Breast cancer in young women and prognosis: How important are proliferation markers?

Eur J Cancer. 2017 Oct;84:278-289. doi: 10.1016/j.ejca.2017.07.044. Epub 2017 Aug 29.

Abstract

Aim: Compared to middle-aged women, young women with breast cancer have a higher risk of systemic disease. We studied expression of proliferation markers in relation to age and subtype and their association with long-term prognosis.

Methods: Distant disease-free survival (DDFS) was studied in 504 women aged <40 years and 383 women aged ≥40 years from a population-based cohort. Information on patient characteristics, treatment and follow-up was collected from medical records. Tissue microarrays were produced for analysis of oestrogen receptor, progesterone receptor (PR), Her2, Ki-67 and cyclins.

Results: Young women with luminal tumours had significantly higher expression of Ki-67 and cyclins. Proliferation markers were prognostic only within this subtype. Ki-67 was a prognostic indicator only in young women with luminal PR+ tumours. The optimal cut-off for Ki-67 varied by age. High expression of cyclin E1 conferred a better DDFS in women aged <40 years with luminal PR- tumours (hazard ratio [HR] 0.47 [0.24-0.92]). Age <40 years was an independent risk factor of DDFS exclusively in women with luminal B PR+ tumours (HR 2.35 [1.22-4.50]). Young women with luminal B PR- tumours expressing low cyclin E1 had a six-fold risk of distant disease compared with luminal A (HR 6.21 [2.17-17.6]).

Conclusions: The higher expression of proliferation markers in young women does not have a strong impact on prognosis. Ki-67 is only prognostic in the subgroup of young women with luminal PR+ tumours. The only cyclin adding prognostic value beyond subtype is cyclin E1. Age is an independent prognostic factor only in women with luminal B PR+ tumours.

Keywords: Age; Breast cancer; Cyclin; Ki-67; Luminal; Population-based; Progesterone receptor; Prognosis; Subtype; Young.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Breast Neoplasms / chemistry*
  • Breast Neoplasms / mortality
  • Breast Neoplasms / pathology
  • Breast Neoplasms / therapy
  • Cell Proliferation*
  • Cyclins / analysis
  • Disease-Free Survival
  • Female
  • Humans
  • Immunohistochemistry
  • Kaplan-Meier Estimate
  • Ki-67 Antigen / analysis*
  • Middle Aged
  • Predictive Value of Tests
  • Proportional Hazards Models
  • Receptor, ErbB-2 / analysis
  • Receptors, Estrogen / analysis
  • Receptors, Progesterone / analysis
  • Registries
  • Risk Factors
  • Sweden
  • Time Factors
  • Tissue Array Analysis
  • Treatment Outcome

Substances

  • Cyclins
  • Ki-67 Antigen
  • Receptors, Estrogen
  • Receptors, Progesterone
  • ERBB2 protein, human
  • Receptor, ErbB-2