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Background: Endogenous sex hormone levels are associated with risks of breast cancer overall and estrogen receptor (ER)-positive breast tumors; however, their associations with ER-negative tumors remain unclear.Methods: In a case-cohort study within the Women's Health Initiative Observational Study among postmenopausal women aged 50-79 years, we examined associations between endogenous testosterone and estradiol levels and the risks of ER-negative and ER-positive breast cancers. Serum levels of bioavailable testosterone and estradiol were assessed at the baseline visit in 317 invasive breast cancer case subjects and in a subcohort of 594 women. Bioavailable sex hormone levels were calculated using the total hormone level and the sex hormone-binding globulin concentration (measured by radioimmunoassays and a chemiluminescent immunoassay, respectively). Cox proportional hazards regression was used for statistical analysis. All statistical tests were two-sided.Result: The unadjusted absolute rates of ER-negative breast cancer for testosterone quartiles 1-4 were 0.34, 0.20, 0.23, and 0.21 per 10,000 person-years, respectively. Compared with women in the lowest quartile of testosterone level, those in quartile 2 had a 56% lower risk of ER-negative cancer (hazard ratio [HR] = 0.44, 95% confidence interval [CI] = 0.23 to 0.85), those in quartile 3 had a 45% lower risk (HR = 0.55, 95% CI = 0.30 to 1.01), and those in quartile 4 had a 49% lower risk (HR = 0.51, 95% CI = 0.28 to 0.94), independent of other risk factors. Estradiol level was not associated with ER-negative breast cancer. ER-positive breast cancer risk increased with higher testosterone levels (P(trend) = .04), but this trend was not statistically significant after adjustment for estradiol (P(trend) = .15). ER-positive cancer risk was approximately twofold higher in women with estradiol levels in quartiles 2-4 compared with women in quartile 1, independent of risk factors.Conclusion: Higher serum levels of bioavailable testosterone are associated with lower risks of ER-negative breast cancer in postmenopausal women. [ABSTRACT FROM AUTHOR]

OBJECTIVES: We sought to assess the extent to which race/ethnicity and socioeconomic status (SES) are independently and jointly related to lifetime morbidity burden by comparing the impact of SES on lifetime morbidity among women of different racial/ethnic groups: white, black, Hispanic, American Indian/Alaska Native (AIAN), and Asian/Pacific Islander (API). METHODS: Using baseline data from the Women's Health Initiative (WHI), a national study of 162,000 postmenopausal women, we measured lifetime morbidity burden using a modified version of the Charlson Index, and measured SES with educational attainment and household income. In multivariable simple polytomous logistic regression models, we first assessed the effect of SES on lifetime morbidity burden among women of each racial/ethnic group, then assessed the combined effect of race/ethnicity and SES. RESULTS: Five percent of all women in the study population had high lifetime morbidity burden. Women with high lifetime morbidity were more likely to be AIAN or black; poor; less educated; divorced, separated, or widowed; past or current smokers; obese; uninsured or publicly insured. Lower SES was associated with higher morbidity among most women. The extent to which morbidity was higher among lower SES compared to higher SES women was about the same among Hispanic women and white women, but was substantially greater among black and AIAN women compared with white women. CONCLUSIONS: This study demonstrates the importance of considering race/ethnicity and class together in relation to health outcomes. [ABSTRACT FROM AUTHOR]

The study evaluated a theory-based breast cancer control program specially developed for less acculturated Latinas. The authors used a quasi-experimental design with random assignment of Latinas into experimental (n = 51) or control (n = 37) groups that completed one pretest and two posttest surveys. The experimental group received the educational program, which was based on Bandura's self-efficacy theory and Freire's empowerment pedagogy. Outcome measures included knowledge, perceived self-efficacy, attitudes, breast self-examination (BSE) skills, and mammogram use. At posttest 1, controlling for pretest scores, the experimental group was significantly more likely than the control group to have more medically recognized knowledge (sum of square [SS] = 17.0, F = 6.58, p < .01), have less medically recognized knowledge (SS = 128.8, F = 39.24, p < .001), greater sense of perceived self-efficacy (SS = 316.5, F = 9.63, p < .01), and greater adeptness in the conduct of BSE (SS = 234.8, F = 153.33, p < .001). Cancer control programs designed for less acculturated women should use informal and interactive educational methods that incorporate skill-enhancing and empowering techniques. [ABSTRACT FROM AUTHOR]