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

Native Hawaiians experience disproportionate rates of cancer incidence and mortality both nationally and in their homeland, Hawai'i. 'Imi Hale--the Native Hawaiian Cancer Awareness, Research, and Training Project, a five-year project funded by the National Cancer Institute, is aimed at reducing the burden of cancer among Native Hawaiians. The project's overall goal is to reduce cancer incidence and mortality among Native Hawaiians through the establishment of a sustainable infrastructure to 1) promote cancer awareness within Native Hawaiian communities, and 2) initiate cancer research, training, and control activities. A community-based project, 'Imi Hale emphasizes community participation, respect for cultural values, and the sharing of information, as we believe that a commitment to involve Native Hawaiians in all activities of the project will help assure that the community's awareness, training, and research priorities are addressed. In the first year of operation, cancer awareness activities included the development of culturally sensitive booklets on breast cancer and the provision of cancer education and screening for members of the Association of the Hawaiian Civic Clubs. Research and training activities included focus groups to explore the perceptions and experiences of cancer survivors, surveys to assess research priorities, the identification of Native Hawaiian researchers and the development of pilot research projects. The work of 'Imi Hale is guided by the hope that Native Hawaiians can reverse the negative effects of cancer and leave a powerful legacy and inheritance for future generations based on good health and well-being. 'Imi Hale means "to establish, as a dynasty; to acquire authority, power; to seek and establish an inheritance for one's children; and to form a friendship so close that one feels welcome in the house of the other." "By using our language for a name, we are invoking and honoring our ancestors, our culture, language and restoration as a nation."
Pac Health Dialog 2001 Sep
PMID:'Imi Hale: establishing an inheritance for Native Hawaiians on cancer awareness, research and training. 1218 May 28

In the present study, we used [3H]norethisterone to explore the bioconversion of this compound to A-ring reduced metabolites in African Green Monkey Kidney CV-1 cells and breast cancer T-47D cells. Additionally, we analyzed the capability of each norethisterone tetrahydro-reduced compound to bind the human oestrogen receptors alpha and beta and transactivate an oestrogen-sensitive reporter gene. The results showed that norethisterone is mainly metabolized to 3 alpha,5 alpha-norethisterone (>85% of total [3H]norethisterone added) by CV-1 and T-47D cells, and that both A-ring tetrahydro-reduced metabolites exhibit different capabilities to displace [3H]17beta-oestradiol from the oestrogen receptor alpha and beta, being 3 alpha,5 alpha-norethisterone the weakest competitor. We also found that 3 alpha,5 alpha-norethisterone and 3beta,5 alpha-norethisterone activate both oestrogen receptors at nanomolar concentrations and that the transactivation induced by the oestrogen receptor alpha was generally higher (1.7- to 4.0-fold) than that provoked by the beta receptor isoform. In oestrogen receptor alpha-transfected CV-1 and T-47 D cells, the oestrogenic-like potency of the 3beta,5 alpha-tetrahydro-reduced form was similar to that exhibited by 17beta-oestradiol and 2.5- to 4.0-fold higher than that shown by the 3 alpha,5 alpha-reduced compound; conversely, in the oestrogen receptor beta system the potency of the natural ligand was higher than that presented by the 3beta,5 alpha-tetrahydro-reduced metabolite. In CV-1 cells expressing the oestrogen receptor beta, the transactivation potency of 3beta,5 alpha-norethisterone was approximately 2-fold higher than that exhibited by its 3 alpha,5 alpha-tetrahydro-reduced isomer, whereas in T-47D cells the potency of the 3 alpha,5 alpha-tetrahydro-reduced compound was slightly higher than that shown by the 3beta,5 alpha A-ring reduced norethisterone metabolite. These results demonstrate that CV-1 and T-47D cells possess the enzymatic machinery to bioconvert norethisterone into the 5 alpha-reduced, 3 alpha-hydroxylated form and that neither 3 alpha,5 alpha- or 3beta,5 alpha-norethisterone exhibit preference or selectivity towards a particular oestrogen receptor isoform to induce a particular oestrogenic effect in these cell lines.
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PMID:Norethisterone is bioconverted to oestrogenic compounds that activate both the oestrogen receptor alpha and oestrogen receptor beta in vitro. 1235 76

Tocotrienols are a subclass of vitamin E compounds that display potent anticancer activity. Determining the anticancer mechanism of action of tocotrienols will provide essential information necessary for understanding the potential health benefits of these compounds in reducing the risk of breast cancer in women. Epidermal growth factor (EGF) is a potent mitogen for normal and neoplastic mammary epithelial cells. Initial events in EGF-receptor (EGF-R) mitogenic-signalling are G-protein activation, stimulation of adenylyl cyclase and cyclic AMP (cAMP) production. Studies were conducted to determine if the antiproliferative effects of tocotrienols are associated with reduced EGF-induced G-protein and cAMP-dependent mitogenic signalling. Preneoplastic CL-S1 mouse mammary epithelial cells were grown in culture and maintained on serum-free media containing 0-25 micro mol/L tocotrienol-rich fraction of palm oil and/or different doses of pharmacological agents that alter intracellular cAMP levels. Tocotrienol-induced effects on EGF-receptor levels of tyrosine kinase activity, as well as EGF-dependent mitogen-activated pathway kinase (MAPK) and Akt activation, were determined by western blot analysis. Results demonstrate that the antiproliferative effects of tocotrienols in preneoplastic mammary epithelial cells do not reflect a reduction in EGF-receptor mitogenic responsiveness, but rather, result from an inhibition in early post-receptor events involved in cAMP production upstream from EGF-dependent MAPK and phosphoinositide 3-kinase/Akt mitogenic signalling. In summary, these data further characterise the mechanism of action of tocotrienols in suppressing preneoplastic mammary epithelial cell proliferation, and advance the current understanding of the potential health benefits of these compounds in reducing the risk of breast cancer in women.
Asia Pac J Clin Nutr 2002
PMID:Role of GTP-binding proteins in reversing the antiproliferative effects of tocotrienols in preneoplastic mammary epithelial cells. 1249 34

Epidemiological and animal studies have indicated that 17beta-estradiol (E2) is involved in breast cancer; however, the mechanism is unclear. We found that E2 could be activated by epoxidation, resulting in its ability to inhibit nuclear DNA-dependent RNA synthesis, and to bind DNA, forming DNA adducts both in vitro and in vivo. Because epoxidation is required for the activation of many chemical carcinogens, including benzo(a)pyrene, 7,12-dimethylbenz(a)anthracene and aflatoxins, we proposed previously that E2 epoxidation is the underlying mechanism for the initiation of breast cancer. The first part of this review is to present the experimental evidence obtained from this laboratory in support of this hypothesis. Based on these newly discovered insights on E2 epoxidation and its initiation role in breast cancer carcinogenesis, a method to screen chemopreventive agents against breast cancer has been developed. This constitutes the second part of the review. Two examples will be used to illustrate the utility of this screening technique. The effect of fat on breast cancer has been a longstanding but unresolved issue. Epidemiological studies provide conflicting results regarding the association of dietary fat and breast cancer. Because vegetable oils contain various amount of mono- and polyunsaturated fatty acids, they are potential antioxidants. Data are presented to show that commercial vegetable oils, independent of their mono- or polyunsaturated fatty acid content, are all able to prevent the formation of E2 epoxide, as measured by the loss of the ability of E2 to inhibit nuclear RNA synthesis in vitro. Tamoxifen (TAM), an anti-estrogen used for breast cancer treatment, has recently been found to have a strong breast cancer preventive effect. The mechanism for this is unknown. Using the same screening technique, we found that when incubated together with E2 for epoxidation, TAM was able to prevent the formation of E2 epoxide, as evidenced by both the loss of the ability of E2 to inhibit nuclear RNA synthesis and the reduced binding of [3H]-labelled E2 to nuclear DNA in a dose-dependent manner. These experimental results suggest that the breast cancer preventive effect of TAM is to prevent the formation of E2 epoxide through a competitive epoxidation mechanism with E2.
Asia Pac J Clin Nutr 2002
PMID:17Beta-estradiol epoxidation as the molecular basis for breast cancer initiation and prevention. 1249 35

In Australia, colorectal, prostate and breast cancers are the most frequently occurring cancers in our society, a pattern that is quite different from that of underdeveloped countries. While diet is largely responsible for these differences, technological advances mean that the solutions can be viewed as systematic, financial, lifestyle or technological. They range from those that require self-discipline and care for personal well-being through to those that are seemingly a quick technological fix that will work in spite of an unhealthy lifestyle. There are three main approaches available for prevention of these cancers: dietary lifestyle, chemoprevention and screening. It has been estimated that the potential for prevention by a healthy dietary lifestyle is excellent and might reduce the burden of breast, prostate and colorectal cancer by 33-55%, 10-20% and 66-75%, respectively. This should be safe and inexpensive and have collateral benefit such as reduced cardiovascular disease and osteoporosis. But, population compliance with more plant-based, less calorie dense foods is uncertain, the most healthy are likely to be the most compliant and evidence for effectiveness when interventional programs are undertaken is disappointing. It is not clear how dependable the dietary approach would be where inherited genetic factors determine risk for one of these cancers. Chemoprevention, the administration of natural or synthetic agents that delay, slow down or inhibit the process of tumorigenesis, are still under development and study. Hormone receptor modulators for breast and derivatives of non-steroidal anti-inflammatory drugs for colorectal cancers seem to have most promise and may reduce tumour incidence or death by as much as 50%. These agents are simpler to comply with than changing dietary lifestyle and they are more potent, hence they may be of particular value in high-risk settings. But they are likely to be more costly and run the risk of adverse effects with few collateral benefits. Screening, or the testing of an individual for a disease when that individual does not have any symptoms or signs suggesting that the disease is present, aims to prevent or delay the development of the cancer. Screening impacts on mortality more so than on incidence, reducing colorectal cancer mortality in the range 15-60% and breast cancer mortality by 23-37%. Screening has the advantage of being effective in high-risk as well as average-risk groups and is an 'easy' solution for the person who elects not to follow a healthy dietary lifestyle. Nonetheless, it is expensive, demanding on resources, provides no collateral benefits and does not have the same potential to reduce incidence of disease as does the dietary approach. With these Western cancers, we are fortunate that there are options for prevention. At least choices are available and some will suite certain circumstances and personalities more than others.
Asia Pac J Clin Nutr 2002
PMID:Preventing cancer: dietary lifestyle or clinical intervention? 1249 55

The degradation of extracellular matrix during cancer invasion results from the action of several protease and protease inhibitor systems. Alpha(1)-Antitrypsin (AAT) is a serine proteinase inhibitor produced by various tumour cells, and its plasma concentration rises during inflammation, infection and malignant diseases. AAT is found in a native, inhibitory active form, but also in other, non-inhibitory forms including cleaved and/or degraded. To test a hypothesis that AAT dependent on its molecular form may have multiple effects on tumour cell behaviour, breast cancer cells, MDA-MB 468, were cultured alone or stimulated with a native AAT or its C-terminal fragment (C-36) at a concentration of 5 micromol/l for 2, 24 and 48 hours. Native AAT added to the cells for 2 hours enhanced transforming growth factor beta 1 (TGFbeta1) levels by 50%, but inhibited cell proliferation (by 61%), reduced interleukin 6 (IL-6) levels (by 87%) and activity (by about 66%), compared with non-stimulated cells. Native AAT showed similar, but less pronounced, effects when added to the cells for 24 and 48 hours. Under the same experimental conditions the cells exposed to the C-36 peptide significantly increased in proliferation, invasiveness and showed higher IL-6 levels. In addition, cells treated with the C-36 for 48 hours increased in NFkappaB (nuclear factor kappa B) activity. These results indicate that AAT, dependent on its molecular form, can both suppress and induce breast tumour cell biological activity in vitro.
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PMID:Multiple effects of alpha1-antitrypsin on breast carcinoma MDA-MB 468 cell growth and invasiveness. 1267 35

One of the objectives of a cancer registry is to provide survival information on subsections of the population that have unfavorable outcomes. A cancer control strategy can be planned on the basis of such information. In the present study, the data of the Songkhla Cancer Registry were analyzed to determine if social and geographic parameters can be used to predict cancer survival. A total of 3423 cases identified in the population-based cancer registry of Songkhla Province registered during 1990-1994, were the subjects of this study. The rest were excluded because of unknown primary cancer sites. Eight leading primary cancer sites were focused on: oral cavity, pharynx, esophagus, colorectum, lung, liver, breast, and cervix uteri. Predictors of survival were derived from items recorded in the registry. Age, gender, extent of disease, cultural belief, life-style, and access to medical care were the predictors of interest. Religion, urban environment, and distance to tertiary care centers were proxies for the last three parameters. Kaplan-Meier plots, Cox regression, and log-rank tests were used for analysis of the hazard ratios. The results revealed a significance of disease extent for survival from oral, colorectal, breast, and cervical cancers. Muslim people had poorer survival rates than those of Buddhists for oral, breast, and cervical cancers. Women with breast cancer living in distant from tertiary medical care centers had a poorer prognosis. For the non-aggressive cancers, early detection and pretreatment counseling for the prevention of unnecessary incomplete treatment is recommended for prolonged survival. With aggressive cancers such as lung, liver, and pharyngeal cancers, there were no significant differences with these parameters investigated. Good quality of life provided by palliative care, not prolongation of survival, is the ultimate goal of medical care services to such patients.
Asian Pac J Cancer Prev 2000
PMID:Social and Geographic Predictors of Cancer Survival: a Role for a Population-based Cancer Registry in Cancer Control. 1271 7

Breast cancer is among the commonest malignant diseases in women. Over the past two decades tamoxifen has been generally accepted as an endocrine therapy of choice for prevention of breast cancer recurrence. Although tamoxifen was thought to have only a few adverse effects, several reports indicate that it is associated with an increase incidence of proliferative and neoplastic changes in the endometrium, with a 1.3 to 7.5 relative risk of developing endometrial carcinoma. The increased risk of endometrial cancer following the use of tamoxifen has stimulated studies on endometrial diagnostic screening methods. During the past ten years several reports have shown the benefits of transvaginal ultrasonography in detecting endometrial pathologies in patients receiving tamoxifen. Sonohysterography has been claimed to be a useful diagnostic tool on differentiating space-occupying lesion, eg. endometrial polyp, from abnormal endometrial-myometrial junction while the contribution of pulsed flow velocity in diagnosis of endometrial pathologies seems to be inconclusive. More recently a few factors have been identified as risk of developing endometrial cancer after tamoxifen use. These include pre-existing endometrial pathologies, obesity, and prior ERT use. This information provides us a more sensible way in following breast cancer patients receiving tamoxifen. It is proposed here that postmenopausal breast cancer patients intend to have tamoxifen treatment should receive a "two - step evaluation". The pretreatment evaluation is aimed to classify patients at risk of later development of endometrial pathologies after being exposed to tamoxifen while the ongoing evaluation is designed to closely follow the patents after the initiation of tamoxifen in hope that this will provide a tool for early diagnosis or hopefully a protective measure against endometrial carcinoma associated with tamoxifen therapy.
Asian Pac J Cancer Prev 2002
PMID:Prevention of Endometrial Cancer in Breast Cancer Patients Taking Tamoxifen : The Gynecologists' Role. 1271 83

To take effective measures for prevention and achieve the goal of reducing the incidence and mortality rate from breast cancer, the method of descriptive epidemiology was used to study the situation regarding female breast cancer in Tianjin. There is an increasing trend for the incidence rate (increasing 51% during the period from 1981 to 1997), though the absolute value is still low in comparison with the developed countries in the world. Furthermore, the mortality rate of breast cancer has been decreasing constantly (decreasing 38% during the same period), while the 5-year, 10-year and 15-year survival rate increased. This may be mostly attributable to work leading to early detection and early diagnosis of breast cancer.
Asian Pac J Cancer Prev 2002
PMID:Analysis of Female Breast Cancer Descriptive Epidemiology in Tianjin, China. 1271 93

Epidemiological studies of cancer of the ovaries, among the leading sites for cancer incidence and mortality in women in very many countries of the world, have pointed to high saturated fat and carbohydrate intake, postmenopausal hormone replacement therapy and use of cosmetic talc as risk factors. Conversely, vegetable consumption, parity, lactation and generally appear to confer protection. Genetic influence also clearly plays a role, women with mutations in the BRCA1 or BRCA2 genes having an elevated risk, for example. Overall there appear to be shared risk factors for breast cancer. However, there are many types of epithelial ovarian cancer and cross-country comparisons of incidence data from various cancer registries in Europe and North America published in the IARC Cancer Incidence in Five Continents Vol VII suggest that only the serous type is linked to mammary tumour development. Thus future studies should concentrate more attention on the individual subtypes of ovarian cancer in order to better establish preventive measures.
Asian Pac J Cancer Prev 2002
PMID:Risk Factors for Ovarian Cancers: Do Subtypes Require Separate Treatment in Epidemiological Studies? 1271 2


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