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

• 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.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Keyword

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

Publication and Content Type

kon (subject category)

ref (subject category)