A prospective investigation of oral contraceptive use and breast cancer mortality: Findings from the Swedish women's lifestyle and health cohort

Ula Nur, Darline El Reda, Dana Hashim, Elisabete Weiderpass

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

Background: The association between oral contraceptive (OC) use and long-term mortality remains uncertain and previous studies have reported conflicting findings. We aim to assess the long-term impact of OC use on all-cause and cancer-specific mortality. Methods: Out of 49,259 participants, we analysed data on 2120 (4.3%) women diagnosed with first primary breast cancer between 1993 and 2012, in the Swedish Women's Lifestyle and Health Study. Kaplan-Meier plots were used to graph the hazard of mortality in association with oral contraceptives use, stage of disease and hormone receptors status at diagnosis. Cox proportional hazard model were used to estimate hazard ratios (HR) between OC use and all-cause mortality. The same association was studied for breast cancer-specific mortality by modelling the log cumulative mortality risk, adjusting for clinical stage at diagnosis, hormone receptor status, body mass index and smoking. Results: Among 2120 women with breast cancer, 1268 (84%) reported ever use of OC and 254 died within 10 years of diagnosis. The risk of death for OC ever-users relative to never-users was: HR = 1.13 (95% CI: 0.66-1.94) for all-cause mortality and HR = 1.29 (95% CI: 0.53-3.18) for breast cancer-specific mortality. A high percentage of women (42.9%) were diagnosed at early stage disease (stage I). Conclusions: Among women with primary breast cancer, OC ever-users compared to never- users did not have a higher all-cause or breast cancer specific-mortality, after the adjustment of risk factors.

Original languageEnglish
Article number807
JournalBMC Cancer
Volume19
Issue number1
DOIs
StatePublished - 14 Aug 2019
Externally publishedYes

Keywords

  • Breast cancer
  • Hormone receptor status
  • Multiple imputation
  • Oral contraceptives
  • Stage
  • Survival

Fingerprint

Dive into the research topics of 'A prospective investigation of oral contraceptive use and breast cancer mortality: Findings from the Swedish women's lifestyle and health cohort'. Together they form a unique fingerprint.

Cite this