Breast Cancer Risk After Recent Childbirth: A Pooled Analysis of 15 Prospective Studies.

ABSTRACT:

Background

Parity is widely recognized as protective for breast cancer, but breast cancer risk may be increased shortly after childbirth. Whether this risk varies with breastfeeding, family history of breast cancer, or specific tumor subtype has rarely been evaluated.

Objective

To characterize breast cancer risk in relation to recent childbirth.

Design

Pooled analysis of individual-level data from 15 prospective cohort studies.

Setting

The international Premenopausal Breast Cancer Collaborative Group.

Participants

Women younger than 55 years.

Measurements

During 9.6 million person-years of follow-up, 18 826 incident cases of breast cancer were diagnosed. Hazard ratios (HRs) and 95% CIs for breast cancer were calculated using Cox proportional hazar

SUBMITTER: Nichols HB 

PROVIDER: S-EPMC6760671 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature