Experimental studies provided evidence about mechanisms by which cholesterol, especially high density lipoprotein cholesterol (HDL-C), could influence carcinogenesis, notably through antioxidant and anti-inflammatory properties. However, prospective studies that investigated the associations between specific lipid metabolism biomarkers and cancer risk provided inconsistent results. The objective was to investigate the prospective associations between total cholesterol (T-C), HDL-C, low density lipoprotein cholesterol, apolipoproteins A1 (apoA1) and B, and triglycerides and overall, breast and prostate cancer risk. Analyses were performed on 7,557 subjects of the Supplémentation en Vitamines et Minéraux Antioxydants Study, a nationwide French cohort study. Biomarkers of lipid metabolism were measured at baseline and analyzed regarding the risk of first primary incident cancer (N = 514 cases diagnosed during follow-up, 1994-2007), using Cox proportional hazards models. T-C was inversely associated with overall (HR(1mmol/L increment) = 0.91, 95 % CI 0.82-1.00; P = 0.04) and breast (HR(1mmol/L increment) = 0.83, 95 % CI 0.69-0.99; P = 0.04) cancer risk. HDL-C was also inversely associated with overall (HR(1mmol/L increment) = 0.61, 95 % CI 0.46-0.82; P = 0.0008) and breast (HR(1mmol/L increment) = 0.48, 95 % CI 0.28-0.83; P = 0.009) cancer risk. Consistently, apoA1 was inversely associated with overall (HR(1g/L increment) = 0.56, 95 % CI 0.39-0.82; P = 0.003) and breast (HR(1g/L increment) = 0.36, 95 % CI 0.18-0.73; P = 0.004) cancer risk. This prospective study suggests that pre-diagnostic serum levels of T-C, HDL-C and ApoA1 are associated with decreased overall and breast cancer risk. The confirmation of a role of cholesterol components in cancer development, by further large prospective and experimental studies, may have important implications in terms of public health, since cholesterol is already crucial in cardiovascular prevention.

Background Metabolomics is a promising molecular tool to identify novel etiologic pathways leading to cancer. Using a targeted approach, we prospectively investigated the associations between metabolite concentrations in plasma and breast cancer risk. Methods A nested case-control study was established within the European Prospective Investigation into Cancer cohort, which included 1624 first primary incident invasive breast cancer cases (with known estrogen and progesterone receptor and HER2 status) and 1624 matched controls. Metabolites (n = 127, acylcarnitines, amino acids, biogenic amines, glycerophospholipids, hexose, sphingolipids) were measured by mass spectrometry in pre-diagnostic plasma samples and tested for associations with breast cancer incidence using multivariable conditional logistic regression. Results Among women not using hormones at baseline (n = 2248), and after control for multiple tests, concentrations of arginine (odds ratio [OR] per SD = 0.79, 95% confidence interval [CI] = 0.70–0.90), asparagine (OR = 0.83 (0.74–0.92)), and phosphatidylcholines (PCs) ae C36:3 (OR = 0.83 (0.76–0.90)), aa C36:3 (OR = 0.84 (0.77–0.93)), ae C34:2 (OR = 0.85 (0.78–0.94)), ae C36:2 (OR = 0.85 (0.78–0.88)), and ae C38:2 (OR = 0.84 (0.76–0.93)) were inversely associated with breast cancer risk, while the acylcarnitine C2 (OR = 1.23 (1.11–1.35)) was positively associated with disease risk. In the overall population, C2 (OR = 1.15 (1.06–1.24)) and PC ae C36:3 (OR = 0.88 (0.82–0.95)) were associated with risk of breast cancer, and these relationships did not differ by breast cancer subtype, age at diagnosis, fasting status, menopausal status, or adiposity. Conclusions These findings point to potentially novel pathways and biomarkers of breast cancer development. Results warrant replication in other epidemiological studies.

The objective of the present study was to conduct the first systematic review and meta-analysis of prospective studies investigating the associations between total cholesterol (TC), HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) levels and the risk of breast cancer. Relevant studies were identified in PubMed (up to January 2014). Inclusion criteria were original peer-reviewed publications with a prospective design. Random-effects models were used to estimate summary hazard ratios (HR) and 95 % CI. Distinction was made between studies that did or did not exclude cancer cases diagnosed during the first years of follow-up, thereby eliminating potential preclinical bias. Overall, the summary HR for the association between TC and breast cancer risk was 0·97 (95 % CI 0·94, 1·00; dose -response per 1 mmol/l increment, thirteen studies), and that between HDL-C and breast cancer risk was 0·86 (95 % CI 0·69, 1·09; dose -response per 1 mmol/l increment, six studies), with high heterogeneity (I 2 ¼ 67 and 47 %, respectively). For studies that eliminated preclinical bias, an inverse association was observed between the risk of breast cancer and TC (dose -response HR 0·94 (95 % CI 0·89, 0·99), seven studies, I 2 ¼ 78 %; highest v. lowest HR 0·82 (95 % CI 0·66, 1·02), nine studies, I 2 ¼ 81 %) and HDL-C (dose -response HR 0·81 (95 % CI 0·65, 1·02), five studies, I 2 ¼ 30 %; highest v. lowest HR 0·82 (95 % CI 0·69, 0·98), five studies, I 2 ¼ 0 %). There was no association observed between LDL-C and the risk of breast cancer (four studies). The present meta-analysis confirms the evidence of a modest but statistically significant inverse association between TC and more specifically HDL-C and the risk of breast cancer, supported by mechanistic plausibility from experimental studies. Further large prospective studies that adequately control for preclinical bias are needed to confirm the results on the role of cholesterol level and its fractions in the aetiology of breast cancer.Key words: Cholesterol: HDL-cholesterol: Breast cancer: Prospective studies: Meta-analysesBreast cancer is one of the leading causes of death among women in developed countries. The association between deregulated lipid metabolism and the risk of CVD is well established (1) . In contrast, regarding breast cancer, the role of biomarkers of lipid metabolism has been less investigated and remains unclear. This is notably the case for blood cholesterol levels, which represent easily measurable markers that are often assessed in clinical practice. Experimental studies have provided evidence about the possible mechanisms by which cholesterol (especially HDL-cholesterol (HDL-C)) could influence carcinogenesis (2 -4) .Since the 1980s and until very recently (5 -10) , many studies have investigated the relationship between total cholesterol (TC) and the risk of breast cancer (5,7,9 -21) , some providing specific results regarding HDL-C (6 -9,15,22 -27) and fewer investigating LDLcholesterol (LDL-C) (7,9,15,16) , apoA1 and apoB (7,9) . These studies ha...

BackgroundIn addition to tumor characteristics and lifestyle factors, cancer relapses are often related to the risk of death but have not been jointly studied. We investigate the prognostic factors of recurrent events and death after a diagnosis of breast cancer and predict individual deaths including a history of recurrences.MethodsThe E3N (Etude Epidémiologique auprès de Femmes de la Mutuelle Générale de l’Education Nationale) study is a prospective cohort study that was initiated in 1990 to investigate factors associated with the most common types of cancer. Overall survival and three types of recurrent events were considered: locoregional recurrence, metastasis, and second primary breast cancer. Recurrent events and death were analyzed using a joint frailty model.ResultsThe analysis included 4926 women from the E3N cohort diagnosed with a first primary invasive breast cancer between June 1990 and June 2008; during the follow-up, 1334 cases had a recurrence (median time of follow-up is 7.2 years) and 469 women died. Cases with high grade, large tumor size, axillary nodal involvement, and negative estrogen and progesterone receptors had a higher risk of recurrence or death. Furthermore, smoking increased the risk of relapse. For cases with a medium risk profile in terms of tumor characteristics and lifestyle factors, the probability of dying between 5 and 10 years after diagnosis was 6, 20 and 36% for 0, 1 or 2 recurrences within the first 5 years after diagnosis, respectively.ConclusionsOur study showed the importance of considering baseline lifestyle characteristics and history of relapses to dynamically predict the risk of death in breast cancer cases. Medical experience coupled with an estimate of a patient’s survival probability that considers all available information for this patient would enable physicians to make better informed decisions regarding their actions and thus improve clinical output.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-4076-4) contains supplementary material, which is available to authorized users.

No abstract

The role of amount and type of dietary fat consumption in the etiology of hepatocellular carcinoma (HCC) is poorly understood, despite suggestive biological plausibility. The associations of total fat, fat subtypes and fat sources with HCC incidence were investigated in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, which includes 191 incident HCC cases diagnosed between 1992 and 2010. Diet was assessed by country-specific, validated dietary questionnaires. A single 24-hr diet recall from a cohort subsample was used for measurement error calibration. Hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated from Cox proportional hazard models. Hepatitis B and C viruses (HBV/HCV) status and biomarkers of liver function were assessed separately in a nested case–control subset with available blood samples (HCC = 122). In multivariable calibrated models, there was a statistically significant inverse association between total fat intake and risk of HCC (per 10 g/day, HR = 0.80, 95% CI: 0.65–0.99), which was mainly driven by monounsaturated fats (per 5 g/day, HR = 0.71, 95% CI: 0.55–0.92) rather than polyunsaturated fats (per 5 g/day, HR = 0.92, 95% CI: 0.68–1.25). There was no association between saturated fats (HR = 1.08, 95% CI: 0.88–1.34) and HCC risk. The ratio of polyunsaturated/monounsaturated fats to saturated fats was not significantly associated with HCC risk (per 0.2 point, HR = 0.86, 95% CI: 0.73–1.01). Restriction of analyses to HBV/HCV free participants or adjustment for liver function did not substantially alter the findings. In this large prospective European cohort, higher consumption of monounsaturated fats is associated with lower HCC risk

Epidemiological studies have reported inconsistent findings for the association between B vitamins and breast cancer (BC) risk. We investigated the relationship between biomarkers of folate and vitamin B12 and the risk of BC in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Plasma concentrations of folate and vitamin B12 were determined in 2,491 BC cases individually matched to 2,521 controls among women who provided baseline blood samples. Multivariable logistic regression models were used to estimate odds ratios by quartiles of either plasma B vitamin. Subgroup analyses by menopausal status, hormone receptor status of breast tumors (estrogen receptor [ER], progesterone receptor [PR] and human epidermal growth factor receptor 2 [HER2]), alcohol intake and MTHFR polymorphisms (677C > T and 1298A > C) were also performed. Plasma levels of folate and vitamin B12 were not significantly associated with the overall risk of BC or by hormone receptor status. A marginally positive association was found between vitamin B12 status and BC risk in women consuming above the median level of alcohol (OR = 1.26; 95% CI 1.00-1.58; P = 0.05). Vitamin B12 status was also positively associated with BC risk in women with plasma folate levels below the median value (OR = 1.29; 95% CI 1.02-1.62; P = 0.03). Overall, folate and vitamin B12 status was not clearly associated with BC risk in this prospective cohort study. However, potential interactions between vitamin B12 and alcohol or folate on the risk of BC deserve further investigation.

Our results suggest that serum lipids are not associated with breast cancer risk overall, but that menopausal status and waist circumference should be considered in further studies.