Frequent loss of endothelin-3 (EDN3) expression due to epigenetic inactivation in human breast cancer

Breast Cancer Research

Table 7 Clinicopathological parameters in relation to EDN3 promoter methylation

Variables	EDN3 promoter
	Number^a	Unmethylated (percentage)	Methylated (percentage)	P value^b
Total	128	39 (30.5)	89 (69.5)
Clinicopathological factors
Age at diagnosis
≤ 59 years	64	22 (34)	42 (66)	0.443
> 59 years	64	17 (29)	47 (71)
Tumour size^c
pT1	44	15 (34)	29 (66)	0.680
pT2 to pT4	72	21 (29)	51 (71)
Lymph node status^c
pN0	57	16 (28)	41 (72)	0.676
pN1 to pN3	51	17 (33)	34 (67)
Histological grade
G1 and G2	68	18 (26)	50 (74)	0.310
G3	49	18 (37)	31 (63)
Histological type
Ductal	103	32 (31)	71 (69)	0.849
Lobular	15	5 (33)	10 (67)
Other	6	1 (17)	5 (83)
Immunohistochemistry
Oestrogen receptor
Negative (IRS^d ≤ 2)	33	11 (33)	22 (67)	0.655
Positive (IRS > 2)	85	24 (28)	61 (72)
Progesterone receptor
Negative (IRS^d ≤ 2)	33	11 (33)	22 (67)	0.655
Positive (IRS > 2)	85	24 (28)	61 (72)

^aOnly female patients with primary invasive breast cancer were included. ^bFisher exact test (two-sided). ^cAccording to the UICC (Union Internationale contre le Cancer): TNM Classification of Malignant Tumours [19]. ^dImmunoreactivity score (IRS) according to Remmele and Stegner [24]. EDN3, endothelin-3.

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