Table 3.
Hazard ratios (HR) and 95% confidence intervals (95% CI) for the association between hysterectomy and risk of Non-Hodgkin lymphoma (NHL) by hormone use
| Never hormone users | Unopposed estrogen users | Interaction test | |||||
|---|---|---|---|---|---|---|---|
| NHL Cases/Person-Years | Age-adjusted HR (95% CI) | Multivariable-adjusted HR (95% CI)1 | NHL Cases/Person-Years | Age-adjusted HR (95% CI) | Multivariable-adjusted HR (95% CI)1 | ||
| Hysterectomy 2 | 0.13 | ||||||
| No | 498/767,106 | Ref | Ref | 75/92,416 | Ref | Ref | |
| Yes | 194/235,436 | 1.25 (1.01 1.54) | 1.35 (1.06 1.71) | 483/615,271 | 1.09 (0.83 1.43) | 1.09 (0.81 1.47) | |
| Collapsed combinations of hysterectomy and oophorectomy | 0.14 | ||||||
| No hysterectomy and no oophorectomy | 479/734,672 | Ref | Ref | 67/86,353 | Ref | Ref | |
| No hysterectomy with oophorectomy | 19/32,434 | 0.88 (0.56 1.39) | 0.88 (0.55 1.39) | 8/6,063 | 1.71 (0.82 3.55) | 1.66 (0.79 3.46) | |
| Hysterectomy without oophorectomy | 84/110,142 | 1.21 (0.96 1.52) | 1.30 (1.00 1.68) | 170/213,954 | 1.17 (0.88 1.55) | 1.15 (0.84 1.58) | |
| Hysterectomy with oophorectomy | 110/125,294 | 1.33 (1.08 1.63) | 1.41 (1.12 1.79) | 313/401,316 | 1.13 (0.86 1.48) | 1.13 (0.84 1.52) | |
| Age of hysterectomy (years) 2 | 0.06 | ||||||
| No hysterectomy and no oophorectomy | 479/734,672 | Ref | Ref | 67/86,353 | Ref | Ref | |
| <40 | 69/87,971 | 1.31 (1.02 1.69) | 1.43 (1.08 1.89) | 120/203,640 | 0.91 (0.67 1.24) | 0.92 (0.66 1.29) | |
| 40–<50 | 84/101,739 | 1.27 (1.01 1.60) | 1.35 (1.04 1.74) | 262/289,728 | 1.30 (0.99 1.71) | 1.29 (0.95 1.75) | |
| 50–<55 | 27/24,140 | 1.59 (1.08 2.35) | 1.63 (1.09 2.43) | 61/78,376 | 1.07 (0.75 1.51) | 1.04 (0.72 1.51) | |
| 55+ | 14/21,586 | 0.85 (0.50 1.44) | 0.88 (0.51 1.51) | 40/43,526 | 1.10 (0.75 1.63) | 1.07 (0.70 1.61) | |
In the multivariable-adjusted models, we adjusted potential confounders, including age at enrollment (in continuous), race (Asian, Black, White or other), Hispanic ethnicity (yes, no, missing), BMI (<25, 25.0 –<30, 30+ kg/m2), education (high school or less, some college/technical training, college or some post-college, and master or higher), diet quality (in continuous), smoking pack-years(never smoked, smoked <5, 5–<20, ≥ 20 pack-years), alcohol intake (non-drinker, past drinker, current and <7 drinks/wk, current and ≥7 drinks/wk), physical activity (<5, 5–<10, 10–<20, 20–<30, 30+ Metabolic equivalent (METs)/week, family history of cancer (yes, no), rheumatoid arthritis ever (yes, no), or lupus yes, no).
This model additionally adjusted for oophorectomy.