Abstract
Purpose
To evaluate cytoplasmic and nuclear ErbB-4 expression in prostate cancer specimens and its association with outcome.
Basic procedures
Specimens of 50 prostate cancer patients were investigated for ErbB-4 overexpression using immunohistochemistry staining. Cytoplasmic and nuclear staining was graded as 0–3 according to its intensity. The prognostic parameters were tumor stage, PSA level, Gleason score, probability of positive lymph nodes (Partin's tables and Roach equation), and 5-year disease free survival (Kattan nomogram).
Main findings
Overexpression of ErbB-4 (≥1) was detected in 30 (60%) patients and overexpression using cytoplasmic and nuclear staining was ≥2 in 19 (38%) and 17 (34%) patients, respectively. In only one third of the specimens was there any similarity between the 2 types of staining. Advanced tumor stage, high pretreatment PSA levels and high Gleason scores were evenly distributed among the patients with low (≤1) and intermediate/high (≥2) ErbB-4 expression. The probability of lymph node involvement and 5-year disease free survival were similar in both types of staining.
Principal conclusions
ErbB-4 was overexpressed (cytoplasmic and nuclear staining) in approximately one third of prostate cancer patients. The rate of similarity between the 2 staining types was only 33%: overexpression was evenly distributed among intermediate/high and low risk prostate cancer patients with both staining methods.