Metabolic Syndrome Is Associated with Increased Breast Cancer Risk: A Systematic Review with Meta-Analysis

Abstract

Background. Although individual metabolic risk factors are reported to be associated with breast cancer risk, controversy surrounds risk of breast cancer from metabolic syndrome (MS). We report the first systematic review and meta-analysis of the association between MS and breast cancer risk in all adult females. Methods. Studies were retrieved by searching four electronic reference databases [PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, and ProQuest through June 30, 2012] and cross-referencing retrieved articles. Eligible for inclusion were longitudinal studies reporting associations between MS and breast cancer risk among females aged 18 years and older. Relative risks and 95% confidence intervals were calculated for each study and pooled using random-effects models. Publication bias was assessed quantitatively (Trim and Fill) and qualitatively (funnel plots). Heterogeneity was examined using Q and I 2 statistics. Results. Representing nine independent cohorts and 97,277 adult females, eight studies met the inclusion criteria. A modest, positive association was observed between MS and breast cancer risk (RR: 1.47, 95% CI, 1.15–1.87; z = 3.13; p = 0.002; Q = 26.28, p = 0.001; I 2 = 69.55%). No publication bias was observed. Conclusions. MS is associated with increased breast cancer risk in adult women.

Prevalence of comorbidities in women with and without breast cancer in Soweto, South Africa: Results from the SABC study

“…[18] Existing lifestyle risk factors and the metabolic syndrome (high blood glucose, high BP, abnormal cholesterol levels and excess fat around the waist) have been associated with increased breast cancer risk, especially in postmenopausal women. [19][20][21][22] Studies in LMICs have shown that the prevalence of the metabolic syndrome in breast cancer patients can be as high as 40%. [21] It has also been reported that about a third of women with breast cancer are likely to experience psychological distress.…”

Association between metabolic syndrome and prognosis of breast cancer: a meta-analysis of follow-up studies

“…Metabolic disorders, such as obesity and insulin resistance, have been suggested to be involved in the pathogenesis and progression of breast cancer [4][5][6]. Metabolic syndrome (MetS), which indicates a cluster of metabolic abnormalities including abdominal adiposity, insulin resistance, hyperglycemia, hypertension, and dyslipidemia [7][8][9][10], has been considered to be a risk factor of a variety of cancers, including breast cancer in postmenopausal women [11,12]. In addition, MetS have been proposed as a prognostic factor in women with breast cancer.…”

Metabolic syndrome and the incidence of lung cancer: a meta-analysis of cohort studies

“…Pathophysiologically, MetS is considered as a status of low-grade chronic inflammation [10], which may also be involved in the pathogenesis of tumor development [11]. Consistently, results of epidemiology studies suggested that presence of MetS may confer higher risks for the development of variety categories of cancers, such the colorectal cancer [12], pancreatic cancer [13], breast cancer [14], endometrial cancer [15], hepatocellular carcinoma [16], and prostate cancer [17]. However, the association between MetS and the incidence of lung cancer, the most common malignant tumor of the world [18], has not been fully determined.…”