Usefulness of hypoxia inducible factor-1 alpha in evaluating the prostatic adenocarcinoma viability following neoadjuvant hormone therapy

Background: In prostatic adenocarcinomas (PAs), the androgen up-regulates hypoxia inducible factor-1 alpha (HIF-1α). It has been reported that the regulation of HIF-1α would become a therapeutic strategy for PAs. This study was designed to elucidate whether or not HIF-1α expression would be associated with PA recurrence after neoadjuvant hormone therapy (NHT). Methods: The 50 radical prostatectomy specimens after NHT were examined as well as needle biopsy specimens before NHT using immunohistochemistry for HIF-1α. Results: The therapeutic effects of 50 cases with NHT were assessed as good (20 cases) or poor (30 cases). The recurrence of PA monitored by the serum prostatic specific antigen (PSA) levels occurred in 21 cases (42%). The hypoxic status was evaluated to be divided into two categories: weak (16 cases) or strong (34 cases). The recurrence ratio was 30% (6/20) of cases with good response and 50% (15/30) of cases with poor response (p < 0.05). HIF-1α expression profiles were as follows: recurrent cases, weak, 19% (4/21); strong, 81% (17/21) (p < 0.05); and non-recurrent cases, weak, 41% (12/29); strong, 59% (17/29) (NS). Compared to PAs with weak HIF-1α expression, PAs with strong HIF-1α expression showed higher PSA levels (12.1 ng/mL vs. 25.0 ng/mL, p < 0.05). Conclusion: HIF-1α is expected to be useful for detection of the viability of PAs after NHT and also for prediction of their clinical outcome. In addition, the expression may contribute to histological identification of the carcinoma cells.