We conducted a large‐scale, hospital‐based case‐control study to evaluate differences and similarities in the risk factors of female breast cancer according to menopausal status. This study is based on a questionnaire survey on life style routinely obtained from outpatients who first visited the Aichi Cancer Center Hospital between January 1, 1988 and December 31, 1992. Among 36,944 outpatients, 1,186 women with breast cancer detected by histological examination were taken as the case group (607 premenopausal women and 445 postmenopausal women) and 23,163 women confirmed to be free of cancer were selected as the control group. New findings and reconfirmed factors of breast cancer were as follows. 1) The risk of at least one breast cancer history among subjects’ first‐degree relatives was relatively high among pre‐ as well as post‐menopausal women. 2) A protective effect of physical activity against breast cancer was observed among both pre‐ and post‐menopausal women. 3) Dietary control decreased the risk of premenopausal breast cancer. 4) Current smoking and drinking elevated the risk of breast cancer in premenopausal women. 5) Decreasing trends of breast cancer risk were associated with intake of bean curd, green‐yellow vegetables, potato or sweet potato, chicken and ham or sausage in premenopausal women, while in postmenopausal women a risk reduction was associated with a more frequent intake of boiled, broiled and/or raw fish (sashimi). Further study will be needed to clarify the age group‐ and/or birth cohort‐specific risk factors for breast cancer among the young generation in Japan.

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To clarify the effects of life-style on gastric cancer by subsite focusing on the proximal part (cardia and fundus) and the distal part (pyloric antrum), a case-control study was conducted at the Aichi Cancer Center in Nagoya, Japan from 1988-1991. This study compared 668 histologically confirmed gastric cancer cases [123 cardia, 218 middle (body), 256 antrum, and 71 unclassified] with 668 controls using a common questionnaire about life-styles as related to smoking, drinking, dietary habits and frequency of food intake. Controls were selected from among outpatients of the same hospital. Controls free of cancer and other specific diseases were matched with cases for sex, age (within 2 years), and time of hospital visit (within 2 months). A Western-style breakfast decreased the risk of antrum cancer, while consumption of greasy food increased the risk of cardia cancer. Fresh vegetables decreased the risk of cancer in both cardia and antrum. Habitual smoking is associated with increased risk of gastric cancer and it is more prominent in cardia cancer, especially in those who are drinkers. Results obtained from this study suggest that risk factors and relative risks of gastric cancer varied by subsite to a considerable degree. Furthermore, the joint effect of smoking and drinking may play an important role in the development of gastric cancer, especially of cardia cancer.

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In Japan the incidence of cervical cancer has been high, but has recently been decreasing gradually, while the incidence of endometrial cancer is running at lower levels but is gradually increasing. To clarify the common and/or specific risk and/or protective factors of cervical cancer (CC) in contrast with endometrial cancer (EC), a comparative case‐control study was conducted at the Aichi Cancer Center Hospital, Japan. In total, 556 CC cases and 145 EC cases were included and 26,751 women, confirmed as free of cancer, were chosen as the common control group. Odds ratio and its 95% confidence interval (95%CI) for each exposure variable were estimated by using an unconditional logistic regression model adjusted for age and first‐visit year. Habitual smoking and experience of pregnancy increased the risk of CC, while decreasing the risk of EC. Greater body mass index (>20), daily intake of fruit and more frequent intake of boiled or broiled fish (>1–2 times/week) decreased the risk of CC, whereas they increased the risk of EC. Daily intake of milk decreased the risk of CC. The results obtained from this study suggest that several EC‐increasing risk factors are in fact CC‐decreasing determinants. The observed risk reduction in both CC and EC by physical exercise and dietary control for health is noteworthy from the public health standpoint and warrants further investigation.