Objective: To study the impact of short-term neoadjuvant hormonal treatment on neuroendocrine (NE) differentiation and the relation of NE differentiation and tumor regression.
Methods: The radical prostatectomy specimens and the biopsy specimens of the same 18 patients with prostate cancer were compared. The effect of hormonal treatment on NE-differentiation was evaluated by specific antibodies against chromogranin A (ChA) and serotonin (5-HT).
Results: The ChA-positive cell count was 3.2 x 10(-5)/microm(2) [(0-5.7) x 10(-5)/microm(2)] before hormonal treatment and 2.3 x 10(-5) microm(2)[(0-6.6) x 10(-5)/microm(2)] afterward (P > 0.05). For the proportion of NE-positive tumor, it was 7.0% (0%-14.9%) and 4.5% (0%-13.1%) (P > 0.05). No correlation existed between NE-differentiation and the neoadjuvant hormonal treatment. The NE cell density did not differ significantly between 12 non-/slightly regressive tumor foci and 6 highly regressive ones (P > 0.05).
Conclusion: Short-term neoadjuvant hormonal therapy does not induce clonal propagation of NE cells. The degree of tumor regression following short-term neoadjuvant hormonal therapy is not correlated with the NE differentiation.