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

Breast Cancer Research

Table 4 Clinicopathological factors in relation to EDN3 protein expression

	EDN3 expression
Variables	Number^a	Low (IRS < 8)	High (IRS ≥ 8)	P value^b
Clinicopathological factors
Age at diagnosis
≤ 59 years	83	36	47	0.632
> 59 years	67	32	35
Tumour size^c
pT1	48	21	27	0.728
pT2 to pT4	100	47	53
Lymph node status^c
pN0	67	29	38	0.742
pN1 to pN3	80	37	43
Histological grade
G1 and G2	83	35	48	0.408
G3	66	33	33
Histological type
Ductal	122	53	69	0.385
Lobular	12	5	7
Other	16	10	6
Tumour focality
Unifocal	130	61	69	0.467
Multifocal	19	7	12
Oestrogen receptor
Negative (IRS^d ≤ 2)	38	19	19	0.698
Positive (IRS > 2)	83	45	38
Progesterone receptor
Negative (IRS^d ≤ 2)	85	41	44	0.704
Positive (IRS > 2)	40	21	19
Her2 status
Negative (IHC: 0; 1+)	105	46	59	0.169
Positive (IHC: 2+; 3+)	23	14	9

^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; IHC, immunohistochemistry.

ISSN: 1465-542X