1,721,476 research outputs found
Abstract 2275: Serum retinol and risk of overall and site-specific cancer in the Alpha Tocopherol, Beta-Carotene Cancer Prevention Study
No full textAbstract
Retinol, one of the most biologically active forms of vitamin A, influences many biologic pathways potentially related to cancer. However, results of observational studies of serum retinol and cancer risk have been mixed. We prospectively examined serum retinol and risk of overall and site-specific cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a randomized, double-blind, placebo controlled trial of α-tocopherol (AT) and β-carotene (BC) supplementation conducted in male smokers in southwestern Finland. At enrollment, overnight fasting blood samples were collected and stored at -70°C protected from light. Serum retinol concentration was measured for all 29,133 participants using reverse-phase high performance liquid chromatography. 10,798 cancer cases occurred through 12/31/2012. Cox proportional hazards models were used to estimate the prospective association between quintiles of baseline serum retinol and overall and site-specific cancer incidence. Known or hypothesized risk factors for cancer were included in the multivariable model (AT and BC supplementation group, cigarettes smoked/day, years smoked, age, BMI, alcohol intake, and serum AT, BC, and cholesterol). Stratified analyses for all subgroups of the covariates (by category or by medians for continuous variables) and follow-up time to diagnosis (<10 vs. ≥10 y) were also performed for overall cancer and for the cancers for which an association with serum retinol was observed. After adjustment for age, higher serum retinol was associated with a lower risk of overall cancer (Q5 vs. Q1: HR=0.93, 95%CI=0.88-0.99, p-trend = 0.04). This finding was attenuated and no longer statistically significant after multivariable adjustment (MV-adj) (Q5 vs. Q1: MV-adj HR= 0.97, 95% CI = 0.91-1.03, p-trend = 0.43). Higher retinol concentrations were associated with increased risk of prostate cancer (Q5 vs. Q1: MV-adj HR=1.28, 95%CI = 1.13-1.45, p-trend < 0.0001) and lower risk of both lung and liver cancers (Q5 vs. Q1: liver MV-adj HR = 0.70, 95%CI = 0.50-0.99,p-trend = 0.03; lung MV-adj HR = 0.80, 95%CI = 0.72-0.88, p-trend < 0.0001). No associations with other cancers were observed. The inverse association between retinol and lung cancer was significantly modified by serum BC with a stronger association among men with higher serum BC (p for interaction = 0.018). No other statistically significant interactions were observed. In this large prospective study, higher serum retinol was associated with increased risk of prostate cancer and lower risk of lung and liver cancers. Understanding the biological mechanisms that underlie these associations may provide insight into retinol’s role in cancer prevention.
Citation Format: Manila Hada, Alison Mondul, Stephanie Weinstein, Demetrius Albanes. Serum retinol and risk of overall and site-specific cancer in the Alpha Tocopherol, Beta-Carotene Cancer Prevention Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2275. doi:10.1158/1538-7445.AM2017-2275</jats:p
Abstract PL04-02: Beta‐carotene chemoprevention trials and lessons for cancer epidemiology and prevention
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Abstract 4270: Family history in first degree relatives and risk of gastric cancer in the alpha-tocopherol, beta-carotene cancer prevention study
No full textAbstract
Background: Studies of the familial associations of gastric cancer risk have largely been limited to case-control approaches which are susceptible to recall bias and cannot distinguish temporality. Furthermore, associations with family history could be explained by shared exposure to Helicobacter pylori infection, the most important environmental risk factor for gastric cancer. Notably, the risks of early onset disease and diffuse-type tumors are thought to have a greater genetic component. We therefore examined in a prospective study the associations of gastric cancer risk with history of gastric cancer in first degree relatives, controlling for H. pylori infection.
Methods: We selected 405 incident gastric cancer cases and 4,129 controls with known H. pylori serology status from the Finnish Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study among male smokers aged 50-69 at baseline. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression with adjustment for H. pylori and other potential confounders. All statistical tests were two-sided.
Results: Family history of gastric cancer was associated with increased risk (OR=1.84, 95% CI=1.32-2.58). The association appeared stronger with gastric cancer in siblings (OR=2.87, 95% CI=1.64-5.03) than with gastric cancer in parents (OR=1.53, 95% CI=1.05-2.24). Distinguishing cases by anatomic subsite, the family history association was significant for noncardia gastric cancer (n=305; OR=2.15, 95% CI=1.50-3.07), but not for cardia cancer (n=100; OR=1.25, 95% CI=0.63-2.49). With regard to histological subtype, family history was significantly associated with both diffuse-type (n=90; OR=2.12, 95% CI=1.10-4.12) and intestinal-type (n=153; OR=1.70, 95% CI=1.02-2.83) gastric cancer. In age-specific analyses, the association with family history was strongest in the youngest age-group at baseline 50-54 years (OR=3.42, 95% CI=1.85-6.30) and absent in the oldest age group 65-69 years (OR=0.85, 95% CI=0.28-2.58).
Conclusion: The results suggest that certain subtypes of sporadic gastric cancer are strongly associated with family history of gastric cancer. These associations do not appear to be explained by the associations with H. pylori infection.
Citation Format: Minkyo Song, Maria Constanza Camargo, Stephanie J. Weinstein, Demetrius Albanes, Charles S. Rabkin. Family history in first degree relatives and risk of gastric cancer in the alpha-tocopherol, beta-carotene cancer prevention study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4270. doi:10.1158/1538-7445.AM2017-4270</jats:p
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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