Borderline ER-Positive Primary Breast Cancer Gains No Significant Survival Benefit From Endocrine Therapy: A Systematic Review and Meta-Analysis

Clin Breast Cancer. 2018 Feb;18(1):1-8. doi: 10.1016/j.clbc.2017.06.005. Epub 2017 Jun 23.

Abstract

Endocrine responsiveness of primary breast cancers with borderline estrogen receptor expression (ER+ [1%-9%]) remains unclear. We aimed at investigating differences in endocrine responsiveness, prognosis, and clinicopathological characteristics between the ER+ (1%-9%) cohort and the ER- cohort or ER+ (≥10%) cohort. Eligible literature published from inception to November 20, 2016 was retrieved from the PubMed database on the basis of Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data on survival outcomes were extracted and pooled odds ratios (ORs), 95% confidence intervals (CIs), and 2-tailed P values are reported. P values of the χ2 test for comparison of clinicopathological characteristics among included patients in the ER+ (1%-9%) cohort and the other 2 cohorts were calculated respectively. The analysis included 6 studies with 16,606 patients. Significant differences were detected between the ER+ (1%-9%) cohort and the other 2 cohorts on the basis of clinicopathological characteristics respectively. When taking all of the patients into analysis without consideration of treatment modality, the ER+ (1%-9%) cohort presented better prognosis than the ER- group in terms of 5-year disease-free survival (OR, 1.47; P = .046) and 5-year overall survival (OR, 1.23; P = .046). However, patients with ER+ (1%-9%) breast cancer who received endocrine therapy seemed to have a prognosis similar to those without any endocrine therapy (P = .684) and those with ER- carcinoma who received endocrine therapy (P = .145). Patients with ER+ (≥10%) tumors had better endocrine responsiveness compared with their ER+ (1%-9%) counterparts (OR, 0.52; P = .034, ER+ [1%-9%] vs. ER+ [≥10%]). Our results indicate that primary breast cancer patients with ER+ (1%-9%) expression gained no significant survival benefit from endocrine therapy, but manifested overall better prognosis than those with ER- cancer.

Keywords: Borderline estrogen receptor; Breast carcinoma; Endocrine treatment; Immunohistochemical staining; Prognosis.

Publication types

  • Comparative Study
  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Antineoplastic Agents, Hormonal / therapeutic use*
  • Breast / pathology
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / mortality
  • Breast Neoplasms / pathology
  • Disease-Free Survival
  • Female
  • Humans
  • Prognosis
  • Receptors, Estrogen / metabolism*
  • Survival Analysis

Substances

  • Antineoplastic Agents, Hormonal
  • Receptors, Estrogen