Artikel
Chromogranin A and neuron-specific enolase serum levels as predictors of treatment outcome in metastatic castration-resistant prostate cancer patients under abiraterone therapy
Suche in Medline nach
Autoren
Veröffentlicht: | 20. April 2016 |
---|
Gliederung
Text
Objective: Neuroendocrine differentiation is a potential mechanism of treatment resistance to novel systemic therapies targeting the androgen-receptor in metastatic castration-resistant prostate cancer (mCRPC). To determine the impact of elevated neuroendocrine serum markers on treatment outcome under abiraterone in mCRPC patients post-chemotherapy.
Patients and methods: Chromogranin A (CGa) and neuron-specific enolase (NSE) were determined in serum drawn before treatment initiation of 45 mCRPC patients. Outcome measures were overall survival (OS), prostate-specific antigen (PSA) response defined by PSA decline ≥50%, PSA progression-free survival (PSA-PFS) and clinical or radiografic PFS.
Results: CGa and NSE concentrations did not correlate (p=0.6). Patients were stratified in a low (n=9), intermediate (n=18) or high (n=18) risk group according to elevation of none, one or both neuroendocrine markers. Risk groups correlated with decreasing median OS (median OS not reached vs. 15.3 vs. 6.6 months; p< 0.001), decreasing median clinical or radiografic PFS (8.3 vs. 4.4 vs. 2.7 months; p=0.001) and decreasing median PSA-PFS (12.0 vs. 3.2 vs. 2.7 months; p=0.012). In multivariate cox regression analysis the combination of CGa and NSE (≥1 marker positive vs. both markers negative) remained significant predictors of OS, clinical or radiografic PFS and PSA-PFS.
We did not observe a correlation with PSA response (63%vs. 35%vs. 31%; p=0.2).
Conclusion: CGa and NSE did not predict PSA response in mCRPC patients treated with abiraterone. However, we observed a correlation with shorter PSA-PFS, clinical or radiografic PFS and OS. This might be due to an elevated risk of developing resistance under abiraterone treatment related to neuroendocrine differentiation.