| ABSTRACT
Introduction: The role of Enhancer-of-zeste homologue 2 (EZH2)
in breast cancer invasion and progression may be attributed to
EZH2-mediated epigenetic repression of tumour cells.
Aim: The study aimed to assess the prognostic value of different
luminal subtypes of breast cancer in association with EZH2
protein expression.
Materials and Methods: A cross-sectional analytical research
study on breast cancer women was performed. The four major
molecular subtypes of breast cancer were defned, as follows:
luminal A, luminal B, HER2-type, and Triple-Negative/Basallike (TNBC). Log Rank (Mantel-Cox) test of equality of survival
function was then performed to assess statistical signifcance
between groups. The effects of variables on Overall Survival
(OS) and Event Free Survival (EFS), was then assessed to give
adjusted Hazard Ratios (HRs) with 95% Confdence intervals
(CIs).
Results: Samples were collected for women with breast cancers,
with follow-up data collected over a 5-year period, with the age
range of 34-75 years. TNBC subgroup was twice as likely to have
high EZH2 expression compared with the luminal A subgroup
(as the reference group) (OR=2.06; 95% CI=0.22 to19.09), and
the luminal B subgroup had a 35% reduced likelihood (OR=0.66;
95% CI=0.26 to1.70). Cox’s Regression analysis showed that
the hazard of mortality was about 3 times more in HER2 subtype
breast cancers than in the luminal A subgroup (HR=3.16; 95%
CI: 1.30-15.45, P<0.005), while the Log Rank (Mantel-Cox) test
showed a statistically signifcant difference in OS by molecular
subtype at all-time points (p≤0.05).
Conclusion: The results provide some interesting insights,
confrming the prognostic differences by molecular subtypes,
in relation to EZH2 protein expression. However, there remains
controversy about the prognostic value of different molecular
subtypes. |