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Emily White

Publications and source records attributed to Emily White.

At least 55 records · Page 3Linked to original sources
PubMed2004

Interlaboratory reliability of microimmunofluorescence test for measurement of Chlamydia pneumoniae-specific immunoglobulin A and G antibody titers.

To evaluate the reliability of Chlamydia pneumoniae-specific immunoglobulin G (IgG) and IgA antibody titers as measured by the microimmunofluorescence (MIF) test, we compared results from 392 individuals using a standard MIF protocol at two academic laboratories. The kappas for dichotomous titers (>/=16 versus <16) were 0.39 for IgA and 0.53 for IgG. Measurement error likely attenuates C. pneumoniae-disease associations; the magnitude of attenuation can be estimated from results of studies such as this one.

Aged↗
PubMed2004

Evaluating organized breast cancer screening implementation: the prevention of late-stage disease?

The objective of our study was to evaluate organized breast cancer screening implementation by measuring the association between screening program enrollment and late-stage disease. Our setting was a health plan using mailed mammography reminders to women ages > or = 40. We conducted yearly cross-sectional summaries of mammography experience and late-stage (regional or distant Surveillance Epidemiology and End Results Reporting (SEER) stage) breast cancer occurrence for all of the health-plan women ages > or = 40 (1986-1998). We estimated the odds of late-stage breast cancer among health-plan and surrounding community women because it was too early to compare changes in mortality. We also estimated the odds of late-stage disease (1995-1998) associated with program enrollment and mammography screening among health-plan women. We found that mammography-within-two-years increased within the health plan from 25.9% to 51.2% among women ages 40-49 and from 32.9% to 74.7% among women ages> or = 50. Health-plan late-stage rates were lower than those in the surrounding community [ages 40-49: odds ratio (OR), 0.87; 95% confidence interval (CI), 0.77-0.99; ages 50-79: OR, 0.86; 95% CI, 0.80-0.92] and declined parallel to the community. Among health-plan cancer cases, women ages > or = 43 who were enrolled in the screening program and who had at least one program mammogram were less likely to have late-stage disease compared with the women not enrolled in the program (OR, 0.31; 95% CI, 0.16-0.61) but the odds of late-stage was also reduced among program-enrolled women not receiving program mammograms (OR, 0.45; 95% CI, 0.21-0.95). We concluded that enrollment in organized screening is associated with increased likelihood of mammography and reduced odds of late-stage breast cancer. Addressing the concerns of un-enrolled women and those without mammograms offers an opportunity for further late-stage disease reduction.

Adult↗
PubMed2004

Chlamydia pneumoniae infection and risk of lung cancer.

Infection with Chlamydia pneumoniae may be associated with an increased risk of lung cancer. We conducted a matched case-control study (508 pairs) nested within a large prospective study to investigate whether IgA antibody titers to C. pneumoniae measured by the microimmunofluorescence test are associated with lung cancer risk after controlling for confounders. Individuals with antibody titers > or = 16 had 1.2 times the risk of lung cancer (95% confidence interval, 0.9-1.6) compared to those with lower titers. There was a significant trend (P = 0.007) of increasing odds ratios with increasing IgA titers primarily due to an odds ratio of 2.8 (95% confidence interval, 1.1-6.7) associated with titers > or = 256. Lung cancer risk associated with IgA titers > or = 16 was stronger among former smokers. To better understand predictors of IgA seropositivity, we also examined demographic, lifestyle, dietary, and medical correlates of IgA titers > or = 16 among controls. Those with race not classified as White or Black were more likely to have IgA titers > or = 16; there were no significant differences in seropositivity by smoking behaviors. In summary, the adjusted odds ratio for lung cancer associated with IgA titers > or = 16 was compatible with a weakly positive association, although nondifferential measurement error of antibody titers may have resulted in a conservative bias. Future studies using precise measures of chronic C. pneumoniae status are needed to better determine the role of this organism in the etiology of lung cancer.

Adult↗
PubMed2003

Breast cancer and nonsteroidal anti-inflammatory drugs: prospective results from the Women's Health Initiative.

We analyzed data from the prospective Women's Health Initiative (WHI) Observational Study to examine the effects of regular use of aspirin, ibuprofen, and other nonsteroidal anti-inflammatory drugs (NSAIDs) on breast cancer risk. We studied a population of 80,741 postmenopausal women between 50 and 79 years of age who reported no history of breast cancer or other cancers (excluding nonmelanoma skin cancer), and we completed a personal baseline interview that elicited comprehensive health information including data on breast cancer risk factors and NSAID use. All of the cases were adjudicated by WHI physicians using pathology reports. Our analysis was based on 1392 confirmed cases of breast cancer. Relative risks (RRs) with 95% confidence intervals (CIs) were estimated with adjustment for age and other breast cancer risk factors. Regular NSAID use (two or more tablets/week) for 5-9 years produced a 21% reduction in the incidence of breast cancer (RR, 0.79; 95% CI, 0.60-1.04); regular NSAID use for 10 or more years produced a 28% reduction (RR, 0.72; CI, 0.56-0.91), and there was a statistically significant inverse linear trend of breast cancer incidence with the duration of NSAID use (P < 0.01). The estimated risk reduction for long-term use of ibuprofen (RR, 0.51; CI, 0.28-0.96) was greater than for aspirin (RR, 0.79; CI, 0.60-1.03). Subgroup analysis by breast cancer risk factors did not result in effect modification. Regular use of acetaminophen (an analgesic agent with little or no anti-inflammatory activity) or low-dose aspirin (<100 mg) was unrelated to the incidence of breast cancer. Our results indicate that the regular use of aspirin, ibuprofen, or other NSAIDs may have a significant chemopreventive effect against the development of breast cancer and underscore the need for clinical trials to confirm this effect.

Age Factors↗
PubMed2003

Recreational physical activity and the risk of breast cancer in postmenopausal women: the Women's Health Initiative Cohort Study.

CONTEXT: Women who are physically active have a decreased risk for breast cancer, but the types, amounts, and timing of activity needed are unknown. OBJECTIVE: To prospectively examine the association between current and past recreational physical activity and incidence of breast cancer in postmenopausal women. DESIGN, SETTING, AND PATIENTS: Prospective cohort study in 74 171 women aged 50 to 79 years who were recruited by 40 US clinical centers from 1993 through 1998. MAIN OUTCOME MEASURE: Incident invasive and in situ breast cancer. RESULTS: We documented 1780 newly diagnosed cases of breast cancer over a mean follow-up of 4.7 years. Compared with less active women, women who engaged in regular strenuous physical activity at age 35 years had a 14% decreased risk of breast cancer (relative risk [RR], 0.86; 95% confidence interval [CI], 0.78-0.95). Similar but attenuated findings were observed for strenuous physical activity at ages 18 years and 50 years. An increasing total current physical activity score was associated with a reduced risk for breast cancer (P =.03 for trend). Women who engaged in the equivalent of 1.25 to 2.5 hours per week of brisk walking had an 18% decreased risk of breast cancer (RR, 0.82; 95% CI, 0.68-0.97) compared with inactive women. Slightly greater reduction in risk was observed for women who engaged in the equivalent of 10 hours or more per week of brisk walking. The effect of exercise was most pronounced in women in the lowest tertile of body mass index (BMI) (<24.1), but also was observed for women in the middle tertile of BMI (24.1-28.4). CONCLUSIONS: These data suggest that increased physical activity is associated with reduced risk for breast cancer in postmenopausal women, longer duration provides most benefit, and that such activity need not be strenuous.

Aged↗
PubMed2003

Selection bias in the assessment of gene-environment interaction in case-control studies.

Selection bias is a common concern in epidemiologic studies, particularly case-control studies. Selection bias in the odds ratio occurs when participation depends jointly on exposure and disease status. General results for understanding when selection bias may affect studies involving gene-environment interactions have not yet been developed. In this paper, the authors show that the assessment of gene-environment interactions will not be subject to selection bias under the assumption that genotype does not influence participation conditional on exposure and disease status. This is true even when selection, including self-selection of subjects, is jointly influenced by exposure and disease and regardless of whether the genotype is related to exposure, disease, or both. The authors present an example to illustrate this concept.

Bias↗
PubMed2003

Reliability and validity of self-report of vitamin and mineral supplement use in the vitamins and lifestyle study.

In the United States, dietary supplements contribute a large proportion of micronutrient intakes. Therefore, it is important to collect accurate information on supplement use for studies of micronutrients and disease risk. This report describes the test-retest reliability and validity of a detailed, self-administered mailed questionnaire on vitamin and mineral supplement use. Participants (n = 220) completed the questionnaire at baseline and 3 months later. During an in-person interview, participants provided spot urine and blood samples, and interviewers transcribed nutrient information from their supplement bottle labels. The questionnaire had very good test-retest reliability for mean supplement intake over the past 10 years, with intraclass correlations ranging from 0.69 for beta-carotene to 0.87 for vitamin E. Pearson's correlation coefficients comparing current supplemental intakes from the questionnaire and interviews/label transcriptions were high, ranging from 0.58 for beta-carotene to 0.82 for chromium; however, for some nutrients, median intakes from the questionnaire were slightly lower than from the interviews. Beta-carotene, vitamin C, and vitamin E (alpha-tocopherol) showed clear linear trends of increasing blood concentrations with higher self-reported supplemental intakes (Pearson's correlation coefficients adjusted for potential confounding factors and diet = 0.31, 0.29, and 0.69, respectively; all p < 0.0001). Creatinine-adjusted spot urinary calcium values were not associated with supplemental calcium intakes (Pearson's r = -0.07). This self-administered questionnaire demonstrated high reproducibility and validity for collecting detailed information on supplement use.

Aged↗
PubMed2003

Design and interpretation of studies of differential exposure measurement error.

Differential exposure measurement error can have more adverse effects on estimates of exposure-disease associations than nondifferential measurement error, yet relatively little has been written about the design and interpretation of validity and reliability studies to assess differential measurement error. In this paper, a simple approximate equation is given for the effect of differential measurement error in a continuous exposure measure on the bias in the odds ratio. From this, it is shown that two parameters need to be estimated in validity/reliability studies in order to interpret the results in terms of the bias in the odds ratio in an epidemiologic study that will use the measure. The first is the correlation between the mismeasured and true exposure. The second is the differential bias (difference between cases and controls in the difference between mean measured and true exposure) relative to the true difference in exposure between cases and controls. It is shown that this latter parameter can be estimated in a method comparison study if one has a comparison measure that is unbiased or has nondifferential bias, so a perfect criterion measure is not needed. Researchers should consider measuring and reporting this parameter in validity/reliability studies when feasible.

Bias↗
PubMed2003

Dietary supplement use and medical conditions: the VITAL study.

BACKGROUND: Over half of U.S. adults use vitamin or mineral supplements, and some are likely using supplements to treat chronic diseases or risk factors for disease. Information on the relationship between supplement use and medical conditions is useful to health professionals to understand the self-medication behavior of their patients, and important for researchers because medical conditions may be potential confounding factors in observational studies of supplement use and disease risk. METHODS: The cross-sectional data in this report are from 45,748 participants, aged 50 to 75 years, who completed a self-administered, mailed questionnaire on current dietary supplement use (multivitamins plus 16 individual vitamins or minerals), medical history (cancer, cardiovascular-related diseases, and other self-reported medical conditions), and demographic characteristics. RESULTS: Supplement use (mean number used at least once a week) was higher among respondents who were older, female, highly educated, Caucasian, and of normal body mass index (all p<0.001). After controlling for these covariates, supplement use was higher among those with the condition for 13 of the 21 conditions examined (p<0.01); only having diabetes or high stress was associated with using fewer supplements. For specific supplements, the strongest associations were for cardiovascular disease and its risk factors with vitamin E, niacin, and folate, and for calcium with indigestion and acid reflux disease. For several conditions, the relative odds of using specific supplements were consistently higher for men than for women. CONCLUSIONS: Supplement use was associated with many medical conditions in this cohort. However, these cross-sectional data do not permit inferences about the temporal sequence. Some associations appeared to be based on evidence for efficacy (e.g., folate with coronary artery disease), and others could be based on misinformation (e.g., selenium with benign prostatic hyperplasia).

Age Distribution↗
PubMed2003

Risk factors for colorectal cancer following breast cancer.

OBJECTIVE: To investigate risk factors for colorectal cancer following breast cancer. METHODS: In this nested case-control study, all women (n = 14,900) with a first primary breast cancer (1978-1992) were identified from the western Washington population-based Surveillance, Epidemiology, and End Results Cancer Registry. Cases (n = 160) developed a second primary colorectal cancer before 1995, at least 6 months after the first cancer diagnosis. Controls (n = 310, matched to the cases on calendar year, age and breast cancer stage) were randomly selected from those who did not develop a second primary cancer and who survived to the case's colorectal cancer diagnosis date. Characteristics of the cases and controls at initial diagnosis were compared using conditional logistic regression. RESULTS: The incidence of colorectal cancer was associated with a family history of breast cancer (v.s. no family history, matched odds ratio (mOR) = 2.1, 95% confidence interval (CI): 1.1-4.1), high body mass index (> or = 30kg/m2 v.s. < 30kg/m2, mOR = 2.2, CI: 1.2-3.9), and lobular breast cancer histology (v.s. ductal, mOR = 2.0, CI: 0.9-4.4). Risk was unrelated to menopausal status, prior hormone replacement therapy and estrogen/progesterone receptor status of the breast tumors. CONCLUSIONS: The risk of developing a second primary colorectal cancer may be elevated among certain subsets of breast cancer patients.

Adult↗
PubMed2003

Allergy and risk of breast cancer among young women (United States).

OBJECTIVE: To investigate the relationship between allergy and risk of breast cancer in women 45 years of age and younger. METHODS: Data were analyzed from a population-based case-control study of breast cancer in western Washington. Cases were women born after 1944 who were diagnosed with invasive breast cancer (n = 747) between January 1983 and April 1990. Controls (n = 958) were similarly aged women ascertained through random-digit dialing. Cases and controls were interviewed about their history of doctor diagnosed allergies, including detailed information on the specific types of allergies and the age of onset. Using logistic regression we examined the associations between allergy history and breast cancer. RESULTS: A history of allergies was associated with a reduced risk of breast cancer for women older than 35 (odds ratio (OR) = 0.77; 95% confidence interval (CI) = 0.60-0.99), but not for women 35 years or younger (OR = 1.30; 95% CI = 0.94-1.81). There was little difference in effect when age of first allergy onset was examined. No specific type of allergy was associated with breast cancer risk. CONCLUSION: Our results provide some evidence that a history of allergy may be associated with a reduced risk of breast cancer for women who develop breast cancer between 35 and 45 years of age. Future studies are needed to verify the relationship between immune responses and breast cancer risk.

Adult↗
PubMed2003

Soy isoflavones do not modulate circulating insulin-like growth factor concentrations in an older population in an intervention trial.

Insulin-like growth factors (IGF) are essential for normal growth and maintenance of lean muscle mass; however, high insulin-like growth factor-I (IGF-I) and low IGF binding protein-3 (IGFBP-3) levels are also associated with several cancers. To test the hypothesis that long-term soy isoflavone supplementation decreases circulating IGF-I concentrations, we conducted a controlled, parallel-arm, double-blind intervention study with 150 participants (85% men), 50-80 y old. Participants were randomly assigned to consume a soy beverage powder daily for 12 mo. The active treatment group (+ISO) received soy protein containing 83 mg isoflavones, whereas the comparison group (-ISO) received soy protein containing 3 mg isoflavones. Serum IGF-I and IGFBP-3 were measured by ELISA. Mean change in serum IGF-I concentrations was similar in the two groups (+1.4 nmol/L in +ISO, +1.2 nmol/L in -ISO; P = 0.74, 95% confidence interval -1.1, +1.5 nmol/L for the 0.21 nmol/L difference between groups), indicating no effect of the isoflavone intervention. Similarly, the changes in IGFBP-3 and the IGF-I/IGFBP-3 ratio were similar in both groups, again showing no effect of +ISO treatment. A 12 mo, 83 mg/d soy isoflavone intervention did not modulate serum IGF in an older, mostly male population.

Aged↗
PubMed2002

Hormone replacement therapy in relation to breast cancer.

CONTEXT: Studies of long-term hormone replacement therapy (HRT) suggest an associated increased risk of breast cancer, but whether this association differs according to histologic type of cancer has not been extensively studied. OBJECTIVE: To determine whether the association between HRT and risk of breast cancer varies by HRT formulation and differs across histologic cancer types. DESIGN, SETTING, AND PARTICIPANTS: Nested case-control study among 705 postmenopausal women enrolled in the Group Health Cooperative of Puget Sound (GHC) who were aged 50 to 74 years and had primary invasive breast cancer diagnosed between July 1, 1990, and December 31, 1995 (cases), and 692 randomly selected aged-matched female members of GHC (controls). MAIN OUTCOME MEASURE: Incidence and type of breast cancer by duration of HRT use in the 5-year period ending 1 year before diagnosis, which was ascertained from computerized pharmacy records. RESULTS: The incidence of breast cancer, all histologic types combined, was increased by 60% to 85% in recent long-term users of HRT, whether estrogen alone or estrogen plus progestin. Longer use of HRT (odds ratio [OR], 3.07 for 57 months or more; 95% confidence interval [CI], 1.55-6.06) and current use of combination therapy (OR, 3.91; 95% CI, 2.05-7.44) were associated with increased risk of lobular breast cancer. Long-term HRT use was associated with a 50% increase in nonlobular cancer (OR, 1.52 for 57 months or more; 95% CI, 1.01-2.29). CONCLUSION: Our data add to the growing body of evidence that recent long-term use of HRT is associated with an increased risk of breast cancer and that such use may be related particularly to lobular tumors.

Aged↗
PubMed2002

Obesity, body size, and risk of postmenopausal breast cancer: the Women's Health Initiative (United States).

OBJECTIVE: Body size is an important modifiable risk factor for breast cancer. Although obesity has generally been found to be associated with increased risk for postmenopausal breast cancer, there remain questions concerning the role of body fat distribution, lifetime weight history, and effects within specific subgroups of women. METHODS: We assessed the relationship of several anthropometric measures and risk of postmenopausal breast cancer in 85,917 women aged 50-79 at entry in the Women's Health Initiative Observational Study. Women were enrolled during 1993-1998 at 40 clinics in the US and 1030 developed invasive breast cancer by April 2000. Upon entry, trained clinical center staff measured each woman's height, weight, and waist and hip circumference. RESULTS: Anthropometric factors were not associated with breast cancer among women who had ever used hormone replacement therapy (HRT). Among HRT non-users, heavier women (baseline body mass index (BMI) >31.1) had an elevated risk of postmenopausal breast cancer (relative risk (RR) = 2.52; 95% confidence interval (CI) = 1.62-3.93), compared to slimmer women (baseline BMI < 22.6). The elevation in risk associated with increasing BMI appeared to be most pronounced among younger postmenopausal women. Change in BMI since age 18, maximum BMI, and weight were also associated with breast cancer in HRT non-users. While both waist and hip circumference were associated with breast cancer risk, their ratio, a measure of fat distribution, was not (RR = 1.33; 95% CI = 0.88-2.01). CONCLUSIONS: Our study confirms previously reported findings that generalized obesity is an important risk factor for postmenopausal breast cancer, but only among women who have never taken HRT. Lifetime weight gain is also a strong predictor of breast cancer. Waist to hip ratio, a measure of weight distribution, does not appear to be related to postmenopausal breast cancer risk.

Aged↗
PubMed2002

Predictors of sensitivity of clinical breast examination (CBE).

Clinical breast examination (CBE) is one of the most common breast cancer screening modalities, but factors that affect its sensitivity are not well understood. We examined the association between CBE sensitivity and tumor, breast and personal characteristics among members of a managed care organization's Breast Cancer Screening Program (BCSP). The study population was 468 screened women 40 years and older diagnosed with invasive breast cancer between 1988 and 1994 within 1 year of a screening CBE. Logistic regression was used to evaluate the likelihood of a true positive versus a false negative CBE result, after adjustment for age, body weight and tumor size. CBE sensitivity increased with larger tumor size (17% for tumors < or = 0.5 cm and 58% for tumors > or = 2.1 cm, adjusted p for trend < 0.001) and decreased with higher body weight (48 and 23% for the lowest and highest quartiles, adjusted p for trend < 0.001). CBE was more sensitive in Asian women compared to white women (88% v.s. 35%, adjusted p = 0.04) and in current users of estrogen and progesterone combination therapy compared to never/former users (52% v.s. 33%, adjusted p = 0.08). There was an inverted U-shaped association between age and CBE sensitivity (40-49: 26%, 50-59: 48%, 60-69: 36%, 70-79: 33%, 80+: 18%, significant for oldest and youngest groups v.s. age 50-59 years). These findings suggest certain groups of women, for example, obese women and younger women, receive less benefit from CBE.

Adult↗
PubMed2002

Screening mammography: clinical image quality and the risk of interval breast cancer.

OBJECTIVE: We evaluated the association between clinical image quality and breast cancer occurrence within 24 months of a negative mammogram. MATERIALS AND METHODS: We identified women with breast cancer who were younger than 40 years old and older and screened from January 1, 1988, through December 31, 1993. We retrospectively assigned Breast Imaging Reporting and Data System (BI-RADS) assessments to their screening mammogram. We classified cancers (invasive or ductal in situ) as "screen-detected" when found after positive assessments (BI-RADS codes 3, 4, and 5) and "interval-detected" when found after negative assessments (BI-RADS codes 1 and 2). One reviewer evaluated mediolateral oblique and craniocaudal views for all cancer cases using a 3-point scale (failure, borderline, pass) for each measure of clinical image quality (positioning, breast compression, contrast, exposure, noise, sharpness, artifacts, overall quality). We used separate logistic regression models and evaluated the odds of interval invasive cancer or invasive plus in situ cancer as a function of each measure of quality using "pass" as the referent group. RESULTS: We found 492 screen-detected and 164 interval-detected cancers that met study criteria. Cancer detection (sensitivity) was highest (84%) among patients with proper breast positioning, but when images failed this measure (33.4%), sensitivity fell to 66.3%. After adjustment for age, film date, and breast density, interval-detected invasive cancers were more likely after images failing positioning (odds ratio, 2.57; 95% confidence interval, 1.28-5.52%). Failures in overall quality were also associated with interval cancers when cases of ductal carcinoma in situ (p = 0.037) were included. CONCLUSION: Invasive breast cancer detection by mammography may be improved through attention to correct positioning.

Adult↗
PubMed2002

Use of the American College of Radiology BI-RADS guidelines by community radiologists: concordance of assessments and recommendations assigned to screening mammograms.

OBJECTIVE: This study evaluated the use of the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) by community radiologists by determining the concordance of assessment categories and recommendations assigned to screening mammograms. MATERIALS AND METHODS: The study comprised the interpretations of 82,620 consecutive screening mammograms by 18 radiologists between January 1, 1995, and December 31, 1998. For all mammograms, assessment categories and recommendations were compared to determine whether they were in accordance with BI-RADS guidelines. Overall patterns of discordance were analyzed, and comparisons of discordant patterns by assessment category, patient age, breast density, and year of examination were made. RESULTS: The overall discordance between BI-RADS assessments and recommendations was low (3%). The assessment with the highest discordance was "probably benign finding" (category 3), at 53.5%. Mammograms obtained in 1998 were almost half as likely to have assessment-recommendation discordance compared with those obtained in 1995 (2.4% vs 4.5%, respectively; odds ratio = 0.52; p < 0.001). Mammograms of women with dense breast tissue were 30% more likely to have lesions assigned discordant assessments and recommendations compared with those of women with fatty tissue (3.4% vs 2.7%, respectively; odds ratio = 1.3; p < 0.001). No differences in the patterns of discordance were found between mammograms of women younger than 50 years and those of women 50 years old and older (p = 0.10). CONCLUSION: There has been improvement in the accurate application of BI-RADS since its introduction. However, variation in the pairing of BI-RADS assessments and recommendations persists. Continued efforts to educate radiologists about the use of BI-RADS and to clarify BI-RADS terms would promote maximum consistency in this use of this reporting method.

Adult↗