Immunohistochemical localization of metallothionein in human prostate cancer

Purpose: We investigated the expression of metallothionein in human prostate cancer. Materials and Methods: Formalin fixed and paraffin embedded tissue specimens from 45 patients with primary prostate cancer were stained for metallothionein using a standard immunohistochemical technique. Results: Metallothionein was detected in 15 of 45 prostate cancers (33.3%). 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<0.001), as well as between middle (5 and 6) and low scores (p<0.05). However, no relationship was found with clinical stage. Conclusions: Our data suggest a close correlation of metallothionein expression with tumor grade and a wide range of metallothionein expression in prostate cancer.