | Self-reported | BMI |
| Li H, 2017 34 | Case–control | China | Mean 47.73 (luminal), 48.62 (HER2+), 49.54 (TNBC) | 2002 – 2010 | 739 | ER, PR, HER2 | Unknown | BMI |
| Yang XR, 2011 35 | Pooled analysis | Different countries (mostly Europe) | Median age 55.3 | 1992 – 2009 | 55580 | ER, PR, HER2, CK5 | Unknown | BMI |