University of Oulu

Tastula, A., Jukkola, A., Alakokkare, A.-E., Nordström, T., Eteläinen, S., Karihtala, P., & Miettunen, J. (2021). Early-Life Risk Factors for Breast Cancer – Prospective Follow-up in the Northern Finland Birth Cohort 1966. Cancer Epidemiology Biomarkers & Prevention 30(4), 616–622.

Early-life risk factors for breast cancer : prospective follow-up in the Northern Finland Birth Cohort 1966

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Author: Tastula, Anniina1,2; Jukkola, Arja3,4; Alakokkare, Anni-Emilia1,2;
Organizations: 1Center for Life Course Health Research, University of Oulu, Oulu, Finland
2Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
3Department of Oncology of Medicine and Radiotherapy, Tampere University Hospital, Tampere, Finland
4Tampere Cancer Center, Faculty of Medicine and Health Technology, University of Tampere, Tampere, Finland
5Infrastructure for Population Studies, Faculty of Medicine, University of Oulu, Oulu, Finland
6Department of Obstetrics and Gynaecology, Oulu University Hospital, Oulu, Finland
7PEDEGO Research Unit, University of Oulu, Oulu, Finland
8Helsinki University Hospital Comprehensive Cancer Center and University of Helsinki, Helsinki, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.6 MB)
Persistent link:
Language: English
Published: American Association for Cancer Research, 2021
Publish Date: 2022-02-09


Background: While some risk factors for breast cancer have been confirmed, less is known about the role of early biological and social risk factors for breast cancer in adult life.

Methods: In a prospective follow-up in the Northern Finland Birth Cohort 1966 consisting of 5,308 women, 120 breast cancers were reported via national registers by the end of 2018. Early risk factors were examined with univariate and multivariate analyses using Cox regression analysis. The main results are reported with HRs and their 95% confidence intervals (CI).

Results: In the multivariate-adjusted models, women whose mothers lived in urban areas (HR, 1.68; 95% CI, 1.13–2.51) during pregnancy, were low educated (HR, 2.40; 95% CI, 1.30–4.45), and had been diagnosed with breast cancer (HR, 1.97; 95% CI, 1.09–3.58) had a higher risk for breast cancer in adult life. Lower BMI at the age of 14 associated nonsignificantly with the risk of breast cancer (Mann–Whitney U test, P = 0.087). No association between birth size and breast cancer risk in adult life was found.

Conclusions: Early-life residence and socioeconomic conditions may have an impact on developing breast cancer in women in adult life. All breast cancer cases of this study were relatively young, and most of them are assumed to be premenopausal.

Impact: This study is one of a few prospective birth cohort studies to examine early-life socioeconomic factors and breast cancer risk in adult life. This study is limited due to small number of cases.

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Series: Cancer epidemiology, biomarkers & prevention
ISSN: 1055-9965
ISSN-E: 1538-7755
ISSN-L: 1055-9965
Volume: 30
Issue: 4
Pages: 616 - 622
DOI: 10.1158/1055-9965.EPI-20-1442
Type of Publication: A1 Journal article – refereed
Field of Science: 3122 Cancers
Funding: A. Tastula’s contribution to the study has been supported by the Health and Biosciences Doctoral Programme, HBS-DP (University of Oulu) and J. Miettunen has received a grant from the Juho Vainio Foundation.
Dataset Reference: Data is available from the NFBC project center based on criteria for accessing confidential data.
Copyright information: © 2021 American Association for Cancer Research. The final authenticated version is available online at