Obesity: A Causative Risk Factor of Breast Cancer (original) (raw)
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Molecular links between obesity and breast cancer
Endocrine Related Cancer, 2006
Breast cancer continues to be a major health problem for women in the USA and worldwide. There is a need to identify and take steps to alter modifiable breast cancer risks. Conditions of obesity and overweight are risk factors that have reached epidemic proportions. This article reviews the evidence in the literature that test mechanism-based hypotheses which attempt to provide a molecular basis for a causal link between obesity and breast cancer risk, particularly the effects of metabolic syndrome and insulin resistance, peripheral estrogen aromatization in adipose tissue, and direct effect of adipokines. Future areas for study and implications for therapy are discussed.
Advances in the Prevention and Treatment of Obesity-Driven Effects in Breast Cancers
Frontiers in Oncology, 2022
Obesity and associated chronic inflammation were shown to facilitate breast cancer (BC) growth and metastasis. Leptin, adiponectin, estrogen, and several pro-inflammatory cytokines are involved in the development of obesity-driven BC through the activation of multiple oncogenic and pro-inflammatory pathways. The aim of this study was to assess the reported mechanisms of obesity-induced breast carcinogenesis and effectiveness of conventional and complementary BC therapies. We screened published original articles, reviews, and meta-analyses that addressed the involvement of obesity-related signaling mechanisms in BC development, BC treatment/prevention approaches, and posttreatment complications. PubMed, Medline, eMedicine, National Library of Medicine (NLM), and ReleMed databases were used to retrieve relevant studies using a set of keywords, including "obesity," "oncogenic signaling pathways," "inflammation," "surgery," "radiotherapy," "conventional therapies," and "diet." Multiple studies indicated that effective BC treatment requires the involvement of diet-and exercise-based approaches in obese postmenopausal women. Furthermore, active lifestyle and diet-related interventions improved the patients' overall quality of life and minimized adverse side effects after traditional BC treatment, including postsurgical lymphedema, post-chemo nausea, vomiting, and fatigue. Further investigation of beneficial effects of diet and physical activity may help improve obesity-linked cancer therapies.
Functions of Obesity-related Hormones in Breast Cancer: A Review
Medical Laboratory Journal, 2017
Obesity is a health problem defined as abnormal or excessive fat accumulation in adipose tissue. Adipokines such as adiponectin, visfatin and resistin are bioactive polypeptides with pro-and anti-inflammatory properties that are secreted by the adipose tissue that are involved in the pathogenesis and prognosis of diseases such as type 2 diabetes, metabolic syndrome and cancer. This survey aimed to review the role of these hormones in the pathogenesis and prognosis of breast cancer in obese postmenopausal women. In obese individuals, increased level of leptin leads to tumorigenesis and progression of breast cancer though JAK/STAT3 pathway. These individuals have decreased level of adiponectin, which has a protective effect against carcinogenesis via AMPK pathway. Obese individuals also have increased level of visfatin, which induces the secretion of proinflammatory cytokines such as TNFα and triggers growth of cancer cells. Similarly, elevated resistin levels increases cell proliferation through PI3K and MAPK pathways. Obesity is associated with the dysregulated secretion of adipokines such as leptin, adiponectin, visfatin and resistin, which could be utilized for early diagnosis of breast cancer.
Minireview: Obesity and Breast Cancer: A Tale of Inflammation and Dysregulated Metabolism
Molecular Endocrinology, 2013
In addition to the spectrum of conditions known collectively as the Metabolic Syndrome, obesity is now recognized to be associated with increased risk of several cancers including colon, endometrial, and breast cancer. Obesity and carcinogenesis share 2 characteristics in common. On the one hand, they involve inflammatory pathways, and on the other hand, they involve dysregulated metabolism. In this review we focus on postmenopausal breast cancer and discuss the metabolic and cellular mechanisms whereby obesity and breast cancer are related. Because a majority of postmenopausal breast tumors are estrogen responsive, we include a discussion of the action of obesity-related factors on estrogen formation within the breast.
Obesity and prognosis of breast cancer
Obesity Reviews, 2006
Obesity has a complicated relationship to both breast cancer risk and the clinical behaviour of the established disease. It is suggested that obesity is associated with both an increased risk of developing breast cancer risk and worse prognosis after disease onset. In post-menopausal women, various measures of obesity such as body mass index, weight, weight gain and waist : hip ratio have all been positively associated with risk of developing breast cancer. In most but not all case-control and prospective cohort studies, an inverse relationship has been found between weight and breast cancer among pre-menopausal women. Some data suggest that adult weight gain and central obesity increase the risk of pre-menopausal breast cancer. Obesity at the time of diagnosis is thought to be significant as a poor prognostic factor. Obesity is associated with adverse outcomes in both pre-and post-menopausal women with breast cancer. Many cancer survivors seek ways to minimize the risk of recurrence and death because of breast cancer. Despite complex and at times controversial data, enough evidence is available at present to suggest that weight management should be a part of the strategy to prevent the occurrence, recurrence and death because of breast cancer. In this review the effect of obesity on the prognosis of breast cancer is examined in detail.
Molecular Links between Central Obesity and Breast Cancer
International Journal of Molecular Sciences, 2019
Worldwide, breast cancer (BC) is the most common malignancy in women, in regard to incidence and mortality. In recent years, the negative role of obesity during BC development and progression has been made abundantly clear in several studies. However, the distribution of body fat may be more important to analyze than the overall body weight. In our review of literature, we reported some key findings regarding the role of obesity in BC development, but focused more on central adiposity. Firstly, the adipose microenvironment in obese people bears many similarities with the tumor microenvironment, in respect to associated cellular composition, chronic low-grade inflammation, and high ratio of reactive oxygen species to antioxidants. Secondly, the adipose tissue functions as an endocrine organ, which in obese people produces a high level of tumor-promoting hormones, such as leptin and estrogen, and a low level of the tumor suppressor hormone, adiponectin. As follows, in BC this leads to the activation of oncogenic signaling pathways: NFκB, JAK, STAT3, AKT. Moreover, overall obesity, but especially central obesity, promotes a systemic and local low grade chronic inflammation that further stimulates the increase of tumor-promoting oxidative stress. Lastly, there is a constant exchange of information between BC cells and adipocytes, mediated especially by extracellular vesicles, and which changes the transcription profile of both cell types to an oncogenic one with the help of regulatory non-coding RNAs.
The Obesity and the Risk of Breast Cancer among Pre and Postmenopausal Women
Asian Pacific journal of cancer prevention : APJCP, 2018
Background: Breast cancer is the most common cancer among women worldwide and the obesity is one of the factors related to the risk of breast cancer mainly in postmenopausal women. This study investigated the association between obesity in pre- and postmenopausal women with the development of breast cancer and the expression of estrogen, progesterone, HeR-2 and triple-negative (TN) receptors. Methods: A case-control study was conducted on 100 patients with recently diagnosed breast cancer and 400 age-matched controls. The women were divided into pre- and post-menopausal groups. Results: The multivariate analysis showed that postmenopausal women with a BMI ≥ 30 kg/m2 at pre-diagnosis and at the most recent measurement were 1.50 (95% CI 1.06-2.13) and 1.56 (95% CI 1.11-2.21) times more likely to develop breast cancer, respectively. These women had a prevalence of obesity of 27.7% when considering pre-diagnosis BMI and 29.4% when analyzing the indicator of recent BMI. When only the cas...
Cancer Prevention Research
Why is obesity only weakly associated with certain "obesitydriven" cancers? Recent population studies identify cohorts of high body mass index (BMI) subjects with unexpectedly reduced risk for breast and colon cancer, and normal BMI subjects with unexpectedly elevated risk for breast cancer, provoking hard thinking about cellular and molecular mechanisms that most strongly couple obesity to cancer occurrence or progression. Emerging work suggests that abnormal metabolism and its associated chronic inflammation make the difference. Type II diabetes, for example, is a chronic inflammatory disease with specific imbalances in T-cell and myeloid-origin cytokines. Inflammation is elevated systemically, measured through blood biomarkers, and locally in adipose tissue. Here, cytokines and chemokines likely modify tumor microenvironments in dan