Lisel Koepl

Metabolic, hormonal and immunological associations with global DNA methylation among postmenopausal women

DNA methylation is an epigenetic modification essential for the regulation of gene expression that has been implicated in many diseases, including cancer. Few studies have investigated the wide range of potential predictors of global DNA methylation, including biomarkers. Here, we investigated associations between DNA methylation and dietary factors, sex-steroid hormones, metabolic, lipid, inflammation, immune and one-carbon biomarkers. Data and baseline biomarker measurements were obtained from 173 overweight/obese postmenopausal women. Global DNA methylation in lymphocyte DNA was measured using the pyrosequencing assay for LINE-1 repeats. We used correlations and linear regression analyses to investigate associations between continuous data and DNA methylation, while t-tests were used for categorical data. Secondary analyses stratified by serum folate levels and multivitamin use were also conducted. There was little variability in LINE-1 methylation (66.3–79.5%). Mean LINE-1 methylation was significantly higher among women with elevated glucose levels. Mean LINE-1 methylation was also higher among women with high CD4+/CD8+ ratio, and lower among women with elevated vitamin B6, but neither reached statistical significance. In analyses stratified by folate status, DNA methylation was negatively associated with sex hormone concentrations (estrone, estradiol, testosterone and sex hormone binding globulin) among women with low serum folate levels (n = 53). Conversely, among women with high serum folate levels (n = 53), DNA methylation was positively associated with several immune markers (CD4/CD8 ratio, NK1656/lymphocytes and IgA). Results from this screening suggest that global DNA methylation is generally stable, with differential associations for sex hormones and immune markers depending on one-carbon status.

Genetic variation in the lipoxygenase pathway and risk of colorectal neoplasia

Arachidonate lipoxygenase (ALOX) enzymes metabolize arachidonic acid to generate potent inflammatory mediators and play an important role in inflammation‐associated diseases. We investigated associations between colorectal cancer risk and polymorphisms in ALOX5, FLAP, ALOX12, and ALOX15, and their interactions with nonsteroidal anti‐inflammatory drug (NSAID) use. We genotyped fifty tagSNPs, one candidate SNP, and two functional promoter variable nucleotide tandem repeat (VNTR) polymorphisms in three US population‐based case‐control studies of colon cancer (1,424 cases/1,780 controls), rectal cancer (583 cases/775 controls), and colorectal adenomas (485 cases/578 controls). Individuals with variant genotypes of the ALOX5 VNTR had a decreased risk of rectal cancer, with the strongest association seen for individuals with one or more alleles of >5 repeats (wild type = 5, OR>5/≥5 = 0.42, 95% CI 0.20–0.92; P = 0.01). Four SNPs in FLAP (rs17239025), ALOX12 (rs2073438), and ALOX15 (rs4796535 and rs2619112) were associated with rectal cancer risk at P ≤ 0.05. One SNP in FLAP (rs12429692) was associated with adenoma risk. A false discovery rate (FDR) was applied to account for false positives due to multiple testing; the ALOX15 associations were noteworthy at 25% FDR. Colorectal neoplasia risk appeared to be modified by NSAID use in individuals with variant alleles in FLAP and ALOX15. One noteworthy interaction (25% FDR) was observed for rectal cancer. Genetic variability in ALOXs may affect risk of colorectal neoplasia, particularly for rectal cancer. Additionally, genetic variability in FLAP and ALOX15 may modify the protective effect of NSAID use against colorectal neoplasia.

Survival and Lifetime Costs Associated With First-Line Bevacizumab Use in Older Patients With Metastatic Colorectal Cancer

INTRODUCTION The objective of this study was to investigate clinical effectiveness and incremental lifetime costs associated with first-line bevacizumab in older patients with metastatic colorectal cancer (mCRC). METHODS Patients diagnosed with mCRC in 2004-2007 were identified from the Surveillance, Epidemiology, and End Results-Medicare database and stratified by first-line treatment (no chemotherapy [CTx], CTx alone, CTx plus bevacizumab). The impact of first-line bevacizumab on survival was investigated using a propensity score adjusted multivariate Cox proportional hazards model. Mean lifetime costs for each cohort were calculated using Medicare claims for all services rendered between diagnosis and end of follow-up, adjusting for death and censoring. RESULTS A total of 4,414 patients (mean age: 77.3 years) were identified, of whom 15% received first-line bevacizumab. Among first-line-treated patients, bevacizumab receipt was associated with improved overall survival (hazard ratio: 0.85 [95% confidence interval: 0.75-0.97]; p = .013), and this benefit was limited to patients who received >1 month of bevacizumab therapy. Median and mean survival were greatest in patients treated with CTx plus bevacizumab relative to CTx alone (CTx plus bevacizumab median 19.4 months [mean 28.0 months] vs. CTx alone median 15.1 months [mean 22.9 months]; p < .001), as were mean lifetime costs (mean per patient cost

Adverse Events Associated With Bevacizumab and Chemotherapy in Older Patients With Metastatic Colorectal Cancer

143,284 vs.

Glutathione peroxidase tagSNPs: Associations with rectal cancer but not with colon cancer

111,280). Compared with CTx alone, CTx plus bevacizumab was associated with a 5.1-month increase in mean survival and a

Genetic Variation in UGT Genes Modify the Associations of NSAIDs with Risk of Colorectal Cancer: Colon Cancer Family Registry

32,004 increase in mean lifetime treatment costs, with an incremental cost of

Satisfaction with cancer care among American Indian and Alaska Natives in Oregon and Washington State: a qualitative study of survivor and caregiver perspectives

75,303 per life-year gained. CONCLUSION Bevacizumab use is associated with longer survival than CTx alone in older patients treated in real-world clinical settings, at an incremental cost of

Performance of a low-dose computed tomography (LDCT) lung cancer screening program: Findings from a registry study.

75,303 per life-year gained.

Genetic variation in UGT genes modify the associations of NSAIDs with risk of colorectal cancer

BACKGROUND The safety of bevacizumab in older mCRC patients is poorly understood. The purpose of this analysis was to determine the prevalence, incidence, and risk factors for treatment-related AEs in older bevacizumab recipients. PATIENTS AND METHODS Patients age ≥65 were identified from SEER-Medicare and categorized by mCRC diagnosis pre and post bevacizumab approval (2001-2003 vs. 2005-2007). Preexisting conditions known to increase bevacizumab-related AE risk were identified in the year before diagnosis. Factors associated with bevacizumab receipt were identified using logistic regression. Incidence rates for all AEs and specific serious AEs were determined. Risk factors for first AE were determined by competing risks regression. RESULTS Of 6821 patients, 3282 (48%) were diagnosed in 2005-2007 of whom 19% received first-line bevacizumab. Likelihood of bevacizumab receipt was lower in patients age ≥ 75 (odds ratio [OR], 0.41; 95% confidence interval [CI], 0.36-0.47), nonwhite patients (OR, 0.67; 95% CI, 0.55-0.81), patients with higher comorbidity index (OR, 0.52; 95% CI, 0.43-0.62), and patients with preexisting cerebrovascular disease (OR, 0.49; 95% CI, 0.33-0.73). AE incidence rate was not increased among first-line bevacizumab recipients relative to first-line chemotherapy recipients. In a competing risk regression adjusting for potential confounders, bevacizumab receipt (2005-2007) was not associated with an increased risk of first AE compared with chemotherapy alone (2001-2007) (hazard ratio, 0.97; 95% CI, 0.87-1.08). CONCLUSION In an older mCRC population, bevacizumab receipt was less likely in older (age ≥ 75) nonwhite patients with preexisting cerebrovascular comorbidities. First-line bevacizumab was not associated with increased AE incidence or risk of first AE compared with chemotherapy alone.

Genetic variation inUGTgenes modify the associations of NSAIDs with risk of colorectal cancer: Colon cancer family registry: Genetic Variants inUgtandCyp2c9, Nsaid Use and Colorectal Cancer Risk

Glutathione peroxidases (GPXs) are selenium‐dependent enzymes that reduce and, thus, detoxify hydrogen peroxide and a wide variety of lipid hydroperoxides. We investigated tagSNPs in GPX1‐4 in relation to colorectal neoplasia in three independent study populations capturing the range of colorectal carcinogenesis from adenoma to cancer. A linkage‐disequilibrium (LD)‐based tagSNP selection algorithm (r2 ≥ 0.90, MAF ≥ 4%) identified 21 tagSNPs. We used an identical Illumina platform to genotype GPX SNPs in three population‐based case–control studies of colon cancer (1,424 cases/1,780 controls), rectal cancer (583 cases/775 controls), and colorectal adenomas (485 cases/578 controls). For gene‐level associations, we conducted principal component analysis (PCA); multiple logistic regression was used for single SNPs. Analyses were adjusted for age, sex, and study center and restricted to non‐Hispanic white participants. Analyses of cancer endpoints were stratified by molecular subtypes. Without correction for multiple testing, one polymorphism in GPX2 and three polymorphisms in GPX3 were associated with a significant risk reduction for rectal cancer at α = 0.05, specifically for rectal cancers with TP53 mutations. The associations regarding the three polymorphisms in GPX3 remained statistically significant after adjustment for multiple comparisons. The PCA confirmed an overall association of GPX3 with rectal cancer (P = 0.03). No other statistically significant associations were observed. Our data provide preliminary evidence that genetic variability in GPX3 contributes to risk of rectal cancer but not of colon cancer and thus provide additional support for differences in underlying pathogenetic mechanisms for colon and rectal cancer.