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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Current medical practice recommends the use of alternatives to estrogen-replacement therapy for the treatment of menopausal sequelae in younger women with breast cancer, although this clinical recommendation is undergoing reappraisal. Until prospective randomized studies addressing hormone use in this population are available, estrogen use in breast cancer patients will remain controversial. Because estrogen-replacement therapy is not the standard of practice and there is limited information available on nonestrogen therapies, women with breast cancer who are menopausal may not be prescribed or counseled about nonestrogen options. The efficacy, safety, and extent of use of most nonestrogen treatment modalities (other hormonal preparations, nonhormonal drugs, homeopathic preparations, and non-drug treatments) are not well documented and, unlike estrogen, many are selective in their benefit and do not share estrogen's universal impact. The use of several nonestrogen approaches for the prevention and treatment of osteoporosis has been promising. Traditional recommendations to maintain skeletal integrity, such as weight-bearing exercise; a diet rich in calcium and limited in caffeine, alcohol, and protein; avoidance of smoking; and measures to minimize trauma have been expanded to include the use or investigation of drugs (either alone or in combination). These drugs include progestins, vitamin D metabolites, injectable and intranasal synthetic salmon calcitonin, bisphosphonates, sodium fluoride, parathyroid hormone, growth factors, tamoxifen, etc. Strict control of the known risk factors, such as smoking, dyslipidemia, and hypertension as well as exercise, weight control, and the use of tamoxifen, are employed for the prevention and treatment of cardiovascular complications.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Nonhormonal alternatives for the management of early menopause in younger women with breast cancer. 799 60

The UK National Case-Control Study Group has examined the relationship between smoking (both own smoking and passive), alcohol consumption and caffeine consumption and the risk of breast cancer. A total of 755 women with breast cancer diagnosed before the age of 36, each with an age-matched general population control, were interviewed, and detailed information on reproductive, contraceptive and medical history, personal attributes and habits were obtained. Additional data on passive smoking were obtained from a subgroup of women. There was no evidence of a statistically significant difference in breast cancer risk between subjects who had ever smoked as much as one cigarette per day and those who had not [relative risk (RR) = 1.01, 95% confidence interval (CI) 0.81-1.26]. Most relative risks for passive smoking exceeded unity, but there was little evidence of significant trends with increasing exposure. The lack of effect of own smoking, and the fact that such smokers are also themselves exposed to the effects of passive smoking, makes any relationship between exposure to others' smoking and breast cancer risk implausible. Alcohol consumption during the year prior to diagnosis and at ages 18 and 25 was examined. Consumers of 0.1-4.9 and 5.0-14.9 g per day generally had non-significantly increased risks compared with never drinkers, but consumers of more than 15 g per day had reduced risks.
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PMID:Alcohol, smoking, passive smoking and caffeine in relation to breast cancer risk in young women. UK National Case-Control Study Group. 801 20

The association of caffeine intake and postmenopausal breast cancer incidence was assessed among 34,388 Iowa women aged 55-69 years in 1986 and followed through 1990. Caffeine intake was assessed by a food frequency questionnaire. Median caffeine intake was 212 mg/day in women who developed breast cancer (n = 580) and 201 mg/day in women who remained free of the disease (p = 0.95). There was no apparent association between breast cancer occurrence and quintile of caffeine intake, either adjusted for age or for multiple breast cancer risk factors. The same was true for regular coffee and other caffeine-containing foods.
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PMID:No association between caffeine intake and postmenopausal breast cancer incidence in the Iowa Women's Health Study. 821 43

Although estrogens have been identified as key endocrine hormones in the control of early mitogenesis and development in the mammary gland, local control of cell proliferation during ductal morphogenesis may be regulated by polypeptides such as TGF-alpha or TGF-beta. Many breast tumors are estrogen dependent, and some breast tumor cell lines are known to produce TGF-alpha, suggesting that the mitogenic pathways controlling early normal mammary growth and the growth of some breast tumors may be similar. While progesterone does not appear to be important in the early program of ductal growth, progesterone and estrogen are necessary for the cyclic proliferation of mammary ductal cells that occurs during the menstrual cycle, and for lobuloalveolar growth during pregnancy. Since increased cell division enhances the chances for the formation of a malignant phenotype in the breast, exogenous hormones containing estrogen alone or estrogen and progesterone may increase breast cancer risk. While DES is no longer prescribed to prevent abortions, it demonstrates that high doses of an estrogen during a period of mammary proliferation can affect breast cancer risk. Whether the addition of progestogens to estrogen replacement therapy enhances breast cancer risk in postmenopausal women remains an unanswered question because of the lack of large, well-controlled prospective studies. There currently is no evidence to indicate that the progestogen-containing subdermal contraceptive Norplant increases breast cancer risk. However, it has not been determined if the elevation of serum estrogens reported in some Norplant users affects breast cancer risk. There is little evidence that combined OCAs enhance breast cancer risk in most women. More research is needed to substantiate the findings that OCA use in young women, especially before a first full-term pregnancy, may enhance breast cancer risk. Animal studies indicate that there are critical periods of susceptibility to chemical carcinogens, since the number and malignancy of tumors are increased when carcinogens are administered to young virgin animals during the proliferative period of ductal morphogenesis. Since the breast appears to be most susceptible to the carcinogenic effects of ionizing radiation during the first decade of life, exposure to other carcinogenic agents during the period of early breast development may be important in determining breast cancer risk. Therefore, more studies are needed to confirm the observation that heavy drinkers and heavy smokers are at higher risk for developing breast cancer when they start smoking or drinking at an early age. The observation that serum and urinary estrogen levels increase with alcohol consumption may provide a basis for the higher risk of developing breast cancer in heavy drinkers. While the restriction of methyxanthine intake may alleviate the symptoms associated with fibrocystic breast disease in some women, there is not enough evidence to suggest that a reduction in caffeine intake will reduce breast cancer risk. Evidence for an association between electromagnetic radiation and breast cancer is limited. Electromagnetic radiation may only pose a risk in certain occupations with exposure to very high levels for extended periods of time. It is not known whether exposure to PCBs transplacentally or though the lipid fraction of human milk can affect breast cancer rates in female offspring. The higher risk of breast cancer in women with elevated DDE levels in their blood underscores the importance of determining the extent to which environmental contaminants affect breast cancer risk.
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PMID:Hormonal and environmental factors affecting cell proliferation and neoplasia in the mammary gland. 877 98

Caffeine intake has been associated with risk of osteoporosis, breast cancer, endometriosis, and fibrocystic breast disease and has been hypothesized to exert its effects through alteration of endogenous hormone levels. This study examined the cross-sectional association of caffeine intake with endogenous androgens, estrogens, and sex hormone-binding globulin in 728 white postmenopausal women aged 42-90 years in the Rancho Bernardo community-based study in 1984-1987. Caffeine intake was inversely associated with age and waist/hip ratio and positively associated with alcohol consumption. Significant inverse associations were noted between caffeine intake and bioavailable testosterone, which persisted after adjustment for age, waist/hip ratio, body mass index, alcohol intake, cigarette smoking, and physical activity (r = -0.10, p = 0.02). At high doses (equivalent to more than 2 cups of coffee or four cans of caffeinated soda daily), caffeine intake was positively associated with plasma estrone before and after adjustment for confounders (r = 0.26, p = 0.05). Sex hormone-binding globulin levels were positively associated with increasing caffeine intake (adjusted r = 0.09, p = 0.03). The positive association of caffeine with estrone and its inverse association with bioavailable testosterone suggest that caffeine's reported association with several chronic conditions may be mediated by an effect on endogenous sex steroids.
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PMID:Caffeine intake and endogenous sex steroid levels in postmenopausal women. The Rancho Bernardo Study. 882 59

Green tea is an aqueous infusion of dried unfermented leaves of Camellia sinensis (family Theaceae) from which numerous biological activities have been reported including antimutagenic, antibacterial, hypocholesterolemic, antioxidant, antitumor and cancer preventive activities. From the aqueous-alcoholic extract of green tea leaves, six compounds (+)-gallocatechin (GC), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG) and caffeine, were isolated and purified. Together with (+)-catechin, these compounds were tested against each of four human tumor cells lines (MCF-7 breast carcinoma, HT-29 colon carcinoma, A-427 lung carcinoma and UACC-375 melanoma). The three most potent green tea components against all four tumor cell lines were EGCG, GC and EGC. EGCG was the most potent of the seven green tea components against three out of the four cell lines (i.e. MCF-7 breast cancer, HT-29 colon cancer and UACC-375 melanoma). On the basis of these extensive in vitro studies, it would be of considerable interest to evaluate all three of these components in comparative preclinical in vivo animal tumor model systems before final decisions are made concerning which of these potential chemopreventive drugs should be taken into broad clinical trials.
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PMID:Inhibitory effect of six green tea catechins and caffeine on the growth of four selected human tumor cell lines. 882 14

We examined the association between menstrual cycle characteristics (cycle length, variability, and bleeding length) and physical and behavioral attributes in 766 women age 29-31 years. Menstrual cycle data were prospectively recorded as part of the Menstruation and Reproductive History Study of college women in Minnesota, begun by Alan Treloar in 1934. Data on lifetime height, weight, physical activity, alcohol and caffeine consumption, and smoking history were collected in 1990 using a self-administered questionnaire. Cycle variability, as measured by the standard deviation of the cycle length, was increased, and menstrual cycles > or = 42 days in length were more common among women in the lowest quartile of Quetelet index [odds ratio (OR) for long cycle = 1.6;95% confidence interval (CI) = 0.82-3.0] and among the most physically active (OR = 1.7;95% CI = 0.93-3.1). Long menstrual cycles were less common (OR = 0.40;95% CI = 0.22-0.73) among women who drank alcohol than among nondrinkers. Variable or long menstrual cycles may reflect anovulation and relatively low levels of estrogen exposure. We would expect, based on our data, reduced estrogen exposure among lean women, physically active women, and those who do not consume alcohol. These findings suggest an explanation for the reported associations between these factors and breast cancer risk.
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PMID:Association of physical and behavioral characteristics with menstrual cycle patterns in women age 29-31 years. 889 89

A study of MCF-7 human breast cancer cells was undertaken to ascertain the degree of apoptosis induction by paclitaxel and if the induction of apoptosis could be enhanced by caffeine. Paclitaxel (0-20 ng/ml) caused concentration-dependent increases in morphologically identifiable apoptotic cells (up to 43% of cell population) and cells with DNA strand breaks (up to 38%), a commonly cited marker of apoptosis. Maximal DNA strand breakage occurred after 16 hr of exposure to paclitaxel and maximal apoptotic-appearing cells occurred after 24 hr. The remaining non-apoptotic paclitaxel-exposed cells were growth arrested in G2. A 4-hr exposure to caffeine concentration-dependently (0-20 mM) increased apoptosis to 88% of the cell population. Our results show induction of apoptosis in breast cancer cells by paclitaxel, and enhancement of this process by caffeine.
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PMID:Paclitaxel-induced apoptosis in MCF-7 breast-cancer cells. 900 63

Regression calibration is a statistical method for adjusting point and interval estimates of effect obtained from regression models commonly used in epidemiology for bias due to measurement error in assessing nutrients or other variables. Previous work developed regression calibration for use in estimating odds ratios from logistic regression. We extend this here to estimating incidence rate ratios from Cox proportional hazards models and regression slopes from linear-regression models. Regression calibration is appropriate when a gold standard is available in a validation study and a linear measurement error with constant variance applies or when replicate measurements are available in a reliability study and linear random within-person error can be assumed. In this paper, the method is illustrated by correction of rate ratios describing the relations between the incidence of breast cancer and dietary intakes of vitamin A, alcohol, and total energy in the Nurses' Health Study. An example using linear regression is based on estimation of the relation between ultradistal radius bone density and dietary intakes of caffeine, calcium, and total energy in the Massachusetts Women's Health Study. Software implementing these methods uses SAS macros.
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PMID:Regression calibration method for correcting measurement-error bias in nutritional epidemiology. 909 18

The biological, social and reproductive characteristics of women who have had twins were compared with those of other parous women using questionnaire data gathered for a prospective cohort study of women aged 35 and over on the island of Guernsey. Data for 97 mothers of twins and 4026 other parous women were available for analysis. The two groups were similar in height, first degree family history of breast cancer, use of hormone replacement therapy or other hormones, age at menarche, length of menstrual cycle and age at first and last birth. The mothers of twins were slightly heavier, more likely to smoke and consume more caffeine, less likely to have used oral contraceptives in the past, slightly younger when reaching the menopause and had a larger number of pregnancies. Adjustment for age did not alter these results. This study does not provide evidence that mothers of twins differ markedly from other parous women across a range of characteristics that might be associated with twinning or associated with breast cancer risk.
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PMID:Social, biological and reproductive characteristics of mothers of twins: implications for breast cancer risk. 948 9


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