The relationship between dietary fat intake and risk of colorectal cancer: evidence from the combined analysis of 13 case-control studies.

The objective of this study was to examine the effects of the intake of dietary fat upon colorectal cancer risk in a combined analysis of data from 13 case-control studies previously conducted in populations with differing colorectal cancer rates and dietary practices. Original data records for 5,287 cases of colorectal cancer and 10,470 controls were combined. Logistic regression analysis was used to estimate odds ratios (OR) for intakes of total energy, total fat and its components, and cholesterol. Positive associations with energy intake were observed for 11 of the 13 studies. However, there was little, if any, evidence of any energy-independent effect of either total fat with ORs of 1.00, 0.95, 1.01, 1.02, and 0.92 for quintiles of residuals of total fat intake (P trend = 0.67) or for saturated fat with ORs of 1.00, 1.08, 1.06, 1.21, and 1.06 (P trend = 0.39). The analysis suggests that, among these case-control studies, there is no energy-independent association between dietary fat intake and risk of colorectal cancer. It also suggests that simple substitution of fat by other sources of calories is unlikely to reduce meaningfully the risk of colorectal cancer.

Perceived religiousness is protective for colorectal cancer: data from the Melbourne Colorectal Cancer Study.

The perceived or self-reported degree of 'religiousness' was obtained by interview from 715 colorectal cancer patients and 727 age/sex matched community controls, as part of a large, comprehensive population-based study of colorectal cancer incidence, aetiology and survival (The Melbourne Colorectal Cancer Study) conducted in Melbourne, Australia. Self-reported or perceived 'religiousness', as defined in the study, was a statistically significant protective factor [relative risk (RR) = 0.70, 95% confidence interval (CI) = 0.6-0.9, P = 0.002]. This statistically significant protection remained after the previously determined major risk factors found in the study, namely a family history of colorectal cancer, dietary risk factors, beer consumption, number of children and age at birth of the first child, were statistically corrected for (P = 0.004). There was no association between Dukes' staging of the cancer and perceived degree of 'religiousness' (P = 0.42). Although self-reported or perceived 'religiousness' was associated with a median survival time of 62 months compared with 52 months in those self-reporting as being 'non-religious', this difference was not statistically significant (P = 0.64).

Laxative use not a risk for colorectal cancer: data from the Melbourne Colorectal Cancer Study.

Commercial laxative use as a risk factor in colorectal cancer was investigated as one part of a large population based epidemiological study of colorectal cancer incidence, aetiology and survival "The Melbourne Colorectal Cancer Study", conducted in Melbourne, Australia. Commercial laxative use was similar in 685 colorectal cancer patients and 723 age/sex matched community based controls. Also, when laxatives were subdivided into various groups containing anthraquinones, phenolphthalein, mineral salts and others, previous laxative intake was similar between cases and controls. Previous use of anthraquinone laxatives and of phenolphthalein containing laxatives was not associated with the risk of colorectal cancer.

Oral and pharyngeal cancer, diet, smoking, alcohol, and serum vitamin A and beta-carotene levels: a case-control study in men.

A case-control study was conducted in Melbourne, Australia. Forty-one men with histologically confirmed squamous cell oral or pharyngeal cancer were compared with 398 male community controls. A statistically significant increase in risk was found for alcohol (ethanol) consumption and for smoking, and there was a synergistic effect for these two exposures. Statistically significant protection was noted with increasing intake of dietary vitamin C, dietary beta-carotene, fruit, vegetables, and dietary fiber. The mean serum levels of beta-carotene and vitamin A were statistically significantly lower when the cases were compared with another set of 88 male controls of a similar age who were hospitalized for minor surgical operations. This study confirms a causal effect of smoking and alcohol and a protective role for a high dietary intake of fruit, vegetables, cereals, and, particularly, beta-carotene- and vitamin C-containing foods.

Dietary intake of fiber and decreased risk of cancers of the colon and rectum: evidence from the combined analysis of 13 case-control studies.

BACKGROUND: Colorectal cancer is a major public health problem in both North America and western Europe, and incidence and mortality rates are rapidly increasing in many previously low-risk countries. It has been hypothesized that increased intakes of fiber, vitamin C, and beta carotene could decrease the risk of colorectal cancer. PURPOSE: The objective of this study was to examine the effects of fiber, vitamin C, and beta-carotene intakes on colorectal cancer risk in a combined analysis of data from 13 case-control studies previously conducted in populations with differing colorectal cancer rates and dietary practices. The study was designed to estimate risks in the pooled data, to test the consistency of the associations across the studies, and to examine interactions of the effects of the nutrients with cancer site, sex, and age. METHODS: Original data records for 5287 case subjects with colorectal cancer and 10,470 control subjects without disease were combined. Logistic regression analysis was used to estimate relative risks and confidence intervals for intakes of fiber, vitamin C, and beta carotene, with the effects of study, sex, and age group being adjusted by stratification. RESULTS: Risk decreased as fiber intake increased; relative risks were 0.79, 0.69, 0.63, and 0.53 for the four highest quintiles of intake compared with the lowest quintile (trend, P < .0001). The inverse association with fiber is seen in 12 of the 13 studies and is similar in magnitude for left- and right-sided colon and rectal cancers, for men and for women, and for different age groups. In contrast, after adjustment for fiber intake, only weak inverse associations are seen for the intakes of vitamin C and beta carotene. CONCLUSION: This analysis provides substantive evidence that intake of fiber-rich foods is inversely related to risk of cancers of both the colon and rectum. IMPLICATIONS: If causality is assumed, we estimate that risk of colorectal cancer in the U.S. population could be reduced about 31% (50,000 cases annually) by an average increase in fiber intake from food sources of about 13 g/d, corresponding to an average increase of about 70%.

Smoking and colorectal cancer risk: data from the Melbourne Colorectal Cancer Study and brief review of literature.

Lifetime smoking data were obtained from 715 colorectal cancer cases and 727 age/sex matched community controls as one part of a large, comprehensive, population-based study of colorectal cancer aetiology and survival in Melbourne, Australia, The Melbourne Colorectal Cancer Study. Statistically significant associations were found for those males smoking handrolled cigarettes and for cigar-/pipe-smoking males with colon cancer. Review of 18 previous case control studies of colorectal cancer showed an elevated risk for cigar-smoking black males in one study, a statistically non-significant increased risk for current smokers in one of 3 cohort studies and a statistically significant elevation of risk for smokers in 2 of 3 studies of adenomatous large-bowel polyps. Although at present there is insufficient evidence to link smoking with large-bowel cancer, the possibility that ingested tobacco is in some way carcinogenic for the colorectal mucosa may be worth further study.

Attributable risk for diet, alcohol, and family history in the Melbourne Colorectal Cancer Study.

From the data obtained in a large comprehensive population-based case-control study of colorectal cancer (The Melbourne Colorectal Cancer Study), attributable risk was calculated for a family history of colorectal cancer in near relatives for diet (when > or = 5 of the 11 previously determined dietary risk factors were present) and for beer consumption (for rectal cancer only). The attributable risk was 11% in the presence of a family history of colorectal cancer and 46% in the presence of five or more dietary risk factors. The attributable risk for rectal cancer in the presence of beer consumption was 31% in males and 11% in females. These data are relevant in the consideration of primary prevention of colorectal cancer in Australia, but their general application needs to be approached with caution in view of major differences in the genetic background and the dietary practices in various regions of the world and in view of the uncertainty of what is achievable change, especially for dietary practices.

Diet, alcohol, smoking, serum beta-carotene, and vitamin A in male nonmelanocytic skin cancer patients and controls.

A case-control study was conducted in Melbourne, Australia of 88 consecutive males admitted for the surgical removal of a nonmelanocytic skin cancer (histologically confirmed basal cell carcinoma and squamous cell carcinoma) and of 88 male control patients admitted for small elective surgical procedures. In both cases and controls, previous diet, alcohol consumption, and smoking habit were investigated and serum beta-carotene and vitamin A levels were measured. A statistically significant inverse relationship was found between the risk of skin cancer and a high intake of fish (p = 0.05); vegetables in general (p < 0.001); beans, lentils, or peas (p < 0.001), carrots, silverbeet (Swiss chard), or pumpkin (p < 0.001); cruciferous vegetables (cabbage, brussel sprouts, or broccoli) (p < 0.001); and beta-carotene- and vitamin C-containing foods (p = 0.004). Cases had a lower mean serum level of beta-carotene (p < 0.001) and vitamin A (p = 0.02) than controls. The incidence of skin cancer in the study was inversely related to the level of serum beta-carotene (p < 0.0001). The correlation coefficient between dietary beta-carotene/vitamin C and serum beta-carotene was 0.22 (p = 0.04). Smoking and alcohol consumption showed no statistically significant association with the risk of nonmelanocytic skin cancer. The results were similar for both cell types. A high intake of vegetables including cruciferous vegetables, beta-carotene- and vitamin C-containing foods, and fish appears to be protective for nonmelanocytic skin cancer, and this deserves further study, as does the possible etiologic relevance of the low serum levels of beta-carotene and vitamin A.

Alcohol consumption and the etiology of colorectal cancer: a review of the scientific evidence from 1957 to 1991.

The relationship between alcohol consumption and colorectal cancer in humans has been examined in 52 major studies in the past 35 years. An association was found in five of the seven correlational studies. An elevated risk was found in about half of the 31 case-control studies and, of these, in 9 of the 10 studies using community controls but in only 5 of the 17 studies using hospital controls (p = 0.008), suggesting that the absence of association when hospital controls are used is due to a high prevalence of alcohol consumption/alcohol-related illness in the hospital controls. Of the 14 cohort studies, an association with alcohol was found in 10, while in 3 of the 4 cohort studies in which an association was not found the alcohol data obtained were somewhat restricted. A positive dose-response effect was found in two of three cohort studies and in all four case-control studies with community controls in which this effect was examined. In both case-control and cohort studies, the association was found for females and males and for colon and rectal cancer. When the type of alcohol consumed was examined separately, beer was the principal type of at-risk alcoholic beverage, with much less risk for spirits and least risk for wine. Statistically significant elevations of risk were more often found in males than in females and slightly more frequently for rectal than for colon cancer and were related almost entirely to beer, rather than to wine or spirit, consumption. The alcohol risk was independent of the dietary risk in those studies that controlled for this factor. There was some confirmatory evidence for alcohol augmentation in rodent models of chemically induced carcinogenesis in six of nine studies. The hypotheses of alcohol as a direct and specific colorectal carcinogen include increased mucosal cell proliferation, the activation of intestinal procarcinogens, and the role of unabsorbed carcinogens, particularly in beer. Also, five of six other human studies showed an association between alcohol/beer consumption and adenomatous polyps, consistent with the hypothesis that alcohol stimulates the colorectal mucosa. General or indirect carcinogenic effects of alcohol include immunodepression, activation of liver procarcinogens, and changes in bile composition, as well as nitrosamine content of alcoholic beverages and increased tissue nitrosamine levels. With alcohol/beer consumption, the overall conclusion on present evidence is that alcohol, particularly beer consumption, is an etiologic factor for colon and rectal cancer for females and males.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of family history of cancer, religion, parity and migrant status on survival in colorectal cancer. The Melbourne Colorectal Cancer Study.

The association between 5-year survival and several risk factors was investigated in 705 histologically confirmed, new cases of colorectal adenocarcinoma as one aspect of a comprehensive population-based study of large bowel cancer incidence, aetiology and survival--the Melbourne Colorectal Cancer Study. 5-year survival was not influenced by the previously determined risk of a family history of colorectal cancer in near-relatives. Similarly, other previously determined risk factors of religion, number of children, age at birth of first child and migrant status did not influence survival.

Personality as a risk factor in large bowel cancer: data from the Melbourne Colorectal Cancer Study.

In a case control study which formed one arm of a large, population-based investigation of colorectal cancer incidence, aetiology and survival. 'The Melbourne Colorectal Cancer Study', among others, 22 psychosocially orientated questions were asked by personal interview of 637 histologically confirmed new cases of colorectal cancer and 714 age/sex frequency matched community controls, from Melbourne (population 2.81 million). Self-reported childhood or adult life 'unhappiness' was statistically significantly more common among the cancer cases, while 'unhappiness with retirement' was similarly distributed among cases and controls. Questions which were formulated to test a particular personality profile as a cancer risk, and which included the elements of denial and repression of anger and of other negative emotions, a commitment to prevailing social norms resulting in the external appearance of a 'nice' or 'good' person, a suppression of reactions which may offend others and the avoidance of conflict, showed a statistically significant discrimination between cases and controls. The risk of colorectal cancer with respect to this model was independent of the previously found risk factors of diet, beer intake, and family history of colorectal cancer, and was also independent of other potential confounding factors of socioeconomic level, marital status, religion and country of birth. Although the results must be interpreted with caution, the data are consistent with the hypothesis that this personality type may play a role in the clinical expression of colorectal cancer and merits further study.

Recent life change and large bowel cancer. Data from the Melbourne Colorectal Cancer Study.

In a large, population based, epidemiological study of colorectal cancer, The Melbourne Colorectal Cancer Study, several etiological factors were investigated. Persons' recent life changes, as well as the degree of upset they experienced as a result of these changes, were included. Interviews with 715 histologically confirmed new cases of colorectal cancer occurring over a 12-month period in Melbourne, Australia, and with 727 age and sex matched community controls were conducted. As one of the methods of assessing any effect of recall bias, 179 hospital controls were also investigated. Major illness or death of a family member, major family problems and major work problems were found to be significantly more common for cases over the 5 years preceding diagnosis compared to controls. Cases also reported being significantly more upset with their recent life changes than did controls. No significant differences in results were found between males and females, or between colon cancer and rectal cancer patients. Although the possibility of recall bias, was not completely controlled for in this study, it was probably not an important factor in explaining case-control differences. Recent life changes, and their perceptions, may have significance in the development of large bowel cancer.

Colorectal polyps, diet, alcohol, and family history of colorectal cancer: a case-control study.

A case-control study was conducted in Melbourne, Australia. Cases (n = 49) were patients who had one or more histologically confirmed adenomatous polyps larger than 1 cm in diameter previously removed by endoscopy. In both the cases and the community controls (n = 727), previous diet, alcohol consumption, and family history of colorectal cancer in near relatives were investigated. The family history rate of colorectal cancer was similar in the two groups. Those with adenomatous polyps were found to have a low fiber/vegetable intake (p = 0.04); in males, there was a high intake of beef (p = 0.04), milk drinks (p = 0.01), and beer (p = 0.05). This study provides further evidence for the hypothesis that dietary factors and alcohol consumption may play a role in the development of adenomatous colorectal polyps and that these factors are similar to dietary risk factors for colorectal cancer.

Survival in patients with large-bowel cancer. A population-based investigation from the Melbourne Colorectal Cancer Study.

Five-year survival data were obtained in 97 percent or 1105 of 1140 new patients with histologically confirmed colorectal adenocarcinoma during a 12-month period in 1981 and 1982, as part of a large comprehensive population-based study of colorectal cancer incidence, etiology, and survival, The Melbourne Colorectal Cancer Study. Fifteen percent of patients were Dukes' A stage, 32 percent were Dukes' B, 25 percent were Dukes' C, and 29 percent were Dukes' D. At five years after diagnosis, the observed survival rate was 36 percent and the adjusted rate was 42 percent. Dukes' staging was a highly discriminating factor in survival (P less than 0.001). Survival rates were better in women than in men and better for patients with colon cancer than for patients with rectal cancer. Survival by Dukes' staging was not affected by colon subsite or by the tumor being the first and single tumor, metachronous tumor, or synchronous tumor. The survival of younger patients was better for Dukes' stages A, B, and C, and worse for Dukes' D. Survival was worse in the presence of bowel perforation in Dukes' C and D stages. Within Dukes' D (incurable cases), survival was best in the absence of hepatic metastases, slightly worse when only hepatic metastases were present, and poorest in the presence of both hepatic and extrahepatic metastases. Statistical modeling of survival determinants other than staging indicated that cell differentiation had the largest effect (survival decreasing with poor cell differentiation), followed by site (survival worse for rectal cancer than colon cancer), then age (survival better for younger patients), while bowel perforation had the smallest effect on survival.

Balloon dilatation of biliary strictures: experience and review of the literature.

Patients who develop strictures after repeated biliary surgery are a complex management problem. Reoperation in these patients, who may also have cirrhosis, portal hypertension and non-dilated ducts, is hazardous even in experienced centres. The new technique of percutaneous balloon dilatation has been used increasingly in such cases. A review of the literature and the experience with this technique in five patients with recurrent biliary strictures is presented. Its use is recommended in patients who present with recurrent problems when a previous biliary-intestinal anastomosis has failed as well as in those who develop stricture following multiple procedures involving the biliary system.

Oral contraceptive use does not protect against large bowel cancer.

The association between oral contraceptive (OC) use and colorectal cancer was examined in 190 female colorectal cancer cases and 200 age-matched female controls in data derived from a population-based study of large bowel cancer, "The Melbourne Colorectal Cancer Study" conducted in Melbourne, Australia. There were 47 cases (24 colon cancer, 23 rectal cancer cases) and 39 controls, who were past OC users. After adjustment was made for the confounding factors of age, number of children and age at birth of first child, a statistically significant risk was found among rectal cancer OC users, but not among colon cancer OC users (RR rectal cancer = 2.04, 95% CI = 1.00-4.14, p = 0.04; RR colon cancer = 1.17, 95% CI = 0.59-2.29, p = 0.60). These risks were not affected by adjustment for socioeconomic level, country of birth, religion, previous diet and family history of colorectal cancer. Rectal cancer risk was higher among those OC users who were also beer drinkers (RR = 6.96, 95% CI 2.09-23.1, p = 0.001).

Body weight and physical activity as predictors of colorectal cancer risk.

The associations between colorectal cancer and body weight (expressed as body mass index) and between colorectal cancer and physical activity were examined in 715 histologically confirmed cases of colorectal adenocarcinoma and 727 age- and sex-matched controls. The data were obtained from a large, population-based study, The Melbourne Colorectal Cancer Study, which was conducted in Melbourne, Australia. There was a statistically significant increase in the risk of rectal cancer but not of colon cancer in overweight and obese males but not in females. This association for males remained statistically significant after adjustment was made for dietary risk factors previously established for this study (Nutr Cancer 9, 21-42, 1987), with the exception of sodium intake, which produced a downward modification of the relative risk close to unity. The increased risk of rectal cancer in overweight and obese males was modified by beer intake, which was previously found to be a risk for rectal cancer in males in this study. Various levels of physical activity were not statistically significantly associated with the risk of colorectal cancer in either males or females. Also, the colorectal cancer risks associated with the body mass index were not significantly altered by adjustment for the physical activity level.