Hormonal contraception and risk of breast cancer and breast cancer in situ among Swedish women 15-34 years of age: A nationwide register-based study.

ABSTRACT:

Background

Evidence on a possible association between newer hormonal contraceptives (HC) and risk of breast cancer remains inconclusive, especially as concerns progestogen-only methods.

Methods

In this nationwide prospective cohort study, all Swedish women aged 15-34 at study start on January 1^st 2005, or who turned 15 years during the study period, were followed until December 31^st 2017. Using information from seven National Registers, we assessed the risk ratio of developing breast cancer and breast cancer in situ in relation to different HC using Poisson regression. We adjusted the analyses for several known confounders of breast cancer.

Findings

This cohort included 1.5 million women providing more than 14 million person-years. During the stu

SUBMITTER: Niemeyer Hultstrand J 

PROVIDER: S-EPMC9340531 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature