TABLE D-1 Summary of Estimates of Population Attributable Risk for Risk Factors for Breast Cancer
Source | Study Location and Type | Study Population Characteristics |
United States | ||
Madigan et al. (1995) | U.S. Cohort |
NHANES I Epidemiologic Follow-up Study (NHEFS) (1971-1987) Women, ages 25-74 at initial examination 7,508 in analytic cohort 193 breast cancer cases |
Rockhill et al. (1998) |
U.S. |
Carolina Breast Cancer Study (1993-1996) |
Tseng et al. (1999) |
U.S. |
NHANES III (1988-1994) |
Risk Factors and Relative Risk Estimatesa | Population Attributable Risk in Percentb (95% CI, where available) | Impact on Absolute Risk | |
History of breast cancer in 1st degree relative = 2.6 Income in upper two thirds of U.S. population = 1.7 Age at first birth > than 29 yrs = 1.9 Nulliparity = 1.8 |
Estimates for U.S. All factors: 41 (1.6-80.0) Family history: 9 (3.0-15.2) Higher income: 19 (-4.3-42.1) Later age at first birth or nulliparity: 30 (5.6-53.3) Estimates for NHEFS All factors: 47 (16.7-76.7) Family history: 8 (2.3-13.9) Higher income: 23 (5.4-39.9) Later age at first birth or nulliparity: 30 (8.9-51.4) |
NHEFS age adjusted baseline incidence per 100,000 (standardized to 1970 U.S. population) History of breast cancer in 1st degree relative = 470 Income in upper two thirds of U.S. population = 259 Age at first birth > than 29 = 260 Nulliparity = 259 |
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Early menarche (< age 12 = 1.24; age 12-13 = 1.08) Later age of first full-term pregnancy (≥ age 20) 1.08 to 1.53, depending on age group Breast cancer in mother or sister = 1.36 History of benign breast biopsy = 1.06 |
All: 25 (6-48) With menarche at < age 14 and first birth at ≥ age 20, or nulliparity All: 15 ( ̴5-20) With menarche at < age 12 and first birth at ≥ age 30, or nulliparity |
Not reported | |
Alcohol consumption None = 1.0 Light (0.1-6.4 g/day) = 1.0 Moderate (6.5-25.9 g/day) = 1.1 Heavy (≥ 26 g/day) = 1.3 |
Alcohol consumption: 2 ( ̴1.2-2.9) | Not reported |
Source | Study Location and Type | Study Population Characteristics |
Clarke et al. (2006) | U.S. Survey data for risk factor prevalence Published literature for RRs Incidence from California Cancer Registry (1998-2002) |
California Health Interview Survey, 2001 White, non-Hispanic women, ages 40-79 Analysis for counties and hypothetical populations 3,781,621 women 13,019 breast cancer cases |
Sprague et al. (2008) | U.S. Unmatched case-control Cases from cancer registries; population-based controls |
Collaborative Breast Cancer Study— Wisconsin, Massachusetts, New Hampshire (1996?2000) Women, ages 20?69 (95% white, non-Hispanic) 3,499 cases 4,213 controls |
Risk Factors and Relative Risk Estimatesa | Population Attributable Risk in Percentb (95% CI, where available) | Impact on Absolute Risk | |
Alcohol (2+ drinks/day on 10+ days/mo) = 1.4 HT (E+P) = 1.26 Physical inactivity (no vigorous/moderate activity in past month) = 1.3 |
Alcohol: 3.5 HT (E+P): 4.4 Physical inactivity: 7.5 |
Alcohol: 450 cases/yr HT (E+P): 567 cases/yr Physical inactivity: 1,422 cases/yr |
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Not modifiable |
Not modifiable 57.3 (47.5-65.4) |
Not reported |
Source | Study Location and Type | Study Population Characteristics |
Europe and Canada | ||
Mezzetti et al. (1998) | Italy Case-control |
Unmatched hospital cases (ages 23-74, median 55 yrs) and controls (ages 20-74, median 56 yrs) (1991-1994) 2,569 cases 2,588 controls |
Bakken et al. (2004) | Norway Cohort Cases identified from national cancer registry |
Norwegian Women and Cancer study Postmenopausal women, ages 45-64, recruited in 1991-1992 or 1996-1997 31,451 in cohort |
Neutel and Morrison (2010) |
Canada |
National Population Health Survey (1994-2006) |
Risk Factors and Relative Risk Estimatesa | Population Attributable Risk in Percentb (95% CI, where available) | Impact on Absolute Risk | |
Low levels of physical activity = 1.5 Alcohol consumption (> 20 g/day) = 1.25 |
Aggregate: 19.2 (1.5-36.8) Physical activity: 11.6 (-0.1-23.3) Alcohol: 10.7 (4.4-17.0) |
Not reported | |
HT, ever used = 1.9 HT, current use = 2.1 (HT formulations different from those in U.S.) |
Current use of HT: 27 | 300 cases/yr | |
Modifiable risk factors: Alcohol (> 9 drinks/wk) = 1.4 HT use = 1.4 Obesity (BMI ≥ 30 kg/m(2)) = 1.4 Physical inactivity = 1.15 Smoking, current = 1.25 |
2000 All: 28.9 Alcohol: 1.8 HT use: 11.5 Obesity: 7.6 Physical inactivity: 8.0 Smoking: 3.8 2006 All: 23.6 Alcohol: 2.6 HT use: 5.2 Obesity: 8.8 Physical inactivity: 6.4 Smoking: 3.1 |
Not reported |
Source | Study Location and Type | Study Population Characteristics |
Barnes et al. (2010) | Germany Case-control |
Mammary carcinoma Risk factor Investigation (MARIE) (2001-2005) Postmenopausal women, ages 50-74 3,074 cases 6,386 controls |
Friedenreich et al. (2010) | Europe (15 countries) Survey data for risk factor prevalence Review of published literature for RR Incidence from estimates by IARC |
Eurobarometer, Wave 58.2 (2002) Incidence (2008) |
Risk Factors and Relative Risk Estimatesa | Population Attributable Risk in Percentb (95% CI, where available) | Impact on Absolute Risk | |
Not modifiable Age at menarche (< age 15 yrs) = 1.11-1.16 Age at menopause (≥ age 45 yrs) = 1.12-1.36 Parity (< 3 births) = 1.08-1.30 1st degree family history = 1.49 History of benign breast disease = 1.24 |
Not modifiable: 37.2 (27.1-47.2) Age at menarche: 7.7 (0.2-14.1) Age at menopause: 12.0 (3.9-20.2) Parity: 10.9 (1.3-18.8) 1st degree family history: 5.7 (4.1-7.5) History of benign breast disease: 7.9 (4.4-11.6) |
Not reported | |
Modifiable Alcohol (≥ 1 g/day) = 0.93-0.93 BMI (> 22.4 kg/m(2)) = 0.93-1.06 HT, current use (E, E+P, or other) = 1.19-2.25 Physical activity (< 76.5 MET hrs/wk of recreational activities since age 50 yrs) = 1.16-1.23 |
Modifiable: 26.3 (13.7-37.5) Alcohol: -7.6 (-21.1-3.6) BMI: 2.4 (-2.8-7.4) HT: 19.4 (15.9-23.2) Physical activity: 12.8 (5.5-20.8) |
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Physical activity = 0.75 Sufficiently active (3,000 MET-minutes in 7 days or 1,500 MET-minutes of vigorous activity over 3 or more days) Not sedentary (≥ 600 METminutes over 7 days) |
Insufficiently active: 20 Sedentary: 10 |
Insufficiently active: 83,353 cases/yr Sedentary: 42,837 cases/yr |
Source | Study Location and Type | Study Population Characteristics |
Petracci et al. (2011) | Italy Model to predict absolute risk; tested with independent data |
Absolute risks: Florence cancer registry (1989-1993) For model development: Case—control subjects (1991–1994), ages 20–74 For validation: Florence-EPIC cohort (1998–2004), ages 35–64 |
NOTES: Variation across studies in estimated PAR values reflects differences in the prevalence of exposure, in overlap among multiple risk factors, in susceptibility to the risk factor, and in the degree of control for confounding. For these and other reasons, the PARs should be viewed as ballpark estimates based on current science and the assumption that measured associations for these factors are primarily causal.
REFERENCES
Bakken, K., E. Alsaker, A. E. Eggen, and E. Lund. 2004. Hormone replacement therapy and incidence of hormone-dependent cancers in the Norwegian Women and Cancer study. Int J Cancer 112(1):130–134.
Barnes, B. B., K. Steindorf, R. Hein, D. Flesch-Janys, and J. Chang-Claude. 2010. Population attributable risk of invasive postmenopausal breast cancer and breast cancer subtypes for modifiable and non-modifiable risk factors. Cancer Epidemiol 35(4):345–352.
Clarke, C., D. Purdie, and S. Glaser. 2006. Population attributable risk of breast cancer in white women associated with immediately modifiable risk factors. BMC Cancer 6(1):170.
Friedenreich, C. M., H. K. Neilson, and B. M. Lynch. 2010. State of the epidemiological evidence on physical activity and cancer prevention. Eur J Cancer 46(14):2593–2604.
Madigan, M. P., R. G. Ziegler, J. Benichou, C. Byrne, and R. N. Hoover. 1995. Proportion of breast cancer cases in the United States explained by well-established risk factors. J Natl Cancer Inst 87(22):1681–1685.
Mezzetti, M., C. La Vecchia, A. Decarli, P. Boyle, R. Talamini, and S. Franceschi. 1998. Population attributable risk for breast cancer: Diet, nutrition, and physical exercise. J Natl Cancer Inst 90(5):389–394.
Risk Factors and Relative Risk Estimatesa | Population Attributable Risk in Percentb (95% CI, where available) | Impact on Absolute Risk | |
Aggregate contribution of elimination of risk factors (no alcohol consumption, physical activity of ≥ 2 hrs per week, and BMI at age ≥ 50 yrs of < 25 kg/m2) |
Entire population 10-yr period Age 45: 20.5 (11.0-29.2) Age 55: 24.5 (14.7-34.2) Age 65: 24.5 (14.6-34.1) |
Absolute risk reduction from elimination of risk factors, reported in percentage point change (95% CI) Entire population 10-yr period Age 45: 0.6 (0.3-1.0) Age 55: 0.8 (0.5-1.1) Age 65: 0.9 (0.5-1.3) 20-yr period Age 45: 1.4 (0.7-2.0) Age 55: 1.6 (0.9-2.3) Age 65: 1.6 (0.9-2.3) |
Abbreviations: BMI, body mass index; CI, confidence interval; E, estrogen-only hormone therapy; E+P, estrogen–progestin hormone therapy; EPIC, European Prospective Investigation into Cancer; HT, hormone therapy; IARC, International Agency for Research on Cancer; MET, metabolic equivalent; NHANES, National Health and Nutrition Examination Survey; PAR, population attributable risk; RR, relative risk.
aIncludes relative risks or odds ratios, when reported; range of relative risks provided when multiple risk categories were used in the original report.
bPopulation attributable risk is the fraction of all cases of breast cancer in the studied population in which the factor of interest appears to play a role.
Neutel, C. I., and H. Morrison. 2010. Could recent decreases in breast cancer incidence really be due to lower HRT use? Trends in attributable risk for modifiable breast cancer risk factors in Canadian women. Can J Public Health 101(5):405–409.
Petracci, E., A. Decarli, C. Schairer, R. M. Pfeiffer, D. Pee, G. Masala, D. Palli, M. H. Gail. 2011. Risk factor modification and projections of absolute breast cancer risk. J Natl Cancer Inst 103(13):1037–1048.
Rockhill, B., C. R. Weinberg, and B. Newman. 1998. Population attributable fraction estimation for established breast cancer risk factors: Considering the issues of high prevalence and unmodifiability. Am J Epidemiol 147(9):826–833.
Sprague, B. L., A. Trentham-Dietz, K. M. Egan, L. Titus-Ernstoff, J. M. Hampton, and P. A. Newcomb. 2008. Proportion of invasive breast cancer attributable to risk factors modifiable after menopause. Am J Epidemiol 168(4):404–411.
Tseng, M., C. R. Weinberg, D. M. Umbach, and M. P. Longnecker. 1999. Calculation of population attributable risk for alcohol and breast cancer (United States). Cancer Causes Control 10(2):119–123.
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