Objective: To evaluate the effect of neoadjuvant androgen deprivation therapy (NADT) on the cellular proliferative activity in primary prostate cancer and lymph node metastases using proliferating cell nuclear antigen (PCNA) immunostaining.
Material and methods: Metastatic pelvic lymph nodes and tumoral prostatic tissue were obtained from 21 patients after radical prostatectomy and pelvic lymphadenectomy. Sixteen patients received NADT for 3 months prior to surgery; five patients did not and were evaluated as a control group. Histopathologic analysis was performed using PCNA immunostaining. and histopathologic findings of primary tumors and lymph node metastases after NADT were reported. Clinical follow-up was performed for a mean of 43.7 months.
Results: Evaluation of PCNA immunostaining of lymph node metastases in the 16 treated patients revealed a mean positivity for metastatic tumor of 4.5% (SD 3.1%); the corresponding value for the five patients who were not treated with NADT was 19.6% (SD 0.94%) (p < 0.05). In four of the treated cases the proliferative activity in the lymph node metastases was greater than that in the other 12 (9.3% and 3.0%, respectively) and no histopathologic regressive changes were observed in these four cases. The residual tumoral proliferative activity in lymph nodes was greater than that in primary tumors (4.5% and 1.3%, respectively).
Conclusions: This study shows that the nodal metastases were responsive to hormonal therapy, as assessed by PCNA staining, although a greater residual proliferative activity was observed after NADT in lymph node metastases in comparison with the primary prostatic tumor. This can be attributed to a metastatic phenotype less responsive to hormonal therapy compared to the primary tumor.