Objectives: To clarify the influence of androgen deprivation therapy (ADT) on the volume of the anatomic zones of the prostate and the tissue component of the transition zone.
Methods: Thirty patients with prostate cancer arising and localizing in the peripheral zone were enrolled in this study. The volume of anatomic zones was measured using magnetic resonance imaging before and 6 months after ADT (castration and flutamide). Binary images were constructed to analyze the tissue components of the transition zone.
Results: The volumes after ADT in the whole prostate, transition zone, and peripheral zone were significantly smaller than the corresponding volumes before ADT (P <0.001). A small correlation was found between the reduction rates of the transition zone after therapy and the stromal rates of the transition zone (r(s) = 0.375, P = 0.041).
Conclusions: The present results revealed that, not only the epithelial region in the transition zone, but also the stromal region, was sensitive to androgen and the volume of the transition zone was reduced during ADT regardless of its histologic components.