Table 1.

Midkine expression is increased in the late stage prostate cancers. Normal and prostate cancer tissue microarray slides were immunohistochemically stained for midkine, using rabbit anti-midkine antibodies and ABC elite kit with DAB substrate, and counterstained by hematoxylin. The grading was assigned to each tissue core by a consensus review of two pathologists.

Tissue	No.	Gleason score	P	Midkine stain			P
		median (range)		-	+	++
Normal	18			17	1	0	§
Early stage cancer	40	6 (5 – 7)	*	37	3	0	†
Late stage cancer	71	9 (8–10)		41	24	6	‡

"-" indicates ≤ 20% of epithelial cells were immunopositive;

"+" indicates 20–50% of epithelial cells were immunopositive;

"++" indicates ≥ 50% of epithelial cells were immunopositive.

* P < 0.001, Gleason scores, early stage cancer v.s. late stage cancer.

§ P > 0.05, normal v.s. early stage cancer.

† P < 0.001, early stage cancer v.s. late stage cancer.

‡ P < 0.001, normal v.s. late stage cancer.