Hormonal content and potency of oral contraceptives and breast cancer risk among young women

A small study of women with early-onset breast cancer published in 1983 initially sparked the debate about combination oral contraceptives and breast cancer by suggesting that a woman's risk of breast cancer increased if she used oral contraceptives early in life, particularly pills with high progestin potency (Pike et al, 1983). Evidence from a multitude of case–control and cohort studies conducted in the 1980s and early 1990s subsequently found a modest (approximately 20–40%) but consistent excess in breast cancer risk associated with recent oral contraceptive use among women younger than 45 years of age (Collaborative Group on Hormonal Factors in Breast Cancer, 1996a). Whether this excess risk is ubiquitous for all pill types or attributable to specific oral contraceptive preparations is considerably less well studied

Reproductive factors and specific histological types of breast cancer: prospective study and meta-analysis

Little is known about how reproductive factors affect the risk of breast cancers of different histology. In an analysis of prospective data on 1.2 million middle-aged UK women, we used proportional hazards models to estimate the relative risks of six histological types in relation to menarche, childbearing and menopause. During 8.7 million person-years of follow-up, 17 923 ductal, 3332 lobular, 1062 tubular, 944 mixed ductal lobular, 330 mucinous and 117 medullary cancers were diagnosed. The effect of both age at menarche and age at first birth was greatest for lobular tumours; relative risks per 5-year increase in age at menarche for ductal, lobular, and tubular cancers were 0.93 (0.87–0.99), 0.65 (0.56–0.76), and 0.75 (0.57–0.98), respectively (P-value for heterogeneity=0.0001); and the relative risks per 5-year increase in age at first birth were 1.10 (1.07–1.12), 1.23 (1.17–1.29), and 1.13 (1.03–1.23), respectively (P-value for heterogeneity=0.0006). Increasing parity reduced the risk of each tumour type, except medullary cancers, but the reduction in risk was greater for mucinous cancers than for any other subtype considered (P<0.05 for comparison with each other subtype in turn). The effect of menopause did not vary significantly by tumour histology. Meta-analysis of published results on the effects of age at menarche and age at first birth on ductal and lobular cancers were in keeping with our findings

Selective estrogen receptor modulators inhibit growth and progression of premalignant lesions in a mouse model of ductal carcinoma in situ

INTRODUCTION: Ductal carcinoma in situ (DCIS) is a noninvasive premalignant lesion and is considered a precursor to invasive carcinoma. DCIS accounts for nearly 20% of newly diagnosed breast cancer, but the lack of experimentally amenable in vivo DCIS models hinders the development of treatment strategies. Here, we demonstrate the utility of a mouse transplantation model of DCIS for chemoprevention studies using selective estrogen receptor modulators (SERMs). This model consists of a set of serially transplanted lines of genetically engineered mouse mammary intraepithelial neoplasia (MIN) outgrowth (MIN-O) tissue that have stable characteristics. We studied the ovarian-hormone-responsiveness of one of the lines with a particular focus on the effects of two related SERMs, tamoxifen and ospemifene. METHODS: The estrogen receptor (ER) status and ovarian-hormone-dependence of the mouse MIN outgrowth tissue were determined by immunohistochemistry and ovarian ablation. The effects of tamoxifen and ospemifene on the growth and tumorigenesis of MIN outgrowth were assessed at 3 and 10 weeks after transplantation. The effects on ER status, cell proliferation, and apoptosis were studied with immunohistochemistry. RESULTS: The MIN-O was ER-positive and ovarian ablation resulted in reduced MIN-O growth and tumor development. Likewise, tamoxifen and ospemifene treatments decreased the MIN growth and tumor incidence in comparison with the control (P < 0.01). Both SERMs significantly decreased cell proliferation. Between the two SERM treatment groups, there were no statistically significant differences in MIN-O size, tumor latency, or proliferation rate. In contrast, the ospemifene treatment significantly increased ER levels while tamoxifen significantly decreased them. CONCLUSION: Tamoxifen and ospemifene inhibit the growth of premalignant mammary lesions and the progression to invasive carcinoma in a transplantable mouse model of DCIS. The inhibitory effects of these two SERMs are similar except for their effects on ER modulation. These differences in ER modulation may suggest different mechanisms of action between the two related SERMs and may portend different long-term outcomes. These data demonstrate the value of this model system for preclinical testing of antiestrogen or other therapies designed to prevent or delay the malignant transformation of premalignant mammary lesions in chemoprevention

Impact of interventions to reduce sugar-sweetened beverage intake in children and adults: a protocol for a systematic review and meta-analysis

Background: Sugar-sweetened beverages (SSBs) have been stressed as relevant targets of public health interventions considering the negative outcomes derived from their excessive intake. Though the evidence from published literature grows to support a cause-and-effect association of SSBs with obesity and other diseases, little is known on the effectiveness that strategies alone or as part of multi-component programmes have had to influence this particular dietary behaviour across all ages. Therefore, this review and meta-analysis aim to evaluate the effect that interventions have had to decrease their consumption or increase water intake in children and adults so as to guide the design of future programmes and inform policy making. Methods: Included studies in this review will be randomised controlled trials and quasi-experimental interventions (with a control group) that have reported baseline and post-intervention intakes of SSBs or water and that have been published from 1990 in any language. A thorough search will be performed in MEDLINE, EMBASE, Scopus, Web of Science, Cochrane's central register of controlled trials, and the Global Health Library. Two independent reviewers will conduct initial screening of potentially included articles and will later extract data to analyse domains of intervention design and delivery (with emphasis on behaviour change techniques used as rationale), as well as results in changes on consumption patterns and behavioural determinants. Internal and external validity of each study will also be appraised. A meta-analysis will be performed if a sufficient number of studies are available, and if not, a narrative review will be conducted instead. Discussion: The results from this review aim to strengthen public health initiatives tackling obesity through improvements in non-alcoholic drinking patterns. As a subject of growing attention globally, this review will help determine which strategies available are the most effective in different contexts. Knowledge gained from this work will also aid resource allocation in future research and government agendas

The Neurotensin Receptor-1 Pathway Contributes to Human Ductal Breast Cancer Progression

BACKGROUND: The neurotensin (NTS) and its specific high affinity G protein coupled receptor, the NT1 receptor (NTSR1), are considered to be a good candidate for one of the factors implicated in neoplastic progression. In breast cancer cells, functionally expressed NT1 receptor coordinates a series of transforming functions including cellular migration and invasion. METHODS AND RESULTS: we investigated the expression of NTS and NTSR1 in normal human breast tissue and in invasive ductal breast carcinomas (IDCs) by immunohistochemistry and RT-PCR. NTS is expressed and up-regulated by estrogen in normal epithelial breast cells. NTS is also found expressed in the ductal and invasive components of IDCs. The high expression of NTSR1 is associated with the SBR grade, the size of the tumor, and the number of metastatic lymph nodes. Furthermore, the NTSR1 high expression is an independent factor of prognosis associated with the death of patients. CONCLUSION: these data support the activation of neurotensinergic deleterious pathways in breast cancer progression

Reassessing the Evidence Hierarchy in Asthma: Evaluating Comparative Effectiveness

Classical randomized controlled trials are the gold standard in medical evidence because of their high internal validity. However, their necessarily strict design can limit their external validity and the ability to extrapolate these data to real world patients. Therefore, alternatively designed studies may play a complementary role in evaluating the comparative effectiveness of therapies in nonidealized patients in more naturalistic, real world settings. Observational studies have high external validity and can evaluate real world outcomes. Their strength lies in hypothesis generation and testing and in identifying areas in which further clinical trials may be required. Pragmatic trials are designed to maximize applicability of trial results to usual care settings by relying on clinically important outcomes and enrolling a wide range of participants. A combination of these approaches is preferable and necessary

Dietary patterns and risk of breast cancer

Background: Evidence is emerging that prudent/healthy dietary patterns might be associated with a reduced risk of breast cancer. Methods: Using data from the prospective Melbourne Collaborative Cohort Study, we applied principal factor analysis to 124 foods and beverages to identify dietary patterns and estimated their association with breast cancer risk overall and by tumour characteristics using Cox regression. Results: During an average of 14.1 years of follow-up of 20 967 women participants, 815 invasive breast cancers were diagnosed. Among the four dietary factors that we identified, only that characterised by high consumption of fruit and salad was associated with a reduced risk, with stronger associations observed for tumours not expressing oestrogen (ER) and progesterone receptors (PR). Compared with women in the lowest quintile of the factor score, the hazard ratio for women in the highest quintile was 0.92 (95% confidence interval (CI)=0.70-1.21; test for trend, P=0.5) for ER-positive or PR-positive tumours and 0.48 (95% CI=0.26-0.86; test for trend, P=0.002) for ER-negative and PR-negative tumours (test for homogeneity, P=0.01). Conclusion: Our study provides additional support for the hypothesis that a dietary pattern rich in fruit and salad might protect against invasive breast cancer and that the effect might be stronger for ER- and PR-negative tumours. © 2011 Cancer Research UK All rights reserved

Cross-species comparison of aCGH data from mouse and human BRCA1- and BRCA2-mutated breast cancers

Background: Genomic gains and losses are a result of genomic instability in many types of cancers. BRCA1- and BRCA2-mutated breast cancers are associated with increased amounts of chromosomal aberrations, presumably due their functions in genome repair. Some of these genomic aberrations may harbor genes whose absence or overexpression may give rise to cellular growth advantage. So far, it has not been easy to identify the driver genes underlying gains and losses. A powerful approach to identify these driver genes could be a cross-species comparison of array comparative genomic hybridization (aCGH) data from cognate mouse and human tumors. Orthologous regions of mouse and human tumors that are commonly gained or lost might represent essential genomic regions selected for gain or loss during tumor development. Methods: To identify genomic regions that are associated with BRCA1- and BRCA2-mutated breast cancers we compared aCGH data from 130 mouse Brca1?/?;p53?/?, Brca2?/?;p53?/? and p53?/? mammary tumor groups with 103 human BRCA1-mutated, BRCA2-mutated and non-hereditary breast cancers. Results: Our genome-wide cross-species analysis yielded a complete collection of loci and genes that are commonly gained or lost in mouse and human breast cancer. Principal common CNAs were the well known MYCassociated gain and RB1/INTS6-associated loss that occurred in all mouse and human tumor groups, and the AURKA-associated gain occurred in BRCA2-related tumors from both species. However, there were also important differences between tumor profiles of both species, such as the prominent gain on chromosome 10 in mouse Brca2?/?;p53?/? tumors and the PIK3CA associated 3q gain in human BRCA1-mutated tumors, which occurred in tumors from one species but not in tumors from the other species. This disparity in recurrent aberrations in mouse and human tumors might be due to differences in tumor cell type or genomic organization between both species. Conclusions: The selection of the oncogenome during mouse and human breast tumor development is markedly different, apart from the MYC gain and RB1-associated loss. These differences should be kept in mind when using mouse models for preclinical studies.MediamaticsElectrical Engineering, Mathematics and Computer Scienc

Ovulation-stimulation drugs and cancer risks: a long-term follow-up of a British cohort

To assess long-term health effects of ovarian-stimulation drugs we followed-up for over 20 years a British cohort of 7355 women with ovulatory disorders, 43% of whom were prescribed ovarian-stimulation drugs, and identified a total of 274 deaths and 367 incident cancers. Relative to the general population, the cohort experienced lower mortality from most causes, including from all neoplasms combined, and lower incidence of cervical cancer, but higher incidence of cancers of the breast (relative risk: 1.13; 95% CI 0.97, 1.30) and corpus uteri (2.02; 1.37, 2.87). There were, however, no significant differences in the risk of cancers of the breast, corpus uteri, ovary, or of any other site, between women who had been prescribed ovarian-stimulation drugs and those who had not. Further analyses by type of drug and dose revealed a dose–response gradient in the risk of cancer of the corpus uteri (P for linear trend=0.03), with women given ⩾2250 mg of clomiphene having a 2.6-fold (2.62; 0.94, 6.82) increase in risk relative to those who were not treated. These findings do not support strong associations between ovulation-stimulation drugs and cancer risks, but they indicate the need for continued monitoring to establish whether risks are elevated in certain subgroups of users