| Popis: |
BACKGROUND: Enzalutamide and apalutamide are potent next-generation androgen receptor (AR) antagonists used in metastatic and non-metastatic prostate cancer. Metabolic, hormonal and immunologic effects of deep AR suppression are unknown. We hypothesized that enzalutamide and apalutamide suppress 11β-hydroxysteroid dehydrogenase-2 (11β-HSD2), which normally converts cortisol to cortisone, leading to elevated cortisol concentrations, increased ratio of active to inactive glucocorticoids and possibly suboptimal response to immunotherapy. On-treatment glucocorticoid changes might serve as an indicator of active glucocorticoid exposure and resultant adverse consequences. PATIENTS AND METHODS: Human kidney tissues were stained for AR and 11β-HSD2 expression. Patients in 3 trials [neoadjuvant apalutamide plus leuprolide, enzalutamide +/− PROSTVAC for metastatic castration-resistant prostate cancer (CRPC) and enzalutamide +/− PROSTVAC for non-metastatic castration-sensitive prostate cancer (CSPC)] were analyzed for cortisol and its metabolites using liquid chromatography-mass spectrometry (LC-MS/MS). Progression-free survival (PFS) was determined in the metastatic CRPC study of enzalutamide +/− PROSTVAC for those with glucocorticoid changes above and below the median. RESULTS: Concurrent AR and 11β-HSD2 expression occurs only in the kidneys of men. A statistically significant rise in cortisol concentration, cortisol/cortisone ratio and tetrahydrocortisol/tetrahydrocortisone ratio with AR antagonist treatment occurred uniformly across all 3 trials. In the trial of enzalutamide +/− PROSTVAC for metastatic CRPC, high cortisol/cortisone ratio in the enzalutamide arm was associated with significantly improved PFS. However, in the enzalutamide + PROSTVAC arm, the opposite trend was observed. CONCLUSION: Enzalutamide and apalutamide treatment toggles renal 11β-HSD2 and significantly increases indicators of and exposure to biologically active glucocorticoids, which is associated with clinical outcomes. |
