Research
Print page Print page
Switch language
The Capital Region of Denmark - a part of Copenhagen University Hospital
Published

Cumulative incidence of cardiovascular events under tamoxifen and letrozole alone and in sequence: a report from the BIG 1-98 trial

Research output: Contribution to journalJournal articleResearchpeer-review

  1. A catalog of curated breast cancer genes

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. Breast cancer mortality and overdiagnosis after implementation of population-based screening in Denmark

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. Induction of PIK3CA alterations during neoadjuvant letrozole may improve outcome in postmenopausal breast cancer patients

    Research output: Contribution to journalJournal articleResearchpeer-review

  4. Patterns in detection of recurrence among patients treated for breast cancer

    Research output: Contribution to journalJournal articleResearchpeer-review

  1. A catalog of curated breast cancer genes

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. DBCG Kvalitetsdatabase for Brystkræft – resumé af årsrapport 2020

    Research output: Contribution to journalJournal articleCommunication

  3. A careful reassessment of anthracycline use in curable breast cancer

    Research output: Contribution to journalReviewResearchpeer-review

  • Manuela Rabaglio
  • Zhuoxin Sun
  • Rudolf Maibach
  • Anita Giobbie-Hurder
  • Bent Ejlertsen
  • Vernon J Harvey
  • Patrick Neven
  • István Láng
  • Hervé Bonnefoi
  • Andrew Wardley
  • Barbara Ruepp
  • Monica Castiglione
  • Alan S Coates
  • Richard D Gelber
  • Aron Goldhirsch
  • Marco Colleoni
  • Beat Thürlimann
  • Meredith M Regan
View graph of relations

BACKGROUND: Compared to tamoxifen, adjuvant treatment with aromatase inhibitors improves disease outcomes of postmenopausal women with hormone receptor-positive early breast cancer. In the international, randomized, double-blind BIG 1-98 trial, 8010 women were randomized to receive tamoxifen, letrozole, or sequential use of the agents for 5 years. With a focus on switching between agents, we investigated cardiovascular events over the entire 5-year treatment period.

METHODS: Of the 6182 patients enrolled, 6144 started trial treatment and were included in this analysis. Adverse events occurring during study treatment until 30 days after cessation were considered. Eight cardiovascular event types were defined. Cumulative incidence of events were estimated using the Kaplan-Meier method, without consideration for competing events. Multivariable Cox models estimated hazard ratios (HR) with 95% confidence intervals (CI) for pairwise comparisons of treatment arms.

RESULTS: While on study treatment, 6.5% of patients (n = 397) had any cardiac events reported; for 2.4%, the event was grades 3-5, of which 11 (0.2%) were grade 5. Letrozole monotherapy was associated with higher risk of grade 1-5 ischemic heart disease (HR = 1.81; 95% CI, 1.06-3.08) compared with tamoxifen monotherapy. Patients assigned sequential tamoxifen →letrozole (HR = 1.59; 95% CI, 0.92-2.74) or sequential letrozole → tamoxifen (HR = 1.20; 95% CI, 0.68-2.14) showed a lesser degree of risk elevation. Patients assigned to tamoxifen-containing regimens had significantly higher risk of grade 1-5 thromboembolic events (tamoxifen monotherapy HR = 2.10; 95% CI, 1.42-3.12; tamoxifen → letrozole HR = 1.96; 95% CI, 1.32-2.92; letrozole → tamoxifen HR = 1.56; 95% CI 1.03-2.35) as compared with patients assigned letrozole alone.

CONCLUSION: When initiating or switching between adjuvant endocrine treatments in postmenopausal patients, age and medical history, with special attention to prior cardiovascular events, should be balanced with expected benefit of the treatment.

Original languageEnglish
JournalBreast Cancer Research and Treatment
Volume185
Issue number3
Pages (from-to)697-707
Number of pages11
ISSN0167-6806
DOIs
Publication statusPublished - Feb 2021

    Research areas

  • Aromatase inhibitor, Adjuvant endocrine therapy, Tamoxifen, Letrozole, Cardiovascular events

ID: 61368548