Association of Selenoprotein and Selenium Pathway Genotypes with Risk of Colorectal Cancer and Interaction with Selenium Status.

Selenoprotein genetic variations and suboptimal selenium (Se) levels may contribute to the risk of colorectal cancer (CRC) development. We examined the association between CRC risk and genotype for single nucleotide polymorphisms (SNPs) in selenoprotein and Se metabolic pathway genes. Illumina Goldengate assays were designed and resulted in the genotyping of 1040 variants in 154 genes from 1420 cases and 1421 controls within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Multivariable logistic regression revealed an association of 144 individual SNPs from 63 Se pathway genes with CRC risk. However, regarding the selenoprotein genes, only TXNRD1 rs11111979 retained borderline statistical significance after adjustment for correlated tests (PACT = 0.10; PACT significance threshold was P < 0.1). SNPs in Wingless/Integrated (Wnt) and Transforming growth factor (TGF) beta-signaling genes (FRZB, SMAD3, SMAD7) from pathways affected by Se intake were also associated with CRC risk after multiple testing adjustments. Interactions with Se status (using existing serum Se and Selenoprotein P data) were tested at the SNP, gene, and pathway levels. Pathway analyses using the modified Adaptive Rank Truncated Product method suggested that genes and gene x Se status interactions in antioxidant, apoptosis, and TGF-beta signaling pathways may be associated with CRC risk. This study suggests that SNPs in the Se pathway alone or in combination with suboptimal Se status may contribute to CRC development.

Evaluation of Treatment Patterns and Survival Outcomes in Elderly Pancreatic Cancer Patients: A Surveillance, Epidemiology, and End Results-Medicare Analysis.

BACKGROUND: Management of pancreatic cancer (PC) in elderly patients is unknown; clinical trials exclude patients with comorbidities and those of extreme age. This study evaluated treatment patterns and survival outcomes in elderly PC patients using linked Surveillance, Epidemiology, and End Results (SEER) and Medicare data. MATERIALS AND METHODS: Histology codes 8140, 8500, 8010, 8560, 8490, 8000, 8260, 8255, 8261, 8263, 8020, 8050, 8141, 8144, 8210, 8211, or 8262 in Medicare Parts A and B were identified. Data regarding demographic, characteristics, treatments, and vital status between 1998 and 2009 were collected from the SEER. Determinants of treatment receipt and overall survival were examined using logistic regression and Cox proportional hazards models, respectively. RESULTS: A total of 5,975 patients met inclusion. The majority of patients were non-Hispanic whites (85%) and female (55%). Most cases presented with locoregional stage disease (74%); 41% received only chemotherapy, 30% chemotherapy and surgery, 10% surgery alone, 3% radiation, and 16% no cancer-directed therapy. Patients with more advanced cancer, older age, and those residing in areas of poverty were more likely to receive no treatment. Among patients 66-74 years of age with locoregional disease, surgery alone (hazard ratio [HR] = 0.54; 95% confidence interval [CI]: 0.39-0.74) and surgery in combination with chemotherapy (HR = 0.69; 95% CI: 0.53-0.91) showed survival benefit as compared with the no treatment group. Among patients ≥75 years of age with locoregional disease, surgery alone (HR = 2.04; 95% CI: 0.87-4.8) or in combination with chemotherapy (HR = 1.59; 95% CI: 0.87-2.91) was not associated with better survival. CONCLUSION: Treatment modality and survival differs by age and stage. Low socioeconomic status appears to be a major barrier to the receipt of PC therapy among Medicare patients. IMPLICATIONS FOR PRACTICE: Elderly patients with cancer are under-represented on clinical trials and usually have comorbid illnesses. The management of elderly patients with pancreatic cancer is unknown, with many retrospective experiences but low sample sizes. Using Surveillance, Epidemiology, and End Results-Medicare linked data to analyze treatment patterns and survival of elderly patients with pancreatic cancer on a larger population scale, this study highlights treatment patterns and their effect on survival and proposes possible obstacles to access of care in elderly patients with pancreatic cancer other than Medicare coverage.