C. Pasche

Food groups and colorectal cancer risk

SummaryMost studies of diet and colorectal cancer have considered nutrients and micronutrients, but the role of foods or food groups remains open to debate. To elucidate the issue, we examined data from a case–control study conducted between 1992 and 1997 in the Swiss canton of Vaud. Cases were 223 patients (142 men, 81 women) with incident, histologically confirmed colon (n = 119) or rectal (n = 104) cancer (median age 63 years), linked with the Cancer Registry of the Swiss Canton of Vaud, and controls were 491 subjects (211 men, 280 women, median age 58 years) admitted to the same university hospital for a wide spectrum of acute non-neoplastic conditions unrelated to long-term modifications of diet. Odds ratios (OR) were obtained after allowance for age, sex, education, smoking, alcohol, body mass index, physical activity and total energy intake. Significant associations were observed for refined grain (OR = 1.32 for an increase of one serving per day), and red meat (OR = 1.54), pork and processed meat (OR = 1.27), alcohol (OR = 1.28), and significant protections for whole grain (OR = 0.85), raw (OR = 0.85) and cooked vegetables (OR = 0.69), citrus (OR = 0.86) and other fruits (OR = 0.85), and for coffee (OR = 0.73). Garlic was also protective (OR = 0.32 for the highest tertile of intake). These findings in a central European population support the hypothesis that a diet rich in refined grains and red meat increases the risk of colorectal cancer; they, therefore, support the recommendation to substitute whole grains for refined grain, to limit meat intake, and to increase fruit and vegetable consumption.

Food groups and risk of oral and pharyngeal cancer

The role of specific food groups and diet variety on the risk of oral and pharyngeal cancer has been considered using data from a case‐control study conducted between 1992 and 1997 in the Swiss Canton of Vaud. Cases were 156 patients (126 males, 30 females) aged under 75 (median age 56) years with incident, histologically confirmed cancer of the oral cavity and pharynx, and controls were 284 subjects (246 males, 38 females, median age 57 years), admitted to the same university hospital for a wide spectrum of acute, non‐neoplastic conditions unrelated to tobacco and alcohol consumption or to long‐term modification of diet. After allowance for education, alcohol, tobacco and total energy intake, significant trends of increasing risk with more frequent intake emerged for eggs (OR = 2.3 for the highest tertile), red meat (OR = 2.1) and pork and processed meat (OR = 3.2). Inverse trends in risk were observed for milk (OR = 0.4 for the highest tertile), fish (OR = 0.5), raw vegetables (OR = 0.3), cooked vegetables (OR = 0.1), citrus fruit (OR = 0.4) and other fruits (OR = 0.2). The addition of a serving per day of fruit or vegetables was associated with an about 50% reduction in oral cancer risk. The most favourable diet for oral cancer risk is therefore given by infrequent consumption of red and processed meat and eggs and, most of all, frequent vegetable and fruit intake. Diet diversity was inversely related to oral and pharyngeal cancer: ORs were 0.35 for the highest tertile of total diversity, 0.24 for vegetable and 0.34 for fruit diversity. In terms of attributable risk, high meat intake accounted for 49% of oral and pharyngeal cancers in this population, low vegetable intake for 65% and low fruit intake for 54%. Int. J. Cancer 77:705–709, 1998.

Combined effect of tobacco and alcohol on laryngeal cancer risk: a case-control study

Objective: To provide information on the effects of alcohol and tobacco on laryngeal cancer and its subsites. Methods: This was a case–control study conducted between 1992 and 2000 in northern Italy and Switzerland. A total of 527 cases of incident squamous-cell carcinoma of the larynx and 1297 hospital controls frequency-matched with cases on age, sex, and area of residence were included. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using multiple logistic regression. Results: In comparison with never smokers, ORs were 19.8 for current smokers and 7.0 for ex-smokers. The risk increased in relation to the number of cigarettes (OR = 42.9 for ≥25 cigarettes/day) and for duration of smoking (OR = 37.2 for ≥40 years). For alcohol, the risk increased in relation to number of drinks (OR = 5.9 for ≥56 drinks per week). Combined alcohol and tobacco consumption showed a multiplicative (OR = 177) rather than an additive risk. For current smokers and current drinkers the risk was higher for supraglottis (ORs 54.9 and 2.6, respectively) than for glottis (ORs 7.4 and 1.8) and others subsites (ORs 10.9 and 1.9). Conclusions: Our study shows that both cigarette smoking and alcohol drinking are independent risk factors for laryngeal cancer. Heavy consumption of alcohol and cigarettes determined a multiplicative risk increase, possibly suggesting biological synergy.

Resveratrol and breast cancer risk.

Resveratrol is a non-flavonoid polyphenol that has attracted attention as a potential anticancer agent in vitro and in vivo, but scanty epidemiological data are available. We have therefore analysed the relation between dietary intake of resveratrol and breast cancer risk using data from a case–control study conducted between 1993 and 2003 in the Swiss Canton of Vaud on 369 cases and 602 controls. Compared with the lowest tertile of total resveratrol intake, the multivariate odds ratios (OR) were 0.50 for the intermediate and 0.39 for the highest tertile, and the trend in risk was significant. A significant inverse association was observed for resveratrol from grapes (OR = 0.64 and 0.55), but not for wine. The inverse relation between resveratrol and breast cancer risk was not explained by several potential confounding factors, including detailed allowance for alcohol intake, nor attributable to a non-specific favourable effect of fruit on breast cancer risk.

Selected micronutrients and colorectal cancer. a case-control study from the canton of Vaud, Switzerland.

The association between dietary intake of various micronutrients and colorectal cancer risk was analysed using data from a case-control study conducted between 1992 and 1997 in the Swiss Canton of Vaud. Cases were 223 subjects (142 (64%) males, 81 (36%) females; median age 63 years) with incident, histologically confirmed colon (n=119; 53%) or rectal (n=104; 47%) cancer, and controls were 491 subjects (211 (43%) males, 280 (57%) females; median age 58 years; range 27-74) admitted to the same university hospital for a wide spectrum of acute non-neoplastic conditions, unrelated to long-term modifications of diet. Dietary habits were investigated using a validated food frequency questionnaire (FFQ). Odds ratios (OR) were obtained after allowance for age, sex, education, smoking, alcohol, body mass index, physical activity, and total energy and fibre intake. No significant association was observed for calcium, retinol, folate, vitamin D or E. The risk of colorectal cancer was directly associated with measures of iron intake (OR=2.43 for the highest tertile, 95% confidence interval (CI): 1.2-5.1) and inversely associated with vitamin C (OR=0.45; 95% CI: 0.3-0.8), and non-significantly with total carotenoids (OR=0.66, 95% CI: 0.4-1.1). Among various individual carotenoids considered, inverse associations were observed for alpha-carotene, beta-carotene and lutein/zeaxanthin. These findings were consistent across the strata of gender and age, and support the hypothesis that selected micronutrients have a favourable effect on colorectal carcinogenesis.

Refined and whole grain cereals and the risk of oral, oesophageal and laryngeal cancer.

Objective: To investigate the possible differential role of refined and whole grain cereals on the risk of upper digestive and respiratory tract neoplasms.Design: Hospital-based case–control study.Setting: University Hospital of Lausanne, Switzerland.Subjects: A total of 156 incident cases of cancers of the oral cavity and pharynx, 101 of the oesophagus, 40 of the larynx, and 349 control subjects admitted for a wide spectrum of acute non-neoplastic conditions.Intervention: Trained interviewers collected information using a structured and validated questionnaire. Odds ratios (OR) of various cancers for a tertile increment of intake of refined and whole grains were estimated using unconditional multiple logistic regression.Results: Refined grains were directly related to the risk of cancer of the oral cavity and pharynx (OR=1.9 for the highest tertile), oesophagus (OR=3.7) and larynx (OR=4.0). In contrast, whole grain cereals were protective, with OR of 0.6 for oral cavity and pharynx, 0.3 for oesophagus, and 0.7 for larynx. For the three sites combined, the OR for the highest tertile was 5.7 for refined grains and 0.5 for wholegrains. The trends in risk for refined grains were significant for all sites and their combination, and for wholegrain for oesophageal cancer and all sites.Conclusions: Even if inference on causality and the biological interpretation remain open to discussion, the present data indicate and further quantify that refined cereals are an unfavourable, but whole grain ones a favourable indicator of the risk of upper aerodigestive and respiratory tract neoplasms.Sponsorship: Swiss Foundation for Research Against Cancer and Vaud Cantonal League against Cancer.European Journal of Clinical Nutrition (2000) 54, 487–489

Food groups and oesophageal cancer risk in Vaud, Switzerland.

The influence of food groups on oesophageal cancer risk was analysed using data from a case-control study conducted between 1992 and 1999 in the Swiss Canton of Vaud on 101 incident, histologically confirmed cases (92 squamous cell, 9 adenocarcinomas) and 327 controls admitted to hospital for acute, non-neoplastic conditions. Multivariate odds ratios (OR) were computed after allowance for age, sex, tobacco, alcohol and non-alcohol energy. Significant increased risks emerged for red meat (OR = 1.7 for an increase of one serving per day), pork and processed meat (OR = 1.6), and eggs (OR = 1.5), whereas inverse associations were observed for milk (OR = 0.7), raw and cooked vegetables (OR = 0.5), citrus and other fruits (OR = 0.5), as well as for a more varied diet (OR = 0.5). Most associations were apparently stronger in heavy alcohol drinkers, suggesting an interaction between poor diet and alcohol drinking in oesophageal carcinogenesis.

Occupational and leisure time physical activity and the risk of breast cancer

The relationship between occupational and leisure-time activity and the risk of breast cancer was analysed using data from a case-control study conducted in the Swiss Canton of Vaud between 1993 and 1998 on 246 incidents, histologically confirmed breast cancer cases and 374 controls below the age of 75 years, admitted to the same network of hospitals for acute, non neoplastic non hormone-related conditions. For occupational physical activity, the multivariate odds ratios (OR) for the highest versus the lowest level of physical activity were 0.6 (95% confidence interval, CI = 0.35-1.04) when aged 15 to 19 years, 0.5 (95% CI = 0.26-0.98) when aged 30 to 39 years, and 0.68 (95% CI = 0.36-1.28) when aged 50 to 59. For leisure time physical activity, the ORs were 0.4 (95% CI = 0.26-0.69), 0.5 (95% CI = 0.30-0.81), and 0.4 (95% CI = 0.22-0.80) for the highest versus the lowest level, respectively, in the three age groups, and an inverse trend in risk was significant in all groups. This study, based on one of the few European datasets on the issue, further suggests that physical activity is a favourable indicator of breast cancer risk.

Occupational and leisure-time physical activity and the risk of colorectal cancer.

The relation between various measures of physical activity and colorectal cancer risk was considered in a case-control study conducted between 1992 and 1997 in the Swiss canton of Vaud. Cases were 223 patients (142 men, 81 women) below age 75, with colon (n = 119) or rectal (n = 104) cancer; controls were 491 patients (211 men, 280 women) admitted to hospital for acute, non-neoplastic conditions. Compared with the lowest level of physical activity at age 30-39 years, the odds ratios (OR) of colorectal cancer for the highest level were 0.44 (95% confidence interval, CI, 0.26-0.73) for occupational and 0.53 (95% CI 0.33-0.86) for leisure-time activity. An inverse association was also observed for physical activity at age 15-19 and 50-59 years. The inverse relation between physical activity and colorectal cancer was observed across strata of sex, age, education, body mass index and alcohol drinking; was somewhat stronger in subjects reporting high total energy, and low vegetable and fibre intakes; and was observed across various colon subsites and rectum. In terms of population attributable risk, increasing physical activity would avoid one-fifth to one-third of incident colorectal cancer cases.

Dietary fibre and the risk of colorectal cancer

The relationship between various types of fibre and colorectal cancer risk was investigated using data from a case-control study conducted in the Swiss Canton of Vaud between January 1992 and December 2000. The study included 286 cases of incident, histologically-confirmed colorectal cancers (149 colon and 137 rectal cancers) admitted to the University Hospital of Lausanne, and 550 controls whose admission diagnosis was of acute, non-neoplastic diseases. Dietary habits were investigated using a validated food frequency questionnaire (FFQ). Odds ratios (ORs) were computed after allowance for age, sex, education, physical activity and energy intake. Fibre was analysed both as a continuous variable and in tertiles. There was a significant inverse relationship of total fibre intake (determined by the Englyst method as non-starch polysaccharides) and of its components with the risk of colorectal cancer. ORs for a difference in intake of one standard deviation from the mean fibre intake of the control distribution was 0.57 for total fibres, 0.55 for soluble non-cellulose polysaccharides (NCPs), 0.58 for total insoluble fibres, 0.57 for cellulose, 0.62 for insoluble NCP and 0.62 for lignin. When fibre was classified according to its source, the OR was 0.60 for vegetables, 0.78 for fruit and 0.74 for grain fibre. The ORs were similar for colon and rectal cancer and consistent across the strata of the major covariates and of several types of fibres.