Diurnal variation of testosterone and estradiol: a source of bias in comparative studies on breast cancer

Panico, Salvatore; Pisani, Paola; Muti, Paola; Recchione, C; Cavalleri, A; Totis, A.; Berrino, Franco

doi:10.1007/bf03350695

Cited by 34 publications

(15 citation statements)

References 10 publications

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“…We adjusted for year of blood draw to account for any possible degradation in the analytes over time and adjusted for hour of the blood draw to adjust for possible diurnal variation, particularly of the androgens. 33 We were unable to document how the volunteers who gave blood for the breast cancer marker study, carried out in the 1970s and 1980s, differed from those who did not because no information was collected from those who did not participate; however, it is likely that any selection factors were similar for all study subjects included in this analysis. We also excluded some women who met the eligibility criteria for our study, but did not have serum or slides available.…”

Section: Discussionmentioning

confidence: 99%

Serum concentrations of estrogens, sex hormone‐binding globulin, and androgens and risk of breast cancer in postmenopausal women

Adly

Hill

Sherman

et al. 2006

Intl Journal of Cancer

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We assessed the relationship between serum concentrations of estrogens, androgens, and sex hormone-binding globulin and risk of breast cancer among postmenopausal women. Study participants provided serum prior to breast biopsy or mastectomy in 3 hospitals in Grand Rapids, Michigan between 1977 and 1987. A total of 179 subjects with localized breast cancer were compared to 152 subjects with nonproliferative breast changes that have not been associated with elevated breast cancer risk. Increasing serum concentrations of estrone and estrone sulfate were associated with increases in breast cancer risk; the odds ratios (ORs) in the fourth quartiles compared to the first were 2.3 (95% confidence interval (CI) 1.1-4.6) for both (p-trend 5 0.02 and 0.03, respectively). Estradiol and bioavailable estradiol concentrations were associated with nonstatistically significant increases in risk. Androstenediol levels were associated with risk (p-trend 5 0.01); the OR in the fourth compared to the first quartile was 2.2 (95% CI 1.0-4.6). Testosterone, dehydroepiandrosterone and androstenedione levels were not associated with increased risk. Sex hormone-binding globulin was associated with a nonsignificant decrease in risk. Associations with estrone and estrone sulfate persisted after adjustment for androstenediol (ORs for fourth compared to first quartiles were 2.0 (95% CI 0.9-4.5) and 2.2 (95% CI 1.0-4.6), respectively (p-trend 5 0.16 for both). The association with androstenediol was attenuated after adjustment for estrone (OR for fourth compared to first quartile was 1.6 (95% CI 0.7-3.6); p-trend 5 0.13). Higher serum concentrations of estrogens were associated with increased breast cancer risk in postmenopausal women. Androgen levels were not independently associated with substantially increased risk. ' 2006 Wiley-Liss, Inc.Key words: breast cancer; estrogens; androgens; androstenediol Epidemiologic, experimental and animal data strongly implicate estrogens in the etiology of breast cancer. 1 The relationship between endogenous androgen levels (testosterone, androstenedione, dehydroepiandrosterone (DHEA)) and breast cancer risk is less clear, with both epidemiologic and experimental data providing conflicting results. 2-6 A metabolite of DHEA, 5-androstene-3b, 17b-diol (androstenediol), which in vitro acts as an estrogen in estradiol-deficient medium and as an androgen in an estrogen-rich medium, has been linked to increased breast cancer risk in postmenopausal women in one study. 7 Androgens could act to stimulate the breast directly or indirectly by providing the raw material for the synthesis of estrogens in peripheral or mammary adipose tissue.In this report, we assess the relationship between serum concentrations of estrogens, sex hormone-binding globulin and androgens, including androstenediol, to risk of localized breast cancer in postmenopausal women. Women undergoing biopsy in the same hospitals as the cases but diagnosed with nonproliferative breast conditions not related to elevated risk of breast cancer served a...

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Section: Discussionmentioning

confidence: 99%

Serum concentrations of estrogens, sex hormone‐binding globulin, and androgens and risk of breast cancer in postmenopausal women

Adly

Hill

Sherman

et al. 2006

Intl Journal of Cancer

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show abstract

“…Moreover, this study like previous studies used only a single blood sample for the determination of estradiol levels. It has been reported that time of day has little effects on estradiol concentrations in postmenopausal women (Panico et al, 1990), however there seems to be an influence of lifestyle variables (Cauley et al, 1989) and a relatively low stability of the measurement over time (Cauley et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

Endogenous Estradiol and Testosterone Levels Are Associated with Cognitive Performance in Older Women and Men

Wolf

Kirschbaum

2002

Hormones and Behavior

218

140

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“…From the present findings it may be inferred that the SCN is capable of monitoring the circadian, menstrual and circannual rhythms of circulating levels of sex hormones in humans from early puberty onwards until late adulthood [70, 71, 72, 73, 74, 75]. …”

Section: Discussionmentioning

confidence: 99%

Sex Hormone Receptors Are Present in the Human Suprachiasmatic Nucleus

Kruijver¹,

Swaab²

2002

Neuroendocrinology

155

102

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The suprachiasmatic nucleus (SCN) is the clock of the brain that orchestrates circadian and circannual biological rhythms, such as the rhythms of hormones, body temperature, sleep and mood. These rhythms are frequently disturbed in menopause and even more so in dementia and can be restored in postmenopausal women by sex hormone replacement therapy (SHRT). Although it seems clear, both from clinical and experimental studies, that sex hormones influence circadian rhythms, it is not known whether this is by a direct or an indirect effect on the SCN. Therefore, using immunocytochemistry in the present study, we investigated whether the human SCN expresses sex hormone receptors in 5 premenopausal women and 5 young men. SCN neurons appeared to contain estrogen receptor-α (ERα), estrogen receptor-β (ERβ) and progesterone receptors. Median ratings of ER immunoreactivity per individual and per gender group revealed a statistically significantly stronger nuclear ERα expression pattern in female SCN neurons (p < 0.05). No significant sexual dimorphic tendency was observed for nuclear ERβ (p > 0.1) and progesterone receptors (p > 0.7). These data seem to support previously reported functional and structural SCN differences in relation to sex and sexual orientation and indicate for the first time that estrogen and progesterone may act directly on neurons of the human biological clock. In addition, the present findings provide a potential neuroendocrine mechanism by which SHRT can act to improve or restore SCN-related rhythm disturbances, such as body temperature, sleep and mood.

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Diurnal variation of testosterone and estradiol: a source of bias in comparative studies on breast cancer

Cited by 34 publications

References 10 publications

Serum concentrations of estrogens, sex hormone‐binding globulin, and androgens and risk of breast cancer in postmenopausal women

Serum concentrations of estrogens, sex hormone‐binding globulin, and androgens and risk of breast cancer in postmenopausal women

Endogenous Estradiol and Testosterone Levels Are Associated with Cognitive Performance in Older Women and Men

Sex Hormone Receptors Are Present in the Human Suprachiasmatic Nucleus

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