A case-control study of breast cancer in Tianjin, China
In a population-based case-control study of breast cancer in Tianjin, China, involving 300 cases and 300 population controls interviewed during 1985-1986, a number of strong risk factors were identified. Although average age at menarche was late by Western standards in this developing country (14.4...
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Published in | Cancer epidemiology, biomarkers & prevention Vol. 1; no. 6; pp. 435 - 439 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Association for Cancer Research
01.09.1992
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Subjects | |
Online Access | Get full text |
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Summary: | In a population-based case-control study of breast cancer in Tianjin, China, involving 300 cases and 300 population controls
interviewed during 1985-1986, a number of strong risk factors were identified. Although average age at menarche was late by
Western standards in this developing country (14.4 years), it was clearly related to risk. Women with their first menstrual
period at age 12 years or earlier had 80% greater risk than women who started at age 17 years or later. Age at first full-term
pregnancy was also strongly related to risk, with women whose first birth after age 30 years having 3.2 times the risk of
women whose first birth was under age 20 years. Other established breast cancer risk factors in Western populations (family
history of breast cancer, a history of benign breast disease, and use of oral contraceptives late in reproductive life) were
also risk factors in this population. Parity and duration of lactation were both strongly protective against breast cancer
development in univariate analyses. These two variables were highly correlated with each other and with age at first full-term
pregnancy. Although the effects of each variable dissipated somewhat in multivariate analysis, our data strongly suggest that
both parity and lactation independently contribute to breast cancer risk. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1055-9965 1538-7755 |