Animal products and K-ras codon 12 and 13 mutations in colon carcinomas

K-ras gene mutations (codons 12 and 13) were determined by PCR-based mutant allele-specific amplification (MASA) in tumour tissue of 185 colon cancer patients: 36␑arboured mutations, of which 82 ere located in codon 12. High intakes of animal protein, calcium and poultry were differently associated with codon 12 and 13 mutations: odds ratios (OR) and 95␌onfidence intervals (95␌I) for codon 12 versus codon 13 were 9.0 (2.0–42), 4.1 (1.4–12) and 15 (1.4–160), respectively. In case–control comparisons, high intakes of animal protein and calcium were positively associated with colon tumours harbouring codon 12 mutations [for animal protein per 17 g, OR (95␌I) = 1.5 (1.0–2.1); for calcium per 459 mg, 1.2 (0.9–1.6)], while inverse associations were observed for tumours with K-ras mutations in codon 13 [for animal protein 0.4 (0.2–1.0); for calcium 0.6 (0.3–1.2)]. Transition and transversion mutations were not differently associated with these dietary factors. These data suggest a different dietary aetiology of colon tumours harbouring K-ras codon 12 and 13 mutations

Dietary patterns associated with male lung cancer risk in the Netherlands Cohort Study

The objective of this article was to study the association between dietary patterns and lung cancer incidence in the Netherlands Cohort Study on Diet and Cancer. The baseline measurement of this prospective case cohort study that was completed by 58,279 men in 1986 included a self-administered questionnaire on dietary intake, smoking habits, and other covariates. Follow-up was established by computerized record linkage to cancer registries and a pathology register. After 9.3 years of follow-up, 1,426 confirmed cases of incident male lung cancer were detected. Five dietary patterns were identified by exploratory factor analysis in a randomly sampled subcohort (n = 2,190). The dietary pattern labeled "salad vegetables" was associated with decreased risk of lung cancer [rate ratios (RR)Q5, 0.75; 95% confidence interval (CI), 0.55-1.01], after multivariate adjustment. This inverse association was most evident among current and former smokers. A dietary pattern labeled "sweet foods" was also inversely associated with lung cancer risk (RR Q5, 0.62; 95% CI, 0.43-0.89). However, the higher intake of monosaccharides and disaccharides, fruits, and lower consumption of alcohol associated with this pattern could not account for its full protective effect. The "pork, processed meat, and potatoes" pattern was nonsignificantly associated with increased risk (RRQ5, 1.44; 95% CI, 0.99-2.09), and this positive association was most evident among current smokers. The other dietary patterns characterized by brown/white bread substitution and by consumption of cooked vegetables were not associated with lung cancer risk. These results show how studying both single factors and dietary patterns gives more insight into the complex, and often seemingly inconsistent, associations between diet and cancer

p53 Over-expression and p53 mutations in colon carcinomas : relation to dietary risk factors

Epidemiological studies have suggested that dietary factors may differently affect p53-dependent and p53-independent pathways to colon cancer. Results of such studies may depend on the method used to assess p53 status. This case-control study of 185 colon-cancer cases and 259 controls examines this relation, using both immunohistochemistry and SSCP(exons 5- 8)/sequencing to detect p53 abnormalities. Of 185 carcinomas analyzed using immunohistochemistry, 81 (44%) were categorized as p53 over-expression, p53 mutations were detected in 59 tumors (32%). A slight increase in risk observed for intake of saturated fat was largely due to an increased risk in cases without p53 over-expression (OR per 16.1 g/day, 1.46; 95% CI, 1.08- 1.97), and no association in cases with p53 over-expression (OR, 1.07, 95% CI, 0.78-1.47). However, findings were less pronounced when cases were classified by mutation analysis (wild-type OR, 1.33; 95% CI, 1.01-1.75; mutated OR, 1.16; 95% CI, 0.81-1.65). Similar results were observed for total fat intake. For other nutrients and for vegetable and meat food groups no differences in risk for either p53 pathway were observed, independent of the laboratory technique used. Interestingly, in cases with transversion mutations in the p53 gene, an increased risk was observed for saturated fat (OR, 2.00; 95% CI, 0.97-4.14), in contrast to those with mutations at CpG sites (OR, 0.93; 95% CI, 0.55-1.57). An increase in colon-cancer risk for the p53-independent pathway due to fat intake, is more pronounced when using immunohistochemistry. However, mutation analysis is needed to study the possible association with a small group of tumors with transversion mutations

Animal products and K-ras codon 12 and 13 mutations in colon carcinomas

K-ras gene mutations (codons 12 and 13) were determined by PCR-based mutant allele-specific amplification (MASA) in tumour tissue of 185 colon cancer patients: 36␑arboured mutations, of which 82 ere located in codon 12. High intakes of animal protein, calcium and poultry were differently associated with codon 12 and 13 mutations: odds ratios (OR) and 95␌onfidence intervals (95␌I) for codon 12 versus codon 13 were 9.0 (2.0–42), 4.1 (1.4–12) and 15 (1.4–160), respectively. In case–control comparisons, high intakes of animal protein and calcium were positively associated with colon tumours harbouring codon 12 mutations [for animal protein per 17 g, OR (95␌I) = 1.5 (1.0–2.1); for calcium per 459 mg, 1.2 (0.9–1.6)], while inverse associations were observed for tumours with K-ras mutations in codon 13 [for animal protein 0.4 (0.2–1.0); for calcium 0.6 (0.3–1.2)]. Transition and transversion mutations were not differently associated with these dietary factors. These data suggest a different dietary aetiology of colon tumours harbouring K-ras codon 12 and 13 mutations

Animal products and K-ras codon 12 and 13 mutations in colon carcinomas

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