Natural killer cell activity in metastatic castration resistant prostate cancer patients treated with enzalutamide

Metastatic castration resistant prostate cancer (mCRPC) is still the lethal stage for the whole spectrum of prostate cancer disease. Even though different treatment options have been introduced in the last decade with a significant survival improvement for this population, a lack of more reliable prognostic and predictive markers is still one of the main clinical challenges in management of mCRPC. The aim of this study was to investigate the correlation between Natural Killer cell activity (NKA) and both treatment effect and outcomes in patients with mCRPC treated with enzalutamide. A total of 87 patients with mCRPC treated with enzalutamide as the first line treatment were enrolled. NKA was estimated at baseline and prior to each treatment cycle. Endpoints included both treatment effect with biochemical response (BR), biochemical progression (BP) and radiological progression (RP), as well as outcome data with overall survival (OS), radiologic progression free survival (rPFS), and time to next treatment (TTT). At the time of BR, interferon-gamma (IFNγ) decreased significantly compared to levels detected at baseline (z-score = 2.33, p = 0.019). Regarding outcome data, the whole cohort was divided into four groups according to the change of IFNγ level during the first 3 cycles of enzalutamide treatment. In group 1 (n = 42) the IFNγ level remained within a normal range (≥ 250 pg/mL),while in group 2 (n = 7) it increased from an abnormal (< 250 pg/mL) to a normal level. In group 3 (n = 13) it dropped to an abnormal level, and it remained at an abnormal level during treatment in group 4 (n = 17). Patients in group 2 showed the worst prognosis with shorter both rPFS and TTT (HR 4.30, p = 0.037; and HR 6.82, p = 0.011, respectively). In this study inverse correlations between NKA and both treatment response and outcomes was observed in mCRPC patients receiving enzalutamide, suggesting an unfavourable role of NK cells in the late stage of PCa.

Circulating miR-141 and miR-375 are associated with treatment outcome in metastatic castration resistant prostate cancer

Metastatic castration resistant prostate cancer (mCRPC) is associated with high mortality, where monitoring of disease activity is still a major clinical challenge. The role of microRNAs (miRs) has been widely investigated in prostate cancer with both diagnostic and prognostic potential. The aim of this study was to investigate the relationship between circulating miRs and treatment outcome in mCRPC patients. The relative expression of five miRs (miR-93-5p, -125b-1-5p, -141-3p, -221-3p, and miR-375-3p) was investigated in plasma samples from 84 mCRPC patients; 40 patients were treated with docetaxel (DOC cohort) and 44 patients with abiraterone (ABI cohort). Blood was sampled at baseline before treatment start and at radiological progression. The plasma levels of four miRs; miR-93-5p, -141-3p, -221-3p, and miR-375-3p decreased significantly after treatment initiation in patients receiving docetaxel, and for miR-141-3p and miR-375-3p the level increased again at the time of radiological progression. In the patients treated with abiraterone, the plasma level of miR-221-3p likewise decreased significantly after the first treatment cycle. High baseline levels of both miR-141-3p and miR-375-3p were significantly associated with a shorter time to radiological progression in both cohorts. Additionally, high baseline levels of miR-141-3p and miR-221-3p were significantly associated with a shorter overall survival (OS) in the ABI cohort, while high levels of miR-141-3p and miR-375-3p were significantly associated with shorter OS in the DOC cohort. Plasma levels of miR-141-3p and miR-375-3p may predict time to progression in mCRPC patients treated with docetaxel or abiraterone. The clinical impact of these findings is dependent on validation in larger cohorts.

Association between circulating miRNA-141 and miRNA-375 and treatment outcome in metastatic castration-resistant prostate cancer

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Background: Metastatic castration resistant prostate cancer (mCRPC) is associated with high mortality. Monitoring of disease activity at this stage, with lack of validated prognostic models, is still a major clinical challenge. The role of microRNAs (miRNAs) has been widely investigated in prostate cancer with both diagnostic and prognostic potential. The aim of this study was to investigate the relationship between circulating miRNAs and treatment outcome in mCRPC patients. Methods: The relative expression of four miRNAs was investigated in plasma samples from 84 mCRPC patients; 40 patients were treated with docetaxel and 44 patients with abiraterone. Real-time polymerase chain reaction was used for analysis. Blood was sampled at baseline, before the second treatment cycle, and at radiological progression (RP). Associations to prognoses were analyzed using the Cox Regression analyses. Results: The plasma levels of all four miRNAs decreased significantly after treatment initiation in patients receiving docetaxel, and for miRNA-141 and miRNA-375 the level increased again at the time of RP. High baseline levels of miRNA-141 were significantly associated with a shorter time to RP in patients receiving both abiraterone, hazard ratio (HR) 3.18 (95% confidence interval (CI) 1.31-7.32), p < 0.01, and docetaxel HR 2.56 (95% CI 1.45-4.50), p < 0.01, and a shorter overall survival (OS), HR 3.20 (95% CI 1.25-9.37), p = 0.02, and HR 1.77 (95% CI 1.07-2.83), p = 0.02, respectively. Likewise, high baseline levels of miRNA-375 were also significantly associated with a shorter time to RP in both cohorts and OS in patients receiving docetaxel. Conclusions: Plasma levels of miRNA-141 and miRNA-375 were of prognostic importance in patients with mCRPC receiving both abiraterone and docetaxel and may be used in treatment monitoring irrespective of treatment modality.