Apolipoprotein D expression in benign and malignant prostate tissues.

Background: Apolipoprotein D (ApoD), a protein component of the human plasma lipid transport system, is an androgen regulated protein in both breast and prostate cancer cell lines.
Methods: Here we examined, by immunohistochemical assay, the ApoD expression in normal, benign and malignant prostate tissues.
Results: ApoD was detected in the two analyzed normal prostate tissues, in 16 (94.1%) of 17 benign prostatic hyperplasias, and in 36 (63.1%) of 57 prostate carcinomas. In prostate carcinomas, ApoD immunostaining values did not show significant relationship neither with age of the patients, stage and histologic grade of the tumors, nor with preoperative serum levels of prostatic specific antigen (PSA). However, ApoD-negative immunostaining predicted shorter survival duration in the subgroup of 46 patients with nonresectable prostate cancer (p = 0.02).
Conclusions: Our results led us to consider that Apo D expression by prostate carcinomas migth be of clinical usefulness for identificating lesions with different evolution.