Plasma extracellular vesicle circRNA signature and resistance to abiraterone in metastatic castration-resistant prostate cancer.

BACKGROUND: We aimed to develop and validate a plasma extracellular vesicle circular RNA (circRNA)-based signature that can predict overall survival (OS) in first-line abiraterone therapy for metastatic castration-resistant prostate cancer (mCRPC) patients. METHODS: In total, 582 mCRPC patients undergoing first-line abiraterone therapy from four institutions were sorted by three phases. In the discovery phase, 30 plasma samples from 30 case-matched patients with or without early progression were obtained to generate circRNA expression profiles using RNA sequencing. In the training phase, differentially expressed circRNAs were examined using digital droplet PCR in a training cohort (n = 203). The circRNA signature was constructed using a least absolute shrinkage and selection operator Cox regression to predict OS. In the validation phase, the prognostic ability of this signature was prospectively validated in two external cohorts (Cohort I, n = 183; Cohort II, n = 166). RESULTS: We developed a five-circRNA signature, based on circCEP112, circFAM13A, circBRWD1, circVPS13C and circMACROD2, which successfully stratified patients into high-risk and low-risk groups. The prognostic ability of this signature was prospectively validated in two external cohorts (P < 0.0001, P < 0.0001). Patients with high-risk scores had shorter OS than patients with low-risk scores. CONCLUSION: This five-circRNA signature is a reliable predictor of OS for mCRPC patients undergoing abiraterone.

Combined analysis of CRMP4 methylation levels and CAPRA-S score predicts metastasis and outcomes in prostate cancer patients.

The present study analyzed the predictive value of combined analysis of collapsin response mediator protein 4 (CRMP4) methylation levels and the Cancer of the Prostate Risk Assessment (CAPRA-S) Postsurgical score of patients who required adjuvant hormone therapy (AHT) after radical prostatectomy (RP). We retrospectively analyzed 305 patients with prostate cancer (PCa) who received RP and subsequent androgen deprivation therapy (ADT). Two hundred and thirty patients with clinically high-risk PCa underwent immediate ADT, and 75 patients with intermediate risk PCa underwent deferred ADT. CRMP4 methylation levels in biopsies were determined, and CAPRA-S scores were calculated. In the deferred ADT group, the values of the hazard ratios for tumor progression and cancer-specific mortality (CSM) in patients with ≥15% CRMP4 methylation were 6.81 (95% CI: 2.34-19.80) and 12.83 (95% CI: 2.16-26.10), respectively. Receiver-operating characteristic curve analysis indicated that CRMP4 methylation levels ≥15% served as a significant prognostic marker of tumor progression and CSM. In the immediate ADT group, CAPRA-S scores ≥6 and CRMP4 methylation levels ≥15% were independent predictors of these outcomes (uni- and multi-variable Cox regression analyses). The differences in the 5-year progression-free survival between each combination were statistically significant. Combining CAPRA-S score and CRMP4 methylation levels improved the area under the curve compared with the CRMP4 or CAPRA-S model. Therefore, CRMP4 methylation levels ≥15% were significantly associated with a poor prognosis and their combination with CAPRA-S score accurately predicted tumor progression and metastasis for patients requiring AHT after RP.

Prospective validation of DACH2 as a novel biomarker for prediction of metastasis and prognosis in muscle-invasive urothelial carcinoma of the bladder.

Metastasis is the main cause of death from muscle-invasive urothelial carcinoma of the bladder (UCB), and the metastatic potential of tumors is often unpredictable. The role of Dachshund homolog 2 gene (DACH2) in tumorigenesis remains unexplored. We aimed to investigate whether DACH2 can be used as a biomarker to predict metastasis and prognosis of muscle-invasive UCB in a sequential training and validation fashion. For the training set (n = 40), compared with UCB patients without lymph node (LN) metastasis, both DACH2 protein and mRNA expression were greatly increased in case-matched patients with LN metastasis. For the independent validation set (n = 243), patients with primary UCB that did not express DACH2 had a longer metastasis-free survival (MFS) and overall survival (OS) than did those with tumors expressing DACH2 (5-year MFS: 88% [95% CI 80-96] versus 19% [95% CI 7-31], p < 0.001; 5-year OS: 93% [95% CI 87-99] versus 37% [95% CI 23-51], p < 0.001). Multivariable analysis of DACH2 status showed hazard ratios of 7.34 (95% CI 3.15-11.87, p < 0.001) for MFS and 3.96 (95% CI 2.04-7.16, p < 0.001) for OS which were much higher than hazard ratios associated with other independent risk factors. Collectively, DACH2 is an independent prognostic marker that can be used at initial diagnosis of UCB to identify patients who have a high potential to develop metastasis.