Table 2.
Table of characteristics for case-control pairs in EPIC-Italy and the Generations Study
| EPIC-Italy | The Generations Study | |||||
|---|---|---|---|---|---|---|
| Cases (n = 162) | Controls (n = 162) | Cases (n = 339) | Controls (n = 339) | P b | ||
| Age | Mean (st.dev.), years | 52.9 (7.2) | 53.0 (7.1) | 53.9 (10.3) | 54.1 (10.4) | 0.054 |
| Time to diagnosis | Mean (st.dev.), years | 5.3 (4.4) | NA | 4.0 (2.4) | NA | 0.022 |
| Menopausal status | n (%) | 0.690 | ||||
| Premenopausal | 52 (32.1%) | 49 (30.2%) | 135 (39.8%) | 127 (37.5%) | ||
| Postmenopausal | 85 (52.5%) | 87 (53.7%) | 204 (60.2%) | 212 (62.5%) | ||
| Age at menarche | Mean (st.dev.), years | 12.7 (1.4) | 12.7 (1.7) | 12.7 (1.4) | 12.7 (1.5) | 0.914 |
| Age at menopause | Mean (st.dev.), years | 50.2 (3.7) | 49.1 (3.8) | 50.3 (4.3) | 50.1 (4.5) | 0.126 |
| Number of pregnancies | Mean (st.dev.) | 1.6 (1.1) | 1.7 (1.0) | 1.9 (1.1) | 1.9 (1.2) | 4 × 10 −4 |
| Ever breastfed | n (%) | 103 (63.6%) | 112 (69.1%) | 265 (78.2%) | 274 (80.8%) | 0.179 |
| Breastfeeding duration | Mean (st.dev.), years | 0.7 (0.6) | 0.8 (0.7) | 0.9 (1.0) | 0.8 (0.9) | 2 × 10 −5 |
| BMI | Mean (st.dev.), kg/m2 | 25.8 (4.1) | 25.3 (4.3) | 25.7 (4.3) | 25.2 (4.3) | 0.626 |
| Alcohol consumptiona | Mean (st.dev.) | 5.5 (7.0) | 7.4 (9.9) | 15.8 (16.7) | 14.6 (15.5) | 2 × 10 −26 |
| Smoking status | n (%) | 8 × 10 −10 | ||||
| Smoker | 31 (19.1%) | 36 (22.2%) | 25 (7.4%) | 23 (6.8%) | ||
| Former | 23 (14.2%) | 41 (25.3%) | 98 (28.9%) | 86 (25.4%) | ||
| Never | 106 (65.4%) | 85 (52.5%) | 216 (63.7%) | 230 (67.9%) | ||
| Smoking duration | Mean (st.dev.), years | 8.1 (12.6) | 10.6 (13.4) | 4.4 (9.0) | 3.9 (9.0) | 4 × 10 −10 |
| OC ever | n (%) | 59 (36.4 %) | 67 (41.4 %) | 253 (74.6%) | 256 (75.5%) | < 2 × 10 −16 |
| OC duration | Mean (st.dev.), years | 4.1 (5.1) | 5.6 (5.8) | 8.1 (6.4) | 8.8 (6.8) | 4 × 10 −9 |
| HRT ever | n (%) | 23 (14.2 %) | 28 (17.3 %) | 239 (70.5%) | 241 (71.1%) | 2 × 10 −7 |
| HRT duration | Mean (st.dev.), years | 2.8 (2.7) | 2.6 (3.4) | 6.7 (5.7) | 5.4 (4.3) | 5 × 10 −8 |
aAlcohol consumption in the Generations Study reported in average units per week, converted to average gram per day by multiplying with 8 (1 unit = 8 g alcohol) and dividing by 7
bP values indicate differences between all subjects from EPIC-Italy and all subjects from the Generations Study: t test for continuous variables, chi-squared test for categorical variables