Characterization of the intra-prostatic immune cell infiltration in androgen-deprived prostate cancer patients

IntroductionOur goal was to study the hormonal regulation of immune cell infiltration in prostate cancer patients treated by androgen deprivation therapy (ADT) using an optimized computer-assistance quantification approach.MethodsThe relative density of immune cell subtypes (CD3+, CD8+, CD20+, CD56+, CD68+ and Foxp3+) was analyzed by immunohistochemistry in archived prostate specimens from control patients (radical prostatectomy only, n = 40) and ADT-treated patients (ADT prior to radical prostatectomy, n = 35) using an image analysis software and a whole-slide scanner.ResultsADT-treated patients had significantly increased relative density of CD3+ (p < 0.001) and CD8+ T lymphocytes (p < 0.001) as well as CD68+ macrophages (p < 0.001). Elevated abundance of CD56+ Natural Killer (NK) cells was associated with a lower risk of prostate cancer progression (p = 0.044), while a high density of CD68+ macrophages was related to an increased risk of biochemical recurrence (p = 0.011).ConclusionsOur results demonstrate that the infiltration of specific immune cell subtypes is modulated by ADT. Furthermore our data confirm that NK cells have a protective role against tumor progression while macrophages seem to favor the development of advanced prostate cancer.