Characterization of membranous and cytoplasmic EGFR expression in human normal renal cortex and renal cell carcinoma

Table 1 Immunostaining expression of membranous EGFR in normal parenchymal and RCC tissues.

Characteristic	Patients	Membranous EGFR protein expression (mean score ± SE)		P value*
Characteristic	No. (%)	Normal renal tubular cells	RCC
Total				<0.001
Sex
Male	46 (73)	0.1 ± 0.1	2.1 ± 0.1	<0.001
Female	17 (27)	0.2 ± 0.1	2.1 ± 0.2	<0.001
P value^†		0.172	0.98
Grade
I	9 (14)	0.2 ± 0.1	1.9 ± 0.3	0.001
II	29 (46)	0.1 ± 0.1	2 ± 0.2	<0.001
III	9 (14)	0	2.3 ± 0.3	<0.001
IV	14 (23)	0.1 ± 0.1	2.2 ± 0.2	<0.001
ND	2 (3)	0	1.5 ± 0.5
P value^‡		0.679	0.641
Stage
Organ-confined (T1-2N0M0)	41 (65)	0.1 ± 0.1	2.1 ± 0.1	<0.001
Locally advanced (T3-4N0M0)	15 (24)	0.1 ± 0.1	1.9 ± 0.2	<0.001
Metastatic (N1-2 or M1)	7 (11)	0.1 ± 0.1	2 ± 0.4	0.002
P value^‡		0.989	0.766
Histological type
Conventional	54 (86)	0.1 ± 0.1	2.2 ± 0.1	<0.001
Non-conventional	9 (14)	0.1 ± 0.1	1.3 ± 0.4	0.01
P value^†		0.894	0.006

NOTE: Expression of membranous EGFR was evaluated the intensity of membranous immunostaining and categorized as either 1+ (weak); 2+ (moderate) and 3+ (strong). Non-conventional type included papillary, chromophobe, sarcomatoid and collecting duct. Abbreviations: RCC, renal cell carcinoma; SE, standard error; TNM, tumor-node-metastasis; ND, not determined. *: paired sample t test, †: Independent-sample t test for two groups, ‡: One-way ANOVA for three or more groups.

ISSN: 1423-0127