Glucose and lipoprotein biomarkers and breast cancer severity using data from the Swedish AMORIS cohort.

BACKGROUND: The lipid and glucose metabolisms are postulated as possible intermediary mechanisms in linking obesity and breast cancer (BC). Links between serum lipid and glucose biomarkers and BC risk has been observed in the Swedish Apolipoprotein MORtality RISk (AMORIS) cohort. We conducted a follow-up analysis including information on tumour characteristics. METHODS: One thousand eight hundred twenty-four women diagnosed with BC, with serum biomarker levels of glucose, triglycerides, cholesterol (total, HDL, and LDL), and apolipoproteins A-1 and B recorded in a routine health check at baseline were included. BC severity was split into categories (good, moderate, and poor prognosis) based on ER status, TNM stage, and age at diagnosis. Proportional odds models were used to obtain odds ratios (ORs) and 95% confidence intervals (CI), with the interval time between baseline measurement and BC diagnosis accounted for. RESULTS: Serum glucose and the ApoB/ApoA-1 ratio showed a non-statistically significant positive association with BC severity (proportional OR: 1.25 (95%CI: 0.92-1.70) for glucose (

Progression of breast cancer following locoregional ipsilateral recurrence: importance of interval time.

BACKGROUND: Studies comparing prognosis of breast cancer (BC) patients with and without locoregional recurrence (LR) present conflicting results. We aimed to improve our understanding of the impact of LR on prognosis by examining a large cohort of patients treated at Guy's and St Thomas' NHS Foundation Trust. METHODS: Risk factors associated with BC-specific death were investigated using Cox proportional hazards regression in 5199 women diagnosed between 1975 and 2007. Breast cancer-specific death following LR was assessed with Poisson regression. RESULTS: Overall, 552 women (11%) developed LR, with a median follow-up time of 4.28 years. Known factors associated with BC-specific death (tumour stage, grade, and nodal status) were of significance in our data. Women with a shorter disease-free interval had a worse prognosis. For instance, the HR for BC-specific death among women undergoing mastectomy with an LR 0.5-1 year after diagnosis of their primary tumour was 6.67 (95% CI: 3.71-11.99), when compared with women who did not experience LR. CONCLUSIONS: It often remains difficult to distinguish between a genuine LR and a new primary. The HRs for risk of BC-specific death following a second lesion suggest that they may act as a marker of systemic disease, large tumour burden, or depleted host defence. The clinically highly relevant impairment in prognosis calls for further research into the underlying mechanisms. We showed that for at least 15 years of follow-up, the prognosis in women following the occurrence of an LR may benefit from careful diagnostic and therapeutic management.

Serum glucose and risk of cancer: a meta-analysis.

BACKGROUND: Raised serum glucose has been linked to increased risk of many solid cancers. We performed a meta-analysis to quantify and summarise the evidence for this link. METHODS: Pubmed and Embase were reviewed, using search terms representing serum glucose and cancer. Inclusion and exclusion criteria focused on epidemiological studies with clear definitions of serum glucose levels, cancer type, as well as well-described statistical methods with sufficient data available. We used 6.1 mmol/L as the cut-off for high glucose, consistent with the WHO definition of metabolic syndrome. Random effects analyses were performed to estimate the pooled relative risk (RR). RESULTS: Nineteen studies were included in the primary analysis, which showed a pooled RR of 1.32 (95% CI: 1.20 - 1.45). Including only those individuals with fasting glucose measurements did not have a large effect on the pooled RR (1.32 (95% CI: 1.11-1.57). A stratified analysis showed a pooled RR of 1.34 (95% CI: 1.02-1.77) for hormonally driven cancer and 1.21 (95% CI: 1.09-1.36) for cancers thought to be driven by Insulin Growth Factor-1. CONCLUSION: A positive association between serum glucose and risk of cancer was found. The underlying biological mechanisms remain to be elucidated but our subgroup analyses suggest that the insulin- IGF-1 axis does not fully explain the association. These findings are of public health importance as measures to reduce serum glucose via lifestyle and dietary changes could be implemented in the context of cancer mortality.

Family history of breast cancer and its association with disease severity and mortality.

A family history (FH) of breast cancer (BC) is known to increase an individual's risk of disease onset. However, its role in disease severity and mortality is less clear. We aimed to ascertain associations between FH of BC, severity and BC-specific mortality in a hospital-based cohort of 5354 women with prospective information on FH. We included women diagnosed at Guy's and St Thomas' NHS Foundation Trust between 1975 and 2012 (n = 5354). BC severity was defined and categorized as good, moderate, and poor prognosis. Data on BC-specific mortality was obtained from the National Cancer Registry and medical records. Associations between FH and disease severity or BC-specific mortality were evaluated using proportional odds models and Cox proportional hazard regression models, respectively. Available data allowed adjustment for potential confounders (e.g., treatment, socioeconomic status, and ethnicity). FH of any degree was not associated with disease severity at time of diagnosis (adjusted proportional OR: 1.00 [95% CI: 0.85 to 1.17]), which remained true also after stratification by period of diagnosis. FH of BC was not associated with BC-mortality HR: 0.99 (95% CI: 0.93 to 1.05). We did not find evidence to support an association between FH of BC and severity and BC-specific mortality. Our results indicate that clinical management should not differ between women with and without FH, when the underlying mutation is unknown.

Serum lipid profiles and cancer risk in the context of obesity: four meta-analyses.

The objective here was to summarize the evidence for, and quantify the link between, serum markers of lipid metabolism and risk of obesity-related cancers. PubMed and Embase were searched using predefined inclusion criteria to conduct meta-analyses on the association between serum levels of TG, TC, HDL, ApoA-I, and risk of 11 obesity-related cancers. Pooled relative risks (RRs) and 95% confidence intervals were estimated using random-effects analyses. 28 studies were included. Associations between abnormal lipid components and risk of obesity-related cancers when using clinical cutpoints (TC ≥ 6.50; TG ≥ 1.71; HDL ≤ 1.03; ApoA-I ≤ 1.05 mmol/L) were apparent in all models. RRs were 1.18 (95% CI: 1.08-1.29) for TC, 1.20 (1.07-1.35) for TG, 1.15 (1.01-1.32) for HDL, and 1.42 (1.17-1.74) for ApoA-I. High levels of TC and TG, as well as low levels of HDL and ApoA-I, were consistently associated with increased risk of obesity-related cancers. The modest RRs suggest serum lipids to be associated with the risk of cancer, but indicate it is likely that other markers of the metabolism and/or lifestyle factors may also be involved. Future intervention studies involving lifestyle modification would provide insight into the potential biological role of lipid metabolism in tumorigenesis.

Gamma-glutamyl transferase and C-reactive protein as alternative markers of metabolic abnormalities and their associated comorbidites: a prospective cohort study.

BACKGROUND: Recent studies suggested that gamma-glutamyl transferase (GGT) and C-reactive protein (CRP) are good markers of metabolic abnormalities. We assessed the link between GGT, CRP and common metabolic abnormalities, as well their link to related diseases, such as cancer and cardiovascular disease (CVD). METHODS: We selected 333,313 subjects with baseline measurements of triglycerides (TG), total cholesterol (TC), glucose, GGT and CRP in the Swedish AMORIS study. Baseline measurement of BMI was available for 63,900 persons and 77,944 had baseline measurements of HDL. Pearson correlation coefficients between CRP, GGT, and metabolic components (TG, HDL, BMI and TC) were calculated. To investigate the combined effect of GGT and CRP we created a score ranging from 0 to 6 and used Cox proportional hazard models to evaluate its association with CVD and cancer. RESULTS: 21,216 individuals developed cancer and 47,939 CVD. GGT and TG had the strongest correlation (r=0.22). An increased risk of cancer was identified with elevated levels of GGT or CRP or both markers (GGT-CRP score ≥3); the greatest risk of cancer was found when GGT-CRP score = 6 (HR: 1.40 (95%CI: 1.31-1.48) and 1.60 (1.47-1.76) compared to GGT-CRP score = 0, respectively). CONCLUSION: While GGT and CRP have been shown to be associated with metabolic abnormalities previously, their association to the components investigated in this study was limited. Results did demonstrate that these markers were predictive of associated diseases, such as cancer.

Lipid profiles and risk of breast and ovarian cancer in the Swedish AMORIS study.

BACKGROUND: Obesity is a risk factor for breast and ovarian cancer; the mechanisms of action are not completely understood. Perturbed lipid metabolism often accompanies obesity; we therefore ascertained the associations between lipid components and breast and ovarian cancer risk in a prospective cohort study. METHODS: A total of 234,494 women with baseline measurements of triglycerides and total cholesterol and glucose were selected from the AMORIS database.A total of 27,394 had measurements of high-density lipoprotein, low-density lipoprotein, apolipoprotein (Apo) B, and A-I. Associations between quartiles and dichotomized values of lipid components and breast and ovarian cancer risk were analyzed using Cox proportional hazard models. RESULTS: We identified 6,105 women diagnosed with breast cancer and 808 women diagnosed with ovarian cancer. A weak trend was observed between triglycerides and breast cancer (HR, 1.01, 95% Confidence Interval, 0.94-1.09; 0.93 (0.86-1.00) 0.91 (0.84-0.99), second, third, and fourth quartiles; P = 0.01). No other associations between lipid components and risk of breast cancer or ovarian cancer showed statistical significance. CONCLUSIONS: A weak protective association was found between levels of triglycerides and risk of breast cancer. IMPACT: An analysis including information on tumour characteristics of ovarian cancer and breast cancer may provide more insight in possible links between lipid metabolism and the risk of these cancers.