The epidemiology of bladder cancer: a second look

Bladder cancer etiology. A different perspective

The descriptive epidemiologic features of bladder cancer and lung cancer in Los Angeles County were studied for the period 1972-1976, using data from the Los Angeles County/University of Southern California Cancer Surveillance Program. The incidence pattern for bladder cancer was found to differ markedly from the pattern observed for lung cancer. As expected, the descriptive pattern for lung cancer closely paralleled the known epidemiology of cigarette smoking; in addition, it was consistent with the expected pattern of an occupationally linked disease. In contrast, the pattern observed for bladder cancer indicated that factors other than cigarette smoking and occupational exposures may be etiologically important. The available descriptive epidemiology of coffee consumption, unlike that of cigarette smoking, is consistent with the pattern of bladder cancer occurrence in Los Angeles. Available analytic studies on the association of bladder cancer and coffee consumption are consistent with a causal relationship.

An epidemiological study of bladder cancer in a predominantly rural district

A case-control study was performed on 212 bladder cancer patients (165 male + 47 female) and 259 control persons (165 male + 94 female) matched according to age and geographic area. Twenty-five determinants of assumed importance were examined. Bivariate analysis revealed a significantly increased relative risk (RR) of developing bladder cancer associated with cigarette smoking, cigarillos smoking, pipe smoking, tobacco chewing, industrial work, previous venereal disease, work with petroleum or asphalt, consumption of alcohol, work with oil or gasoline, and work with chemical materials. A multivariate logistic analysis showed that cigarette and cigarillos smoking involved the highest significant risks. An analogous logistic analysis of the negatively associated determinants revealed never smokers and farmers to be the weakest independent variables.

Epidemiologic survey of bladder cancer in greater New Orleans

Primary ancestry of the patients and controls in this study was not statistically different but the Jewish population had a significantly increased incidence of bladder cancer. Over-all, a significantly greater number of patients smoked filtered cigarettes, began drinking artificially sweetened beverages at an earlier age, drank artificially sweetened beverages for a greater number of years, consumed a greater number of glasses of artificially sweetened beverages weekly and related a history of urinary tract infections. A significantly increased incidence of bladder cancer was noted in individuals employed by certain types of companies, by certain job titles and by certain job material handled. Analysis of the data failed to show any significant difference in years of consumption of coffee, amount of various types of coffee or tea consumed, consumption of various nonalcoholic and alcoholic beverages, including source of drinking water, use of hair dye, incidence of diabetes mellitus, family history of urinary cancer and a history of pelvic irradiation or bladder stones.

Intra-uterine exposure to saccharin and risk of bladder cancer in man

Animal experiments show that rats fed saccharin are more likely to develop bladder tumours if they have been exposed to saccharin in utero through their mothers' food. The risk of bladder tumours in humans following in utero exposure to saccharin has not been evaluated previously. In Denmark the use of saccharin increased sharply during the second World War as a result of scarcity of sugar, and import and export figures indicate that saccharin consumption was on average 4-5 times higher during the war-time period than in the pre-war decade. The risk of bladder tumours at ages 20-34 was 1.0 (95% confidence interval 0.7-1.6) among men born in 1941-1945 compared with men born 1931-1940. Among women the risk was 0.3 (0.1-1.0). This study provides no evidence of an increased risk of human bladder cancer during the first 30-35 years of life associated with in utero saccharine exposure.

Evidence of a multiplicative effect between cigarette smoking and occupational exposures in the aetiology of bladder cancer

A case-control study on urinary tract cancer in men is ongoing in the Province of Torino. The analysis of tobacco smoke and occupational histories of the first 225 case-control pairs is described. The overall relative risks (RR) for tobacco smoke and for occupations known to entail a risk for bladder cancer were respectively 4.8 (95% confidence limits (C.L.) 2.4--9.3) and 1.7 (1.0--2.7). There was a clearcut dose-response relationship between different categories of cigarette consumption and risk for urinary tract cancer. For each level of cigarette consumption, relative risks were compared between men reporting and non-reporting occupation at risk. This analysis suggested a multiplicative effect between the 2 factors.

Occupational cancer of the urinary bladder

The occupational etiology of bladder cancer has been known for more than 70 yr. The best-known etiologic agents are aromatic amines such as 2-naphthylamine and benzidine. The proportion of bladder cancers due to occupational exposure varies with the industrialization of the area in question. In heavily industrialized countries occupational exposure may be associated with as much as 25% of cases in men. Industries with a confirmed or highly probable increased risk of bladder cancer are dyestuff and chemical manufacture, pigment and paint manufacture, cable manufacture, textile works (dyeing), leather works, the coal tar industry, and the gas industry. In addition to these relatively well established risk industries, a number of occupations have been shown to be associated with an increased risk of bladder cancer in epidemiologic studies. These include barbers, butchers, clerks, electricians, hairdressers, mechanics, medical occupations, metalworkers, painters, photographers, plumbers, shoemakers and shoe repairers, tailors, and textile workers. The etiologic agents in these occupations are obscure and it is difficult to know whether these associations are causal.

Associations between cancer incidence and alcohol/cigarette consumption among five ethnic groups in Hawaii

The average annual age-adjusted incidence rates of cancer for 15 sites were determined for 10 ethnic-sex groups in Hawaii. Consumption rates for cigarettes, beer, wine and hard liquor were also determined for the same 10 groups based on personal interview of a sample of 9920 individuals. Covariance analysis was used to adjust each exposure variable for the other three, and the cancer incidence rates were then linearly regressed on these covariance-adjusted consumption rates. Statistically significant regression coefficients were found for cancer of the tongue/mouth, pharynx, larynx, pancreas, lung, kidney and bladder regressed on cigarette consumption. Eight cancer sites, including tongue/mouth, pharynx, larynx, oesophagus, stomach, pancreas, lung and kidney, had significant positive regression coefficients for beer consumption which could not be explained by outlying values on the scattergram. Significant associations were also suggested between wine consumption and pharyngeal cancer and between hard-liquor consumption and pharyngeal, laryngeal and possibly brain cancer. No association was found between beer consumption and colorectal cancer. Multiple regression analysis with sex, cigarettes and alcoholic beverage as independent variables consistently found sex to be least important in determining cancer risk. This study supports the hypothesis that beer consumption may play a role in cancer risk for several sites. It is suggested that future studies of alcoholic beverages and cancer should examine not only types of alcoholic beverages, but individual brands of each type in an attempt to identify cancer risk due to carcinogens in only certain brands.

Artificial sweeteners and human bladder cancer. Preliminary results

3010 patients with cancer of the urinary bladder and 5783 controls drawn from the general population of ten geographic areas of the U.S.A. were interviewed. Subjects who reported over having used artificial sweeteners or artificially sweetened foods or beverages showed no elevation in risk. However, positive associations between various measures of use of artificial sweeteners and risk of bladder cancer were seen in several subgroups. Inconsistencies in the data suggest that the positive associations may be due to chance, but it is noteworthy that the subgroups were those chosen, a priori, to test hypotheses derived from laboratory experiments.

Artificial sweetener use and bladder cancer: a case-control study

In a case-control study of 302 male and 65 female bladder cancer patients and an equal number of other patients matched to them in age, sex, hospital, and hospital-room status, no association was found between use of artificial sweeteners or diet beverages and bladder cancer. No dose-response was observed with respect to quantity or duration of use of the two combined. No evidence was found to suggest that artificial sweeteners or diet beverages promote the tumorigenic effect of tobacco smoking. Artificial sweetener and diet beverage use strongly reflected socioeconomic status among controls with various diagnoses.

Artificial sweeteners and cancer of the lower urinary tract

We evaluated the relation between cancer of the lower urinary tract and the use of artificial sweeteners in a case-control study of 592 patients with lower-urinary-tract cancer (94 per cent of whom had a bladder tumor) and 536 controls chosen from the general population of the study area. A history of use or artificial sweeteners and exposure to other known or suspected risk factors was determined by interview. In those who had used dietetic beverages and in those who had used sugar substitutes, the relative risk of lower-urinary-tract cancer was estimated as 0.9 (0.7 to 1.2, 95 per cent confidence interval), as compared with 1 in nonusers of artificial sweeteners. Among men, the relative risk was 0.8 (0.6 to 1.1) in those who had used dietetic beverages and 0.8 (0.5 to 1.1) in those who had used sugar substitutes. Among women, the corresponding relative risks were 1.6 (0.9 to 2.7) and 1.5 (0.9 to 2.6). Increasing frequency of duration of use of artificial sweeteners was not consistently associated with increasing relative risk. This study suggests that, as a group, users of artificial sweeteners have little or no excess risks of cancer of the lower urinary tract.

Nutrients, vitamins and minerals in cancer prevention: facts and fallacies

In this paper, a summary is first presented of the important facts that have linked diet and dietary habits to human cancers, with the purpose of identifying the sources and extent of food fallacies that associate "nutrients, vitamins, and minerals" in cancer prevention. Then examples are presented of the many fallacies that persuade consumers to make dangerous, inappropriate and/or ineffective dietary choices. Minimizing food faddism and dietary quackery with its false claims about diet and cancer requires an important counterchallenge on the part of health professionals. There is a great need to determine the possible role of nutrients and dietary components in the development of neoplastic disease in human populations in order to develop rational and safe food and nutrition policies. Concurrently, nutrition education should receive increased research support in order to improve techniques and approaches for informing policy makers, the food industry and public accurately and objectively of the recent advances in the study of nutrition and cancer prevention and their practical and health significance.