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Number of children and death from hormone‐dependent cancers
Author(s) -
Lund Eiliv
Publication year - 1990
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910460608
Subject(s) - norwegian , medicine , confidence interval , ovary , gynecology , cancer , breast cancer , hormone , relative risk , risk factor , obstetrics , demography , philosophy , linguistics , sociology
The association between number of children of current marriage reported by 431,604 women aged 45‐74 years at the Norwegian Census in 1970 and mortality, at follow‐up through 1985, from hormone‐dependent cancers, i. e., cancers of breast, corpus uteri and ovary combined, has been investigated. The reduction in age‐adjusted mortality was 9.6% (95% confidence interval; 8.3–10.9%) for each child with no deviation from linearity. Women with 8‐11 children had a relative risk of 0.34 (0.25–0.47) compared to nullipara. Adjustment for age at first birth slightly changed the effect of number of children on mortality to 9.3% per child. The reduction in mortality per child was for cancer of the breast 7.2%, corpus uteri 12.2% and ovary 12.7%. Our findings indicate that having few children is a major risk factor for death from the 3 hormone‐dependent cancers combined.