Table 3.

Adjusted hazard ratios and 95% confidence intervals for the associations between red meat and poultry and total invasive breast cancer risk by estrogen receptor and time-varying menopausal status^a using “Addition” and “Substitution” models

	Quartile 1	Quartile 2	Quartile 3	Quartile 4	P for trend
Total Invasive Breast Cancer
Red Meat
No. of cases	340	366	398	432
Addition modelb	1.00 (ref)	1.03 (0.88–1.20)	1.11 (0.94–1.32)	1.23 (1.02–1.48)	0.01
Substitution modelc	1.00 (ref)	1.02 (0.87–1.21)	1.13 (0.93–1.37)	1.29 (1.03–1.61)	0.01
Poultry
No. of cases	392	407	371	366
Addition modelb	1.00 (ref)	0.98 (0.85–1.14)	0.87 (0.75–1.02)	0.85 (0.72–1.00)	0.03
Substitution modelc	1.00 (ref)	0.93 (0.79–1.09)	0.78 (0.65–0.94)	0.72 (0.58–0.89)	0.002
ER+ Invasive Breast Cancer
Red Meat
No. of cases	258	269	304	329
Addition modelb	1.00 (ref)	1.01 (0.84–1.21)	1.15 (0.94–1.39)	1.27 (1.03–1.57)	0.01
Substitution modelc	1.00 (ref)	1.00 (0.83–1.20)	1.13 (0.91–1.41)	1.29 (1.00–1.67)	0.03
Poultry
No. of cases	291	308	285	276
Addition modelb	1.00 (ref)	1.02 (0.86–1.21)	0.93 (0.77–1.11)	0.90 (0.75–1.10)	0.2
Substitution modelc	1.00 (ref)	0.96 (0.80–1.15)	0.81 (0.66–1.00)	0.74 (0.58–0.95)	0.01
ER- Invasive Breast Cancer
Red Meat
No. of cases	38	48	51	56
Addition modelb	1.00 (ref)	1.13 (0.72–1.78)	1.17 (0.72–1.89)	1.24 (0.73–2.09)	0.5
Substitution modelc	1.00 (ref)	1.12 (0.70–1.80)	1.33 (0.77–2.30)	1.67 (0.87–3.22)	0.1
Poultry
No. of cases	51	49	43	50
Addition modelb	1.00 (ref)	0.76 (0.51–1.15)	0.61 (0.39–0.95)	0.66 (0.41–1.04)	0.1
Substitution modelc	1.00 (ref)	0.71 (0.45–1.10)	0.59 (0.35–0.99)	0.66 (0.36–1.22)	0.4
Premenopausal Invasive Breast Cancer
Red Meat
No. of cases	64	71	93	73
Addition modelb	1.00 (ref)	1.05 (0.73–1.51)	1.32 (0.90–1.93)	1.06 (0.69–1.62)	1.0
Substitution modelc	1.00 (ref)	0.98 (0.67–1.43)	1.15 (0.75–1.76)	0.92 (0.56–1.52)	0.6
Poultry
No. of cases	66	68	76	91
Addition modelb	1.00 (ref)	0.85 (0.59–1.21)	0.88 (0.61–1.27)	1.06 (0.73–1.55)	0.4
Substitution modelc	1.00 (ref)	0.75 (0.51–1.12)	0.73 (0.47–1.13)	0.93 (0.56–1.53)	0.6
Postmenopausal Invasive Breast Cancer
Red Meat
No. of cases	276	295	303	358
Addition modelb	1.00 (ref)	1.02 (0.86–1.22)	1.07 (0.88–1.29)	1.28 (1.04–1.56)	0.006
Substitution modelc	1.00 (ref)	1.03 (0.86–1.24)	1.12 (0.90–1.39)	1.41 (1.10–1.81)	0.002
Poultry
No. of cases	326	338	294	274
Addition modelb	1.00 (ref)	1.02 (0.87–1.19)	0.87 (0.73–1.04)	0.80 (0.66–0.96)	0.005
Substitution modelc	1.00 (ref)	0.97 (0.81–1.15)	0.79 (0.64–0.96)	0.66 (0.52–0.84)	0.0002

Abbreviations: ER, estrogen receptor.

^aTime-varying menopausal status contributed to follow-up time at risk for either premenopausal or post-menopausal breast cancer and was considered for both incident cases and non-cases.

^bAddition model: adjusted for age (as the primary time scale), race/ ethnicity (non-Hispanic White, non-Hispanic Black, or other), household income (< $49,999, $50,000-$99,999, or ≥$100,000), educational attainment (high school degree or less, some college, college degree or higher), baseline menopausal status (binary), body mass index (BMI; continuous), interaction term between baseline menopausal status and BMI, waist-to-hip ratio (continuous), total energy intake (kcal/day), consumption of vegetables (quintiles), consumption of fruit (quintiles), percent calories from fat (quartiles), dairy consumption (quartiles), number of relatives diagnosed with breast cancer before the age of 50 (0, 1, or ≥2), lifetime duration of breastfeeding (none and tertiles among women with any breastfeeding, wk), hormone therapy (none, estrogen only, or both estrogen and progesterone), parity (0, 1, 2, or ≥3 births), birth control pill use (never, former, or current), alcohol consumption (never, drinker, current <1 drink/day, current 1–1.9 drinks/day, or current s≥ 2 drinks/day), total MET-hours of leisure-time physical activity per week (quintiles), and smoking status (≥20 pack years, <20 and ≥10 pack years, < 10 and > 0 pack years or never smoker); and additional adjustment for consumption of other meat categories (quartiles).

^cSubstitution model: adjusted for the same covariates as addition model, except that poultry consumption is replaced by combined consumption of red meat and poultry (quartiles) in a substitution model of red meat, whereas red meat consumption is replaced by combined consumption of red meat and poultry (quartiles) in a substitution model of poultry.