The abnormal expression of retinoic acid receptor-β, P53 and Ki67 protein in normal, premalignant and malignant esophageal tissues

Table 1 Expression of the biomarkers in all kinds of esophageal tissues

Biomarker	% (positive/total)
	Normal	Mild Dysplasia	Severe dysplasia	SSC	AC	AC-SSC
RAR-β	94.3 (33/35)	67.9 (19/28)	58.1 (18/31)a	54.4 (92/169)	51.7 (15/29)	45.0 (9/20)
P53	5.7 (2/35)	10.7 (3/28)	51.6 (16/31)b	56.8 (96/169)	62.1 (18/29)	60.0 (12/20)
Ki67	5.9 (2/34)	21.4 (6/28)	58.1 (18/31)c	62.1 (105/169)	58.6 (17/29)	65.0 (13/20)

^aP < 0.01 vs χ² test between normal tissues and severe dysplastic tissues.

^bP < 0.0001 vs χ² test between normal tissues and severe dysplastic tissues.

^cP < 0.00002 vs χ² test between normal tissues and severe dysplastic tissues.

Table 2 Expression of the biomarkers in normal, dysplastic, and malignant esophageal tissues

Biomarker	% (positive/total)
	Normal	dysplasia	tumor
RAR-β	94.3 (33/35)	62.7 (37/59)a	53.2 (116/218)b
P53	5.7 (2/35)	32.2 (19/59)c	57.8 (126/218)
Ki67	5.9 (2/34)	40.7 (24/59)d	61.9 (135/218)

^aP = 0.016 vs χ² test between normal tissues and dysplastic tissues.

^bP < 0.0003 vs χ² test between normal tissues and tumor tissues.

^cP = 0.006 vs χ² test between normal tissues and dysplastic tissues.

^dP < 0.0008 vs χ² test between normal tissues and dysplastic tissues.

Table 3 Expression of RAR-β in the three subtypes of esophageal squamous cell carcinomas

Tumor differentiation	% (positive/total)
Well differentiated SCC	62.7 (42/67)
Moderately differentiated	55.1 (43/78)
Poorly differentiated	29.2 (7/24)a

^aP < 0.005 vs χ² test between well differentiated and poorly diffentiated SSCs.