21-gene recurrence score testing in the older population with estrogen receptor-positive breast cancer

J Geriatr Oncol. 2019 Mar;10(2):322-329. doi: 10.1016/j.jgo.2018.07.006. Epub 2018 Aug 6.

Abstract

Introduction: The 21-gene recurrence score (RS) (Oncotype Dx, Genomic Health, Redwood City Ca) has not been validated in an older cohort with estrogen receptor (ER)-positive breast cancer. The objective of this study was to evaluate RS validity in a group of older women with ER-positive breast cancer.

Methods: Utilizing the Surveillance, Epidemiology, and End Results Program (SEER) database with available RS, we evaluated women with ER-positive breast cancer aged 18-69 and those 70 years of age and older from 2004 to 2014. We utilized multivariable logistic regression models to evaluate factors associated with RS testing as well as a high-risk categorization for those who underwent testing. Survival was analyzed using Kaplan Meier curves and Cox proportional hazard models.

Results: We identified 363,876 women aged 18-69 years and 147,107 women aged 70 years and older. A smaller proportion of patients in the older group (8%) underwent RS testing than in the younger group (18%). Of the patients who underwent testing, distribution of RS was similar between groups. High-risk categorization independently predicted a higher likelihood of death for older patients (hazard ratio 1.47, 95% confidence interval 1.15-1.90). Among patients with high-risk RS, chemotherapy was associated with a decreased risk of death in the younger group, but not in the older group.

Conclusion: Older women are less likely to receive RS testing, but when tested, older patients have a similar distribution of RS as compared to younger patients. While high-risk categorization in the older cohort was prognostic, chemotherapy was not associated with improved survival.

Keywords: Breast Cancer; Genomic Testing; Geriatric; Recurrence Score.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Carcinoma / genetics*
  • Carcinoma / metabolism
  • Carcinoma / pathology
  • Female
  • Genetic Testing
  • Humans
  • Kaplan-Meier Estimate
  • Logistic Models
  • Middle Aged
  • Neoplasm Recurrence, Local / epidemiology
  • Neoplasm Recurrence, Local / genetics*
  • Receptors, Estrogen / metabolism
  • Reproducibility of Results
  • Risk Assessment
  • SEER Program
  • Survival Rate
  • United States / epidemiology
  • Young Adult

Substances

  • Receptors, Estrogen