Tamoxifen treated patients have a better survival than patients treated with aromatase inhibitors - A population based registry study in Sweden

Research output: Contribution to journalPublished meeting abstract


Background. Randomised trials suggest that therapy with aromatase inhibitors improves survival in breast cancer compared with tamoxifen therapy in postmenopausal cases with hormone receptor positive breast cancer. Whether these results from randomized studies transform into the general population is unknown. We have therefore compared survival for all breast cancer cases in Sweden diagnosed 2000-2008 (n=54406) who received adjuvant antihormonal therapy. Material and methods. The study includes all women with BC diagnosed in Sweden between 2000 through 2008 (n=54406). The women had no previous cancer diagnosis during the period of 1958-1999. Dates of birth, BC diagnosis and TNM-stage where directly extracted from the cancer registry. The women's antihormonal therapy was gathered from the Swedish Prescription Registry (22213 women were on antihormonal therapy). Information regarding the cause of death and date of death was obtained from the Cause of Death Registry and tbe Swedish Population Register up until the 31st of December 2012 and 31st of December 2013 respectively. The breast cancer death and overall death have been calculated and the survival was compared between tamoxifen and aromatase inhibitor treated breast cancer patients. Analyses were adjusted for TNM-stage and age at diagnosis and restricted to women aged 50 and above. Results. Patients being treated with tamoxifen had a better breast cancer prognosis compared with aromatase inhibitor treated patients (HR 0.54, 95%CI 0.48-0.61). Restricting the analysis to stage 1 disease confirmed a better prognosis for tamoxifen treated women (HR 0.48, 95%CI 0.34-0.66). A better prognosis could be seen in all age strata studies, 50-60.61-70.71-90. The findings for overall survival gave similar results. Conclusion .This population based observational study show that women treated with aromatase inhibitors have a worse overall and breast cancer specific survival compared with tamoxifen treated women regardless of age and tumor stage.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology


  • aromatase inhibitor, tamoxifen, adjuvant, hormone receptor, human, patient, survival, register, population, Sweden, breast cancer, female, therapy, death, cause of death, cancer staging, diagnosis, prognosis, cancer prognosis, cancer patient, cancer mortality, prescription, cancer registry, cancer specific survival, cancer diagnosis, observational study, overall survival
Original languageEnglish
Article numberAbstract P1-12-10
JournalCancer Research
Issue number9 Suppl
Publication statusPublished - 2015
Publication categoryResearch
Event37th San Antonio Breast Cancer Symposium - San Antonio, Texas, United States
Duration: 2014 Dec 92014 Dec 13