Association between Bmi1 and clinicopathological status of esophageal squamous cell carcinoma

Table 2 Relationship between Bmi-1 protein expression in ESCC tissues and clinicopathological status

Parameter	> 50%	10%-50%	< 10%	P
Age (yr)
≥ 60	23	9	4	0.784
< 60	21	7	6
Histological grade
I	7	3	3	0.079
II	28	5	6
III	9	8	1
Lymph node metastases
+	11	9	3	0.073
-	33	7	7
Stage
III/IV	9	4	1	0.691
I/II	35	12	9
Location
Nucleus	0	7	8	0.000
Cytoplasm	30	18	16
Both nucleus and cytoplasm	5	15	20

ESCC was subjected to immunohistochemistry using antibodies to Bmi1. χ² test was used to detect the difference between Bmi1 oncoprotein and clinicopathological status.