Estrogen-regulated non-reproductive behaviors and breast cancer risk: animal models and human studies

Personality risk factors of occurrence of female breast cancer: a case-control study in China

To investigate the association of personality traits with breast cancer risk, a case-control study was conducted from May 2014 to February 2017, in which the case group consisted of 262 women with breast cancer and 262 without (control group). The Eysenck Personality Questionnaire (EPQ) (88-question Adult Edition) and another self-assessment questionnaire that contained open questions to obtain more specific character traits were used to complete this survey. The results of the E scale showed that 121 women (46.18%) in the case group and 94 women (35.88%) in the control group were extroverted. The results of the N scale showed that 150 women (57.25%) in the case group and 86 women (32.82%) in the control group had unstable personality. Adjusting for other confounding factors, extroversion and unstable personality were risk factors for breast cancer (E scale: OR = 1.70, 95% CI = 1.28-2.15; N scale: OR = 3.18, 95% CI = 1.77-4.91). Personality instability was a higher risk factor than extroversion was. People with unstable personalities were 3.18 times more likely to have breast cancer than were those who had stable personalities. The results of the self-assessment questionnaire suggested that the more frequent character traits mentioned were being concerned over everything, irritable, and perfectionistic, seeking to prevail over others, and being manipulative and oversensitive.

Cancer in working-age is not associated with childhood adversities

BACKGROUND

Early life events are studied as potential causes of cancer. The objective here was to study childhood adversities in the etiology of cancer.

METHODS

The material comprised a population based random sample of 25 898 individuals among the Finnish working-aged population. In 1998 they were requested through six questions in a postal questionnaire to recall their childhood adversities. The cases consisted of people with cancer diagnosed 2000-2006 and registered in the Finnish Cancer Registry (n = 384). The rest of the sample consisted of cancer-free controls.

RESULTS

The most common adversities were prolonged financial difficulties, serious conflicts in the family and someone in the family having been seriously or chronically ill. The cancer patients reported more prolonged financial difficulties and someone seriously or chronically ill in the family. They reported less parental divorce than the controls. The associations were not statistically significant after adjusting for age, sex, education, and health behaviour. Nor was there a significant difference in the total number of childhood adversities between the study group and the controls.

CONCLUSION

On the whole, these cancer patients had not experienced more childhood adversities than the controls. According to our findings, there is no cause to attribute development of cancer in working age to childhood adversities. This information may also give relief to other family members.

Identification of risk factors for breast cancer for women in istanbul

BACKGROUND

Breast cancer is the most common cancer type seen in women, accounts for 18% of all cancer types in women and the risk of a woman to get breast cancer during her life is 11%. These notified rates enable breast cancer to be defined as a preventable and if pre-diagnosed, a treatable cancer type, despite it was regarded as a terrifying type of cancer in the past.

OBJECTIVE

The aim of the study was to determine the lifestyle pattern of women without breast cancer in Istanbul.

METHOD

The study was carried out as a descriptive and cross-sectional study with 1000 women.

RESULTS

The majority of the women (29.7%) were in the 35-44 year old age group. Out of these 93.1% gave birth before the age of 30, 29.5% breastfed for 7-12 months, 65.8% started menarche between 13-15 years of age (mean of 13.3 years), 15.5% were in menopause and had entered menopause at a mean age of 46.5 years. Their mean body mass index was 24.3kg/m(2) and 24.5% of them preferred foods containing high fat content. The majority of the women (85.4%) did not participate in sports regularly. One third (30.3%) of the women had underwent Breast Self Examination. There was a positive family history of breast cancer for 12.1% of the women.

CONCLUSION

Sedentary lifestyles, lower Breast Self Examination and routine mammography rates and family histories of breast cancer were the risk factors that needed to be given priority for further action.

Estrogen and its metabolites are carcinogenic agents in human breast epithelial cells

Estrogens play a crucial role in the development and evolution of human breast cancer. However, it is still unclear whether estrogens are carcinogenic to the human breast. There are three mechanisms that have been considered to be responsible for the carcinogenicity of estrogens: receptor-mediated hormonal activity, a cytochrome P450 (CYP)-mediated metabolic activation, which elicits direct genotoxic effects by increasing mutation rates, and the induction of aneuploidy by estrogen. To fully demonstrate that estrogens are carcinogenic in the human breast through one or more of the mechanisms explained above it will require an experimental system in which, estrogens by itself or one of the metabolites would induce transformation phenotypes indicative of neoplasia in HBEC in vitro and also induce genomic alterations similar to those observed in spontaneous malignancies. In order to mimic the intermittent exposure of HBEC to endogenous estrogens, MCF-10F cells that are ERalpha negative and ERbeta positive were first treated with 0, 0.007, 70 nM and 1 microM of 17beta-estradiol (E(2)), diethylstilbestrol (DES), benz(a)pyrene (BP), progesterone (P), 2-OH-E(2), 4-hydoxy estradiol (4-OH-E(2)) and 16-alpha-OH-E(2) at 72 h and 120 h post-plating. Treatment of HBEC with physiological doses of E(2), 2-OH-E(2), 4-OH-E(2) induce anchorage independent growth, colony formation in agar methocel, and reduced ductulogenic capacity in collagen gel, all phenotypes whose expression are indicative of neoplastic transformation, and that are induced by BP under the same culture conditions. The presence of ERbeta is the pathway used by E(2) to induce colony formation in agar methocel and loss of ductulogenic in collagen gel. This is supported by the fact that either tamoxifen or the pure antiestrogen ICI-182,780 (ICI) abrogated these phenotypes. However, the invasion phenotype, an important marker of tumorigenesis is not modified when the cells are treated in presence of tamoxifen or ICI, suggesting that other pathways may be involved. Although we cannot rule out the possibility, that 4-OH-E(2) may interact with other receptors still not identified, with the data presently available the direct effect of 4-OH-E(2) support the concept that metabolic activation of estrogens mediated by various cytochrome P450 complexes, generating through this pathway reactive intermediates that elicit direct genotoxic effects leading to transformation. This assumption was confirmed when we found that all the transformation phenotypes induced by 4-OH-E(2) were not abrogated when this compound was used in presence of the pure antiestrogen ICI. The novelty of these observations lies in the role of ERbeta in transformation and that this pathway can successfully bypassed by the estrogen metabolite 4-OH-E(2). Genomic DNA was analyzed for the detection of micro-satellite DNA polymorphism using 64 markers covering chromosomes (chr) 3, 11, 13 and 17. We have detected loss of heterozygosity (LOH) in ch13q12.2-12.3 (D13S893) and in ch17q21.1 (D17S800) in E(2), 2-OH-E(2), 4-OH-E(2), E(2) + ICI, E(2) + tamoxifen and BP-treated cells. LOH in ch17q21.1-21.2 (D17S806) was also observed in E(2), 4-OH-E(2), E(2)+ICI, E(2)+tamoxifen and BP-treated cells. MCF-10F cells treated with P or P+E(2) did not show LOH in the any of the markers studied. LOH was strongly associated with the invasion phenotype. Altogether our data indicate that E(2) and its metabolites induce in HBEC LOH in loci of chromosomes 13 and 17, that has been reported in primary breast cancer, that the changes are similar to those induced by the chemical carcinogen (BP) and that the genomic changes were not abrogated by antiestrogens.

Stress, coping, and immune function in breast cancer

Research has found suggestive links between emotional distress and immune and neuroendocrine measures in cancer patients. Furthermore, several studies have reported that participation in psychological support groups is associated with better health outcomes for cancer patients. However, controversy exists surrounding these findings, and the mechanisms behind such effects are unclear. This article integrates current evidence from several lines of research concerning the relations among coping, psychological adjustment, cortisol and immune function, and disease progression in breast cancer patients. A biopsychosocial model is evaluated in which coping and psychological adjustment are associated with alterations in cortisol levels, immune function, and potential long-term medical outcomes in breast cancer patients. Although strong evidence suggests that coping and psychosocial intervention can improve psychological outcomes for breast cancer patients, potential effects on physiological outcomes remain speculative.

Personality characteristics and the risk of breast cancer: a prospective cohort study

Various personality characteristics have been suggested to increase the risk of breast cancer but reliable epidemiologic data on this issue are limited. We prospectively investigated the relationship between personality characteristics and the risk of breast cancer in 12,499 Finnish women aged 18 years or more. In health questionnaires in 1975 and 1981, these women completed at least one of the following personality scales: Eysenck extroversion, Bortner type A behaviour and author-constructed measure of hostility. They also reported about other potential breast cancer risk factors. From 1976-1996, 253 cases of breast cancer were identified by record linkage with the Finnish Cancer Registry. Proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). The multivariable HRs of breast cancer for women with intermediate level (scores 3-6) and high level (7-9) of extroversion in 1975 were 1.18 (95% CI 0.87-1.60) and 0.97 (95% CI 0.64-1.47), respectively, compared to those with low level (0-2). These results remained unaltered when the level of extroversion was determined as the average of the 1975 and 1981 reports. There was also no increase in breast cancer risk in relation to type A behaviour and hostility. Furthermore, we observed no substantial joint effects of personality characteristics on the risk of breast cancer. In conclusion, our data do not support the existence of an important role for personality in the aetiology of breast cancer. These findings are reassuring to those who have believed the contrary.

Stress of daily activities and risk of breast cancer: a prospective cohort study in Finland

The belief that life stress enhances breast cancer is common, but there are few prospective epidemiological studies on the relationship of life stress and breast cancer. We have investigated the association between stress of daily activities (SDA) and breast-cancer risk in a prospective cohort study of 10,519 Finnish women aged 18 years or more. SDA measures a subject's own appraisal of daily stress. It was assessed in 1975 and 1981 by a self-administered questionnaire, which also provided information on subject characteristics and other known breast-cancer risk factors. Follow-up data for breast cancer from 1976 to 1996 were attained through record linkage to the Finnish Cancer Registry. Study subjects were divided into 3 groups based on their SDA scores in 1975: no stress (23% of subjects), some stress (68%) and severe stress (9%). Hazard ratios (HRs) and respective 95% confidence intervals (CIs) for incidence of breast cancer by level of SDA were obtained from the Cox proportional hazards model. We identified 205 incident breast cancers in the cohort. Multivariable-adjusted HRs for breast-cancer risk were 1.00 (reference), 1.11 (95% CI 0.78-1.57) and 0.96 (95% CI 0.53-1.73) by increasing level of stress. Neither shifting of the SDA cut-off points nor restricting the analysis to women who reported the same level of SDA in 1975 and 1981 materially altered the results. We found no evidence of an association between self-perceived daily stress and breast-cancer risk.

Use of ERE and reporter gene constructs to assess putative estrogenic activity

Estrogens primarily function through the activation of their receptors, which subsequently function as nuclear transcription factors. There are two estrogen receptor (ER) genes, now designated ERa (the classic ER gene) and ER/3. The key consequence of the activation of either gene product is the regulation of gene transcription. The extent and nature of transcription appear to be regulated by a series of coregulator proteins. One of the most sensitive assays for detection of potential estrogenic activity is measurement of the ability of a test compound to influence the transcription of reporter genes. In this regard, many investigators use promoter-reporter constructs. To assess putative estrogenic activity, an estrogen-responsive promoter is generally placed upstream of a reporter gene and transiently transfected into a target cell. When exposed to an estrogenic compound, expression of the reporter gene would normally be induced. We briefly discuss several issues pertinent to the use of these assays and the interpretation of resulting data, including estrogen-responsive, promoter-reporter constructs, reporter genes and measurements of activity, choice of target cell or cell line, transient introduction of promoter-reporter constructs into cells, basic statistical approaches to data analysis, and definitions of agonist, partial agonist, and antagonist.

Animal models of breast cancer: experimental design and their use in nutrition and psychosocial research

This is the second Special Issue addressing the diversity and use of animal models of breast cancer. The previous issue (Breast Cancer Res Treat 39:1-135, 1996), dealt with a variety of topics such as the characteristics of chemically- and virally-induced rodent models, immunobiologies of immunedeficient mice, transgenic mouse models, and models of metastasis. In the first part of this second Special Issue, the articles address animal models for studying life-style factors, including psychosocial, exercise, and nutritional research in breast cancer. In the second section, there is emphasis on the controversial area of dietary fat, with other authors addressing caloric restriction and dietary isoflavonoids, retinoids, and monoterpenes in the third part. In the final section, a series of authors provide suggestions for approaching various issues involving experimental design, including nutritional studies, drug screening models, statistical considerations, quantitation of tumor growth kinetics, and animal husbandry. These articles, and some additional issues raised during the previous Special Issue, are briefly discussed in this overview. They include a further evaluation of the relative merits of 7,12-dimethylbenz(a)anthracene and N-nitroso-N-methylurea as carcinogens, and of the use of the AIN76 and AIN93 semipurified diets in studies of mammary carcinogenesis.