Background: Black women are more likely than white women to have an aggressive subtype of breast cancer that is associated with higher mortality and this may contribute to the observed black-white difference in mortality. However, few studies have investigated the black-white disparity in mortality risk stratified by breast cancer subtype, defined by estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status. Furthermore, it is not known whether additional consideration of p53 protein status influences black-white differences in mortality risk observed when considering subtypes defined by ER, PR and HER2 status.
View Article and Find Full Text PDFAfrican American (AA) women have a higher mortality from breast cancer (BC) compared to European American (EA) women. This may be due to the higher proportion of AA women with tumors that are diagnosed at more advanced stages and are characterized as being estrogen receptor negative (ER-)/progesterone receptor negative (PR-). Our study sought to determine whether self-reported race and percent African ancestry were associated with BC tumor characteristics.
View Article and Find Full Text PDFRacial differences in breast cancer risk, including the risks of hormone receptor subtypes of breast cancer, have been previously reported. We evaluated whether variation in genes related to estrogen metabolism (COMT, CYP1A1, CYP1B1, CYP17A1, CYP19A1, ESR1, GSTM1, GSTP1, GSTT1, HSD17B1, SULT1A1, and UGT1A1) contributes to breast cancer risk and/or racial differences in risk within the CARE study, a multi-centered, population-based case-control study of breast cancer. Genetic variation was assessed as single nucleotide polymorphisms (SNPs), haplotypes, and SNP-hormone therapy (HT) interactions within a subset of 1,644 cases and 1,451 controls, including 949 Black women (493 cases and 456 controls), sampled from the CARE study population.
View Article and Find Full Text PDFBackground: While evidence on the association between oral contraceptive (OC) use and breast cancer generally suggests little or no increased risk, the question of whether breast cancer risk varies by OC formulation remains controversial. Few studies have examined this issue because large samples and extensive OC histories are required.
Study Design: We used data from a multicenter, population-based, case-control investigation.
Purpose: To evaluate the effect of obesity on survival among black women and white women with invasive breast cancer and to determine whether obesity explains the poorer survival of black women relative to white women.
Patients And Methods: We observed 4,538 (1,604 black, 2,934 white) women who were 35 to 64 years of age when diagnosed with incident invasive breast cancer between 1994 and 1998. Multivariate Cox regression models were used to examine the effect of body mass index (BMI, in kilograms per square meter) 5 years before diagnosis on risk of death from any cause and from breast cancer.
Studies consistently demonstrate that physical activity is inversely associated with postmenopausal breast cancer. Whether this association is stronger among non-hormone users or former users of menopausal hormone therapy (HT) is of interest given the marked decline in HT use since 2002. The Women's Contraceptive and Reproductive Experiences Study, a population-based case-control study of invasive breast cancer, recruited white women and black women ages 35-64 years and collected histories of lifetime recreational physical activity and HT use including estrogen-alone therapy (ET) and estrogen plus progestin therapy (EPT).
View Article and Find Full Text PDFRemoval or impairment of ovaries before menopause may affect a woman's breast cancer risk by altering her cumulative exposure to ovarian hormones. The Women's Contraceptive and Reproductive Experiences Study, a population-based, multicenter case-control study of incident invasive breast cancer, recruited women aged 35-64 years (4,490 cases and 4,611 controls) who provided data on ovariectomy, hysterectomy, and tubal sterilization during in-person interviews. Controls were frequency-matched to cases by age, race, and study site.
View Article and Find Full Text PDFCancer Epidemiol Biomarkers Prev
June 2010
Objective: Large body size has been associated with decreased risk of breast cancer in premenopausal women but with increased risk in postmenopausal women. Limited information is available about African-American women and differences by estrogen and progesterone receptor status.
Methods: We analyzed data from the Women's Contraceptive and Reproductive Experiences Study among 3,997 white and African-American breast cancer case patients diagnosed in 1994 to 1998 and 4,041 control participants ages 35 to 64 years.
Epidemiologic studies suggest that some hormone-related risk factors in breast cancer differentially influence risk for disease subtypes classified by the status of the estrogen and progesterone receptors (ER/PR). However, it remains unclear whether human epidermal growth factor receptor 2 (HER2) or p53 expression status further differentiates these exposure-risk group associations. We evaluated the associations of oral contraceptive (OC) use and reproductive factors with incident invasive breast cancer subtypes among 1,197 population-based cases and 2,015 controls from the Los Angeles County or Detroit components of the Women's Contraceptive and Reproductive Experiences Study.
View Article and Find Full Text PDFCancer Epidemiol Biomarkers Prev
August 2009
We investigated the extent to which estrogen receptor (ER) and progesterone receptor (PR) status results from a centralized pathology laboratory agree with ER and PR results from community pathology laboratories reported to two Surveillance, Epidemiology and End Results (SEER) registries (Los Angeles County and Detroit) and whether statistical estimates for the association between reproductive factors and breast cancer receptor subtypes differ by the source of data. The agreement between the centralized laboratory and SEER registry classifications was substantial for ER (kappa = 0.70) and nearly so for PR status (kappa = 0.
View Article and Find Full Text PDFBoth migraine and breast cancer are hormonally mediated diseases, and it is biologically plausible that women with a history of migraine may have a reduced breast cancer risk. However, this relationship has only been assessed in a single relatively small study that was unable to assess the effect of migraine triggers, which are also well-established breast cancer risk factors (e.g.
View Article and Find Full Text PDFPurpose: In the past decade, we have witnessed increasing numbers of individuals entering the field of epidemiology. With the increase also has come a diversity of training and paths by which individuals entered the field. The purpose of this survey was characterization of the epidemiology workforce, its job diversity, and continuing education needs.
View Article and Find Full Text PDFBackground: Early age at first birth and multiparity reduce the risk of estrogen receptor-progesterone receptor (ERPR)-positive breast cancer, whereas breastfeeding reduces the risk of both ERPR-positive and ERPR-negative cancers.
Methods: We used multivariable logistic regression analysis to investigate whether age at first birth (<25 or > or =25 years) and breastfeeding (ever/never) modify the long-term effect of parity on risk of ERPR-positive and ERPR-negative cancer using 1,457 incident breast cancer cases and 1,455 controls ages > or =55 years who participated in the Women's Contraceptive and Reproductive Experiences Study.
Results: Women who gave birth before age 25 years had a 36% reduced risk of breast cancer compared with nulligravida that was not observed for women who started their families at an older age (P(heterogeneity) = 0.
Background: The Breast Cancer Risk Assessment Tool of the National Cancer Institute (NCI) is widely used for counseling and determining eligibility for breast cancer prevention trials, although its validity for projecting risk in African American women is uncertain. We developed a model for projecting absolute risk of invasive breast cancer in African American women and compared its projections with those from the Breast Cancer Risk Assessment Tool.
Methods: Data from 1607 African American women with invasive breast cancer and 1647 African American control subjects in the Women's Contraceptive and Reproductive Experiences (CARE) Study were used to compute relative and attributable risks that were based on age at menarche, number of affected mother or sisters, and number of previous benign biopsy examinations.
Ages at menarche and first birth are established risk factors for breast cancer. The interval between these ages may also affect risk, since the breast is more susceptible to carcinogenic insults during this period than during the parous period. However, few investigators have studied this relation.
View Article and Find Full Text PDFObjective: To estimate breast cancer risk associated with short-term (<6 months) oral contraceptive use, and explore variation in estimates by use characteristics and medical, menstrual, and reproductive history.
Methods: We analyzed data from the Women's Contraceptive and Reproductive Experiences Study. Case subjects were white women and black women, 35-64 years old, diagnosed with invasive breast cancer in July 1994-April 1998.
Although well studied in families at high-risk, the roles of mutations in the BRCA1 and BRCA2 genes are poorly understood in breast cancers in the general population, particularly in Black women and in age groups outside of the very young. We examined the prevalence and predictors of BRCA1 and BRCA2 mutations in 1,628 women with breast cancer and 674 women without breast cancer who participated in a multicenter population-based case-control study of Black and White women, 35 to 64 years of age. Among cases, 2.
View Article and Find Full Text PDFBackground: Important differences in the contributions of certain exposures to the risks of ductal versus lobular breast carcinomas have been observed, but few studies have evaluated the relationships between established breast cancer risk factors and other histologic types.
Methods: Information on family history of cancer and reproductive, hormonal, anthropometric, and lifestyle characteristics were collected in a multicenter population-based case-control study consisting of 3,463 ductal, 274 lobular, 261 ductal-lobular, 91 medullary, 77 tubular, 70 comedo, and 61 mucinous invasive breast carcinoma cases (ages 35-64 years, newly diagnosed 1994-1998) and 4,682 controls. Associations between each of these histologic types and various exposures were evaluated using polytomous regression.
Background: Physical inactivity is a potentially modifiable breast cancer risk factor. Because few data on this relationship exist for black women, we examined the relationship between breast cancer risk and lifetime and time- or age-specific measures of recreational exercise activity among white women and among black women.
Methods: The Women's Contraceptive and Reproductive Experiences Study was a multicenter population-based case-control study of black women and white women aged 35-64 years with newly diagnosed invasive breast cancer.
Although breast cancer familial aggregation has been studied in Caucasians, information for African-Americans is scant. We used family cancer history from the Women's Contraceptive and Reproductive Experiences study to assess the aggregation of breast and gynecological cancers in African-American and Caucasian families. Information was available on 41,825 first and second-degree relatives of Caucasian and 28,956 relatives of African-American participants.
View Article and Find Full Text PDFCancer Epidemiol Biomarkers Prev
December 2004
Objectives: To explore associated biological outcomes and clarify the role of timing of exposure in the alcohol-breast cancer relationship.
Methods: In a population-based study of 4,575 women ages 35 to 64 years diagnosed with invasive breast cancer between 1994 and 1998 and 4,682 controls, we collected details of lifetime alcohol use and factors that could confound or modify the alcohol-breast cancer relationship. We used conditional logistic regression to compute the odds of breast cancer among drinkers relative to nondrinkers at all ages and at ages 35 to 49 and 50 to 64 years separately.
Background: Few studies have investigated the association between reproductive factors and the risk of breast carcinoma among African-American women. The authors assessed whether the number of full-term pregnancies, age at first full-term pregnancy, and total duration of breastfeeding were associated with similar relative risk estimates in white and African-American women in a large multicenter, population-based case-control study of breast carcinoma.
Methods: Case patients were 4567 women (2950 white women and 1617 African-American women) ages 35-64 years with newly diagnosed invasive breast carcinoma between 1994 and 1998.
Animal data indicate that both estrogens and progestins could be carcinogenic and that progestins could serve as tumor promoters. Human studies have not confirmed an increased risk of breast cancer from long-term use of oral contraceptives, but have shown an increased risk from hormone replacement therapy including progestins. The present study analyzed the relationship between breast cancer and use of injectable and implantable progestin-only contraceptives.
View Article and Find Full Text PDFObjective: We examined breast cancer risk related to lifetime exposure to oral contraceptives (OCs) and hormone replacement therapy (HRT) in postmenopausal women.
Methods: The Women's Contraceptive and Reproductive Experiences (CARE) Study was a population-based case-control study that included 1847 postmenopausal women with incident invasive breast cancer, and 1932 control subjects, identified using random digit dialing.
Results: 45% of cases and 49% of controls used both OCs and HRT.
This study was conducted to assess the histopathological features of breast cancers in women diagnosed with breast cancer at 50-64 years of age who have and have not used hormone replacement therapy (HRT). A case-case analysis of the tumors from women aged 50-64 years who participated in a multicenter population-based case-control study of invasive breast cancer was conducted. In-person interviews collected a detailed history of all episodes of hormone use.
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