Table 3. Characteristics of studies included in the review of enterolactone exposure as measured in blood and breast cancer risk.
| First author/ (year)/ country | Parent study | Design (follow-up) | Cases | Controls/ cohort size | Method | Menopausal status | Mean ENL cases (nmol/l) | Mean ENL controls/cohort (nmol/l) | Adjusted confounders |
|---|---|---|---|---|---|---|---|---|---|
| Boccardo et al (2003) Italy | Prospective cohort (6.5 years after cyst aspiration) | 18 | 383 | TR-FIA | Pre-M and Post-M | 14.7 | 19.6 | Age, cyst type and family history | |
| Hultén et al (2002) Sweden | VIP, MONIKA and MSP studies | Nested case–referent | 248 | 492 | TR-FIA | Pre-M and Post-M | 26.8 VIP and MONIKA 19.3 MSP | 22.9 VIP and MONIKA 20.4 MSP | BMI, menopausal status, smoking |
| Kilkkinen et al (2004) Finland | Cross-sectional population surveys | Nested case–control | 206 | 215 | TR-FIA | Pre-M and Post-M | 25.2 | 24.0 | None |
| Olsen et al (2004) Denmark | Diet, Cancer and Health Study | Nested case–control | 381 | 381 | TR-FIA | Post-M | Not provided | Not provided | Age, HRT (through matching of controls) |
| Zeleniuch-Jacquotte et al (2004) United States | NYU Women's Health Study | Nested case–control | 417 | 417 | TR-FIA | Pre-M Post-M | 18.3 18.6 | 15.1 18.9 | Age at 1st live birth and menarche, ln(BMI), family history, ln(height), nulliparity |
| Verheus et al (2007) The Netherlands | Prospect-EPIC | Nested case–control | 383 | 383 | LC/MS | Pre-M/Peri-M Post-M | 2.98 (ng/ml) 2.71 (ng/ml) | 2.66(ng/ml) 2.65 (ng/ml) | Age at menarche and family history (Pre-M) Crude OR (Post-M). |
| Ward et al (2008) United Kingdom | EPIC-Norfolk | Nested case–control (9.5 years; 11 261 person-years) | 219 | 891 | LC/MS | All | 5.83 (ng/ml)* | 5.00 (ng/ml)* | Age, age at menarche, breast-feeding, energy, family history, fat, HRT, OC, menopausal status, parity, social class, weight |
| Pietinen et al (2001) Finland | Kuopio Breast Cancer Study | Population-based case–control | 194 | 208 | TR-FIA | Pre-M Post-M | 16.6 21.2 | 20.7 28.9 | Age at 1st birth and at menarche, alcohol, area, BBD, BMI, education, family history, HRT, OC, physical activity, smoking, waist to hip ratio |
| Piller et al (2006a) Germany | Population-based case–control | 192 | 231 | TR-FIA | Pre-M | 11.6 | 12.2 | Age at menarche, alcohol, BMI, breast-feeding, day of analysis, education, family history, OC, parity, time difference between surgery and blood sampling day |
BBD=benign breast disease; BMI=body mass index; ENL=enterolactone; HRT=hormony replacement therapy; LC=liquid chromatography; MONIKA=Monitoring of Trends and Cardiovascular Disease Study; MS=mass spectrometry; MSP=Mammary Screening Project; NYU=New York University; OC=oral contraceptive; Peri-M=peri-menopausal; Pre-M=pre-menopausal; Post-M=post-menopausal; Prospect-EPIC=Dutch Cohort of the European Prospective Investigation into Diet and Cancer (EPIC) Study; TR-FIA=time-resolved fluoroimmunoassay; VIP=Västerbotten Intervention Project.
*Median values. Mean values not provided.