Table 3.
Associations between the cumulative average intake of lactose and milk (2–6 years between exposure and outcome) in adulthood and risk of invasive EOC by tumor histology in the NHS/NHSII
| Serous/poorly differentiated (n = 403 a) | Endometrioid (n =101) | ||||
|---|---|---|---|---|---|
| Cases/Person-years | Adjusted HR b(95% CI) | Cases/Person-years | Adjusted HR b(95% CI) | P het c | |
| Dairy nutrients | |||||
| Lactose (g/d) d | |||||
| Q1 | 80/518421 | 1.00 (Ref) | 36/518456 | 1.00 (Ref) | 0.002 |
| Q2 | 87/517644 | 1.11 (0.82–1.50) | 25/517695 | 0.70 (0.42 – 1.18) | |
| Q3 | 85/517380 | 1.11 (0.81 –1.51) | 17/517444 | 0.48 (0.27 – 0.87) | |
| Q4 | 83/517278 | 1.16 (0.85 –1.58) | 13/517335 | 0.38 (0.20 – 0.72) | |
| Q5 | 68/517729 | 1.12 (0.81–1.55) | 10/517772 | 0.32 (0.16 – 0.65) | |
| P trend e | 0.50 | < 0.001 | |||
|
| |||||
| Dairy foods | |||||
| Total milk d,f (8 oz glass) | |||||
| <4/month | 50/381412 | 1.00 (Ref) | 25/381435 | 1.00 (Ref) | 0.01 |
| 1/wk | 65/382356 | 1.20 (0.83 – 1.74) | 16/382394 | 0.62 (0.33 – 1.16) | |
| 2–4/wk | 89/536612 | 1.25 (0.88 – 1.77) | 28/536669 | 0.81 (0.47 – 1.39) | |
| 5–7/wk | 164/979778 | 1.20 (0.86 – 1.65) | 25/979885 | 0.39 (0.22 – 0.68) | |
| >1/day | 31/270952 | 1.12 (0.71 – 1.78) | 7/270973 | 0.47 (0.20 – 1.10) | |
| P trend e | 0.82 | 0.01 | |||
| Skim/low fat milk d (8 oz glass) | |||||
| <4/month | 93/579059 | 1.00 (Ref) | 34/579112 | 1.00 (Ref) | 0.05 |
| 1/wk | 65/391569 | 0.96 (0.70 – 1.33) | 17/391603 | 0.72 (0.40 – 1.29) | |
| 2–4/wk | 86/511130 | 1.09 (0.81 – 1.47) | 25/511184 | 0.86 (0.51 – 1.45) | |
| 5–7/wk | 132/853073 | 0.98 (0.75 – 1.29) | 19/853160 | 0.39 (0.22 – 0.69) | |
| >1/day | 26/238742 | 1.01 (0.65 – 1.57) | 6/238762 | 0.55 (0.23 – 1.31) | |
| P trend e | 0.97 | 0.01 | |||
Numbers may not add up to total in analyses of milk intake due to missing data.
Data are Hazard Ratios (95% CI) unless indicated otherwise.
The P-value for heterogeneity (P het) is from the likelihood-ratio test that compares a model with the same estimate for the association with the exposure of interest (e.g., quintiles of lactose intake) across histologic subtypes to a model which allows the association with the exposure of interest to vary across histologic subtypes.
Models were adjusted for total caloric intake (continuous), number of pregnancies (continuous) and parity (ever/never), oral contraceptive pill use (0, <1 yr (ref), 1 – <5 yrs, ≥ 5 yrs), menopausal status (post vs pre/perimenopausal) and tubal ligation (yes vs no). All models were stratified by age in months, cohort and time period. Models were not adjusted for family history of ovarian cancer due to small numbers in the endometrioid category. The associations with age and parity were allowed to vary by histologic subtype in the models.
P-value test for trend using a trend variable based on the median value for each category of intake.
Total milk is the sum of whole milk and skim/low fat milk intake.