Adherence to the European Code Against Cancer in relation to long-term cancer mortality: intercohort comparisons from the Seven Countries Study.
Ocke MC. Bueno-de-Mesquita HB. Feskens EJ. Kromhout D. Menotti A. Blackburn H.
Department of Chronic Disease and Environmental Epidemiology, Bilthoven, The Netherlands. MC.Ocke@rivm.nl
Within the Seven Countries Study, we investigated whether population differences in 25-year cancer mortality and mortality due to cancer of the lung, stomach, and colorectum could be explained by population differences in adherence to the European Code Against Cancer. Baseline surveys were carried out around 1960 on 12,763 middle-aged men constituting 16 cohorts in seven countries; small samples of the cohorts kept dietary records. In 1987, food equivalent composites representing the average food intake of each cohort at baseline were collected locally and analyzed in one central laboratory. The vital status of all participants was verified after 25 years of follow-up. Overall adherence to the first four recommendations of the European Code Against Cancer was inversely related to 25-year total cancer mortality but not to all-cause mortality. The association with cancer mortality was essentially due to the inverse association for adherence to the guideline on smoking only. Each decrease in the percentage of smokers of 3.4% (10% of range) was associated with a relative risk of 0.93 of dying from cancer. Adherence to the recommendation on consumption of vegetables, fruits, and fiber-rich cereals was inversely related to stomach cancer mortality, whereas adherence to the recommendation on body weight, physical activity, and intake of fat was associated with higher stomach cancer mortality.
Depressed p34cdc2 kinase activity and G2/M phase arrest induced by diallyl disulfide in HCT-15 cells.
Knowles LM. Milner JA.
Nutrition Department, Pennsylvania State University, University Park 16802, USA.
The present studies reveal the antiproliferative property of diallyl disulfide (DADS) in cultured human colon tumor cells (HCT-15) relative to its ability to decrease the proportion of cells in the G1 phase and increase the proportion of cells in the G2/M phase. The shift in the proportion of cells blocked in the G2/M phase increased as the concentration and duration of DADS exposure increased. Refeeding DADS-treated cells (50 microM) with complete medium without DADS resulted in a return to normal proliferation rates. Consistent with the G2/M phase arrest, DADS exposure inhibited p34cdc2 kinase activity within four hours of treatment. The maximum depression in p34cdc2 kinase activity (53%) occurred when 25 microM DADS was added to the medium. The present studies suggest that depressed p34cdc2 kinase activity is likely one of the early cellular events that may account for the antiproliferative property of DADS.
Meal frequency and coffee intake in colon cancer.
Favero A. Franceschi S. La Vecchia C. Negri E. Conti E. Montella M.
Servizio di Epidemiologia, Centro di Riferimento Oncologico, Aviano, Italy.
Several studies suggested that frequent eating may increase colon cancer risk. To further clarify this issue, a case-control study was carried out in six areas of Italy on 1,225 incident cases < 75 years of age with histologically confirmed colon cancer and 4,154 control subjects. The controls were hospitalized for acute, nonneoplastic conditions unrelated to long-term dietary modifications. After allowance for education, physical activity, intake of vegetables, and major energy sources, there was a trend of increasing risk with increasing eating frequency (odds ratio for > or = 4 vs. < or = 2 daily meals = 1.24). Coffee intake, which was inversely associated with cancer risk, exerted a modification effect, with an odds ratio of 1.89 for frequent eaters who drank fewer than two cups of coffee per day. Frequent eating increases, whereas high coffee intake decreases, the excretion of bile acids, which are suspected to be carcinogenic to the colon. Thus, it is conceivable that frequent coffee intake may counterbalance the effect of frequent eating.
Vitamin E and colon cancer: is there an association?
Slattery ML. Edwards SL. Anderson K. Caan B.
University of Utah Medical School, Salt Lake City 84108, USA. email@example.com
The role of vitamin E in the etiology and prevention of colon cancer is not clear. It is possible that various forms of vitamin E may act differently in colon tissue and may be effective chemopreventive agents. Previous reports of vitamin E and colon cancer have focused on alpha-tocopherol and have not considered other dietary forms of vitamin E. Data from a study of 1,993 cases and 2,410 controls were used to evaluate the associations between the four most common forms of dietary vitamin E and supplemental vitamin E and colon cancer. After adjusting for other health and life-style factors, we did not observe a statistically significant association between dietary tocopherols and colon cancer. There were, however, suggestions of an inverse association between total alpha-tocopherol equivalents and colon cancer among women diagnosed with colon cancer before the median age of the control population, 67 years [odds ratio (OR) = 0.66, 95% confidence interval (CI) = 0.36-1.22] and a direct association between gamma-tocopherol and colon cancer among these women (OR = 1.44, 95% CI = 0.92-1.93). Women diagnosed with colon cancer when > or = 67 years of age appeared to have some protection from use of vitamin E supplements (OR = 0.80, 95% CI = 0.56-1.15). These data offer only limited support for a protective effect of vitamin E and colon cancer after adjustment for other health and life-style factors.
Alcohol intake and risk of cancers of the colon and rectum.
Tavani A. Ferraroni M. Mezzetti M. Franceschi S. Lo Re A. La Vecchia C.
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
The relationship between alcohol drinking (mainly wine) and risk of colon and rectal cancer was considered in a case-control study conducted between 1991 and 1996 in six Italian centers. Cases were 1,225 patients < 75 years of age with histologically confirmed cancer of the colon and 728 patients with cancer of the rectum; controls were 4,154 patients admitted to hospital for a wide spectrum of acute, nonneoplastic diseases. Compared with never drinkers, the odds ratios (OR) for current drinkers in the higher quintile of total alcohol intake (> 51.82 g ethanol/day) were 1.01 for colon cancer and 0.90 for rectal cancer, and those for ex-drinkers were 1.20 and 1.07, respectively. The OR for wine drinkers in the highest quartile of intake were 1.07 for colon cancer and 0.97 for rectal cancer. No association was found with duration of the habit, time since starting, or age at starting. Among ex-drinkers, no association appeared with time since stopping. No significant heterogeneity was found across strata of age at diagnosis, sex, education, smoking status, physical activity, family history of colorectal cancer, beta-carotene, vitamin C, coffee, total fiber and folate intake, and number of meals per day. No significant association appeared for various intestinal subsites.
Dietary nitrosamines, heterocyclic amines, and risk of gastric cancer: a case-control study in Uruguay.
De Stefani E. Boffetta P. Mendilaharsu M. Carzoglio J. Deneo-Pellegrini H.
Registro Nacional de Cancer, Montevideo, Uruguay.
To study the effects of dietary chemicals like nitrosodimethylamine and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, resulting from the cooking method of red meat, on gastric carcinogenesis, a case-control study was conducted in Uruguay, a country with areas of high rates of gastric cancer. The study involved 340 cases and 698 controls, who were interviewed between January 1993 and December 1996. Dietary nitrosodimethylamine was associated with an increased risk of gastric cancer [odds ratio (OR) = 3.6, 95% confidence interval (CI) = 2.4-5.5], whereas dietary 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (a potent mutagen derived from the frying and broiling of red meat) showed an OR of 3.9 (95% CI = 2.3-6.4). Both chemicals displayed independent effects, and its interaction followed a multiplicative model with an elevated OR of 12.7 (95% CI = 7.7-21.2). These results suggest that salted and barbecued meat, frequent items in the Uruguayan diet, and the resulting chemicals from the cooking methods of both types of meat are significantly associated with a high risk of stomach cancer.