Joint risks in a case-control study of esophageal cancer in Shanxi Province, People's Republic of China.

A multifactorial analysis on the etiology of esophageal cancer was conducted based on a case-control study conducted in Shanxi. The study analyzed the data of 326 cases and 396 controls. The joint risks of two factors were calculated from dichotomous distributions. Three models of factor combinations were assessed: (1) two risk-enhancing factors, (2) two risk-reducing factors, and (3) a risk-enhancing and a risk-reducing factor. The observed joint risks were in the neighborhood of the multiplicative products of single acting risks of individual factors. This was a uniform pattern across three models.

A case-control study of colorectal cancer and its relation to diet, cigarettes, and alcohol consumption in Saitama Prefecture, Japan.

A case-control study of colorectal cancer in relation to dietary, smoking, and drinking habits was undertaken in Saitama Prefecture, Japan. The study was based on 181 newly diagnosed cases of adenocarcinoma of the colorectum at a single institution and 653 general population controls. Dietary habits were investigated on the basis of the intake of 12 foods and 12 food groups in a food intake frequency questionnaire, together with individual food preferences. Preference for salty foods was positively related to the risk of both colon and rectal cancer, and the consumption of seaweed was inversely related to these cancers, both with a dose-response relation. Cigarette smoking was inversely related to colon cancer risk, but not to rectal cancer risk. Alcohol intake tended to be associated inversely with colon cancer, but not with rectal cancer. In the multiple logistic regression, preference for salty foods (positively) and the consumption of seaweed (inversely) were independently related to both colon and rectal cancer risks.

A case-control study of stomach cancer and its relation to diet, cigarettes, and alcohol consumption in Saitama Prefecture, Japan.

A case-control study of stomach cancer in relation to dietary, smoking, and drinking habits was undertaken in Saitama Prefecture, Japan. The study was based on 294 cases of newly diagnosed adenocarcinoma of the stomach at a single institution, 294 general population controls (matched by sex, age, and administrative division), and 202 hospital controls. Dietary habits were investigated based on the intake of 12 separate foods and 12 food groups in a food frequency questionnaire, together with individual food preferences. The consumption of raw vegetables was inversely related to the risk of stomach cancer, with a dose-response relation observed consistently in the comparisons with both sets of controls. Current cigarette smokers (1-29/day) had an increased risk (relative risk = 1.8, 95 percent confidence interval = 1.1-3.0) compared with nonsmokers in the general population controls, but no dose-response effect with heavier cigarette smoking. Alcohol use did not affect the risk of stomach cancer. In the multiple logistic regression, the consumption of raw vegetables showed a protective effect on stomach cancer while cigarette smoking had no significant association, in both sets of controls.

A case-control study of single and multiple stomach cancers in Saitama Prefecture, Japan.

A case-control study of stomach cancer was done in Saitama Prefecture, Japan, in relation to dietary, smoking, and drinking habits. The study was based on two sets of cases (216 male single and 35 male multiple stomach cancer cases newly diagnosed and of adenocarcinoma type), and 483 male controls derived from residents of Saitama Prefecture. Dietary habits were investigated for the intake of 12 separate foods and 12 food groups by means of a food frequency questionnaire, including individual taste preferences. Among the single stomach cancer series, dose-response relationships were observed for 7 dietary items (preference for salty foods, miso soup, boiled fish, pickled vegetables, nuts, raw vegetables, and seaweed) in the multiple logistic regression analysis. As for the multiple stomach cancer case series, dose-response relationships were observed for 3 dietary items (miso soup, fruits, and seaweed) in the multiple logistic regression analysis. Cigarette smoking and alcohol use were not significantly related to the risk of either single or multiple stomach cancer.

Esophageal cancer in Shanxi Province, People's Republic of China: a case-control study in high and moderate risk areas.

Dietary, smoking, and drinking habits, as well as sociopsychological factors and familial history, were investigated in a case-control study on the etiology of esophageal cancer (EC) in two areas of Shanxi (Yangcheng and Linfen), north central China. Data were analyzed from 326 cases and 396 controls. We identified several factors associated with high or low risk; some were common across the areas and others were area-specific. Consumption of millet gruel was associated positively with EC, in a dose-response relationship. An increase in EC risk was seen for consumption of millet soup with noodles, and also with certain sociopsychological factors, in both areas. A large increase in risk was found with consumption of boiled vegetables in Linfen, with a dose-response relationship. EC risk tended to become greater with the increasing intake of moldy foods and of pickled vegetable juice. A positive association between EC risk and family history of EC was observed only in Yangcheng. Soybean consumption was found to be associated with reduced risk. Dental hygiene (brushing teeth) was associated with reduced risk in Linfen. There was a suggestion of increased risk associated with heavy tobacco smoking, but it was not significant in either area. Alcohol consumption had a marginally significant association with risk in the high risk area, but not in Linfen.

Clustering of liver cancer deaths in Saitama Prefecture, Japan.

Cancer statistics in 1965 revealed that people in the eastern part of Saitama had a high risk of developing cancer of the liver. Clusters of liver cancer were also observed in 1975, though less for males than for females. In 1985, traces remained of clusters with higher death rates from liver cancer. A field survey revealed absence of correlation between geographical clustering of liver cancer and HBsAg positivity, geographical HBsAg positivity differences between sexes, and lack of correlation between geographical distribution of HBsAg positivity and death rates from liver diseases (cancer or cirrhosis). There was no geographical relationship of death rates from liver cancer to liver cirrhosis in Saitama. Statistics of the Saitama Cancer Center revealed lower averages than in the rest of Japan for the percentage of HBsAg positivity in HCC inpatients, the percentage of HCC inpatients with liver cirrhosis, and the ratio between the number of patients with HCC and those with cholangio carcinoma. A mail questionnaire revealed that farmers in the eastern part of Saitama had a strong positive association with death from liver cancer. These results suggest that HBV does not play an important role in the clustering of high death rates from liver cancer in Saitama.

[An epidemiological approach to increase mass screening efficiency, by finding high-risk group of esophageal cancer].

An improvement of mass screening efficiency for esophageal cancer was studied by a simple form of questionnaire on the basis of case-control study in Saitama prefecture. This questionnaire consisted of several questions on risk-associating factors and the answers were scored such that the exposure to plural factors was quantified. The high-scored group is then regarded to be at high risk and to be examined for the cancer. The selection of factors for questionnaire was made by estimating the efficiency of screening. The expected detection rates were high with the range from 0.16 to 0.27% for males and 0.04 to 0.09% for females, contrasting to the rates of 0.05 and 0.01% without pre-screening by the questionnaire.

The joint effects of two factors in the aetiology of oesophageal cancer in Japan.

A multifactorial approach to the aetiology of oesophageal cancer was made on the basis of a case-control study in Saitama prefecture, Japan. The joint risks of two factors were calculated directly from joint distributions, following a dichotomous exposure model. Three models of factor combinations were taken into account: two risk enhancing factors, two risk reducing factors, and risk enhancing and reducing factors. We observed remarkable risk elevations in the first model, and the observed joint risks were in the neighbourhood of the multiplicative products of single acting risks of individual factors. The highest odds ratios of about 10 or more were found with combinations of salty foods, excessive intake of rice and alcohol abuse. The second and third models also followed a multiplicative modification of risk. The lowest odds ratios of less than 0.2 were observed in the second model, with combinations of fruits and raw vegetables, fruits and seaweed, and raw vegetables and meat. In the third model, the increased risk caused by an enhancing factor was reduced proportionately to the presence of a risk reducing factor. Finally the dose-response relations of two factors were observed and shown to be categorised into three typical patterns of risk modification, following a three exposure level model. These patterns could be explained by both the dose-response relations of individual factors and the multiplicative modification of risk.