Swedish Apolipoprotein Mortality Risk Study Research Articles

Serum immunoglobulin levels and the risk of bladder cancer in the AMORIS Cohort

BackgroundThe anti-tumour T-cell response in bladder cancer has been shown to correlate with response to treatment and prognosis. However, little is known about the role of humoral immunity in this highly immunogenic human cancer, which is characterised by a high mutation-associated neoantigen load and a strong response to immunotherapy. In the present study, we interrogated the Swedish Apolipoprotein Mortality Risk Study (AMORIS) to explore the relationship between pre-diagnostic serum immunoglobulin levels and the risk of developing bladder cancer. MethodsOur analysis included all AMORIS participants aged 20 years or older, who had all three major serum immunoglobulins (IgA, IgM, IgG) recorded at the same baseline measurement (n = 29,876). All participants were free from bladder cancer at the time of measurement. Samples were obtained between 1985–1996, with follow-up information until 2011. Multivariate Cox proportional hazards regression was used to investigate the association between bladder cancer risk and different levels of pre-diagnostic serum immunoglobulins. ResultsDuring a mean follow-up period of 15.31 years, 163 (0.5%) individuals were diagnosed with bladder cancer. Multivariate Cox regression showed an inverse association between pre-diagnostic serum IgM levels ≥ 1.4 g/L and bladder cancer risk compared to serum IgM levels < 1.4 g/L [HR: 0.68 (95% CI 0.45–1.03)]. Corresponding associations could not be established for serum IgA or IgG. ConclusionOur findings implicate serum IgM in the pathogenesis of bladder cancer and suggest that the concept of humoral immune surveillance against cancer warrants further mechanistic investigation.

Metabolic profiles to predict long-term cancer and mortality: the use of latent class analysis

BackgroundMetabolites are genetically and environmentally determined. Consequently, they can be used to characterize environmental exposures and reveal biochemical mechanisms that link exposure to disease. To explore disease susceptibility and improve population risk stratification, we aimed to identify metabolic profiles linked to carcinogenesis and mortality and their intrinsic associations by characterizing subgroups of individuals based on serum biomarker measurements. We included 13,615 participants from the Swedish Apolipoprotein MOrtality RISk Study who had measurements for 19 biomarkers representative of central metabolic pathways. Latent Class Analysis (LCA) was applied to characterise individuals based on their biomarker values (according to medical cut-offs), which were then examined as predictors of cancer and death using multivariable Cox proportional hazards models.ResultsLCA identified four metabolic profiles within the population: (1) normal values for all markers (63% of population); (2) abnormal values for lipids (22%); (3) abnormal values for liver functioning (9%); (4) abnormal values for iron and inflammation metabolism (6%). All metabolic profiles (classes 2–4) increased risk of cancer and mortality, compared to class 1 (e.g. HR for overall death was 1.26 (95% CI: 1.16–1.37), 1.67 (95% CI: 1.47–1.90), and 1.21 (95% CI: 1.05–1.41) for class 2, 3, and 4, respectively).ConclusionWe present an innovative approach to risk stratify a well-defined population based on LCA metabolic-defined subgroups for cancer and mortality. Our results indicate that standard of care baseline serum markers, when assembled into meaningful metabolic profiles, could help assess long term risk of disease and provide insight in disease susceptibility and etiology.

Serum immunoglobulin levels and the risk of bladder cancer in the AMORIS Cohort

Abstract Background The anti-tumour T-cell response in bladder cancer has been shown to correlate with response to treatment and prognosis. However, little is known about the role of humoral immunity in this highly immunogenic human cancer, which is characterised by a high mutation-associated neoantigen load and a strong response to immunotherapy. In the present study, we interrogated the Swedish Apolipoprotein Mortality Risk Study (AMORIS) to explore the relationship between pre-diagnostic serum immunoglobulin levels and the risk of developing bladder cancer. Methods Our analysis included all AMORIS participants aged 20 years or older, who had all three major serum immunoglobulins (IgA, IgM, IgG) recorded at the same baseline measurement (n = 29,876). All participants were free from bladder cancer at the time of measurement. Samples were obtained between 1985–1996, with follow-up information until 2011. Multivariate Cox proportional hazards regression was used to investigate the association between bladder cancer risk and different levels of pre-diagnostic serum immunoglobulins. Results During a mean follow-up period of 15.31 years, 163 (0.5%) individuals were diagnosed with bladder cancer. Multivariate Cox regression showed an inverse association between pre-diagnostic serum IgM levels ≥ 1.4 g/L and bladder cancer risk compared to serum IgM levels Conclusion Our findings implicate serum IgM in the pathogenesis of bladder cancer and suggest that the concept of humoral immune surveillance against cancer warrants further mechanistic investigation.

A latent class model for competing risks

Survival data analysis becomes complex when the proportional hazards assumption is violated at population level or when crude hazard rates are no longer estimators of marginal ones. We develop a Bayesian survival analysis method to deal with these situations, on the basis of assuming that the complexities are induced by latent cohort or disease heterogeneity that is not captured by covariates and that proportional hazards hold at the level of individuals. This leads to a description from which risk-specific marginal hazard rates and survival functions are fully accessible, 'decontaminated' of the effects of informative censoring, and which includes Cox, random effects and latent class models as special cases. Simulated data confirm that our approach can map a cohort's substructure and remove heterogeneity-induced informative censoring effects. Application to data from the Uppsala Longitudinal Study of Adult Men cohort leads to plausible alternative explanations for previous counter-intuitive inferences on prostate cancer. The importance of managing cardiovascular disease as a comorbidity in women diagnosed with breast cancer is suggested on application to data from the Swedish Apolipoprotein Mortality Risk Study. Copyright © 2017 John Wiley & Sons, Ltd.

Serum Calcium and the Risk of Breast Cancer: Findings from the Swedish AMORIS Study and a Meta-Analysis of Prospective Studies.

To investigate the association between serum calcium and risk of breast cancer using a large cohort and a systematic review with meta-analysis. From the Swedish Apolipoprotein Mortality Risk (AMORIS) Study we included 229,674 women who had baseline measurements of serum total calcium and albumin. Multivariable Cox regression was used to assess the association between total and albumin-corrected calcium and breast cancer risk. For the systematic review, an electronic search of MEDLINE and EMBASE databases was performed to identify other prospective cohorts assessing the relationship between serum calcium and breast cancer risk. We pooled the results of our AMORIS cohort with other eligible studies in a meta-analysis using a random effects model. I2 test was used to assess heterogeneity. In the AMORIS study, 10,863 women were diagnosed with breast cancer (mean follow-up: 19 years). We found an inverse association between total serum calcium and breast cancer when comparing the fourth quartile to the first quartile (HR: 0.94, 95% CI: 0.88–0.99, p value for trend 0.04) and similar results using albumin-corrected calcium. In the systematic review, we identified another two prospective cohorts evaluating pre-diagnostic serum total calcium and breast cancer. Combining these studies and our findings in AMORIS in a meta-analysis showed a protective effect of serum calcium against breast cancer, with a summary RR of 0.80 (95% CI: 0.66–0.97). No substantial heterogeneity was observed. Our findings in AMORIS and the meta-analysis support an inverse association between serum calcium and breast cancer risk, which warrants mechanistic investigations.

Abstract P5-07-06: A competing risks analysis of the association between prediagnostic serum glucose and lipids and breast cancer survival

Abstract Background: Abnormal levels of glucose and lipids may be linked to survival after breast cancer (BC) diagnosis, but their association to other causes of mortality such as cardiovascular (CV) disease may result in a competing risk problem and invalidate conventional analyses. Methods: We assessed serum glucose, triglycerides (TG) and total cholesterol (TC) measured prospectively three months to three years before diagnosis in 1,798 women with BC in the Swedish Apolipoprotein Mortality Risk Study (AMORIS). In addition to using multivariable Cox proportional hazards regression, we employed latent class proportional hazards models to capture any heterogeneity of associations between these markers and BC death. The latter method was extended to include the primary outcome (BC death) and competing outcomes (CV death and death from other causes), allowing latent class-specific hazard estimation for cause-specific deaths. Results: No association between prediagnostic glucose, TG or TC with BC death was observed with Cox regression. With latent class proportional hazards model, two latent classes (Class I and II) were identified in the cohort. Class I, comprising the majority (81.5%) of BC patients, had an increased risk of BC death following higher TG levels (HR: 1.87, 95% CI: 1.01-3.45 for every log TG increase). Lower overall survival was observed in Class II, but no association for BC death was found. On the other hand, TC positively corresponded to CV death in Class II, and similarly, glucose to death from other causes. Conclusion: Higher TG was associated with an increased risk of BC death in the majority of BC patients. Our study also identified a subgroup of BC patients at higher risk of early death likely driven by other metabolic-related diseases, which adds to our understanding into BC survival in presence of competing outcomes. Citation Format: Wulaningsih W, Vahdaninia M, Rowley M, Holmberg L, Garmo H, Malmstrom H, Lambe M, Hammar N, Walldius G, Jungner I, Coolen A, Van Hemelrijck M. A competing risks analysis of the association between prediagnostic serum glucose and lipids and breast cancer survival. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-07-06.

Metabolic serum biomarkers for the prediction of cancer: a follow-up of the studies conducted in the Swedish AMORIS study.

The Swedish Apolipoprotein MOrtality RISk study (AMORIS) contains information on more than 500 biomarkers collected from 397,443 men and 414,630 women from the greater Stockholm area during the period 1985–1996. Using a ten-digit personal identification code, this database has been linked to Swedish national registries, which provide data on socioeconomic status, vital status, cancer diagnosis, comorbidity, and emigration. Within AMORIS, 18 studies assessing risk of overall and site-specific cancers have been published, utilising a range of serum markers representing glucose and lipid metabolism, immune system, iron metabolism, liver metabolism, and bone metabolism. This review briefly summarises these findings in relation to more recently published studies and provides an overview of where we are today and the challenges of observational studies when studying cancer risk prediction.Overall, more recent observational studies supported previous findings obtained in AMORIS, although no new results have been reported for serum fructosamine and inorganic phosphate with respect to cancer risk. A drawback of using serum markers in predicting cancer risk is the potential fluctuations following other pathological conditions, resulting in non-specificity and imprecision of associations observed. Utilisation of multiple combination markers may provide more specificity, as well as give us repeated instead of single measurements. Associations with other diseases may also necessitate further analytical strategies addressing effects of serum markers on competing events in addition to cancer. Finally, delineating the role of serum metabolic markers may generate valuable information to complement emerging clinical studies on preventive effects of drugs and supplements targeting metabolic disorders against cancer.

Serum calcium and risk of gastrointestinal cancer in the Swedish AMORIS study

BackgroundObservational studies have indicated that high calcium intake may prevent colorectal cancer, but as for randomized trials the results are inconclusive. Meanwhile, limited data on the link between serum calcium and cancer risk is available. We investigated the relation between serum calcium and risk of different gastrointestinal cancers in a prospective study.MethodsA cohort based on 492,044 subjects with baseline information on calcium (mmol/L) and albumin (g/L) was selected from the Swedish Apolipoprotein MOrtality RISk (AMORIS) study. Multivariable Cox proportional hazard models were used to analyse associations between standardised levels, quartiles and age/sex-specific categories of serum calcium and risk of oesophageal, stomach, colon, rectal cancer and also colorectal cancer combined, while taking into account serum albumin and other comorbidities.ResultsDuring 12 years of follow-up, we identified 323 incident oesophageal cancers, 782 stomach cancers, 2519 colon cancers, and 1495 rectal cancers. A positive association was found between albumin-adjusted serum calcium and risk of oesophageal [HR: 4.82 (95% CI: 2.07 – 11.19) for high compared to normal age-specific calcium levels] and colon cancer [e.g. HR: 1.07 (95% CI: 1.00 – 1.14) for every SD increase of calcium] as well as colorectal cancer [e.g. HR: 1.06 (95% CI: 1.02-1.11) for every SD increase of calcium] in women. In men there were similar but weaker non-statistically significant trends.ConclusionThe positive relation between serum calcium, oesophageal cancer and colorectal cancer calls for further studies including calcium regulators to evaluate whether there is a true link between calcium metabolism and development of gastrointestinal cancer.

Inorganic phosphate and the risk of cancer in the Swedish AMORIS study

BackgroundBoth dietary and serum levels of inorganic phosphate (Pi) have been linked to development of cancer in experimental studies. This is the first population-based study investigating the relation between serum Pi and risk of cancer in humans.MethodsFrom the Swedish Apolipoprotein Mortality Risk (AMORIS) study, we selected all participants (> 20 years old) with baseline measurements of serum Pi, calcium, alkaline phosphatase, glucose, and creatinine (n = 397,292). Multivariable Cox proportional hazards regression analyses were used to assess serum Pi in relation to overall cancer risk. Similar analyses were performed for specific cancer sites.ResultsWe found a higher overall cancer risk with increasing Pi levels in men ( HR: 1.02 (95% CI: 1.00-1.04) for every SD increase in Pi), and a negative association in women (HR: 0.97 (95% CI: 0.96-0.99) for every SD increase in Pi). Further analyses for specific cancer sites showed a positive link between Pi quartiles and the risk of cancer of the pancreas, lung, thyroid gland and bone in men, and cancer of the oesophagus, lung, and nonmelanoma skin cancer in women. Conversely, the risks for developing breast and endometrial cancer as well as other endocrine cancer in both men and women were lower in those with higher Pi levels.ConclusionsAbnormal Pi levels are related to development of cancer. Furthermore, the in verse association between Pi levels and risk of breast, endometrial and other endocrine cancers may indicate the role of hormonal factors in the relation between Pi metabolism and cancer.

Iron metabolism and risk of cancer in the Swedish AMORIS study

ObjectivesPre-clinical studies have shown that iron can be carcinogenic, but few population-based studies investigated the association between markers of the iron metabolism and risk of cancer while taking into account inflammation. We assessed the link between serum iron (SI), total-iron binding capacity (TIBC), and risk of cancer by levels of C-reactive protein (CRP) in a large population-based study (n = 220,642).MethodsFrom the Swedish Apolipoprotein Mortality Risk (AMORIS) study, we selected all participants (>20 years old) with baseline measurements of serum SI, TIBC, and CRP. Multivariate Cox proportional hazards regression was carried out for standardized and quartile values of SI and TIBC. Similar analyses were performed for specific cancers (pancreatic, colon, liver, respiratory, kidney, prostate, stomach, and breast cancer). To avoid reverse causation, we excluded those with follow-up <3 years.ResultsWe found a positive association between standardized TIBC and overall cancer [HR 1.03 (95 % CI 1.01–1.05)]. No statistically significant association was found between SI and cancer risk except for postmenopausal breast cancer [HR for standardized SI 1.09 (95 % CI 1.02–1.15)]. The association between TIBC and specific cancer was only statistically significant for colon cancer [i.e., HR for standardized TIBC: 1.17 (95 % CI 1.08–1.28)]. A borderline interaction between SI and levels of CRP was observed only in stomach cancer.ConclusionsAs opposed to pre-clinical findings for serum iron and cancer, this population-based epidemiological study showed an inverse relation between iron metabolism and cancer risk. Minimal role of inflammatory markers observed warrants further study focusing on developments of specific cancers.

Serum calcium and incident and fatal prostate cancer in the Swedish AMORIS study

Observational studies have shown a positive association between intake of dairy products as well as serum levels of calcium and prostate cancer (PCa) risk. We studied the association between serum calcium and PCa while also accounting for levels of albumin, a protein to which calcium is bound. A cohort based on 196,022 men with baseline information on calcium (mmol/L) and albumin (g/L) was selected from the Swedish Apolipoprotein MOrtality RISk study. Age-stratified multivariable Cox proportional hazard models were used to analyze associations between calcium and incident and fatal PCa risk. A total of 6,353 men were diagnosed with PCa and 731 died of PCa during mean follow-up of 12years. A weak negative association was found between levels of calcium or albumin-corrected calcium and PCa risk (HR for quartiles of albumin-corrected calcium: 0.95 (0.89-1.02), 0.93 (0.86-1.00), and 0.91 (0.85-0.98) for the 2nd, 3rd, and 4th quartile compared to the 1st; p for trend: 0.012). BMI did not affect these findings. No association was found between calcium levels and fatal PCa. A positive association between Ca and death was observed when censoring for PCa [HR per SD: 1.14 (1.13-1.16)]. The weak negative association between Ca and PCa risk is likely explained by the relation between Ca and death. This illustrates the need to handle competing risks when defining whether Ca is involved in PCa etiology or whether it acts as a marker of other metabolic events in the causal pathway.

Serum calcium and incident and fatal prostate cancer in the Swedish AMORIS study.

36 Background: Many observational studies have shown a positive association between intake of dairy products and prostate cancer (PCa) risk. From a biological point of view it is of interest to study this association as bone was recently shown to be a positive regulator of male fertility which suggests that regulation of bone remodeling and reproduction are linked. Since androgens promote cell proliferation and inhibit prostate cell death, it is possible that calcium (Ca) is linked to PCa risk via its link with the reproductive system. We studied the association between serum Ca and PCa while also accounting for levels of albumin, a protein to which Ca is bound. Methods: A cohort based on 192,183 men with baseline information on Ca (mmol/L) and albumin (g/L) was selected from the Swedish Apolipoprotein MOrtality RISk (AMORIS) study. Age-stratified multivariable Cox proportional hazard models were used to analyze associations between Ca and incident and fatal PCa risk. All models were adjusted for fasting status, glucose levels, socio-economic status, season at time of Ca measurement, Charlson comorbidity index, and history of fractures. Results: A 6,202 men were diagnosed with PCa and 672 died of PCa during mean follow-up of 12 years. A weak negative association was found between PCa risk and Ca (HR per SD: 0.97 (95%CI: 0.95-1.00)). A similar association was also found between albumin-corrected Ca and PCa risk (HR: 0.96 (0.89-1.03), 0.94 (0.87-1.01), and 0.92 (0.86-0.99) for the 2nd, 3rd, and 4th quartile compared to the 1st; P for trend: 0.02). No association was found with fatal PCa, nor was there effect-modification by overweight. A strong positive association between Ca and death was observed when censoring for PCa (HR per SD: 1.13 (95%CI: 1.12-1.15)). Conclusions: Serum levels of Ca were weakly negatively associated with PCa risk in our study when adjusted for age and history of comorbidities and fractures. A negative association between Ca and PCa risk is likely explained by the strong relation between Ca and non-PCa death. These competing risks need to be handled in order to define whether Ca is causally involved in PCa aetiology or whether it only acts a marker of other metabolic events in the causal pathway.

Serum Lipids and the Risk of Gastrointestinal Malignancies in the Swedish AMORIS Study

Background. Metabolic syndrome has been linked to an increased cancer risk, but the role of dyslipidaemia in gastrointestinal malignancies is unclear. We aimed to assess the risk of oesophageal, stomach, colon, and rectal cancers using serum levels of lipid components. Methods. From the Swedish Apolipoprotein Mortality Risk (AMORIS) study, we selected 540,309 participants (> 20 years old) with baseline measurements of total cholesterol (TC), triglycerides (TG), and glucose of whom 84,774 had baseline LDL cholesterol (LDL), HDL cholesterol (HDL), apolipoprotein B (apoB), and apolipoprotein A-I (apoA-I). Multivariate Cox proportional hazards regression was used to assess glucose and lipid components in relation to oesophageal, stomach, colon, and rectal cancer risk. Results. An increased risk of oesophageal cancer was observed in persons with high TG (e.g. HR: 2.29 (95% CI: 1.42–3.68) for the 4th quartile compared to the 1st) and low LDL, LDL/HDL ratio, TC/HDL ratio, log (TG/HDL), and apoB/apoA-I ratio. High glucose and TG were linked with an increased colon cancer risk, while high TC levels were associated with an increased rectal cancer risk. Conclusion. The persistent link between TC and rectal cancer risk as well as between TG and oesophageal and colon cancer risk in normoglycaemic individuals may imply their substantiality in gastrointestinal carcinogenesis.

The interplay between lipid profiles, glucose, BMI and risk of kidney cancer in the Swedish AMORIS study

With exception of cholesterol and total fat intake, associations between lipid biomarkers and kidney cancer have not often been researched. We aimed to assess possible links between lipid profiles and kidney cancer risk in a large prospective cohort study, while also taking into account glucose levels and BMI. A cohort based on 542,924 persons with baseline information on glucose, triglycerides (TGs), total cholesterol (TC) and creatinine was selected from the Swedish Apolipoprotein Mortality Risk study. A subgroup of 85,621 also had baseline measurements of HDL, LDL, apolipoprotein A-I and apoB. Multivariate Cox proportional hazard models were used to analyze associations between quartiles and dichotomized values of these lipid components and kidney cancer risk. During a mean follow-up of 13 years, 958 persons developed kidney cancer. TGs were the only lipid component for which a statistically significant association was found with kidney cancer risk when using both quartiles and a clinical cutoff (hazard ratio: 1.25 (95% CI: 0.99-1.60), 1.29 (1.01-1.66) and 1.66 (1.30-2.13) for the 2nd, 3rd and 4th quartile, compared to the 1st, with p-value for trend: <0.001). The association remained after exclusion of the 95% percentile of TG. Quartiles of glucose were also positively associated with kidney cancer risk, whereas quartiles of TC were negatively associated with kidney cancer risk. This detailed analysis of lipid components only showed a consistent relation between TG levels and kidney cancer risk. Further mechanistic studies are required to assess links between lipid abnormalities and kidney cancer.

Low levels of apolipoprotein A-I and HDL are associated with risk of prostate cancer in the Swedish AMORIS study

A detailed analysis of lipid profiles, using apolipoproteins, has not yet been conducted for prostate cancer (PCa). Since several etiological pathways have been proposed for PCa and lipids, we aimed to study this in a large Swedish cohort with 1,469 primary prostate cancers. A cohort (n = 69,735) of all men aged 35 years or older, whose levels of triglycerides (TG) (mmol/L), total cholesterol (mmol/L), glucose (mmol/L), LDL (mmol/L), HDL (mmol/L), apoB (g/L), and apoA-I (g/L) were measured at baseline, was selected from the Apolipoprotein MOrtality RISk (AMORIS) database. About 2,008 men developed PCa. Multivariate Cox proportional hazard models were used to analyze associations between lipid components and PCa. ApoA-I and HDL were inversely associated with PCa risk (e.g., HR for HDL: 0.93 (95% CI: 0.81-1.07), 0.88 (0.76-1.01), 0.81 (0.70-0.94), for second, third, and fourth quartiles compared with the first quartile; with p for trend: 0.004; HR for apoA-I: 1.00 (0.88-1.13), 0.93 (0.82-1.05), 0.88 (0.77-0.99),), for second, third, and fourth quartiles compared with the first quartile; with p for trend: 0.022). ApoB, LDL, and non-HDL were not associated with PCa risk. Our results show that low HDL and ApoA-I as well as increased lipid ratios are related to increased PCa risk. Experimental studies are required to tease out the underlying biological mechanisms linking these lipid components to PCa.

Gamma-glutamyltransferase and risk of cancer in a cohort of 545,460 persons – the Swedish AMORIS study

BackgroundApart from using gamma-glutamyltransferase (GGT) as a predictor of diabetes, cardiovascular and chronic kidney disease, some evidence suggests GGT as an indicator of cancer risk. We aimed to study the association between GGT and cancer in a large Swedish cohort with 37,809 primary cancers. MethodsIn a cohort of 545,460 persons (aged >20years) who had a measurement of GGT in the Apolipoprotein Mortality Risk (AMORIS) study, multivariate Cox proportional hazards regression was used to investigate categories of GGT (<18, 18–36,36–72, ⩾72U/L) in relation to cancer risk. Stratified analyses were conducted by gender, levels of alanine aminotransferase (ALT) (</⩾50U/L), glucose (</⩾6.11mmol/L) and triglycerides (</⩾1.71mmol/L). ResultsA positive association was found between categories of GGT and overall cancer risk (HR: 1.07 (95%CI: 1.04–1.09,), 1.18 (1.14–1.22), 1.32 (1.26–1.38) for the 2nd, 3rd and 4th categories compared to the 1st). Stratified analyses showed that for those with glucose ⩾6.11mmol/L, the association between GGT and risk of prostate, breast and liver cancer became stronger (e.g. HR for GGT ⩾72U/L and prostate cancer: 1.11 (0.98–1.26) and 1.35 (1.00–1.81) for glucose <6.11 and ⩾6.11mmol/L, respectively). With pancreatic cancer, the association with GGT was weaker for those with elevated glucose levels compared to those with normal levels. No effects of ALT or triglyceride levels on risk were found. ConclusionWe found evidence of associations between elevated GGT and risk of developing different cancers. The strength of this association may vary by glucose levels because hyperglycaemia can result in oxidative stress initiating damaging pathways of carcinogenesis.

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

342 Background: Since multiple epidemiologic studies showed a link between obesity and kidney cancer (KCa), the lipid metabolism is thought to play a role in development of KCa. With the exception of cholesterol and total fat intake, the association between changes in lipid biomarkers and KCa has not often been researched. We assessed the link between lipid profiles and KCa risk in a large prospective cohort study. Methods: A cohort based on 85,261 persons (&gt; 20 years old) with baseline measurements of glucose, triglycerides (TG), total cholesterol, HDL, LDL, apolipoprotein A-I and apoB was selected from the Swedish Apolipoprotein Mortality Risk (AMORIS) study. Multivariate Cox proportional hazards models were used to analyze associations between quartiles and dichotomized values of these lipid components and KCa risk. All models were adjusted for age, gender, socioeconomic status, fasting status, history of kidney disease prior to baseline (ICD9: 580-93), and glucose, cholesterol, and TG levels (depending on the covariate of interest). Results: During a mean follow-up of 12 years, 161 persons developed KCa (58% men). The mean age at baseline was 46 years. TG were the only lipid component for which a statistically significant association was found with risk of KCa (Hazard Ratio (HR): 1.05 (95%CI: 0.59-1.87), 1.77 (1.05-2.98), and 1.77 (1.04-3.02) for the second, third, and fourth quartile, compared to the first, with p-value for trend: 0.008). The lipid ratio of TG and HDL also showed a statistically significant positive association with risk of KCa (HR: 1.21 (0.71-2.08), 1.56 (0.94-2.58), and 1.92 (1.17-3.17) for the second, third, and fourth quartile, compared to the first, with p-value for trend: 0.004). No other associations were found between lipid components and KCa risk. Conclusions: This detailed analysis of lipid components and risk of KCa found a relation between levels of TG and KCa risk. In contrast to previous studies, we did not find an association between cholesterol levels and KCa risk. Lipid profiles based on the markers used in this study do not seem to reflect the etiological pathway that has previously been shown between obesity and KCa. Further mechanistic studies are required to assess the link between lipid deregulation and KCa. No significant financial relationships to disclose.

Association between Levels of C-Reactive Protein and Leukocytes and Cancer: Three Repeated Measurements in the Swedish AMORIS Study

To study levels of C-reactive protein (CRP) and leukocytes, as inflammatory markers, in the context of cancer risk. From the Apolipoprotein MOrtality RISk (AMORIS) study, we selected 102,749 persons with one measurement and 9,273 persons with three repeated measurements of CRP and leukocytes. Multivariate Cox proportional hazards regression was applied to categories of CRP (<10, 10-15, 15-25, 25-50, >50 g/L) and quartiles of leukocytes. An inflammation-based predictive score (IPS) indicated whether someone had CRP levels of more than 10 mg/L combined with leukocytes of more than 10×10(9)/L. Reverse causality was assessed by excluding those with less than 3, 5, or 7 years of follow-up. To analyze repeated measurements of CRP and leukocytes, the repeated IPS (IPSr) was calculated by adding the IPS of each measurement. In the cohort with one measurement, there was a positive trend between CRP and risk of developing cancer, with the lowest category being the 0.99 (0.92-1.06), 1.28 (1.11-1.47), 1.27 (1.09-1.49), and 1.22 (1.01-1.48) for the second to fifth categories, respectively. This association disappeared when excluding those with follow-up of less than 3, 5, or 7 years. The association between leukocytes and cancer was slightly stronger. In the cohort with repeated measurements, the IPSr was strongly associated with cancer risk: 1.87 (1.33-2.63), 1.51 (0.56-4.06), and 4.46 (1.43-13.87) for IPSr=1, 2, and 3 compared with IPSr=0. The association remained after excluding those with follow-up of less than 1 year. Our large, prospective cohort study adds evidence for a link between inflammatory markers and cancer risk by using repeated measurements and ascertaining reverse causality.

Prostate cancer risk in the Swedish AMORIS study

In a cohort including 5112 prostate cancer (pCa) patients, the authors investigated associations among triglycerides (TG), total cholesterol (TC), and pCa while taking into account glucose. A cohort (n = 200,660) based on 4 groups of men, according to age at cohort entry, with TG, TC, and glucose measurements was selected from the Apolipoprotein MOrtality RISk (AMORIS) database. Of these, 5112 men developed pCa. Multivariate Cox proportional hazard models were used to analyze associations among TG, TC, and pCa. Competing risks were assessed graphically. Age-stratified analyses for quartiles of TG, TC, and glucose showed a negative association between glucose and pCa risk (HR, 0.93; 95% CI, 0.86-1.01), 0.93 (0.86-1.01), 0.87 (0.81-0.94) for the second, third, and fourth quartiles compared with the first (P(trend) = .001). Stratified analysis by glucose levels (<6.11 or ≥ 6.11 mmol/L) showed a positive association between hypertriglyceridemia (TG ≥ 1.71 mmol/L) and pCa risk, when there were high glucose levels (HR, 1.23; 95% CI, 1.01-1.48). No association was found for hypercholesterolemia (TC ≥ 6.50 mmol/L). Competing risk analysis showed that protective effects of glucose were overestimated in conventional Cox proportional hazard models and strengthened positive findings between TG and pCa risk. The authors'; findings supported the hypothesis that factors of the glucose and lipid metabolism influence pCa risk. Competing risk assessment showed that it is important to take into account the long natural history and age distribution of pCa when interpreting results. The authors'; findings indicate another reason to fight the increasing prevalence of obesity and dyslipidemia.