Susen Becker

Obesity related hyperinsulinaemia and hyperglycaemia and cancer development

Excess body weight in combination with physical inactivity is a major determinant for the development of insulin resistance with associated hyperglycaemia and hyperinsulinaemia and further leads to tumour development. Several prospective epidemiological studies have shown a direct association between excess weight and common malignancies, such as colon, breast (post-menopausal), endometrial, gallbladder, pancreatic, kidney and oesophageal cancers, but also less frequent malignancies, such as leukaemia, multiple myeloma and non-Hodgkin lymphoma. Insulin resistance and hyperinsulinaemia are certainly key biological mechanisms underlying the relationship between adiposity and tumour development. The anti-diabetic drug, metformin, in addition to reduction of insulin resistance has also shown anti-tumour properties, and is increasingly being considered as a drug to prevent and treat obesity-related cancers. Several biological pathways have been involved in the association between excess body weight, insulin resistance and cancer, such as chronic low-grade inflammation, glucose toxicity, AGE product metabolism and the adenosine monophosphate kinase pathway.

LC-MS-based metabolomics in the clinical laboratory.

The analysis of metabolites in human body fluids remains a challenge because of their chemical diversity and dynamic concentration range. Liquid chromatography (LC) in combination with tandem mass spectrometry (MS/MS) offers a robust, reliable, and economical methodology for quantitative single metabolite analysis and profiling of complete metabolite classes of a biological specimen over a broad dynamic concentration range. The application of LC-MS/MS based metabolomic approaches in clinical applications aims at both, the improvement of diagnostic sensitivity and specificity by profiling a metabolite class instead of a single metabolite analysis, and the identification of new disease specific biomarkers. In the present paper we discuss recent advances in method development for LC-MS/MS analysis of lipids, carbohydrates, amino acids and biogenic amines, vitamins and organic acids with focus on human body fluids. In this context an overview on recent LC-MS/MS based metabolome studies for cancer, diabetes and coronary heart disease is presented.

Postmenopausal serum sex steroids and risk of hormone receptor-positive and -negative breast cancer: a nested case-control study.

Prediagnostic endogenous sex steroid hormone levels have well established associations with overall risk of breast cancer. While evidence toward the existence of distinct subtypes of breast cancer accumulates, few studies have investigated the associations of sex steroid hormone levels with risk of hormone receptor [estrogen receptor (ER) and/or progesterone receptor (PR)] defined breast cancer. In a case–control study nested within the EPIC cohort (European Prospective Investigation into Cancer and Nutrition), estradiol, testosterone, and sex hormone–binding globulin levels were measured in prediagnostic serum samples from postmenopausal women not using hormone replacement therapy at blood donation. A total of 554 women who developed invasive breast cancer with information on receptor status were matched with 821 control subjects. Conditional logistic regression models estimated breast cancer risk with hormone concentrations according to hormone receptor status of the tumor. Sex steroid hormones were associated with risks of not only ER+PR+ breast cancer [estradiol OR for highest vs. lowest tertile = 2.91 (95% CI: 1.62–5.23), Ptrend = 0.002; testosterone OR = 2.27 (95% CI: 1.35–3.81), Ptrend = 0.002] but also of ER-PR- breast cancer [estradiol OR = 2.11 (95% CI: 1.00–4.46), Ptrend = 0.05; testosterone OR = 2.06 (95% CI: 0.95–4.46), Ptrend = 0.03], with associations appearing somewhat stronger in the receptor-positive disease. Serum androgens and estrogens are associated with risks of both hormone receptor–negative as well as receptor–positive breast tumors. Further research is needed to establish through which molecular pathways, and during which evolutionary stages of development, androgens and estrogens can promote the occurrence of both receptor-positive and -negative clinical breast tumors. Cancer Prev Res; 4(10); 1626–35. ©2011 AACR.

Obesity, inflammatory markers, and endometrial cancer risk: a prospective case–control study

Obesity, a major risk factor for endometrial cancer, is a low-grade inflammatory state characterized by elevated concentrations of cytokines and acute phase reactants. The current study had two aims: first to investigate the associations of C-reactive protein (CRP), interleukin 6 (IL6), and IL1 receptor antagonist (IL1Ra) with endometrial cancer risk and second to examine to which extent these markers can influence the association between obesity and endometrial cancer. We conducted a case–control study, nested within the European Prospective Investigation into Cancer and Nutrition, which comprised 305 incident cases of endometrial cancer and 574 matched controls. CRP, IL6, and IL1Ra were measured in prospectively collected blood specimens by immunoassays. Data were analyzed using conditional logistic regression. All statistical tests were two-sided, and P values <0.05 were considered statistically significant. We observed a significant increase in risk of endometrial cancer with elevated levels of CRP (odds ratio (OR) for top versus bottom quartile: 1.58, 95% confidence interval (CI): 1.03–2.41, Ptrend=0.02), IL6 (OR for top versus bottom quartile: 1.66, 95% CI: 1.08–2.54, Ptrend=0.008), and IL1Ra (OR for top versus bottom quartile: 1.82, 95% CI: 1.22–2.73, Ptrend=0.004). After adjustment for body mass index (BMI), the estimates were strongly reduced and became non-significant. The association between BMI and endometrial cancer was also substantially attenuated (∼10–20%) after adjustment for inflammatory markers, even when the effects of C-peptide or estrone had already been taken into account. We provided epidemiological evidence that chronic inflammation might mediate the association between obesity and endometrial cancer and that endometrial carcinogenesis could be promoted by an inflammatory milieu.

Diabetes Mellitus Type 2 - An Independent Risk Factor for Cancer?

Epidemiological findings have shown up to two-fold increases in the risks of cancers of the colorectum, breast, endometrium, kidney (renal cell tumours), liver and pancreas among diabetes patients. In the present review, we address the question whether, on the basis of these epidemiological observations, type 2 diabetes should be considered a specific and independent risk factor for these various forms of cancer, due to its particular metabolic characteristics of glucose intolerance and hyperinsulinemia. On the basis of further epidemiological evidence among non-diabetic individuals, as well as recent studies examining the effects of different types of diabetes treatment on cancer risks, we conclude that chronic elevations in fasting and non-fasting blood levels of glucose and/or insulin are plausible independent risk factors for cancer, but that much of the increase in cancer risks associated with these two metabolic factors may occur within the normoglycaemic and insulinemic (non-diabetic) ranges. Furthermore, for some tumour types (e. g. cancer of the endometrium) the associations of risk with type 2 diabetes may to a large extent be due to, and at least partially confounded by, other obesity-related alterations in (e. g. sex steroid) metabolism that in part are independent of glucose and/or insulin metabolism. Specifically for pancreatic cancer, a major question, addressed in detail by other reviews, is whether associations of risk with plasma glucose, insulin or overt type 2 diabetes could be either a cause, or possibly also a consequence of tumour development (or both).

Postmenopausal Sex Hormones in Relation to Body Fat Distribution

Being overweight or obese increases the risk of postmenopausal breast cancer. A potential reason may be the frequently observed positive association of BMI with endogenous sex hormones and its negative association with sex hormone‐binding globulin (SHBG). The purpose of this study was to investigate whether a womans body fat distribution shows a BMI‐independent association with these breast cancer‐related biomarkers. Performing cross‐sectional analyses among 1,180 postmenopausal women, we assessed whether associations of surrogates for an abdominal (waist circumference; waist‐to‐hip ratio, WHR) and gluteofemoral (hip circumference) fat distribution with estrone, total and free estradiol, androstenedione, total and free testosterone, and SHBG changed after adjustment for, or stratification by, BMI. All anthropometric measures were positively associated with estrogens and free testosterone, and negatively with SHBG. After adjustment for BMI, associations of free estradiol, free testosterone, and SHBG with both waist circumference and WHR remained significant, but all initially significant associations with hip circumference were abolished. In stratified analyses, waist circumference and WHR correlated with free estradiol, free testosterone, and SHBG in women with a BMI < 30 kg/m2 but not in women with a BMI ≥ 30 kg/m2. The latter suggests that in obese women, a possibly unique effect of abdominal fat on these biomarkers may be masked by the already large amount of overall body fat. On the whole, our results indicate that waist circumference and WHR, but not hip circumference, are associated with SHBG and SHBG‐related sex hormones (free estradiol and free testosterone) independently of BMI.

Serum Enterolactone and Prognosis of Postmenopausal Breast Cancer

PURPOSE Lignans--plant-derived compounds with estrogen-dependent and -independent anticarcinogenic properties--have been associated with postmenopausal breast cancer risk, but data are limited regarding their effect on survival. Dietary lignans are metabolized to enterolignans, which are subsequently absorbed and become bioavailable. PATIENTS AND METHODS We assessed the prognosis of 1,140 postmenopausal patients with breast cancer age 50 to 74 years who were diagnosed between 2002 and 2005. Vital status through the end of 2009 was ascertained via local population registries, and deaths were verified by death certificates. Information on recurrences and secondary tumors was verified by clinical records and attending physicians. Associations of postdiagnostic serum enterolactone (a biomarker for dietary lignans) with overall survival and distant disease-free survival were assessed by using Cox proportional hazards models stratified by age at diagnosis and adjusted for prognostic factors. RESULTS Median enterolactone levels for deceased patients and those still alive were 17.0 and 21.4 nmol/L, respectively. During a median of 6.1 years of follow-up after diagnosis, 162 deaths were confirmed. Higher serum enterolactone levels were associated with significantly reduced hazard ratios (HRs) for death (HR per 10 nmol/L increment, 0.94; P = .04; HR for the highest quartile, 0.58; 95% CI, 0.34 to 0.99). For distant disease, HR was 0.94 per 10 nmol/L increment (P = .08) and 0.62 (95% CI, 0.35 to 1.09) for the highest quartile. The highest quartile of serum enterolactone was associated with a significantly reduced risk of death only for estrogen receptor-negative tumors (HR, 0.27; 95% CI, 0.08 to 0.87) but not for estrogen receptor-positive tumors (HR, 0.91; 95% CI, 0.45 to 1.84: P for heterogeneity = .09). CONCLUSION Postmenopausal patients with breast cancer who have high serum enterolactone levels may have better survival.

Fast liquid chromatography–quadrupole linear ion trap-mass spectrometry analysis of polyunsaturated fatty acids and eicosanoids in human plasma ☆

Profiling of polyunsaturated fatty acids (PUFAs) and their oxidized metabolites, mainly eicosanoids, in human plasma by fast liquid chromatography-mass spectrometry is described. Sample preparation involved protein precipitation of 200μL plasma followed by on-line solid-phase extraction. 7 PUFAs and 94 oxidized metabolites were separated utilizing a C-18 column packed with 2.6μm core-shell particles in 7min. The analytes and deuterium-labeled standards were detected via scheduled multiple reaction monitoring transitions (123 sMRM). Simultaneously, linear ion trap fragment spectra were acquired for confirmation, if necessary. The lower limit of quantitation ranged between 200 and 1000ng/mL for the PUFAs and 10-1000pg/mL for the metabolites. The method was applied to a study on plasma samples from 50 healthy subjects.

Primary brain tumours and specific serum immunoglobulin E: a case-control study nested in the European Prospective Investigation into Cancer and Nutrition cohort.

To cite this article: Schlehofer B, Siegmund B, Linseisen J, Schüz J, Rohrmann S, Becker S, Michaud D, Melin B, Bas Bueno‐de‐Mesquita H, Peeters PHM, Vineis P, Tjonneland A, Olsen A, Overvad K, Romieu I, Boeing H, Aleksandrova K, Trichopoulou A, Bamia C, Lagiou P, Sacerdote C, Palli D, Panico S, Sieri S, Tumino R, Sanchez M‐J, Rodriguez L, Dorronsoro M, Duell EJ, Chirlaque M‐D, Barricarte A, Borgquist S, Manjer J, Gallo V, Allen NE, Key TJ, Riboli E, Kaaks R, Wahrendorf J. Primary brain tumours and specific serum immunoglobulin E: a case–control study nested in the European Prospective Investigation into Cancer and Nutrition cohort. Allergy 2011; 66: 1434–1441.

Inflammation marker and risk of pancreatic cancer: a nested case-control study within the EPIC cohort

Background:Established risk factors for pancreatic cancer include smoking, long-standing diabetes, high body fatness, and chronic pancreatitis, all of which can be characterised by aspects of inflammatory processes. However, prospective studies investigating the relation between inflammatory markers and pancreatic cancer risk are scarce.Methods:We conducted a nested case–control study within the European Prospective Investigation into Cancer and Nutrition, measuring prediagnostic blood levels of C-reactive protein (CRP), interleukin-6 (IL-6), and soluble receptors of tumour necrosis factor-α (sTNF-R1, R2) in 455 pancreatic cancer cases and 455 matched controls. Odds ratios (ORs) were estimated using conditional logistic regression models.Results:None of the inflammatory markers were significantly associated with risk of pancreatic cancer overall, although a borderline significant association was observed for higher circulating sTNF-R2 (crude OR=1.52 (95% confidence interval (CI) 0.97–2.39), highest vs lowest quartile). In women, however, higher sTNF-R1 levels were significantly associated with risk of pancreatic cancer (crude OR=1.97 (95% CI 1.02–3.79)). For sTNF-R2, risk associations seemed to be stronger for diabetic individuals and those with a higher BMI.Conclusion:Prospectively, CRP and IL-6 do not seem to have a role in our study with respect to risk of pancreatic cancer, whereas sTNF-R1 seemed to be a risk factor in women and sTNF-R2 might be a mediator in the risk relationship between overweight and diabetes with pancreatic cancer. Further large prospective studies are needed to clarify the role of proinflammatory proteins and cytokines in the pathogenesis of exocrine pancreatic cancer.