Article Figures & Data
Tables
- Table 1.
Characteristics of the study population by level of physical activity at baseline, 182,862 postmenopausal women, NIH-American Association of Retired Persons Diet and Health Study (1995-1996)
Characteristics Total Physical activity (times per week) Inactive <1 1-2 3-4 ≥5 Participants, n (%) 182,862 41,580 (22.7) 26,311 (14.4) 38,713 (21.2) 46,251 (25.3) 30,007 (16.4) Age at baseline (y) 62.1 62.4 61.3 61.8 62.4 62.5 BMI (kg/m2) 26.9 28.6 27.6 26.9 26.0 25.3 Race/ethnicity (%) White 89.9 88.5 90.2 90.6 90.0 90.8 Black 5.5 6.6 5.6 5.0 5.3 4.9 Hispanic 1.9 2.3 1.8 1.8 1.9 1.5 Asian/Pacific Islander/Native American 1.5 1.4 1.3 1.5 1.7 1.6 College education (%) 29.6 21.6 28.5 31.0 33.1 34.2 Family history of breast cancer* (%) 12.4 12.0 12.6 12.5 12.5 12.4 Current smoker (%) 14.4 19.7 17.6 14.8 10.6 9.6 Current MHT use (%) 44.9 37.8 45.3 46.0 48.9 47.0 Age at menarche (y) 12.51 12.46 12.48 12.50 12.53 12.55 Age at first birth in parous women (y) 22.88 22.68 22.78 22.94 23.02 22.97 Parity (no. children) 2.01 2.02 2.01 2.00 2.02 1.99 Age at menopause (y) 46.88 46.46 46.76 46.91 47.11 47.21 Alcohol intake (g/d) 6.0 5.8 6.1 5.8 6.1 6.3 Total energy intake† (kcal/d) 1,597.4 1,623.5 1,557.3 1,583.2 1,576.1 1,647.4 - Table 2.
RR (95% CI) for the association between physical activity and postmenopausal breast cancer incidence among 182,862 postmenopausal women
Physical activity (times per week) Person-years No. cases Age-adjusted RR (95% CI) Multivariate RR* (95% CI) Multivariate RR† (95% CI) Inactive 285,349 1,485 1.0 (Reference) 1.0 (Reference) 1.0 (Reference) <1 184,682 981 1.04 (0.96-1.13) 0.99 (0.91-1.07) 1.00 (0.92-1.08) 1-2 271,497 1,391 0.99 (0.92-1.07) 0.94 (0.87-1.01) 0.96 (0.89-1.03) 3-4 325,701 1,711 1.01 (0.94-1.08) 0.93 (0.87-1.00) 0.97 (0.90-1.04) ≥5 211,557 1,041 0.94 (0.87-1.02) 0.87 (0.81-0.95) 0.92 (0.85-1.00) Ptrend 0.13 <0.001 0.04 ↵* Multivariate models used age as the underlying time metric and were adjusted for race/ethnicity (White, Black, Hispanic, Asian/Pacific Islander/American Indian), education level (<12 years or high school equivalent, 12 years or high school equivalent, post-high school vocational or technical training, some college, college graduate, postgraduate), smoking status (nonsmoker, former, current), family history of breast cancer (no, yes), menopausal hormone use (never, current, past), age at first birth (nulliparous, <20, 20-24, 25-29, ≥30 years), age at menarche (<13, 13-14, ≥15 years), age at menopause (<40, 40-44, 45-49, 50-54, ≥55 years), parity (number of children: 0, 1-2, ≥3), and alcohol intake (g/d; quintiles adjusted for total energy intake).
↵† Additionally adjusted for BMI (<25.0, 25.0-29.9, 30.0-34.9, ≥35.0 kg/m2).
- Table 3.
Multivariate RR (95% CI) for the association between physical activity and breast cancer incidence among postmenopausal women according to selected tumor characteristics
Tumor characteristics* No. cases Physical activity (times per week) Ptrend Pheterogeneity Inactive <1 1-2 3-4 ≥5 Hormone receptor status ER+ 2,083 1.0 (Reference) 1.03 (0.89-1.19) 0.95 (0.83-1.08) 0.98 (0.86-1.11) 0.97 (0.84-1.12) 0.64 0.07 ER− 411 1.0 (Reference) 1.10 (0.81-1.49) 0.85 (0.63-1.14) 0.85 (0.64-1.12) 0.75 (0.54-1.04) 0.03 ER+/PR+ 1,649 1.0 (Reference) 1.00 (0.84-1.18) 0.97 (0.84-1.13) 0.96 (0.83-1.11) 0.96 (0.82-1.13) 0.53 ER+/PR− 338 1.0 (Reference) 1.29 (0.90-1.84) 0.93 (0.65-1.32) 1.17 (0.85-1.60) 1.05 (0.73-1.51) 0.85 ER−/PR+ 48 1.0 (Reference) 1.10 (0.41-2.95) 1.15 (0.47-2.78) 1.29 (0.56-2.95) 0.62 (0.21-1.86) 0.56 0.37 ER−/PR− 359 1.0 (Reference) 1.10 (0.80-1.53) 0.84 (0.61-1.15) 0.81 (0.60-1.10) 0.78 (0.55-1.10) 0.05 Unknown ER or PR 3,039 1.0 (Reference) 0.90 (0.80-1.02) 0.95 (0.85-1.06) 0.92 (0.83-1.01) 0.81 (0.72-0.91) 0.002 Tumor stage In situ 1,176 1.0 (Reference) 1.10 (0.91-1.33) 0.90 (0.75-1.08) 0.93 (0.78-1.10) 0.93 (0.77-1.13) 0.20 0.85 Invasive 5,433 1.0 (Reference) 0.97 (0.88-1.06) 0.95 (0.87-1.03) 0.94 (0.87-1.01) 0.86 (0.79-0.94) 0.001 Localized 3,158 1.0 (Reference) 0.97 (0.86-1.09) 0.95 (0.86-1.06) 1.00 (0.90-1.10) 0.85 (0.76-0.96) 0.04 0.17 Regional/distant 1,298 1.0 (Reference) 0.99 (0.83-1.17) 0.83 (0.71-0.98) 0.74 (0.63-0.86) 0.85 (0.71-1.01) 0.003 0.36† Tumor histology Ductal 3,568 1.0 (Reference) 0.98 (0.88-1.10) 0.96 (0.87-1.06) 0.93 (0.84-1.02) 0.89 (0.80-0.99) 0.02 Lobular 550 1.0 (Reference) 1.24 (0.95-1.63) 0.92 (0.71-1.19) 0.89 (0.69-1.14) 0.87 (0.65-1.15) 0.05 0.41 Ductal-lobular 436 1.0 (Reference) 0.80 (0.58-1.12) 0.80 (0.60-1.08) 0.95 (0.73-1.24) 0.89 (0.66-1.20) 0.96 NOTE: Multivariate models used age as the underlying time metric and were adjusted for race/ethnicity (White, Black, Hispanic, Asian/Pacific Islander/American Indian), education level (<12 years or high school equivalent, 12 years or high school equivalent, post-high school vocational or technical training, some college, college graduate, postgraduate), smoking status (nonsmoker, former, current), family history of breast cancer (no, yes), menopausal hormone use (never, current, past), age at first birth (nulliparous, <20, 20-24, 25-29, ≥30 years), age at menarche (<13, 13-14, ≥15 years), age at menopause (<40, 40-44, 45-49, 50-54, ≥55 years), parity (number of children: 0, 1-2, ≥3), and alcohol intake (g/d; quintiles adjusted for total energy intake).
↵* Hormone receptor status and tumor histology limited to invasive cancers.
↵† P value for comparison of in situ, localized, and regional/distant.
- Table 4.
Multivariate RR (95% CI) for the association between physical activity and breast cancer incidence among postmenopausal women according to BMI, MHT use, and family history of breast cancer
No. cases Physical activity (times per week) Ptrend Pheterogeneity Inactive <1 1-2 3-4 ≥5 BMI (kg/m2) ≥25.0 3,787 1.0 (Reference) 0.98 (0.89-1.08) 0.98 (0.90-1.08) 0.92 (0.84-1.01) 0.86 (0.77-0.96) 0.003 0.07 <25.0 2,822 1.0 (Reference) 1.01 (0.92-1.11) 0.97 (0.89-1.05) 0.99 (0.92-1.08) 0.95 (0.87-1.05) 0.64 MHT use Ever use 4,073 1.0 (Reference) 1.03 (0.93-1.15) 1.00 (0.90-1.10) 1.00 (0.92-1.10) 0.97 (0.88-1.08) 0.34 0.002 Never use 2,528 1.0 (Reference) 0.95 (0.84-1.08) 0.88 (0.79-0.99) 0.86 (0.77-0.96) 0.76 (0.67-0.86) <0.001 Family history Family history 1,193 1.0 (Reference) 0.99 (0.83-1.19) 0.92 (0.78-1.08) 0.75 (0.64-0.89) 0.75 (0.62-0.91) <0.001 0.003 No family history 5,124 1.0 (Reference) 0.99 (0.90-1.09) 0.95 (0.87-1.03) 0.98 (0.90-1.06) 0.88 (0.81-0.97) 0.03 NOTE: Multivariate models used age as the underlying time metric and were adjusted for race/ethnicity (White, Black, Hispanic, Asian/Pacific Islander/American Indian), education level (<12 years or high school equivalent, 12 years or high school equivalent, post-high school vocational or technical training, some college, college graduate, postgraduate), smoking status (nonsmoker, former, current), family history of breast cancer (no, yes), menopausal hormone use (never, current, past), age at first birth (nulliparous, <20, 20-24, 25-29, ≥30 years), age at menarche (<13, 13-14, ≥15 years), age at menopause (<40, 40-44, 45-49, 50-54, ≥55 years), parity (number of children: 0, 1-2, ≥3), and alcohol intake (g/d; quintiles adjusted for total energy intake).
- Table 5.
Multivariate RR (95% CI) for the association between physical activity and breast cancer incidence among postmenopausal women according to joint effect of physical activity and BMI, joint effect of physical activity and MHT use, and joint effect of physical activity and family history of breast cancer
No. cases Physical activity (times per week) Inactive <1 1-2 3-4 ≥5 BMI (kg/m2) ≥25.0 3,787 1.0 (Reference) 0.98 (0.89-1.08) 0.98 (0.90-1.08) 0.92 (0.84-1.01) 0.86 (0.77-0.96) <25.0 2,822 0.84 (0.75-0.94) 0.85 (0.75-0.96) 0.76 (0.68-0.84) 0.84 (0.77-0.92) 0.80 (0.72-0.88) MHT use Ever use 4,073 1.0 (Reference) 1.03 (0.93-1.15) 1.00 (0.90-1.10) 1.01 (0.92-1.10) 0.97 (0.88-1.08) Never use 2,528 0.79 (0.72-0.88) 0.76 (0.67-0.85) 0.70 (0.63-0.78) 0.68 (0.61-0.76) 0.60 (0.53-0.68) Family history Family history 1,193 1.0 (Reference) 0.99 (0.83-1.19) 0.92 (0.78-1.08) 0.75 (0.64-0.89) 0.75 (0.62-0.91) No family history 5,124 0.57 (0.50-0.65) 0.57 (0.50-0.65) 0.54 (0.48-0.62) 0.56 (0.49-0.64) 0.51 (0.44-0.58) NOTE: Multivariate models used age as the underlying time metric and were adjusted for race/ethnicity (White, Black, Hispanic, Asian/Pacific Islander/American Indian), education level (<12 years or high school equivalent, 12 years or high school equivalent, post-high school vocational or technical training, some college, college graduate, postgraduate), smoking status (nonsmoker, former, current), family history of breast cancer (no, yes), menopausal hormone use (never, current, past), age at first birth (nulliparous, <20, 20-24, 25-29, ≥30 years), age at menarche (<13, 13-14, ≥15 years), age at menopause (<40, 40-44, 45-49, 50-54, ≥55 years), parity (number of children: 0, 1-2, ≥3), and alcohol intake (g/d; quintiles adjusted for total energy intake).