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Fertility pattern does not explain social gradient in breast cancer in denmark
Author(s) -
Danø Hella,
Hansen Kasper Daniel,
Jensen Per,
Petersen Jørgen Holm,
Jacobsen Rune,
Ewertz Marianne,
Lynge Elsebeth
Publication year - 2004
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.20203
Subject(s) - fertility , demography , socioeconomic status , social class , incidence (geometry) , breast cancer , cohort study , cohort , gynecology , population , medicine , cancer , sociology , economics , physics , optics , market economy
The present study was undertaken to assess the impact of reproductive behavior on the social class gradient in breast cancer occurrence in Denmark. Objectives were to study whether the gradient across socioeconomic groups could be explained by fertility differences, whether the gradient across educational groups could be explained by fertility differences and whether the effect of socioeconomic group on breast cancer incidence and mortality could be explained by education and vice versa . We studied 674,084 women aged 20–39 at the census on 9 November 1970 for whom we had complete data on fertility history. The cohort was followed up for breast cancer incidence and mortality until 8 November 1998. Fertility history varied considerably across socioeconomic group, where 38% of the academics were childless at the age of 30, in contrast to only 8% of women in agriculture. The academics had the highest risk of breast cancer and women in agriculture had the lowest risk. For incidence, the gradient in the relative risks was 1.74, which changed to 1.49 when fertility history was incorporated and to 1.29 when school education was also taken into account. For school education, women with ≥ 12 years of schooling had the highest risk and women with ≤ 7 years of schooling had the lowest risk. For incidence, the gradient in the relative risk was 1.38, which changed to 1.26 when fertility history was incorporated and to 1.22 when socioeconomic group was also taken into account. © 2004 Wiley‐Liss, Inc.