Table 2. Adjusted odds ratio and 95% confidence interval for endometrial cancer in relation to parity and infertility in the E2C2 pooled analysis.
| Cases Na(%) | Controls Na(%) | OR (95% CI)b | Additionally adjusted for infertility | Additionally adjusted for nulliparity | Additionally adjusted for no. of live births | |
|---|---|---|---|---|---|---|
|
Nulliparity | ||||||
| Parous | 6591 (84) | 10 366 (90) | 1.00 | 1.00 | — | — |
| Nulliparous | 1272 (16) | 1168 (10) | 1.82 (1.65–2.00) | 1.76 (1.59–1.94) | — | — |
|
Number of births | ||||||
| 3+ | 2663 (34) | 4501 (39) | 1.00 | 1.00 | — | — |
| 2 | 2349 (30) | 3788 (33) | 1.22 (1.13–1.32) | 1.21 (1.12–1.31) | — | — |
| 1 | 1579 (20) | 2077 (18) | 1.46 (1.33–1.61) | 1.44 (1.30–1.58) | — | — |
| 0 | 1272 (16) | 1168 (10) | 2.11 (1.90–2.35) | 2.04 (1.83–2.27) | — | — |
| — | — | P-trendc<0.001 | P-trendc<0.001 | — | — | |
|
Infertility | ||||||
| Never | 5573 (71) | 8957 (78) | 1.00 | — | 1.00 | 1.00 |
| Ever | 2304 (29) | 2509 (22) | 1.31 (1.21–1.42) | — | 1.22 (1.13–1.33) | 1.20 (1.11–1.30) |
Abbreviations: CI=confidence interval; OR=odds ratio.
a
Numbers do not add to the total because of missingness.
b
Adjusted for age, study site, race, ever oral contraceptive use, ever menopausal hormone therapy use, interview year and body mass index. Missing set as a separate category for each covariate.
c
P-trend calculated by entering the ordinal values representing categories of parity as a continuous variable in the model.