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Biomedical subjects

M J Stampfer

Publications and source records attributed to M J Stampfer.

At least 325 records · Page 18Linked to original sources
PubMed1994

Reproducibility and validity of a self-administered physical activity questionnaire.

BACKGROUND: The reproducibility and validity of self-administered questionnaires on physical activity and inactivity were examined in a random (representative) sample of the Nurses' Health Study II cohort and a random sample of African-American women in that cohort. METHODS: Repeat questionnaires were administered 2 years apart. Past-week activity recalls and 7-day activity diaries were the referent methods; these instruments were sent to participants four times over a 1-year period. RESULTS: The 2-year test-retest correlation for activity was 0.59 for the representative sample (n = 147) and 0.39 for the African-American sample (n = 84). Correlations between activity reported on recalls and that reported on questionnaire were 0.79 and 0.83 for the representative and African-American samples, respectively. Correlations between activity reported in diaries and that reported on questionnaire were 0.62 and 0.59, respectively. Test-retest coefficients for inactivity were 0.52 and 0.55, respectively. Correlations between inactivity reported in diaries and that reported on questionnaire were 0.41 and 0.44, respectively. CONCLUSION: The simple, short questionnaires on activity and inactivity used in the Nurses' Health Study II are reasonably valid measures for epidemiological research.

Adult↗
PubMed1994

Trans-fatty acids intake and risk of myocardial infarction.

BACKGROUND: Concern that trans-fatty acids formed in the partial hydrogenation of vegetable oils may increase the risk of coronary disease has existed for several decades, but direct evidence on this relation in humans is limited. METHODS AND RESULTS: With a case-control design, we studied the association between intake of trans-fatty acids and a first acute myocardial infarction among 239 patients admitted to one of six hospitals in the Boston area and 282 population control subjects. Intake of trans-fatty acids was estimated using a previously validated food frequency questionnaire. After adjustment for age, sex, and energy intake, intake of trans-fatty acids was directly related to risk of myocardial infarction (relative risk for highest compared with lowest quintile, 2.44; 95% confidence interval, 1.42, 4.19; for trend P < .0001). This relation remained highly significant after adjustment for established coronary risk factors, multivitamin use, and intake of saturated fat, monounsaturated fat, linoleic acid, dietary cholesterol, vitamins E and C, carotene, and fiber. Intake of margarine--the major source of trans-isomers--was significantly associated with risk of myocardial infarction. CONCLUSIONS: These data support the hypothesis that intake of partially hydrogenated vegetable oils may contribute to the risk of myocardial infarction.

Boston↗
PubMed1994

Dietary iron intake and risk of coronary disease among men.

BACKGROUND: We prospectively studied iron intake in relation to the incidence of coronary disease in a 4-year follow-up of 44,933 men (with no previous history of cardiovascular disease) aged 40 to 75 years in 1986 who completed a food frequency questionnaire at baseline. METHODS AND RESULTS: We documented 844 incident cases of coronary disease (249 nonfatal myocardial infarctions, 137 coronary disease fatalities, and 458 bypass operations or angioplasties). After adjustment for established risk factors, there was no significant association between total iron intake and risk of coronary heart disease. Men in the highest quintile of total intake (median, 37 mg/d) had a relative risk (RR) of fatal coronary disease or nonfatal myocardial infarction of 0.73 (95% confidence intervals [CI], 0.51, 1.06) compared with men in the lowest quintile of intake (median, 11 mg/d). Dietary intake of heme iron--mainly from red meat--also was not significantly associated with risk of coronary heart disease. However, incidence of fatal coronary disease or nonfatal myocardial infarction was higher among men in the top quintile of heme iron intake compared with men in the lowest quintile (RR, 1.42; 95% CI, 1.02, 1.98). This association remained after adjustment for dietary cholesterol and fats. Heme iron but not total iron intake was positively correlated with serum ferritin among 123 members of the cohort who participated in a validation study. CONCLUSIONS: These results do not support the hypothesis that dietary iron in general increases coronary risk in men; they are consistent, however, with an increased risk of myocardial infarction among men with higher intake of heme iron, which is itself positively associated with iron stores.

Adult↗
PubMed1994

Prospective study of phobic anxiety and risk of coronary heart disease in men.

BACKGROUND: To examine prospectively the association between self-reported symptoms of phobic anxiety and subsequent risk of coronary heart disease, a 2-year follow-up study was conducted of a cohort of 33,999 US male health professionals, aged 42 to 77 years in 1988, who were free of diagnosed cardiovascular disease at baseline. Levels of phobic anxiety were assessed using the Crown-Crisp index, a short, diagnostic self-rating scale used for common phobias. Main outcomes were incidents of coronary heart disease consisting of nonfatal myocardial infarction (MI) and fatal coronary heart disease (CHD). METHODS AND RESULTS: One hundred sixty-eight incident cases of CHD occurred during 2 years of follow-up (128 cases of nonfatal MI and 40 cases of fatal CHD). The age-adjusted relative risk of fatal CHD among men with highest levels of phobic anxiety (scoring 4 or higher on the Crown-Crisp index) was 3.01 (95% confidence interval, 1.31 to 6.90) compared with men with the lowest levels of anxiety (scoring 0 or 1 on the phobia index). Risk of fatal CHD increased with levels of phobic anxiety (P trend = .002). When fatal CHD was further categorized into sudden and nonsudden coronary death, the excess risk was confined to sudden death (relative risk among men scoring 3 or higher on the phobia index was 6.08; 95% confidence interval, 2.35 to 15.73). No association was found between phobic anxiety and risk of nonfatal MI. These findings remained essentially unchanged after adjusting for a broad range of cardiovascular risk factors. CONCLUSIONS: The specificity, strength, and dose-response gradient of the association, together with the consistency and biological plausibility of the experimental and epidemiologic evidence, support a strong causal association between phobic anxiety and fatal CHD.

Adult↗
PubMed1994

Plasma concentration of cross-linked fibrin degradation product (D-dimer) and the risk of future myocardial infarction among apparently healthy men.

BACKGROUND: Plasma levels of D-dimer, the primary degradation product of cross-linked fibrin, are elevated in several acute thrombotic disorders. However, whether elevated D-dimer levels among healthy individuals are associated with future coronary thrombosis is unknown. METHODS AND RESULTS: To evaluate whether levels of D-dimer are associated with the occurrence of future myocardial infarction (MI) among apparently healthy men, levels were measured in plasma samples collected at baseline from 296 participants in the Physicians' Health Study who later developed a first MI and from an equal number of age- and smoking status-matched control subjects who remained free of vascular disease during a mean follow-up period of 60.2 months. In univariate analyses, baseline plasma concentrations of D-dimer in the upper ranges of normal were associated with elevated risks of MI. Specifically, the relative risk of future MI for individuals with baseline D-dimer concentration exceeding the 95th percentile of the control distribution was two times higher than that of individuals with lower levels (relative risk [RR], 2.02; 95% confidence interval [CI], 1.04 to 4.02; P = .04). This association persisted in multivariate analyses controlling for nonlipid cardiovascular risk factors (RR, 2.12; 95% CI, 1.05 to 4.28; P = .04) and for lipoprotein(a) (RR, 2.02; 95% CI, 1.04 to 3.94; P = .03). In contrast, this association was attenuated and no longer statistically significant in analyses that controlled for total and high-density lipoprotein cholesterol (RR, 1.74; 95% CI, 0.78 to 3.91; P = .2) or for endogenous tissue-type plasminogen activator and its primary inhibitor, plasminogen activator inhibitor type 1 (RR, 1.58; 95% CI, 0.67 to 3.77; P = .3). CONCLUSIONS: Elevated levels of D-dimer are associated with increased risks of future MI, although they do not appear to be an independent predictor when other risk factors are considered. As the presence of D-dimer in plasma reflects ongoing fibrin degradation, these data support the hypothesis that activation of the endogenous fibrinolytic system occurs many years in advance of coronary arterial occlusion.

Adult↗
PubMed1994

A prospective study of plasma homocyst(e)ine and risk of ischemic stroke.

BACKGROUND AND PURPOSE: Several studies have reported elevated circulating homocyst(e)ine levels in subjects with cerebral atherosclerosis. We assessed prospectively whether high plasma levels of homocyst(e)ine affect risk of ischemic stroke and evaluated whether high blood pressure modifies any such effect. METHODS: The study sample was drawn from the Physicians' Health Study, a randomized, double-blind, placebo-controlled trial of aspirin and beta-carotene in 22,071 US male physicians. A total of 14,916 subjects 40 to 84 years old with no prior history of stroke, transient ischemic attack, or myocardial infarction provided blood samples at baseline and were followed for 5 years, with 99.7% morbidity and 100% mortality follow-up. Using a nested case-control design, we assayed homocyst(e)ine in samples from 109 subjects who subsequently developed ischemic stroke and 427 control subjects. RESULTS: The mean plasma concentration of homocyst(e)ine was slightly higher in subjects with stroke (11.1 +/- 4.0 [+/- SD] nmol/mL) than in control subjects (10.6 +/- 3.4 nmol/mL), but the difference was not statistically significant (P = .12). The crude odds ratio of ischemic stroke for subjects in the upper 20% (> 12.7 nmol/mL) compared with those in the bottom 80% of homocyst(e)ine levels was 1.4 (95% confidence interval, 0.8 to 2.2). The odds ratio was 1.2 (95% confidence interval, 0.7 to 2.0) after controlling for several risk factors and other potential confounders. In subgroup analyses, elevated homocyst(e)ine levels appeared to be more strongly predictive of ischemic stroke in normotensive subjects and in men 60 years or younger. Although not statistically significant, in these subgroups increases in risks of 100% and 70%, respectively, were observed for men in the upper 20% of homocyst(e)ine values. CONCLUSIONS: In this study, the data were compatible with a small but nonsignificant association between elevated plasma homocyst(e)ine and risk of ischemic stroke. However, since the sample size is small and the confidence intervals are wide, either no association or a moderate increase in risk cannot be excluded, particularly in subgroups otherwise at low risk, eg, younger men and those with normal blood pressure.

Adult↗
PubMed1994

Obesity, fat distribution, and weight gain as risk factors for clinical diabetes in men.

OBJECTIVE: To investigate the relation between obesity, fat distribution, and weight gain through adulthood and the risk of non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: We analyzed data from a cohort of 51,529 U.S. male health professionals, 40-75 years of age in 1986, who completed biennial questionnaires sent out in 1986, 1988, 1990, and 1992. During 5 years of follow-up (1987-1992), 272 cases of NIDDM were diagnosed among men without a history of diabetes, heart disease, and cancer in 1986 and who provided complete health information. Relative risks (RRs) associated with different anthropometric measures were calculated controlling for age, and multivariate RRs were calculated controlling for smoking, family history of diabetes, and age. RESULTS: We found a strong positive association between overall obesity as measured by body mass index (BMI) and risk of diabetes. Men with a BMI of > or = 35 kg/m2 had a multivariate RR of 42.1 (95% confidence interval [CI] 22.0-80.6) compared with men with a BMI < 23.0 kg/m2. BMI at age 21 and absolute weight gain throughout adulthood were also significant independent risk factors for diabetes. Fat distribution, measured by waist-to-hip ratio (WHR), was a good predictor of diabetes only among the top 5%, while waist circumference was positively associated with the risk of diabetes among the top 20% of the cohort. CONCLUSIONS: These data suggest that waist circumference may be a better indicator than WHR of the relationship between abdominal adiposity and risk of diabetes. Although early obesity, absolute weight gain throughout adulthood, and waist circumference were good predictors of diabetes, attained BMI was the dominant risk factor for NIDDM; even men of average relative weight had significantly elevated RRs.

Adult↗
PubMed1994

Postmenopausal estrogen and cardiovascular disease.

When data from the significant studies are assembled and analyzed, what is known about the impact of supplemental estrogen on the risk of cardiovascular disease in women after the menopause? What are the best clinical guidelines today?

Cardiovascular Diseases↗
PubMed1994

A prospective study of symptomatic gallstones in women: relation with oral contraceptives and other risk factors.

OBJECTIVE: To examine the relation between oral contraceptives (OCs), body mass index (BMI), weight change, alcohol use, parity, smoking, and symptomatic gallstones in women less than 45 years of age. METHODS: In this prospective study, associations between the various self-reported exposures and symptomatic gallstones were assessed in 96,211 female United States nurses with 425 cases of gallstones, using multiple logistic regression. RESULTS: We found little relation between ever-use of OCs and symptomatic gallstones (relative risk [RR] 1.2, 95% confidence interval [CI] 0.9-1.6), although there was a modest elevation in risk for long-term use (RR 1.5, 95% CI 1.0-2.2 for 10-14 years; RR 1.6, 95% CI 1.0-2.4 for 15 or more years). There was also an increased risk in current users of OCs (RR 1.6, 95% CI 1.1-2.4). The risk of symptomatic gallstones increased with increasing BMI and weight gain since age 18. Women with four or more births had an elevated risk of symptomatic gallstones (RR 2.0, 95% CI 1.3-3.2), and current cigarette smokers had a slightly higher risk than never-smokers (RR 1.3, 95% CI 1.0-1.7). The risk decreased with increasing alcohol intake. CONCLUSION: We found no substantial increase in the risk of symptomatic gallstones among ever-OC users, although current and long-term users had somewhat elevated risks. Body mass index remains the strongest predictor of symptomatic gallstones among young women.

Adult↗
PubMed1994

Postmenopausal hormone use and cholecystectomy in a large prospective study.

OBJECTIVE: To examine the association between postmenopausal hormone use and cholecystectomy. METHODS: A prospective cohort study was performed, with follow-up every 2 years. Participants were 54,845 postmenopausal United States nurses, who reported both hormone use and cholecystectomy on mailed questionnaires. RESULTS: Cholecystectomy was reported by 1750 women during 8 years of follow-up. After adjusting for confounding factors, women currently using postmenopausal hormones were at an increased risk of cholecystectomy (relative risk [RR] 2.1, 95% confidence interval [CI] 1.9-2.4) compared to never-users. For current users, the risk of cholecystectomy increased with increasing duration of hormone use (RR 2.6, 95% CI 2.2-3.1 for 10 years or more) and higher doses of estrogen (RR 2.4, 95% CI 2.0-2.9 for users of 1.25 mg or more). Although the risk for past hormone users decreased substantially in women who had discontinued use 1-2.9 years ago (RR 1.6, 95% CI 1.2-2.0), a small risk persisted for women who had stopped taking hormones 5 or more years previously (RR 1.3, 95% CI 1.1-1.6). However, after controlling for time since last use, duration of past use had little or no effect on the risk of cholecystectomy (RR 1.4 and RR 1.7 for past users of less than 2 years and 10 or more years' duration, respectively). CONCLUSION: Women using postmenopausal hormones are at an increased risk of cholecystectomy. Women and their physicians should consider the spectrum of risks and benefits when deciding whether to take hormones.

Cholecystectomy↗
PubMed1993

Tubal ligation, hysterectomy, and risk of ovarian cancer. A prospective study.

OBJECTIVE: To assess whether tubal ligation and hysterectomy affect subsequent risk of ovarian cancer. DESIGN: Prospective cohort study with 12 years of follow-up. SETTING: United States, multistate. PARTICIPANTS: A total of 121,700 female registered nurses who were 30 to 55 years of age in 1976; the follow-up rate was 90% as of 1988. MAIN OUTCOME MEASURE: Ovarian cancer of epithelial origin confirmed by medical record review. RESULTS: We observed a strong inverse association between tubal ligation and ovarian cancer, which persisted after adjustment for age, oral contraceptive use, parity, and other ovarian cancer risk factors (multivariate relative risk [RR], 0.33; 95% confidence interval [CI], 0.16 to 0.64). The association was similar when we assessed tubal ligation status at the baseline questionnaire and excluded cases in the first 4 years to eliminate any possible short-term decrease in risk due to screening of the ovaries during ligation surgery. We noted a weaker inverse association between simple hysterectomy and ovarian cancer (RR, 0.67; 95% CI, 0.45 to 1.00). Neither vasectomy nor condom use by a partner was associated with risk of ovarian cancer. CONCLUSIONS: These data indicate that tubal ligation, and perhaps hysterectomy, may substantially reduce risk of epithelial ovarian cancer.

Adult↗
PubMed1993

Smoking cessation in relation to total mortality rates in women. A prospective cohort study.

OBJECTIVE: To examine the temporal relationship between stopping smoking and total mortality rates among middle-aged women. DESIGN: Prospective cohort study with 12 years of follow-up. SETTING: Registered nurses residing in the United States. PARTICIPANTS: 117,001 female registered nurses, ages 30 to 55 years, who were free of manifest coronary heart disease, stroke, and cancer (except nonmelanoma skin cancer) in 1976. MAIN OUTCOME MEASURES: Total mortality, further categorized into deaths from cardiovascular diseases, cancers, and violent deaths. RESULTS: A total of 2847 deaths (933 among "never smokers," 799 among former smokers, and 1115 among current smokers) occurred during 1.37 million person-years of follow-up. The multivariate relative risks for total mortality compared with never smokers were 1.87 (95% CI, 1.65 to 2.13) for current smokers and 1.29 (CI, 1.14 to 1.46) for former smokers. Participants who started smoking before the age of 15 years had the highest risks for total mortality (multivariate relative risk, 3.15; CI, 2.16 to 4.59), cardiovascular disease mortality (relative risk, 9.94; CI, 5.15 to 19.19), and deaths from external causes of injury (relative risk, 5.39; CI, 1.84 to 15.78). Compared with continuing smokers, former smokers had a 24% reduction in risk for cardiovascular disease mortality within 2 years of quitting. The excess risks for total mortality and both cardiovascular disease and total cancer mortality among former smokers approached the level of that for never smokers after 10 to 14 years of abstinence. The health benefits of cessation were clearly present regardless of the age at starting and daily number of cigarettes smoked. CONCLUSIONS: The risk of cigarette smoking on total mortality among former smokers decreases nearly to that of never smokers 10 to 14 years after cessation.

Adult↗
PubMed1993

A prospective study of lipoprotein(a) and the risk of myocardial infarction.

OBJECTIVE: To assess prospectively the risk of myocardial infarction (MI) associated with elevated levels of lipoprotein(a) (Lp[a]). DESIGN: Nested case-control study using prospectively collected plasma samples. SETTING: Participants in the Physicians' Health Study. PARTICIPANTS: A total of 14,916 male physicians aged 40 to 84 years with no prior history of MI or stroke provided plasma samples at baseline and were followed up prospectively for an average period of 60.2 months. Samples from 296 physicians who subsequently developed MI were analyzed for Lp(a) level together with paired controls, matched for smoking status and age. MAIN OUTCOME MEASURE: Fatal or nonfatal acute MI. RESULTS: The distribution of Lp(a) level among cases was virtually identical to that of controls (P = .88), and there was no significant difference between groups for median Lp(a) levels (103.0 mg/L vs 102.5 mg/L; P = .73). In analyses controlling for age and smoking status, we found no evidence of association between increasing level of Lp(a) and risk of MI (relative risks from lowest to highest quintiles of Lp(a): 1.00, 0.97, 0.83, 0.88, and 1.07; P for trend = .93) or a threshold effect at any prespecified cutoff of Lp(a) level (relative risks associated with Lp[a] levels above the 25th, 50th, 75th, 90th, and 95th percentiles of the control distribution, respectively: 1.04, 1.00, 1.19, 1.00, and 1.07; all P values nonsignificant). Further adjustment for both lipid and nonlipid cardiovascular risk factors had no material impact. CONCLUSIONS: In this prospective study of predominantly middle-aged white men, we found no evidence of association between Lp(a) level and risk of future MI. These data do not support the use of Lp(a) level as a screening tool to define cardiovascular risk among this population.

Adult↗
PubMed1993

A prospective study of dietary fat and risk of prostate cancer.

BACKGROUND: The strong correlation between national consumption of fat and national rate of mortality from prostate cancer has raised the hypothesis that dietary fat increases the risk of this malignancy. Case-control and cohort studies have not consistently supported this hypothesis. PURPOSE: We examined prospectively the relationship between prostate cancer and dietary fat, including specific fatty acids and dietary sources of fat. We examined the relationship of fat consumption to the incidence of advanced prostate cancer (stages C, D, or fatal cases) and to the total incidence of prostate cancer. METHODS: We used data from the Health Professionals Follow-up Study, which is a prospective cohort of 51529 U.S. men, aged 40 through 75, who completed a validated food-frequency questionnaire in 1986. We sent follow-up questionnaires to the entire cohort in 1988 and 1990 to document new cases of a variety of diseases and to update exposure information. As of January 31, 1990, 300 new cases of prostate cancer, including 126 advanced cases, were documented in 47855 participants initially free of diagnosed cancer. The Mantel-Haenszel summary estimator was used to adjust for age and other potentially confounding variables. Multiple logistic regression was used to estimate relative risks (RRs) when controlling simultaneously for more than two covariates. RESULTS: Total fat consumption was directly related to risk of advanced prostate cancer (age- and energy-adjusted RR = 1.79, with 95% confidence interval [CI] = 1.04-3.07, for high versus low quintile of intake; P [trend] = .06). This association was due primarily to animal fat (RR = 1.63; 95% CI = 0.95-2.78; P [trend] = .08), but not vegetable fat. Red meat represented the food group with the strongest positive association with advanced cancer (RR = 2.64; 95% CI = 1.21-5.77; P = .02). Fat from dairy products (with the exception of butter) or fish was unrelated to risk. Saturated fat, monounsaturated fat, and alpha-linolenic acid, but not linoleic acid, were associated with advanced prostate cancer risk; only the association with alpha-linolenic acid persisted when saturated fat, monounsaturated fat, linoleic acid, and alpha-linolenic acid were modeled simultaneously (multivariate RR = 3.43; 95% CI = 1.67-7.04; P [trend] = .002). CONCLUSION: The results support the hypothesis that animal fat, especially fat from red meat, is associated with an elevated risk of advanced prostate cancer. IMPLICATIONS: These findings support recommendations to lower intake of meat to reduce the risk of prostate cancer. The potential roles of carcinogens formed in cooking animal fat and of alpha-linolenic acid in the progression of prostate cancer need to be explored.

Adult↗
PubMed1993

A prospective study of the intake of vitamins C, E, and A and the risk of breast cancer.

BACKGROUND: Although it has been hypothesized that large intakes of the antioxidant vitamins C, E, and A reduce the risk of breast cancer, few prospective data are available. METHODS: We prospectively studied 89,494 women who were 34 to 59 years old in 1980 and who did not have cancer. Their intakes of vitamins C, E, and A from foods and supplements were assessed at base line and in 1984 with the use of a validated semiquantitative food-frequency questionnaire. RESULTS: Breast cancer was diagnosed in 1439 women during eight years of follow-up. After multivariate adjustment for known risk factors, the relative risk among women in the highest quintile group for intake of vitamin C as compared with the risk among those in the lowest quintile group was 1.03 (95 percent confidence interval, 0.87 to 1.21); for vitamin E, after vitamin A intake had been controlled for, the relative risk was 0.99 (95 percent confidence interval, 0.83 to 1.19). In contrast, among women in the highest quintile group for intake of total vitamin A the relative risk was 0.84 (95 percent confidence interval, 0.71 to 0.98; P for trend = 0.001). Among women in the lowest quintile group for intake of vitamin A from food, consumption of vitamin A from supplements was associated with a reduced risk (P = 0.03). The significant inverse association of vitamin A intake with the risk of breast cancer was also found on study of data based on the 1984 questionnaire and four years of follow-up. CONCLUSIONS: Large intakes of vitamin C or E did not protect women in our study from breast cancer. A low intake of vitamin A may increase the risk of this disease; any benefit of vitamin A supplements may be limited to women with diets low in vitamin A.

Adult↗
PubMed1993

Family history, age, and risk of breast cancer. Prospective data from the Nurses' Health Study.

OBJECTIVE: To examine prospectively the risk of breast cancer as influenced by a maternal history of breast cancer, the mother's age at diagnosis, or a sister's history of breast cancer. DESIGN: Prospective cohort study with biennial follow-up. SETTING/PARTICIPANTS: 117,988 women in the Nurses' Health Study aged 30 to 55 years in 1976, followed up through 1988 (1.3 million person-years of follow-up). RESULTS: We identified 2389 incident cases of invasive breast cancer. Compared with women without a maternal history of breast cancer, the age-adjusted relative risk (RR) of breast cancer was highest among women whose mother was diagnosed before the age of 40 years (RR, 2.1 [95% confidence interval, 1.6 to 2.8]). The RR decreased with advancing maternal age at time of diagnosis to 1.5 (95% confidence interval, 1.1 to 2.2) for maternal diagnosis after the age of 70 years. Having a sister with a history of breast cancer also was related to increased risk; for women with one sister with breast cancer compared with those with one sister without such a history, the age-adjusted RR was 2.3 (95% confidence interval, 1.6 to 3.4). Women whose mother and sister both had a history of breast cancer had an RR of 2.5 (95% confidence interval, 1.5 to 4.2) compared with those without a family history. These associations did not differ appreciably when stratified by age; menopausal status; history of benign breast disease; body mass index; age at menarche; or parity or age at first birth of the women at risk. The results remained unchanged when we controlled for these risk factors in multivariate models. Despite slightly greater mammography surveillance and earlier detection of tumors among women with a family history of breast cancer, detection bias is unlikely to account for more than a small part of the observed association. CONCLUSIONS: Risk of breast cancer is approximately doubled among women whose mother had breast cancer diagnosed before the age of 40 years or who have a sister with breast cancer, and remains elevated even for those whose mothers were diagnosed with breast cancer at the age of 70 years or older. However, the risk associated with a mother or sister history of breast cancer is smaller than suggested by earlier retrospective studies. Overall, within this population of middle-aged women, only 2.5% of breast cancer cases are attributable to a positive family history.

Adult↗