| 1. |
- Bjørge, Tone, et al.
(författare)
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BMI and weight changes and risk of obesity-related cancers : a pooled European cohort study
- 2019
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 1464-3685 .- 0300-5771. ; 48:6, s. 1872-1885
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obesity is an established risk factor for several cancers. Adult weight gain has been associated with increased cancer risk, but studies on timing and duration of adult weight gain are relatively scarce. We examined the impact of BMI (body mass index) and weight changes over time, as well as the timing and duration of excess weight, on obesity- and non-obesity-related cancers. METHODS: We pooled health data from six European cohorts and included 221 274 individuals with two or more height and weight measurements during 1972-2014. Several BMI and weight measures were constructed. Cancer cases were identified through linkage with national cancer registries. Hazard ratios (HRs) of cancer with 95% confidence intervals (CIs) were derived from time-dependent Cox-regression models. RESULTS: During follow-up, 27 881 cancer cases were diagnosed; 9761 were obesity-related. The HR of all obesity-related cancers increased with increasing BMI at first and last measurement, maximum BMI and longer duration of overweight (men only) and obesity. Participants who were overweight before age 40 years had an HR of obesity-related cancers of 1.16 (95% CI 1.02, 1.32) and 1.15 (95% CI 1.04, 1.27) in men and women, respectively, compared with those who were not overweight. The risk increase was particularly high for endometrial (70%), male renal-cell (58%) and male colon cancer (29%). No positive associations were seen for cancers not regarded as obesity-related. CONCLUSIONS: Adult weight gain was associated with increased risk of several major cancers. The degree, timing and duration of overweight and obesity also seemed to be important. Preventing weight gain may reduce the cancer risk.
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| 2. |
- Bjørge, Tone, et al.
(författare)
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Metabolic risk factors and ovarian cancer in the metabolic syndrome and cancer project
- 2011
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 40:6, s. 1667-1677
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: No studies have so far evaluated the impact of the metabolic syndrome (MetS) as an entity on ovarian cancer risk. The authors aimed to examine the association between factors in the MetS, individually and combined, and risk of ovarian cancer incidence and mortality. METHODS: Altogether, 290 000 women from Austria, Norway and Sweden were enrolled during 1974-2005, with measurements taken of height, weight, blood pressure and levels of glucose, cholesterol and triglycerides. Relative risks (RRs) of ovarian cancer were estimated using Cox regression for each MetS factor in quintiles and for standardized levels (z-scores), and for a composite z-score for the MetS. RRs were corrected for random error in measurements. RESULTS: During follow-up, 644 epithelial ovarian cancers and 388 deaths from ovarian cancer were identified. There was no overall association between MetS and ovarian cancer risk. Increasing levels of cholesterol [RR 1.52, 95% confidence interval (95% CI) 1.01-2.29, per 1-U increment of z-score] and blood pressure (RR 1.79, 95% CI 1.12-2.86) conferred, however, increased risks of mucinous and endometrioid tumours, respectively. In women below the age of 50 years, there was increased risk of ovarian cancer mortality for MetS (RR 1.52, 95% CI 1.00-2.30). Increasing levels of BMI (RR 1.17, 95% CI 1.01-1.37) conferred increased risk of ovarian cancer mortality in women above the age of 50 years. CONCLUSION: There was no overall association between MetS and ovarian cancer risk. However, increasing levels of cholesterol and blood pressure increased the risks of mucinous and endometrioid tumours, respectively. Increasing levels of BMI conferred an increased risk of ovarian cancer mortality in women above the age of 50 years.
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| 3. |
- Fritz, Josef, et al.
(författare)
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The triglyceride-glucose index as a measure of insulin resistance and risk of obesity-related cancers
- 2020
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 49:1, s. 193-204
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The role of insulin resistance as a mediator in the association of body mass index (BMI) with site-specific cancer risk has, to our knowledge, never been systematically quantified.METHODS: Altogether 510 471 individuals from six European cohorts, with a mean age of 43.1 years, were included. We used the triglyceride glucose product (TyG index) as a surrogate measure for insulin resistance. We fitted Cox models, adjusted for relevant confounders, to investigate associations of TyG index with 10 common obesity-related cancers, and quantified the proportion of the effect of BMI mediated through TyG index on the log-transformed hazard ratio (HR) scale.RESULTS: During a median follow-up of 17.2 years, 16 052 individuals developed obesity-related cancers. TyG index was associated with the risk of cancers of the kidney HR per one standard deviation increase 1.13, 95% confidence interval: 1.07 to 1.20], liver (1.13, 1.04 to 1.23), pancreas (1.12, 1.06 to 1.19), colon (1.07, 1.03 to 1.10) and rectum (1.09, 1.04 to 1.14). Substantial proportions of the effect of BMI were mediated by TyG index for cancers of the pancreas (42%), rectum (34%) and colon (20%); smaller proportions for kidney (15%) and liver (11%). Little or no mediation was observed for breast (postmenopausal), endometrial and ovarian cancer. Results were similar for males and females, except for pancreatic cancer where the proportions mediated were 20% and 91%, respectively.CONCLUSIONS: The TyG index was associated with increased risk of cancers of the digestive system and substantially mediated the effect of BMI, suggesting that insulin resistance plays a promoting role in the pathogenesis of gastrointestinal cancers.
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| 4. |
- Larose, Tricia L., et al.
(författare)
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Circulating cotinine concentrations and lung cancer risk in the Lung Cancer Cohort Consortium (LC3)
- 2018
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Ingår i: International Journal of Epidemiology. - : Oxford University Press. - 0300-5771 .- 1464-3685. ; 47:6, s. 1760-1771
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Tidskriftsartikel (refereegranskat)abstract
- Background: Self-reported smoking is the principal measure used to assess lung cancer risk in epidemiological studies. We evaluated if circulating cotinine—a nicotine metabolite and biomarker of recent tobacco exposure—provides additional information on lung cancer risk.Methods: The study was conducted in the Lung Cancer Cohort Consortium (LC3) involving 20 prospective cohort studies. Pre-diagnostic serum cotinine concentrations were measured in one laboratory on 5364 lung cancer cases and 5364 individually matched controls. We used conditional logistic regression to evaluate the association between circulating cotinine and lung cancer, and assessed if cotinine provided additional risk-discriminative information compared with self-reported smoking (smoking status, smoking intensity, smoking duration), using receiver-operating characteristic (ROC) curve analysis.Results: We observed a strong positive association between cotinine and lung cancer risk for current smokers [odds ratio (OR ) per 500 nmol/L increase in cotinine (OR500): 1.39, 95% confidence interval (CI): 1.32–1.47]. Cotinine concentrations consistent with active smoking (≥115 nmol/L) were common in former smokers (cases: 14.6%; controls: 9.2%) and rare in never smokers (cases: 2.7%; controls: 0.8%). Former and never smokers with cotinine concentrations indicative of active smoking (≥115 nmol/L) also showed increased lung cancer risk. For current smokers, the risk-discriminative performance of cotinine combined with self-reported smoking (AUCintegrated: 0.69, 95% CI: 0.68–0.71) yielded a small improvement over self-reported smoking alone (AUCsmoke: 0.66, 95% CI: 0.64–0.68) (P = 1.5x10–9).Conclusions: Circulating cotinine concentrations are consistently associated with lung cancer risk for current smokers and provide additional risk-discriminative information compared with self-report smoking alone.
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| 5. |
- Orho-Melander, Marju, et al.
(författare)
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Blood lipid genetic scores, the HMGCR gene and cancer risk : A Mendelian randomization study
- 2018
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 47:2, s. 495-505
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is unclear whether there are causal associations between blood lipids, statin use and cancer risks. Under certain assumptions, Mendelian randomization analysis of a genetic marker for an exposure eliminates reverse causation and confounding. Methods: We applied Mendelian randomization analysis to genetic scores, comprising 26–41 single-nucleotide polymorphisms (SNPs), as instrumental variables (IVs) for triglycerides and low- and high-density lipoprotein cholesterol (LDLC, HDLC), using a prospective cohort of 26 904 individuals in which there were 6607 incident cancers. We also investigated cancer risk for a SNP (rs12916) in the gene encoding hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the targeted enzyme in statin treatment. We used logistic regression and SNP pleiotropy-adjusted analyses to estimate the odds ratio per standard deviation (OR). Results: The OR for the triglyceride IV as a predictor of any cancer was 0.91 [95% confidence interval (CI): 0.80–1.03] unadjusted, and 0.87 (95% CI: 0.78–0.95) from the pleiotropy-adjusted analysis. For the HMGCR rs12916 per LDLC-lowering T-allele, the OR was 1.09 (95% CI: 1.01–1.18) for prostate cancer and 0.89 (95% CI: 0.82–0.96) for breast cancer. The LDLC IV was not associated with prostate cancer or breast cancer. There were no associations between IVs and cancers of the lung, colon or bladder. Conclusions: Under the assumptions of Mendelian randomization, there is a causal and negative association between serum triglycerides and risk of any cancer. Further, the HMGCR genetic variant might be associated with risks of prostate and breast cancers but the biological mechanisms behind these findings are unclear, as the LDLC IV was not associated with these cancers.
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| 6. |
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| 7. |
- Stocks, Tanja, et al.
(författare)
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Metabolic risk score and cancer risk : pooled analysis of seven cohorts
- 2015
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Ingår i: International Journal of Epidemiology. - : Oxford University Press. - 0300-5771 .- 1464-3685. ; 44:4, s. 1353-1363
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Tidskriftsartikel (refereegranskat)abstract
- Background: There are few data on the joint influence of metabolic factors on risk of separate cancers. Methods: We analysed data on body mass index, blood pressure and plasma levels of glucose, total cholesterol and triglycerides from seven European cohorts comprising 564 596 men and women with a mean age of 44 years. We weighted those factors equally into a standardized metabolic risk score [MRS, mean = 0, standard deviation (SD) = 1], with an individual's level indicated as SDs from the sex-and cohort-specific means. Cancer hazard ratios were calculated by Cox regression with age as timescale and with relevant adjustments including smoking status. All statistical tests were two-sided. Results: During a mean follow-up of 12 years, 21 593 men and 14 348 women were diagnosed with cancer. MRS was linearly and positively associated with incident cancer in total and at sites (P<0.05). In men, risk per SD MRS was increased by 43% (95% confidence interval: 27-61) for renal cell cancer, 43% (16-76) for liver cancer, 29% (20-38) for colon cancer, 27% (5-54) for oesophageal cancer, 20% (9-31) for rectal cancer, 19% (4-37) for leukaemias, 15% (1-30) for oral cancer and 10% (2-19) for bladder cancer. In women, risk increases per SD MRS were 56% (42-70) for endometrial cancer, 53% (29-81) for pancreatic cancer, 40% (16-67) for renal cell cancer, 27% (9-47) for cervical cancer and 17% (3-32) for rectal cancer. Conclusion: This largest study to date on the joint influence of metabolic factors on risk of separate cancers showed increased risks for several cancers, in particular renal cell and liver cancer in men and endometrial and pancreatic cancer in women.
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