Indiana University-Purdue University Indianapolis (IUPUI) / Since exposure to carcinogens can occur in the environment from various point sources, cancer risk assessment attempts to define and limit potential exposure such that the risk of developing cancer is negligible. While cancer risk assessment is widely used with certain methodologies well accepted in the scientific literature and regulatory guidances, there are still gaps which increase uncertainties when assessing risk including: (1) mixtures of genotoxins, (2) genotoxic metabolites, and (3) nongenotoxic carcinogens. An in silico model was developed to predict the cancer risk of a genotoxin which improved methodology for a single compound and mixtures. Monte Carlo simulations performed with a carcinogenicity potency database to estimate the overall carcinogenic risk of a mixture of genotoxic compounds showed that structural similarity would not likely increase the overall cancer risk. A cancer risk model was developed for genotoxic metabolites using excretion material in both animals and humans to determine the probability not exceeding a 1 in 100,000 excess cancer risk. Two model nongenotoxic compounds (fenofibrate and methapyraline) were tested in short-term microarray studies to develop a framework for cancer risk assessment. It was determined that a threshold for potential key events could be derived using benchmark dose analysis in combination with well developed ontologies (Kegg/GO), which were at or below measured tumorigenic and precursor events. In conclusion, informatics was effective in advancing toxicology-based cancer risk assessment using databases and predictive techniques which fill critical gaps in its methodology.

Bibliography: leaves 150-166. / ix, 166, xxii leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / To assess the role of acetylator status and glutathione S-transferase[mu] (GST[mu]) null phenotype on the risk for development of colorectal neoplasms in humans and to determine whether this was influenced by the dietary intake of meat. / Thesis (M.D.)--University of Adelaide, Dept. of Medicine, 1995?

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MCur / Department of Advanced Nursing Science / Historically, cancer is regarded as a disease with very devastating effects on human beings because it leads to many deaths across the world, compared to AIDS, tuberculosis and malaria collectively. Cancer diagnosis has impacted negatively on patients and their immediate families and has caused unbearable consequences. Unlike other chronic diseases, cancer patients undergo different types of treatments which affect their well-being and as a result they tend to have different experiences to those of other chronic diseases sufferers. The study design used was a quantitative cross sectional survey. The purpose was to investigate the impact of cancer diagnosis on cancer patients in Vhembe district. The target population included all patients in the Vhembe District of Limpopo, South Africa who have been diagnosed with cancer in the past six months. Using a probability simple random, a sample of 207 patients diagnosed with cancer, from seven selected hospitals in Vhembe District were selected as respondents and a self -administered questionnaire was used to collect data. Data was analysed using a software package for descriptive statistics (SPSS version 23). Graphs, tables and charts were used to display the results visually and chi-square to compare variables. Ethical principles of privacy, anonymity, informed consent were considered. The findings revealed that cancer diagnosis has negative outcomes as patients experience physical hardship, psychological stress, financial difficulties, as well as interference with family and social life. The study recommended that cancer patients and their families, be supported through the cancer journey. / NRF