Promoter methylation-associated loss of ID4expression is a marker of tumour recurrence in human breast cancer

Table 3 Univariate analysis of clinicopathological parameters influencing recurrence-free survival (RFS) and overall survival (OS)

Variable	RFS			OS
	n^a	events	P-value^d	n	events	P-value
*Clinicopathological factors:*
Tumour size^b
pT1	44	14	0.142	45	7	0.396
pT2-4	77	35		79	16
Lymph node status^b
pN0	55	11	0.021	54	6	0.033
pN1-3	59	24		59	15
Histological grade
G1	11	3	0.018	10	1	0.019
G2	60	15		58	7
G3	60	30		54	17
Histological type
invasive ductal	107	33	0.006	106	23	0.877
invasive lobular	18	9		18	2
other	9	7		9	2
Oestrogen receptor status
negative (IRS^c 0–2)	46	15	0.701	45	12	0.027
positive (IRS 3–12)	82	32		82	14
Progesterone receptor status
negative (IRS^c 0–2)	43	18	0.240	43	11	0.059
positive (IRS 3–12)	85	29		84	15
ID4 promoter methylation
negative	39	8	0.036	39	5	0.169
positive	76	28		75	16

^aOnly female patients with primary, unilateral, invasive breast cancer were included. ^bAccording to TNM classification by Sobin and Wittekind [37]. ^c IRS = Immuno-reactive score according to Remmele and Stegner [38]. ^dFisher's exact test. Significant P-values are marked in bold face.