Adjuvant tamoxifen adherence in men with early-stage breast cancer

Oluchi Oke, Jiangong Niu, Mariana Chavez-MacGregor, Hui Zhao, Sharon H. Giordano

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Background: Most breast cancers (BCs) in men are hormone receptor–positive. Adjuvant tamoxifen is part of the standard treatment of these patients. Small, single-institution studies have suggested that men have high rates of discontinuing adjuvant endocrine treatment. The authors examined rates of tamoxifen discontinuation and medication adherence in a large population-based cohort of male patients with BC. Methods: In the Surveillance, Epidemiology, and End Results–Medicare database, male patients with invasive nonmetastatic BC, diagnosed between 2007 and 2013, who were ≥65 years old, had Part D coverage, and had tamoxifen prescriptions within 1 year of diagnosis were identified. Adherence was defined as a medication possession ratio of ≥80% among those patients who were filling tamoxifen prescriptions. Logistic regression model was used to assess predictors of tamoxifen adherence. Results: A total of 451 patients met eligibility criteria. The median age at diagnosis was 75 years. The median follow-up was 32.5 months. The rates of tamoxifen discontinuation were 15.8%, 24.3%, 31.3%, 36.9%, and 48.3% at 1, 2, 3, 4, and 5 years after diagnosis, respectively. Among the men who were still taking tamoxifen, the corresponding adherence rates were 76.9%, 73.6%, 68.7%, 64.8%, and 60.2%. In the adjusted model, significant predictors of lower adherence included residing in a high poverty area (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.28-2.12) and a Charlson comorbidity score of ≥2 (OR, 0.46; 95% CI, 0.22-0.97). Conclusion: Older men with breast cancer have high rates of tamoxifen discontinuation, with 48% of all patients discontinuing tamoxifen before the end of year 5. Additionally, even among those patients continuing tamoxifen, a substantial number of patients are nonadherent. Further research should evaluate potentially modifiable reasons for treatment discontinuation and lack of adherence to tamoxifen.

Original languageEnglish (US)
Pages (from-to)59-64
Number of pages6
Issue number1
StatePublished - Jan 1 2022


  • adherence
  • hormone receptor positive
  • male breast cancer (MBC)
  • medication possession ratio (MPR)
  • tamoxifen

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


Dive into the research topics of 'Adjuvant tamoxifen adherence in men with early-stage breast cancer'. Together they form a unique fingerprint.

Cite this