Table 3.
HRs and 95% CIs for the association categories of cumulative average intake of total olive oil and breast cancer tumor subtypes in the NHS and NHSII.
| Never or <1 per month | >0– ≤ 4.5 g/d ( >0 to ≤1 teaspoon) | >4.5– ≤7 g/d ( >1 teaspoon to ≤1/2 TBS) | >7 g/d ( >1/2 TBS) | P- trend | |
|---|---|---|---|---|---|
| ER-negative breast cancer (case n = 1416) | |||||
| N° cases/ Person-years | 386/1100933 | 759/1934091 | 127/313200 | 144/403532 | |
| Age-adjusted model | 1 (Ref.) | 1.16 (1.02, 1.32) | 1.19 (0.97, 1.46) | 1.03 (0.84, 1.25) | 0.80 |
| Multivariable model | 1 (Ref.) | 1.13 (0.98, 1.28) | 1.16 (0.93, 1.44) | 1.01 (0.81, 1.25) | 0.69 |
| ER-positive breast cancer (case n = 6860) | |||||
| N° cases/ Person-years | 1,646/1099737 | 3,638/1931419 | 679/312702 | 897/402820 | |
| Age-adjusted model | 1 (Ref.) | 1.13 (1.06, 1.20) | 1.22 (1.11, 1.33) | 1.19 (1.09, 1.30) | <0.01 |
| Multivariable model | 1 (Ref.) | 1.03 (0.97, 1.10) | 1.07 (0.97, 1.18) | 1.03 (0.93, 1.13) | 0.71 |
| p-heterogeneitya = 0.99 | |||||
| Luminal A breast cancer (case n = 2668) | |||||
| N° cases/ Person-years | 765/972970 | 1,361/1336018 | 248/194625 | 294/236045 | |
| Age-adjusted model | 1 (Ref.) | 1.07 (0.97, 1.17) | 1.19 (1.03, 1.38) | 1.10 (0.95, 1.26) | 0.13 |
| Multivariable model | 1 (Ref.) | 1.00 (0.91, 1.10) | 1.08 (0.92, 1.26) | 0.97 (0.83, 1.12) | 0.88 |
| Luminal B breast cancer (case n = 1220) | |||||
| N° cases/ Person-years | 305/973399 | 654/1336630 | 116/194737 | 145/236181 | |
| Age-adjusted model | 1 (Ref.) | 1.21 (1.05, 1.39) | 1.30 (1.04, 1.61) | 1.24 (1.01, 1.51) | 0.11 |
| Multivariable model | 1 (Ref.) | 1.14 (0.99, 1.32) | 1.22 (0.97, 1.53) | 1.15 (0.92, 1.44) | 0.38 |
| HER2-enrichedb (case n = 226) | |||||
| N° cases/ Person-years | 58/973632 | 127/1337102 | 23/194816 | 18/236290 | |
| Age-adjusted model | 1 (Ref.) | 1.28 (0.93, 1.76) | 1.42 (0.87, 2.33) | 0.86 (0.50, 1.48) | 0.53 |
| Multivariable model | 1 (Ref.) | 1.17 (0.84, 1.62) | 1.27 (0.76, 2.13) | 0.77 (0.43, 1.37) | 0.33 |
| Basal-like tumorsb (case n = 260) | |||||
| N° cases/ Person-years | 100/973596 | 121/1337109 | 18/194823 | 21/236288 | |
| Age-adjusted model | 1 (Ref.) | 0.99 (0.75, 1.30) | 1.02 (0.61, 1.70) | 1.00 (0.62, 1.62) | 0.96 |
| Multivariable model | 1 (Ref.) | 1.01 (0.76, 1.33) | 1.05 (0.62, 1.78) | 1.03 (0.61, 1.72) | 0.88 |
| p-heterogeneitya = 0.54 | |||||
Results are expressed as Hazard Ratios (HR) and 95% Confidence Intervals (95% CI).
Multivariable model: adjusted for ethnicity (white, non-white), Southern European/Mediterranean ancestry (yes, no), age at menarche ( <12, 12, 13, 14, >14 years), menopausal status and age at menopause (premenopausal, <45, 45–49, 50–52, 53 + , unknown), postmenopausal hormone use (never user, past user, current user– estrogen only for <5 years, current user – estrogen only for ≥5 years, current estrogen + progestin user for <5 years, current estrogen + progestin user for ≥5 years, current user of other types), oral contraceptive use history (never, ever), parity and age at first birth (nulliparous, 1 child before age 25, 1 child at ≥25 years of age, 2+ children before age 25, 2+ children ≥25 years of age), breastfeeding history (never, breastfed for ≤ 6 months, breastfed for > 6 months), family history of breast cancer (yes or no), history of biopsy-confirmed benign breast disease (yes or no), height ( <1.60, 1.60–1.64, 1.65–1.69, 1.70–1.74, 1.75 + m), cumulatively updated total caloric intake (kcal/day, quintiles), physical activity (continuous MET-hours/week), neighborhood-based socioeconomic status indicator (continuous), BMI at age 18 ( <20.0, 20.0–21.9, 22.0–23.9, 24.0–26.9, ≥27.0) and AHEI-2010 (without alcohol and polyunsaturated fatty acids components, quintiles).
NHS Nurses’ Health Study, NHSII Nurses’ Health Study II.
aFor testing heterogeneity by subtype, we used the Lunn–McNeil approach, for multivariable model 1.
bDue to smaller sample sizes in analyses, to ensure that models would run, covariate categorizations were simplified.