Table 2. Odds ratios (ORs) and 95% confidence intervals (CIs) for gallbladder cancer in relation to reproductive factors by biliary stone status.
Without biliary stones
|
With biliary stones
|
||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Reproductive factors | Controlsa | Casesa | ORb | (95% CI)b | P-valueb | Controlsa | Casesa | ORb | (95% CI)b | P-valueb | ORc | (95% CI)c | P-valuec |
Total | 422 | 36 | — | — | 123 | 233 | — | — | |||||
Parity | |||||||||||||
0 | 11 | 2 | — | — | 5 | 2 | — | — | — | — | |||
1 | 67 | 10 | 1 | Reference | 13 | 16 | 1 | Reference | 1 | Reference | |||
2 | 104 | 4 | — | — | 20 | 39 | 2.02 | (0.77–5.31) | 1.77 | (0.64–4.87) | |||
3 (⩾3 for no stones) | 240 | 20 | 1.21 | (0.25–5.84) | 33 | 43 | 1.35 | (0.52–3.49) | 1.23 | (0.44–3.43) | |||
4 | — | — | — | — | 21 | 53 | 2.89 | (1.02–8.23) | 2.55 | (0.81–8.05) | |||
5 | — | — | — | — | 17 | 42 | 2.86 | (0.95–8.62) | 2.38 | (0.69–8.15) | |||
⩾6 | — | — | — | — | 14 | 37 | 2.99 | (0.93–9.65) | 2.43 | (0.65–9.07) | |||
P-trendd | — | — | 0.57 | — | — | 0.03 | — | — | 0.16 | ||||
P-interaction | 0.09 | ||||||||||||
Age at first birth (years) e | |||||||||||||
⩾27 | 112 | 9 | 1 | Reference | 32 | 36 | 1 | Reference | 1 | Reference | |||
24–26 | 84 | 10 | 1.83 | (0.66–5.06) | 21 | 39 | 1.77 | (0.84–3.71) | 1.74 | (0.81–3.76) | |||
21–23 | 100 | 9 | 1.21 | (0.39–3.82) | 28 | 74 | 2.56 | (1.28–5.13) | 2.36 | (1.12–4.99) | |||
⩽20 | 115 | 6 | 0.59 | (0.16–2.22) | 36 | 81 | 1.96 | (0.97–3.95) | 1.86 | (0.84–4.15) | |||
P-trendd | 0.39 | 0.06 | 0.13 | ||||||||||
P-interaction | 0.07 | ||||||||||||
Age at menarche (years) | |||||||||||||
⩽13 | 79 | 5 | 1 | Reference | 31 | 26 | 1 | Reference | 1 | Reference | |||
14–15 | 149 | 11 | 1.10 | (0.35–3.43) | 44 | 87 | 2.29 | (1.20–4.40) | 2.20 | (1.12–4.29) | |||
16–17 | 136 | 12 | 1.32 | (0.43–4.03) | 34 | 83 | 2.71 | (1.37–5.33) | 2.60 | (1.29–5.24) | |||
⩾18 | 58 | 8 | 2.33 | (0.67–8.14) | 14 | 33 | 2.61 | (1.12–6.09) | 2.28 | (0.96–5.39) | |||
P-trendd | 0.17 | 0.02 | 0.04 | ||||||||||
P-interaction | 0.86 | ||||||||||||
Parity and age at first birth (years) | |||||||||||||
0–1 and ⩾24 | — | — | — | — | 10 | 14 | 1 | Reference | — | — | |||
2–3 and ⩾24 | — | — | — | — | 31 | 43 | 1.47 | (0.52–4.16) | — | — | |||
⩾4 and ⩾24 | — | — | — | — | 12 | 18 | 1.86 | (0.49–6.94) | — | — | |||
0–1 and ⩽23 | — | — | — | — | 2 | 2 | — | — | |||||
2–3 and ⩽23 | — | — | — | — | 22 | 39 | 1.77 | (0.59–5.20) | — | — | |||
⩾4 and ⩽23 | — | — | — | — | 40 | 114 | 3.26 | (1.06–10.03) | — | — | |||
Parity and age at menarche (years) | |||||||||||||
0–1 and ⩽15 | — | — | — | — | 12 | 12 | 1 | Reference | — | — | |||
2–3 and ⩽15 | — | — | — | — | 37 | 44 | 1.48 | (0.49–4.40) | — | — | |||
⩾4 and ⩽15 | — | — | — | — | 26 | 57 | 3.19 | (0.95–10.69) | — | — | |||
0–1 and ⩾16 | — | — | — | — | 6 | 6 | 1.12 | (0.21–6.09) | — | — | |||
2–3 and ⩾16 | — | — | — | — | 16 | 36 | 2.56 | (0.79–8.21) | — | — | |||
⩾4 and ⩾16 | — | — | — | — | 26 | 74 | 4.01 | (1.19–13.58) | — | — |
Gallbladder cancer cases compared with population controls with a gallbladder (n=545).
Adjusted for age (continuous), education and body mass index.
Further adjusted for age first birth (continuous), age menarche (continuous) and parity; each factor is not self-adjusted.
Linear test of trend using continuous variable.
Among women with at least one full-term birth (n=568 controls).