Immunohistochemical analysis of inflammatory cells in benign and precancerous lesions and carcinoma of the prostate

Abstract

Objective: Inflammation is an important cause of tumorigenesis in various types of malignancy. Mediators derived from inflammatory cells are associated with cancer proliferation, angiogenesis, and DNA damage. In the present study, we immunohistochemically examined the infiltration patterns of inflammatory cells in benign glands including glandular hyperplasia, and in prostatic intraepithelial neoplasia and adenocarcinoma.

Methods: Formalin-fixed, paraffin-embedded tissues were obtained from 100 patients with prostate cancer. All patients underwent radical prostatectomy. We assessed the number of infiltrating T cells (CD3(+)), B cells (CD20(+), CD79alpha(+)), and macrophages (CD68(+), CD204(+)) in benign and malignant prostate tumors.

Results: CD68(+) macrophages infiltrated benign glands to a higher extent than those of adenocarcinoma. In contrast, the number of CD204(+) cells was higher in malignant glands than in benign glands. There was no significant difference in the number of infiltrating T cells between benign and malignant tumors; however, the number of infiltrating B cells was significantly reduced in malignant glands.

Conclusions: Inflammation of the prostate may act on prostate carcinomas; particularly that involving M2 macrophage infiltration may play a significant role in prostate carcinogenesis.