Parkin gene mutations are not common, but its epigenetic inactivation is a frequent event and predicts poor survival in advanced breast cancer patients

Table 5 Univariate and multivariate overall survival analysis of different prognostic variables and Parkin methylation in breast cancer patients by cox proportional hazard model

Variables	Univariate analysis			Multivariate analysis
Variables	Hazard ratio	95% CI	P Value	Hazard ratio	95% CI	P Value
Age (< 50 yr. vs. ≥50 yr.)	1.535	0.688–3.422	0.295	–	–	–
Weight (< 60 kg vs. ≥60 kg)	0.720	0.408–1.270	0.295	–	–	–
Tumour size (< 4 cm vs. ≥4 cm)	1.322	0.745–2.347	0.340	–	–	–
Clinical Stage (I + II vs. III + IV)	1.409	1.028–1.930	0.033*	1.541	1.139–2.083	0.005*
Histological^a grade (WD vs. MD + PD)	3.659	1.641–8.162	0.002*	3.316	1.462–7.524	0.004*
Lymph Node (Neg. vs. Pos.)	3.427	1.812–6.483	< 0.0001*	2.769	1.453–5.277	0.002*
Menopause (Pre vs. Post)	2.184	0.979–.4.870	0.056	–	–	–
ER^b (Neg. vs. Pos.)	0.843	0.476–1.491	0.557	–	–	–
PR^c (Neg. vs. Pos.)	0.717	0.380–1.356	0.306	–	–	–
Her-2^d (Neg. vs. Pos.)	1.784	0.999–3.184	0.050	–	–	–
TNBC^e (No vs. Yes)	0.839	0.450–1.563	0.579	–	–	–
Methylation (Meth. vs. Unmeth.)	2.892	1.528–5.474	0.001*	2.286	1.190–4.389	0.013*

^a WD Well differentiated, MD Moderately differentiated, PD Poorly differentiated
^b Estrogen receptor
^c Progesterone receptor
^d human epidermal growth factor receptor 2
^e Triple Negative breast cancer, *Significant Correlation (P < 0.05)