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Volume 1 Journal of Blood Disorders and Treatment World Hematology 2018
October 22-23, 2018
Page 14
Hematology and Oncology Congress
October 22-23, 2018 Warsaw, Poland
10th World
Hormonal contraception and the risk of breast cancer
Background: We know little about the risk of breast cancer in users of newer types of hormonal contraception and in users of
hormone intrauterine devices.
Method: We assessed associations between hormonal contraception use and invasive breast cancer risk in a nationwide
prospective cohort study following all women inDenmark aged 15-49 years without previous cancer, venous thromboembolism
or infertility treatment. Nationwide registers provided individually updated information about use of hormonal contraception,
breast cancer diagnoses and information on potential confounders.
Result: Among 1.8 million women followed on average for 10.9 years with a total of 19.6 million person-years, 11,517 breast
cancers occurred. Compared to never users, the relative risk of breast cancer among all current and recent users was 1.2 (95%
CI 1.1-1.3), increasing from 1.1 (1.0-1.2) with less than one year of use to 1.4 (1.3-1.5) with more than 10 years of use. There
was little evidence that the risk varied by type of progestogen in the combined formulations. Current or recent users of the
progestin-only intrauterine system also experienced an increased relative risk of breast cancer of 1.2 (1.1-1.3). The overall
absolute mean increase in breast cancers among current and recent users of any hormonal contraceptive for all ages was 13
(10-16) per 100,000 person-years, approximately one extra breast cancer for every 7690 women using hormonal contraception
for one year, the absolute risk difference increased by age.
Conclusion: Breast cancer risk was increased among current and recent users of contemporary hormonal contraception and
increased with longer durations of use however, absolute increases in risk were small and the same products protects against
ovarian cancer.
Biography
Ojvind Lidegaard is a Professor of Obstetrics and Gynecology at The Juliane Marie Centre, Rigshospitalet, Copenhagen University Hospital and the University of Copen-
hagen, Denmark. He is also the Head of the National Quality Database in Early Pregnancy and Abortion. His main research areas include gynecological endocrinology,
fetal exposure, postnatal diseases, gynecological cancer, early pregnancy and obstetrics.
Ojvind Lidegaard
University of Copenhagen, Denmark
Ojvind Lidegaard, J Blood Disord Treat 2018, Volume 1