Article Figures & Data
Tables
- Table 1.
Characteristics of the study population by hours per week of physical activity, The Sister Study
<1 hour per week 1–6 hours per week ≥7 hours per week N = 17,192 (33.9%) N = 29,046 (57.3%) N = 4,438 (8.8%) N (%) N (%) N (%) Age at baseline (mean, SD) 54.9 (9.0) 55.8 (9.0) 57.3 (8.6) Race/ethnicity Non-Hispanic white 13,601 (79.1) 24,897 (85.7) 3,892 (87.7) Non-Hispanic black 1,890 (11.0) 2,284 (7.9) 274 (6.2) Hispanic 1,197 (7.0) 1,162 (4.0) 144 (3.3) Other 503 (2.9) 697 (2.4) 126 (2.8) Missing 1 (–) 6 (–) 2 (–) Highest level of education Less than high school 361 (2.1) 232 (0.8) 30 (0.7) High school graduate 3,259 (19.0) 3,472 (12.0) 416 (9.4) Some college 6,578 (38.3) 9,334 (32.1) 1,208 (27.2) College degree or higher 6,993 (40.7) 16,004 (55.1) 2,783 (62.7) Missing 1 (–) 4 (–) 1 (–) Residence type Urban 3,325 (19.4) 5,635 (19.4) 908 (20.5) Suburban 6,140 (35.8) 11,532 (39.7) 1,757 (39.7) Small town 3,632 (21.2) 6,112 (21.1) 990 (22.4) Rural 3,996 (23.3) 5,652 (19.5) 758 (17.1) Other 54 (0.3) 73 (0.3) 16 (0.4) Missing 45 (–) 42 (–) 9 (–) Parity Nulliparous 2,825 (16.4) 5,332 (18.4) 1,017 (23.0) Parous 14,361 (83.6) 23,694 (81.6) 3,413 (77.0) Missing 6 (–) 20 (–) 8 (–) Alcohol use Never 834 (4.9) 980 (3.4) 122 (2.8) Former 3,357 (19.6) 3,792 (13.1) 550 (12.4) Current, <1 drink/day 11,150 (65.0) 20,037 (69.1) 2,945 (66.5) Current, 1+ drink/day 1,822 (10.6) 4,202 (14.5) 811 (18.3) Missing 29 (–) 35 (–) 10 (–) Smoking status Never 9,511 (55.3) 16,490 (56.8) 2,451 (55.2) Past 5,557 (32.3) 10,741 (37.0) 1,763 (39.7) Current 2,123 (12.4) 1,811 (6.2) 224 (5.1) Missing 1 (–) 4 (–) 0 (–) - Table 2.
HRs and 95% CIs for the associations between physical activity and breast cancer risk, The Sister Study
Overall Premenopausal Postmenopausal PY N cases HRa,b (95% CI) N cases HRa (95% CI) N cases HRa (95% CI) Total average hours/week Continuous 421,807 3,017 0.99 (0.97–1.00) 533 1.03 (1.00–1.06) 2,460 0.98 (0.96–0.99) 0–<1 140,497 1,035 1.00 170 1.00 859 1.00 1–<4 173,872 1,220 0.91 (0.84–0.99) 225 1.13 (0.92–1.38) 983 0.87 (0.79–0.95) 4–<7 70,425 506 0.90 (0.81–1.01) 95 1.29 (1.00–1.66) 408 0.83 (0.74–0.94) ≥7 37,013 256 0.85 (0.74–0.98) 43 1.35 (0.96–1.89) 210 0.77 (0.66–0.90) Total average MET-hours/week Continuous (IQR increase) 421,807 3,017 0.97 (0.93–1.00) 533 1.08 (1.01–1.16) 2,460 0.92 (0.89–0.97) Quartile 1 102,481 791 1.00 121 1.00 666 1.00 Quartile 2 110,532 753 0.86 (0.78–0.95) 131 0.99 (0.77–1.27) 616 0.83 (0.74–0.93) Quartile 3 101,971 736 0.88 (0.79–0.97) 126 1.14 (0.88–1.47) 602 0.83 (0.74–0.92) Quartile 4 106,822 737 0.83 (0.75–0.92) 155 1.25 (0.98–1.60) 576 0.75 (0.67–0.85) At least one activity in the past 12 months No 69,105 524 1.00 73 1.00 449 1.00 Yes 352,943 2,493 0.89 (0.81–0.98) 460 1.26 (0.98–1.62) 2,011 0.82 (0.74–0.91) - Table 3.
HRs and 95% CIs for the associations between hours/week of physical activity and breast cancer risk by invasive ER status, The Sister Study
ER− ER+ N cases HRa (95% CI) N cases HRa (95% CI) Total average hours/week Continuous 304 0.98 (0.94–1.02) 1,733 0.98 (0.97–1.00) 0–<1 105 1.00 599 1.00 1–<4 134 1.06 (0.82–1.37) 696 0.87 (0.78–0.97) 4–<7 42 0.82 (0.57–1.18) 294 0.86 (0.75–1.00) ≥7 23 0.85 (0.54–1.35) 144 0.78 (0.65–0.94) Total average MET-hours/week Continuous (IQR increase) 304 0.97 (0.86–1.09) 1,733 0.94 (0.89–0.99) Quartile 1 79 1.00 455 1.00 Quartile 2 71 0.86 (0.62–1.18) 429 0.83 (0.73–0.95) Quartile 3 91 1.20 (0.88–1.63) 429 0.85 (0.74–0.97) Quartile 4 63 0.80 (0.57–1.12) 420 0.78 (0.68–0.90) At least one activity in the past 12 months No 45 1.00 306 1.00 Yes 259 1.18 (0.85–1.63) 1,427 0.84 (0.74–0.95) Abbreviations: −, negative; +, positive.
↵aAdjusted for race, residence type, education, parity, alcohol use, and smoking status.
- Table 4.
Evaluation of effect-measure modification by family history score for the associations between physical activity and breast cancer incidence, by menopausal status, The Sister Study
Family history score Physical activity N cases Stratified HRa (95% CI) Ratio of stratified HRs P Postmenopausal Low (<median) <7 hours/week 987 1.00 ≥7 hours/week 90 0.80 (0.64–0.99) High (≥median) <7 hours/week 1,043 1.00 ≥7 hours/week 98 0.91 (0.74–1.11) 1.14 (0.84–1.53) 0.4 Low (<median) IQR increase in MET-hours/week 1,077 0.95 (0.88–1.01) High (≥median) IQR increase in MET-hours/week 1,141 0.92 (0.86–0.98) 0.97 (0.88–1.07) 0.6 Premenopausal Low (<median) <7 hours/week 108 1.00 ≥7 hours/week 7 0.78 (0.36–1.68) High (≥median) <7 hours/week 333 1.00 ≥7 hours/week 31 1.34 (0.93–1.94) 1.72 (0.73–4.02) 0.2 Low (<median) IQR increase in MET-hours/week 115 1.02 (0.86–1.20) High (≥median) IQR increase in MET-hours/week 364 1.10 (1.02–1.19) 1.08 (0.90–1.31) 0.4 ↵aAdjusted for race, residence type, education, parity, alcohol use, and smoking status.
Additional Files
Supplementary Data
- Supplemental Table S1 - This table shows the main associations between physical activity and breast cancer risk restricted to invasive cases.
- Supplemental Table S2 - This table shows the associations for modification by family history risk score when restricted to invasive cases.
- Supplemental Table S3 - This table shows the main associations between physical activity and breast cancer risk when women who are known BRCA 1 or 2 mutation carriers are excluded.
- Supplemental Table S4 - This table shows the associations for modification by family history risk score when women who are known BRCA 1 or 2 mutations carriers are excluded.
- Supplemental Table S5 - This table shows the main associations between physical activity and breast cancer risk when additionally adjusted for BMI.
- Supplemental Table S6 - This table shows the associations for modification by family history risk score when additionally adjusted for BMI.
January 2019
Volume 28, Issue 1
Volume 28, Issue 1
Adult Physical Activity and Breast Cancer Risk in Women with a Family History of Breast Cancer
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