Table 4.
Hazard ratios (HR) and 95% confidence intervals (95% CI) for the association between hysterectomy, oophorectomy and risk of Non-Hodgkin’s lymphoma (NHL) subtypes1
| Diffuse large B-cell lymphoma (DLBCL) | Follicular lymphoma (FL) | Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) | ||||
|---|---|---|---|---|---|---|
| NHL Cases | Multivariable-adjusted HR (95% CI) | NHL Cases | Multivariable-adjusted HR (95% CI) | NHL Cases | Multivariable-adjusted HR (95% CI) | |
| Hysterectomy 2 | ||||||
| No | 278 | Ref | 174 | Ref | 76 | Ref |
| Yes | 207 | 1.20 (0.89 1.62) | 151 | 1.39 (0.95 2.02) | 58 | 1.54 (0.87 2.72) |
| Never hormone users 2 | ||||||
| Hysterectomy (No) | 135 | Ref | 83 | Ref | 36 | Ref |
| Hysterectomy (Yes) | 65 | 1.48 (0.96 2.28) | 29 | 1.22 (0.66 2.25) | 18 | 1.41 (0.62 3.23) |
| Unopposed estrogen users 2 | ||||||
| Hysterectomy (No) | 27 | Ref | 12 | Ref | 3 | Ref |
| Hysterectomy (Yes) | 124 | 0.83 (0.50 1.38) | 103 | 1.27 (0.63 2.55) | 33 | - |
| Interaction between hysterectomy and hormone use 2 | 0.01 | 0.84 | 0.87 | |||
| Collapsed combinations of hysterectomy and oophorectomy | ||||||
| No hysterectomy and no oophorectomy | 267 | Ref | 169 | Ref | 74 | Ref |
| Hysterectomy without oophorectomy | 86 | 1.21 (0.89 1.65) | 54 | 1.33 (0.90 1.97) | 17 | 1.25 (0.66 2.37) |
| Hysterectomy with oophorectomy | 121 | 1.02 (0.76 1.37) | 97 | 1.40 (0.98 2.00) | 41 | 1.80 (1.06 3.08) |
| Never hormone users | ||||||
| No hysterectomy and no oophorectomy | 129 | Ref | 82 | Ref | 35 | Ref |
| Hysterectomy without oophorectomy | 29 | 1.51 (0.96 2.38) | 12 | 0.99 (0.50 1.97) | 7 | 1.21 (0.48 3.05) |
| Hysterectomy with oophorectomy | 36 | 1.60 (1.05 2.44) | 17 | 1.21 (0.66 2.19) | 11 | 1.48 (0.66 3.32) |
| Unopposed estrogen users | ||||||
| No hysterectomy and no oophorectomy | 24 | Ref | 10 | Ref | 3 | Ref |
| Hysterectomy without oophorectomy | 55 | 0.91 (0.53 1.54) | 37 | 1.47 (0.69 3.13) | 9 | _ |
| Hysterectomy with oophorectomy | 69 | 0.61 (0.36 1.01) | 66 | 1.39 (0.68 2.85) | 24 | _ |
| Interaction between combinations of hysterectomy and oophorectomy and hormone use | 0.03 | 0.28 | 0.99 | |||
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).
Oophorectomy was additionally adjusted for in these analyses.