Table 2.

Cumulative average coffee and tea consumption and risk of endometrial cancer in the NHS cohort

Coffee intake, RR (95% CI)
<1 cup/d1 cup/d2–3 cups/d≥4 cups/dPtrend
Person-years301,317211,400514,014256,514
No. of cases16814027589
Age-adjusted1.000.95 (0.76–1.19)0.81 (0.67–0.98)0.61 (0.47–0.79)<0.001
Multivariable-adjusteda1.001.04 (0.83–1.31)0.93 (0.76–1.14)0.75 (0.57–0.97)0.02
Multivariable-adjustedb1.000.94 (0.73–1.19)0.94 (0.77–1.16)0.68 (0.52–0.90)0.01
Caffeinated coffee intake, RR (95% CI)
<1 cup/d1 cup/d2–3 cups/d≥4 cups/dPtrend
Person-years423,877240,812434,482184,075
No. of cases25515121254
Age-adjusted1.000.94 (0.77–1.15)0.79 (0.66–0.95)0.57 (0.43–0.77)<0.001
Multivariable-adjusteda1.001.01 (0.82–1.24)0.89 (0.74–1.08)0.70 (0.51–0.95)0.02
Multivariable-adjustedb1.000.97 (0.79–1.21)0.92 (0.76–1.12)0.66 (0.48–0.91)0.02
Decaffeinated coffee intake, RR (95% CI)c
<1 cup/mo1 cup/mo to <1 cup/d1 cup/d≥2 cups/dPtrend
Person-years311,761368,383139,250107,655
No. of cases1702459854
Age-adjusted1.001.02 (0.84–1.24)1.10 (0.85–1.41)0.87 (0.64–1.19)0.57
Multivariable-adjusteda1.000.92 (0.75–1.14)0.96 (0.74–1.25)0.78 (0.57–1.08)0.23
Multivariable-adjustedb1.000.90 (0.72–1.11)1.01 (0.78–1.32)0.72 (0.52–1.01)0.20
Tea intake, RR (95% CI)
<1 cup/mo1 cup/mo to <1 cup/d1 cup/d≥2 cups/dPtrend
Person-years235,463677,960194,971162,849
No. of cases9238511771
Age-adjusted1.001.18 (0.94–1.49)1.39 (1.06–1.84)1.20 (0.88–1.63)0.25
Multivariable-adjusteda1.001.10 (0.87–1.40)1.24 (0.94–1.65)1.06 (0.77–1.46)0.70
Multivariable-adjustedb1.000.97 (0.77–1.22)1.21 (0.92–1.59)0.94 (0.69–1.30)0.77
  • aAdjusted for age (mo, continuous), BMI (kg/m2, continuous), age at menopause [pre-/unknown menopause, <45 y, 45–46 y, 47–48 (ref), 49–50 y, 51–52 y, and ≥53 y], age at menarche [<12 y, 12 y (ref), and >12 y], parity and age at last birth [nulliparous (ref), parity 1–2 and age at last birth <30 y, parity 1–2 and age at last birth parity ≥30 y, parity 3–4 and age at last birth <30 y, parity 3–4 and age at last birth ≥30 y, parity ≥5 and age at last birth <30 y, and parity ≥5 and age at last birth ≥30 y], duration of oral contraceptive use [never (ref), <3 y, past 3–5 y, and past >5 y], postmenopausal hormone use [premenopausal, postmenopausal never (ref), past PMH, current PMH estrogen only, current PMH estrogen with progesterone], pack-years of smoking [never (ref), >0–10 pack-years, >10–20 pack-years, >20–30 pack-years, >30–40 pack-years, >40 pack-years], alcohol intake [0 (ref), 0.1–4.9g/d, 5.0–14.9g/d, >15.0g/d], and total energy intake [kcal/d, continuous]. Caffeinated coffee and decaffeinated coffee intakes were mutually adjusted in the model. Total coffee intake was adjusted for tea analysis.

  • bExcluded cases that occurred during the first 2-year follow-up period (n = 33 cases) to minimize the possibility that preclinical disease influenced dietary assessment. For decaffeinated coffee analysis, 28 cases were excluded.

  • cFollow-up from 1984.