Table 1.
The association between reproductive factors and risk of ESCC among women participating in the Golestan Case-Control Study
| Reproductive factors |
ESCC cases (%) N= 149 |
Controls (%) N= 290 |
Unadjusted OR (95% CI) |
Adjusted OR ∫ (95% CI) |
|
|---|---|---|---|---|---|
| No. of Pregnancies | |||||
| Continuous | 8.4 (3.5) * | 9.0 (3.4) * | 0.95 (0.89–1.01) | 0.98 (0.91–1.06) | |
| Arbitrary categories | |||||
| 0 – 3 | 11 (7.4) | 15 (5.2) | Referent | Referent | |
| 4 – 6 | 33 (22.1) | 45 (15.5) | 1.06 (0.43–2.66) | 0.83 (0.25–2.77) | |
| 7 – 8 | 31 (20.8) | 69 (23.8) | 0.63 (0.26–1.50) | 0.50 (0.16–1.57) | |
| 9 – 10 | 32 (21.5) | 77 (26.5) | 0.56 (0.23–1.34) | 0.47 (0.15–1.50) | |
| ≥ 11 | 42 (28.2) | 84 (29.0) | 0.67 (0.28–1.61) | 0.73 (0.24–2.26) | |
| P trend | 0.12 | 0.59 | |||
| Quartiles | |||||
| Quartile 1 (0 – 6) | 44 (29.5) | 60 (20.7) | Referent | Referent | |
| Quartile 2 (7 – 8) | 31 (20.8) | 69 (23.8) | 0.60 (0.34–1.07) | 0.57 (0.29–1.14) | |
| Quartile 3 (9 – 10) | 32 (21.5) | 77 (26.5) | 0.53 (0.30–0.96) | 0.55 (0.28–1.09) | |
| Quartile 4 (≥ 11) | 42 (28.2) | 84 (29.0) | 0.64 (0.36–1.15) | 0.84 (0.43–1.64) | |
| P trend | 0.14 | 0.69 | |||
| No. of live-births | |||||
| Continuous | 6.8 (3.0) * | 8.2 (3.2) * | 0.85 (0.79–0.92) | 0.86 (0.79–0.95) | |
| Arbitrary categories | |||||
| 0 – 3 | 18 (12.1) | 19 (6.6) | Referent | Referent | |
| 4 – 5 | 32 (21.5) | 30 (10.3) | 1.23 (0.51–2.96) | 0.90 (0.29–2.80) | |
| 6 – 7 | 34 (22.8) | 66 (22.8) | 0.58 (0.26–1.28) | 0.33 (0.12–0.92) | |
| 8 – 9 | 33 (22.1) | 87 (30.0) | 0.39 (0.18–0.85) | 0.31 (0.11–0.85) | |
| ≥ 10 | 32 (21.5) | 88 (30.3) | 0.35 (0.16–0.77) | 0.34 (0.12–0.93) | |
| P trend | <0.001 | 0.003 | |||
| Quartiles | |||||
| Quartile 1 (0 – 5) | 50 (33.6) | 49 (16.9) | Referent | Referent | |
| Quartile 2 (6 – 7) | 34 (22.8) | 66 (22.8) | 0.51 (0.28–0.91) | 0.36 (0.17–0.73) | |
| Quartile 3 (8 – 9) | 33 (22.1) | 87 (30.0) | 0.34 (0.19–0.61) | 0.33 (0.16–0.67) | |
| Quartile 4 (≥ 10) | 32 (21.5) | 88 (30.3) | 0.31 (0.17–0.57) | 0.36 (0.17–0.76) | |
| P trend | <0.001 | 0.005 | |||
| No. of miscarriages/stillbirths | |||||
| Continuous | 1.5 (2.1) * | 0.8 (1.2) * | 1.37 (1.19–1.57) | 1.49 (1.24–1.78) | |
| Arbitrary categories | |||||
| 0 | 69 (46.3) | 175 (60.3) | Referent | Referent | |
| 1 | 25 (16.8) | 56 (19.3) | 1.15 (0.67–1.97) | 1.38 (0.71–2.69) | |
| 2 | 19 (12.7) | 24 (8.3) | 2.10 (1.07–4.11) | 2.54 (1.10–5.86) | |
| ≥ 3 | 36 (24.2) | 35 (12.1) | 3.04 (1.68–5.51) | 4.43 (2.11–9.33) | |
| P trend | <0.001 | <0.001 | |||
CI, confidence interval; ESCC, esophageal squamous cell carcinoma; OR, odds ratio.
∫
Multivariate models were adjusted for duration of residence in rural areas, ethnicity, education level, marital status, tobacco and opium use, quintiles of wealth score, and daily vegetable intake (variables as shown in Supplementary Table 1). Results for the number of live-births were additionally adjusted for quartiles of miscarriages/stillbirths, and results for miscarriage/stillbirth were additionally adjusted for the quartiles of live-births.
*
Mean (standard deviation).