Endocrine treatment and incidence of relapse in women with oestrogen receptor-positive breast cancer in Europe: a population-based study

European High Resolution Working Group on breast cancer

Research output: Contribution to journalArticlepeer-review


PURPOSE: Endocrine therapy (ET) is the mainstream adjuvant treatment for ER-positive breast cancer (BC). We analysed 9293 ER-positive BC patients diagnosed in nine European countries in 2009-2013 to investigate how comorbidities at diagnosis, age, stage and subtype affected ET use over time, and relapse.

METHODS: Adjusted odds ratios (ORs) and 95% confidence intervals (95%CIs) of receiving ET were estimated according to Charlson comorbidity, age, stage and subtype using logistic regression. The 2-year cumulative incidence and adjusted sub-hazard ratios (SHRs) of relapse were estimated using competing risk analysis, with all-cause death as the competing event. The z-test was used to assess differences in the proportion of patients receiving ET in 1996-1998 and 2009-2013.

RESULTS: Ninety percent of the patients started adjuvant ET, range 96% (Belgium, Estonia, Slovenia, Spain)-75% (Switzerland). ORs of starting ET were lower for women aged > 75 years, with severe comorbidities, or luminal B HER2-positive cancer. The factors independently increasing the risk of relapse were: not receiving ET (SHR 2.26, 95%CI 1.02-5.03); severe comorbidity (SHR 1.94, 95%CI 1.06-3.55); luminal B, either HER2 negative (SHR 3.06, 95%CI 1.61-5.79) or positive (SHR 3.10, 95%CI 1.36-7.07); stage II (SHR 3.20, 95%CI 1.56-6.57) or stage III (SHR 7.41, 95%CI 3.48-15.73). ET use increased significantly but differently across countries from 51-85% in 1996-1998 to 86-96% in 2009-2013.

CONCLUSIONS: ER-positive BC patients in Europe are increasingly prescribed ET but between-country disparities persist. Older women and women with severe comorbidity less frequently receive ET. ET omission and severe comorbidity independently predict early disease relapse.

Original languageEnglish
Pages (from-to)439-450
Number of pages12
JournalBreast Cancer Research and Treatment
Issue number2
Publication statusPublished - Sep 2020


  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Antineoplastic Agents, Hormonal/therapeutic use
  • Breast Neoplasms/drug therapy
  • Comorbidity
  • Databases, Factual
  • Estrogen Receptor alpha/metabolism
  • Europe/epidemiology
  • Female
  • Humans
  • Incidence
  • Middle Aged
  • Neoplasm Recurrence, Local/epidemiology
  • Young Adult

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