Immunohistochemical Localization of Metallothionein in Human Prostate Cancer

Abstract

We investigated the expression of metallothionein in human prostate cancer. Formalin fixed and paraffin embedded tissue specimens from 45 patients with primary prostate cancer were stained for metallothionein using a standard immunohistochemical technique. Metallothionein was detected in 15 of 45 prostate cancers (33.3 percent). Cytoplasmic and nuclear staining occurred in most cells. Additionally, metallothionein was found in basement membrane surrounding the cancer cells in 2 cases with metallothionein expression, and in secretory products of the lumen in a few cases. Statistical analysis for metallothionein expression related to tumor grade revealed a significant difference between high (7 to 10) and low (2 to 4) Gleason scores (p less than 0.001), as well as between middle (5 and 6) and low scores (p less than 0.05). However, no relationship was found with clinical stage. Our data suggest a close correlation of metallothionein expression with tumor grade and a wide range of metallothionein expression in prostate cancer.