Variables | No. controls | All cases versus controls | ER+PR+ cases versus controls | ER- PR- cases versus controls | ER+PR+ cases versus ER- PR- cases | |||
---|---|---|---|---|---|---|---|---|
Number of cases | OR (95% CI) | Number of cases | OR (95% CI) | Number of cases | OR (95% CI) | OR (95% CI) | ||
Age at menarche, years | ||||||||
≤ 11 | 90 | 400 | 1.00 | 188 | 1.00 | 92 | 1.00 | 1.00 |
12 | 109 | 532 | 1.13 (0.83–1.55) | 278 | 1.24 (0.88–1.75) | 119 | 1.18 (0.79–1.77) | 1.04 (0.74–1.47) |
13 | 121 | 475 | 0.88 (0.65–1.21) | 231 | 0.87 (0.62–1.24) | 110 | 0.94 (0.62–1.41) | 0.93 (0.65–1.33) |
≥ 14 | 120 | 318 | 0.61 (0.44–0.85) | 157 | 0.60 (0.42–0.86) | 64 | 0.59 (0.38–0.92) | 1.02 (0.67–1.53) |
Trend p value | 0.0007 | 0.0006 | 0.008 | 0.85 | ||||
Number of full-term pregnanciesa | ||||||||
None | 125 | 564 | 1.00 | 301 | 1.00 | 113 | 1.00 | 1.00 |
1 | 85 | 347 | 0.91 (0.66–1.25) | 157 | 0.77 (0.55–1.10) | 82 | 1.06 (0.70–1.62) | 0.70 (0.49–1.02) |
2 | 139 | 492 | 0.81 (0.61–1.07) | 251 | 0.77 (0.57–1.06) | 106 | 0.95 (0.64–1.39) | 0.84 (0.60–1.18) |
3 | 56 | 224 | 0.81 (0.56–1.18) | 100 | 0.69 (0.45–1.04) | 54 | 1.06 (0.65–1.73) | 0.68 (0.44–1.05) |
≥ 4 | 35 | 98 | 0.49 (0.31–0.78) | 45 | 0.47 (0.28–0.80) | 30 | 0.72 (0.39–1.33) | 0.65 (0.37–1.15) |
Trend p value | 0.008 | 0.005 | 0.50 | 0.09 | ||||
Age at first full-term pregnancy for parous women, yearsa,b | ||||||||
<22 | 68 | 316 | 1.00 | 126 | 1.00 | 96 | 1.00 | 1.00 |
22–27 | 89 | 333 | 1.07 (0.72–1.58) | 149 | 1.14 (0.73–1.78) | 81 | 0.92 (0.56–1.50) | 1.25 (0.81–1.94) |
28–31 | 78 | 265 | 1.03 (0.66–1.60) | 134 | 1.17 (0.71–1.93) | 57 | 0.82 (0.46–1.45) | 1.42 (0.85–2.37) |
≥ 32 | 80 | 247 | 0.92 (0.57–1.48) | 144 | 1.23 (0.72–2.10) | 38 | 0.56 (0.30–1.07) | 2.22 (1.24–3.98) |
Trend p value | 0.65 | 0.49 | 0.08 | 0.009 | ||||
Duration of breastfeeding for parous women, monthsa,b | ||||||||
0 | 38 | 247 | 1.00 | 102 | 1.00 | 63 | 1.00 | 1.00 |
<1 | 23 | 144 | 0.99 (0.56–1.77) | 65 | 1.01 (0.53–1.90) | 38 | 1.19 (0.59–2.39) | 0.82 (0.47–1.44) |
1–6 | 80 | 273 | 0.58 (0.37–0.91) | 131 | 0.57 (0.34–0.94) | 68 | 0.72 (0.41–1.27) | 0.77 (0.47–1.26) |
7–23 | 110 | 322 | 0.52 (0.33–0.82) | 165 | 0.52 (0.31–0.87) | 63 | 0.55 (0.31–0.98) | 0.97 (0.59–1.61) |
≥ 24 | 64 | 175 | 0.51 (0.30–0.86) | 90 | 0.49 (0.27–0.87) | 40 | 0.62 (0.32–1.21) | 0.77 (0.42–1.39) |
Trend p value | 0.001 | 0.002 | 0.03 | 0.63 | ||||
BMI 1 year before reference date, kg/m2 | ||||||||
<25 | 257 | 939 | 1.00 | 495 | 1.00 | 183 | 1.00 | 1.00 |
25–29 | 95 | 425 | 1.18 (0.89–1.55) | 209 | 1.11 (0.82–1.50) | 101 | 1.41 (0.99–2.02) | 0.81 (0.59–1.10) |
30–34 | 51 | 221 | 1.01 (0.70–1.44) | 94 | 0.88 (0.59–1.30) | 61 | 1.43 (0.91–2.23) | 0.60 (0.40–0.89) |
≥ 35 | 37 | 140 | 0.88 (0.58–1.34) | 56 | 0.69 (0.43–1.11) | 40 | 1.18 (0.70–2.01) | 0.61 (0.38–0.99) |
Trend p value | 0.82 | 0.20 | 0.16 | 0.005 | ||||
Duration of COC use, years | ||||||||
Never | 47 | 244 | 1.00 | 128 | 1.00 | 47 | 1.00 | 1.00 |
<1 | 73 | 295 | 0.78 (0.51–1.18) | 133 | 0.70 (0.44–1.12) | 59 | 0.76 (0.43–1.33) | 0.93 (0.57–1.52) |
1–4 | 108 | 429 | 0.80 (0.54–1.19) | 227 | 0.81 (0.53–1.25) | 90 | 0.87 (0.52–1.46) | 0.92 (0.59–1.43) |
5–9 | 115 | 362 | 0.62 (0.42–0.93) | 173 | 0.57 (0.37–0.88) | 90 | 0.82 (0.49–1.37) | 0.71 (0.45–1.12) |
≥ 10 | 97 | 395 | 0.84 (0.56–1.26) | 193 | 0.76 (0.49–1.18) | 99 | 1.27 (0.75–2.14) | 0.61 (0.39–0.96) |
Trend p value | 0.30 | 0.16 | 0.18 | 0.008 | ||||
Alcohol drinking status during reference agec | ||||||||
Never | 141 | 558 | 1.00 | 251 | 1.00 | 138 | 1.00 | 1.00 |
Former | 90 | 328 | 0.96 (0.71–1.31) | 162 | 1.02 (0.72–1.44) | 74 | 0.88 (0.59–1.33) | 1.14 (0.79–1.64) |
Current | 209 | 839 | 1.05 (0.81–1.36) | 441 | 1.17 (0.88–1.55) | 173 | 0.93 (0.67–1.30) | 1.25 (0.93–1.68) |
Average number of alcoholic drinks per week in recent 5 years | ||||||||
Never | 141 | 558 | 1.00 | 251 | 1.00 | 138 | 1.00 | 1.00 |
<3 | 130 | 481 | 1.01 (0.76–1.35) | 248 | 1.11 (0.81–1.53) | 101 | 0.89 (0.61–1.30) | 1.22 (0.87–1.71) |
3–5 | 49 | 171 | 0.93 (0.63–1.37) | 90 | 1.01 (0.66–1.54) | 34 | 0.76 (0.45–1.28) | 1.31 (0.81–2.11) |
6–11 | 32 | 157 | 1.16 (0.75–1.81) | 82 | 1.26 (0.78–2.03) | 34 | 1.06 (0.60–1.86) | 1.20 (0.74–1.94) |
> 12 | 17 | 127 | 1.77 (1.01–3.08) | 68 | 2.10 (1.17–3.79) | 27 | 1.71 (0.87–3.38) | 1.24 (0.73–2.09) |
Trend p value | 0.12 | 0.03 | 0.42 | 0.23 | ||||
Drinking alcohol but not in the recent five years | 71 | 231 | 0.88 (0.63–1.22) | 115 | 0.92 (0.63–1.34) | 51 | 0.80 (0.51–1.26) | 1.14 (0.76–1.73) |