TABLE 2.
Age-adjusted odds ratios and 95% confidence intervals for reproductive factors associated with all non-Hodgkin lymphoma and with the subtypes follicular lymphoma and diffuse large-cell lymphoma among women in a population-based case-control study, San Francisco Bay Area, California, 1988–1993
| Reproductive factor | Controls (n = 836) |
All NHL* cases (n = 581) |
FL* cases (n = 173) |
DLCL* cases (n = 233) |
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| No. | % | No. | % | OR* | CI* | No. | % | OR† | CI | No. | % | OR‡ | CI | |
| Age at menarche (years) | ||||||||||||||
| ≤11 | 167 | 20 | 110 | 19 | 1.0§ | 35 | 21 | 1.0§ | 46 | 20 | 1.0§ | |||
| 12–13 | 415 | 50 | 308 | 53 | 1.1 | 0.85, 1.5 | 83 | 49 | 0.96 | 0.62, 1.5 | 130 | 56 | 1.1 | 0.78, 1.7 |
| 14 | 128 | 15 | 87 | 15 | 1.0 | 0.72, 1.5 | 29 | 17 | 1.1 | 0.63, 1.9 | 32 | 14 | 0.91 | 0.55, 1.5 |
| >14 | 123 | 15 | 72 | 12 | 0.89 | 0.61, 1.3 | 23 | 14 | 0.90 | 0.51, 1.6 | 25 | 11 | 0.74 | 0.43, 1.3 |
| p-trend | 0.43 | 0.90 | 0.17 | |||||||||||
| No. of pregnancies | ||||||||||||||
| Never pregnant¶ | 116 | 15 | 80 | 14 | 1.0§ | 20 | 12 | 1.0§ | 38 | 17 | 1.0§ | |||
| 1–3 | 410 | 50 | 317 | 55 | 1.1 | 0.81, 1.5 | 104 | 60 | 1.4 | 0.79, 2.4 | 122 | 53 | 0.67 | 0.43, 1.0 |
| 4 | 125 | 15 | 78 | 14 | 0.90 | 0.60, 1.4 | 22 | 13 | 0.89 | 0.44, 1.8 | 27 | 12 | 0.43 | 0.24, 0.78 |
| >4 | 174 | 21 | 98 | 17 | 0.81 | 0.55, 1.2 | 26 | 15 | 0.77 | 0.39, 1.5 | 43 | 19 | 0.53 | 0.31, 0.90 |
| p-trend | 0.06 | 0.05 | 0.01 | |||||||||||
| No. of livebirths | ||||||||||||||
| 0 | 55 | 7 | 28 | 5 | 0.74 | 0.43, 1.3 | 6 | 3 | 0.77 | 0.29, 2.1 | 12 | 5 | 0.64 | 0.31, 1.3 |
| 1–2 | 299 | 36 | 238 | 41 | 1.2 | 0.82, 1.6 | 85 | 49 | 1.6 | 0.88, 2.8 | 85 | 36 | 0.63 | 0.40, 1.0 |
| 3 | 173 | 21 | 123 | 21 | 1.0 | 0.71, 1.5 | 35 | 20 | 1.0 | 0.54, 2.0 | 47 | 20 | 0.58 | 0.34, 0.99 |
| ≥4 | 191 | 23 | 112 | 19 | 0.85 | 0.58, 1.2 | 27 | 16 | 0.73 | 0.37, 1.4 | 51 | 22 | 0.56 | 0.33, 0.94 |
| p-trend | 0.44 | 0.14 | 0.04 | |||||||||||
| Age at birth of first child (years) | ||||||||||||||
| ≤21 | 189 | 24 | 141 | 26 | 1.1 | 0.76, 1.6 | 37 | 22 | 1.2 | 0.64, 2.3 | 54 | 24 | 0.70 | 0.42, 1.2 |
| 22–24 | 179 | 23 | 119 | 22 | 1.0 | 0.67, 1.4 | 35 | 21 | 1.1 | 0.56, 2.0 | 52 | 24 | 0.69 | 0.41, 1.2 |
| 25–28 | 158 | 20 | 118 | 21 | 1.1 | 0.75, 1.6 | 38 | 23 | 1.3 | 0.70, 2.6 | 47 | 21 | 0.70 | 0.41, 1.2 |
| >28 | 135 | 17 | 95 | 17 | 1.0 | 0.70, 1.5 | 37 | 22 | 1.5 | 0.80, 3.0 | 30 | 14 | 0.51 | 0.29, .91 |
| p-trend | 0.92 | 0.17 | 0.06 | |||||||||||
| Hysterectomy/oophorectomy | ||||||||||||||
| No | 555 | 66 | 381 | 66 | 1.0 | 116 | 67 | 1.0 | 154 | 66 | 1.0 | |||
| Yes | 281 | 34 | 200 | 34 | 1.0 | 0.81, 1.3 | 57 | 33 | 1.1 | 0.75, 1.6 | 79 | 34 | 1.0 | 0.74, 1.4 |
NHL, non-Hodgkin lymphoma; FL, follicular lymphoma; DLCL, diffuse large-cell lymphoma; OR, odds ratio; CI, confidence interval.
Number of pregnancies, number of livebirths, and age at birth of first child were also adjusted for marital status and lifetime number of sexual partners.
Age at birth of first child was adjusted for age group and marital status. Number of pregnancies and number of livebirths were also adjusted for marital status and education.
Referent.
Referent group for all subsequent reproductive factors in this table.