The authors conducted a case-control study to elucidate the risk factors of breast cancer among Korean women. The breast cancer cases(n=212) were recruited from surgically proven cases in the Department of Surgery. Asan Medical Center from June
1986 to
July 1993. Controls(n=226) were also recruited from the Asan Medical Center. The authors collected information on demographic, reproductive and dietary factors by direct interviews. The distribution of risk factors was compared between the case
and
controls to yield odds ratios with 95 percent confidence intervals.
Parity was significantly associated with breast cancer risks: parous women showed significantly reduced risk of breast cancer (49 percent) compared to nulliparous women. The number of parity and the age of the first full-term pregnancy also
showed
negative and positive correlations, respectively. History of lactation and oral contraceptive usage, however, was not associated with breast cancer risks. Obese women showed a significantly increased risk, especially among premonopausal women.
Intake frequencies of several food items influenced the risks: intake of ribs and meaty soups increased the risks, but intake of green vegetables decreased the incidence of breast cancer. Concerning dietary nutrients, caloric intake as well as
protein
and fat intake were significantly related to an increased risk of breast cancer. These effects were accentuated among postmenopausal women. Multivariate analysis controlling for age, reproductive factors, and body mass index, however, showed no
significant effects regarding dietary nutrients.
These results, being the first report on the risk factors of breast cancer among Korean, identified similar risk factor profiles to those of other ethnic groups about the reproductive factors Until now, as in other countries, no definite result
on
the
effect of dietary factors was observed. Further research on the methodologic issues of dietary assessment and statistical analysis is required as well as the conduct of a well-designed cohort study.
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