Chinese Expert Consensus on the Diagnosis and Treatment of Castration-Resistant Prostate Cancer (2019 Update)

Real-world treatment of metastatic hormone-sensitive prostate cancer in the USA, Europe and Asia

Aim: To characterize real-world patients with metastatic hormone-sensitive prostate cancer (mHSPC) and treating physicians and evaluate treatment trends and baseline concordance versus guidelines internationally. Materials & methods: Retrospective, cross-sectional data from the Ipsos Global Oncology Monitor database 2018-2020 were used for descriptive analysis of mHSPC patients, treating physicians and treatment utilization. Results: Among the 6198 mHSPC patients from five countries, the most common treatment was either androgen deprivation therapy (ADT) monotherapy or first-generation androgen receptor inhibitor + ADT. Second-generation androgen receptor inhibitor use was only initiating but increasing over the study period. Conclusion: Despite contemporaneous guidelines recommending treatment intensification of ADT in combination with novel antihormonals or docetaxel, 76.1% of reported mHSPC patients received non-guideline-concordant care.

OCT4‑positive circulating tumor cells may predict a poor prognosis in patients with metastatic castration‑resistant prostate cancer treated with abiraterone plus prednisone therapy

Octamer-binding transcription factor 4 (OCT4) and circulating tumor cells (CTCs) are key factors associated with tumor metastasis and drug resistance in cancer. The present prospective study aimed to investigate the prevalence of OCT4-positive (OCT4+) CTCs and the potential association with the clinical features and survival of patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone + prednisone. In total, 70 patients with mCRPC treated with abiraterone + prednisone were enrolled in the present study and peripheral blood samples were collected prior to treatment initiation to determine CTC count via a Canpatrol system. RNA in situ hybridization was performed for OCT4+ CTC quantification. Lactate dehydrogenase (LDH) was detected by automatic biochemical analyzer (AU54000, OLYMPUS). Results demonstrated that 34 (48.6%), 21 (30.0%) and 15 (21.4%) patients harbored OCT4+ (CTC+/OCT4+) or OCT4-negative CTCs (CTC+/OCT4-) or were CTC-negative (CTC-), respectively. Notably, CTC+/OCT4+ occurrence was associated with visceral metastasis and high levels of LDH. In addition, radiographic progression-free survival [rPFS; median, 15.0, 95% confidence interval (CI), 9.6-20.4 vs. not reached vs. median, 29.5, 95% CI, 18.6-40.4 months; P=0.001] and overall survival (OS) were significantly decreased (median, 27.3, 95% CI, 20.1-34.5 vs. not reached vs. not reached; P=0.016) in CTC+/OCT4+ compared with CTC+/OCT4- and CTC- patients. Subsequently, the adjustment was performed by multivariate Cox regression models, which revealed that CTC+/OCT4+ (vs. CTC+/OCT4- or CTC-) was independently associated with decreased rPFS [hazard ratio (HR), 3.833; P<0.001] and OS (HR, 3.938; P=0.008). In conclusion, OCT4+ CTCs were highly prevalent in patients with mCRPC and associated with visceral metastasis and increased levels of LDH. Thus, the presence of OCT4+ CTCs may serve as an independent prognostic factor for patients with mCRPC treated with abiraterone + prednisone.

Gambogenic acid induces apoptosis and autophagy through ROS-mediated endoplasmic reticulum stress via JNK pathway in prostate cancer cells

Prostate cancer (PCa) is the most common malignant tumor in males, which frequently develops into castration-resistant prostate cancer (CRPC) with limited therapies. Gambogenic acid (GNA), a flavonoids compound isolated from Gamboge, exhibits anti-tumor capacity in various cancers. Our results showed that GNA revealed not only antiproliferative and pro-apoptotic activities but also the induction of autophagy in PCa cells. In addition, autophagy inhibitor chloroquine enhanced the pro-apoptosis effect of GNA. Moreover, the activation of JNK pathway and the induction of apoptosis and autophagy triggered by GNA were attenuated by JNK inhibitor SP600125. We also found that GNA significantly promoted reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress. Meanwhile, suppressing ER stress with 4-phenylbutyric acid (4-PBA) markedly blocked the activation of JNK pathway induced by GNA. Further research indicated that ROS scavenger N-acetyl-L-cysteine (NAC) effectively abrogated ER stress and JNK pathway activation induced by GNA. Furthermore, NAC and 4-PBA significantly reversed GNA-triggered apoptosis and autophagy. Finally, GNA remarkably suppressed prostate tumor growth with low toxicity in vivo. In conclusion, the present study revealed that GNA induced apoptosis and autophagy through ROS-mediated ER stress via JNK signaling pathway in PCa cells. Thus, GNA might be a promising therapeutic drug against PCa.

The novel transcriptomic signature of angiogenesis predicts clinical outcome, tumor microenvironment and treatment response for prostate adenocarcinoma

Angiogenesis plays the critical roles in promoting tumor progression, aggressiveness, and metastasis. Although few studies have revealed some angiogenesis-related genes (ARGs) could serve as prognosis-related biomarkers for the prostate cancer (PCa), the integrated role of ARGs has not been systematically studied. The RNA-sequencing data and clinical information of prostate adenocarcinoma (PRAD) were downloaded from The Cancer Genome Atlas (TCGA) as discovery dataset. Twenty-three ARGs in total were identified to be correlated with prognosis of PRAD by the univariate Cox regression analysis, and a 19-ARG signature was further developed with significant correlation with the disease-free survival (DFS) of PRAD by the least absolute shrinkage and selection operator (LASSO) Cox regression with tenfold cross-validation. The signature stratified PRAD patients into high- and low-ARGs signature score groups, and those with high ARGs signature score were associated with significantly poorer outcomes (median DFS: 62.71 months vs unreached, p < 0.0001). The predicting ability of ARGs signature was subsequently validated in two independent cohorts of GSE40272 & PRAD_MSKCC. Notably, the 19-ARG signature outperformed the typical clinical features or each involved ARG in predicting the DFS of PRAD. Furthermore, a prognostic nomogram was constructed with three independent prognostic factors, including the ARGs signature, T stage and Gleason score. The predicted results from the nomogram (C-index = 0.799, 95%CI = 0.744-0.854) matched well with the observed outcomes, which was verified by the calibration curves. The values of area under receiver operating characteristic curve (AUC) for DFS at 1-, 3-, 5-year for the nomogram were 0.82, 0.83, and 0.83, respectively, indicating the performance of nomogram model is of reasonably high accuracy and robustness. Moreover, functional enrichment analysis demonstrated the potential targets of E2F targets, G2M checkpoint pathways, and cell cycle pathways to suppress the PRAD progression. Of note, the high-risk PRAD patients were more sensitive to immune therapies, but Treg might hinder benefits from immunotherapies. Additionally, this established tool also could predict response to neoadjuvant androgen deprivation therapy (ADT) and some chemotherapy drugs, such as cisplatin, paclitaxel, and docetaxel, etc. The novel ARGs signature, with prognostic significance, can further promote the application of targeted therapies in different stratifications of PCa patients.

Recommendations on Weight Loss and Healthy Lifestyle in Prostate Cancer Clinical Guidelines: A Systematic Review

Obesity is associated with negative prostate cancer outcomes (e.g., specific mortality, all-cause mortality, biochemical recurrence, etc.), according to the current scientific literature. Nevertheless, recommendations on weight loss and healthy lifestyles are poorly covered by clinicians. We aimed at identifying these recommendations from clinical practice guidelines (CPGs) for prostate cancer. We systematically searched MEDLINE, EMBASE, Web of Science, Scopus, guideline databases and online sources for CPGs updated from January 2015 to August 2021. The searches were independently conducted by two researchers, without language restrictions. A total of 97 prostate cancer guidelines, including 84 (86.6%) CPGs and 13 (13.4%) consensus statements, were included. Recommendations on reaching and maintaining a healthy weight or healthy lifestyles were provided by 7 (7.2%) and 13 (13.4%) documents, respectively. No differences regarding recommendations were found by type of document, year of publication or country. Our results suggest that professional societies and governments should update prostate cancer guidelines to include these recommendations for improving prostate cancer prognosis.

Silencing of LINC01963 enhances the chemosensitivity of prostate cancer cells to docetaxel by targeting the miR-216b-5p/TrkB axis

Docetaxel (DTX) treatment effectively prolongs the overall survival of patients with prostate cancer. However, most patients eventually develop resistance to chemotherapy and experience tumor progression or even death. Long noncoding RNAs (lncRNAs) affect docetaxel chemosensitivity. However, the biological role and regulatory mechanisms of lncRNAs in docetaxel-resistant prostate cancer remain unclear. Differences in lncRNAs were evaluated by lncRNA sequencing and evaluated using quantitative real-time polymerase chain reaction, and TrkB expression was measured through western blot analysis. Proliferation was measured using the MTS, while apoptosis and cell cycle were measured using flow cytometry. In addition, migration and invasion were measured using transwell assays. Forty-eight female BALB/c nude mice were used for subcutaneous tumorigenicity and lung metastasis assays. We found that LINC01963 was overexpressed in the PC3-DR cells. LINC01963 silencing enhanced the chemosensitivity of PC3-DR to docetaxel and inhibited tumorigenicity and lung metastasis, while LINC01963 overexpression enhanced the chemoresistance of PC3 cells to docetaxel. It was found that LINC01963 bind to miR-216b-5p. The miR-216b-5p inhibitor reversed the suppressive effect of sh-LINC01963 on PC3-DR cell proliferation, migration, and invasion. Furthermore, miR-216b-5p can bind to the 3'-UTR of NTRK2 and inhibit TrkB protein levels. TrkB enhances docetaxel resistance in prostate cancer and reverses the effects of LINC01963 silencing and miR-216b-5p overexpression. In conclusion, silencing LINC01963 inhibited TrkB protein level to enhance the chemosensitivity of PC3-DR to docetaxel by means of competitively binding to miR-216b-5p. This study illustrates that LINC01963 is a novel therapeutic target for treating prostate cancer patients with DTX resistance.

Drug Repurposing of Pantoprazole and Vitamin C Targeting Tumor Microenvironment Conditions Improves Anticancer Effect in Metastatic Castration-Resistant Prostate Cancer

The effective and economical therapeutic strategy for metastatic castration-resistant prostate cancer (mCRPC) is still requested from patients, who are not available for Lu-177 or Ra-223 treatment. Drug repurposing as a cost-effective and time-saving alternative to traditional drug development has been increasingly discussed. Proton pump inhibitors (PPIs) such as pantroprazole, which are commonly used as antacids, have also been shown to be effective in cancer chemoprevention via induction of apoptosis in multiple cancer cell lines. Vitamin C is an essential micronutrient for human body, has been proposed as a potential anti-cancer agent. In this context, have we investigated the combination of vitamin C and pantoprazole for the management of metastatic castration-resistant prostate cancer (mCRPC). Six chosen human adenocarcinoma cell lines were used to investigate the influence of pantoprazole on the microenvironment of cancer cells (extracellular pH and production of exosomes). Tumor growth and tumor 18F-FDG uptake in PC3 xenografts were analyzed following varied treatment. Our in vitro Results have suggested that pantoprazole enhanced the cytotoxic activity of vitamin C by regulating pH values and production of exosomes in cancer cells. Moreover, the synergistic effect of pantoprazole and vitamin C was pH-dependent since pantoprazole was more effective at a slightly acidic pH. In vivo, the combined treatment using pantoprazole and vitamin C produced better therapeutic outcomes than treatment with vitamin C or pantoprazole alone, as demonstrated via tumor growth and uptake of 18F-FDG. Therefore, we suggest that pantoprazole combined with vitamin C could be as a possible strategy to manage mCRPC.

Identification of immune cell infiltration pattern and related critical genes in metastatic castration-resistant prostate cancer by bioinformatics analysis

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) is the lethal stage of prostate cancer and the main cause of morbidity and mortality, which is also a potential target for immunotherapy.

METHOD

In this study, using the Approximate Relative Subset of RNA Transcripts (CIBERSORT) online method, we analysed the immune cell abundance ratio of each sample in the mCRPC dataset. The EdgeR (an R package) was used to classify differentially expressed genes (DEGs). Using the Database for annotation, visualisation and interactive exploration (DAVID) online method, we performed functional enrichment analyses. STRING online database and Cytoscape tools have been used to analyse protein-protein interaction (PPI) and classify hub genes.

RESULTS

The profiles of immune infiltration in mCRPC showed that Macrophages M2, Macrophages M0, T cells CD4 memory resting, T cells CD8 and Plasma cells were the main infiltration cell types in mCRPC samples. Macrophage M0 and T cell CD4 memory resting abundance ratios were correlated with clinical outcomes. We identified 1102 differentially expressed genes (DEGs) associated with the above two immune cells to further explore the underlying mechanisms. Enrichment analysis found that DEGs were substantially enriched in immune response, cell metastasis, and metabolism related categories. We identified 20 hub genes by the protein-protein interaction network analysis. Further analysis showed that three critical hub genes, CCR5, COL1A1 and CXCR3, were significantly associated with prostate cancer prognosis.

CONCLUSION

Our findings revealed the pattern of immune cell infiltration in mCRPC, and identified the types and genes of immune cells correlated with clinical outcomes. A new theoretical basis for immunotherapy may be given by our results.

Comprehensive analysis of tumour mutational burden and its clinical significance in prostate cancer

BACKGROUND

The tumorigenesis of prostate cancer involves genetic mutations. Tumour mutational burden (TMB) is an emerging biomarker for predicting the efficacy of immunotherapy.

RESULTS

Single-nucleotide polymorphisms were the most common variant type, and C>T transversion was the most commonly presented type of single-nucleotide variant. The high-TMB group had lower overall survival (OS) than the low-TMB group. TMB was associated with age, T stage and N stage. Functional enrichment analysis of differentially expressed genes (DEGs) showed that they are involved in pathways related to the terms spindle, chromosomal region, nuclear division, chromosome segregation, cell cycle, oocyte meiosis and other terms associated with DNA mutation and cell proliferation. Six hub genes, PLK1, KIF2C, MELK, EXO1, CEP55 and CDK1, were identified. All the genes were associated with disease-free survival, and CEP55 and CDK1 were associated with OS.

CONCLUSIONS

The present study provides a comprehensive analysis of the significance of TMB and DEGs and infiltrating immune cells related to TMB, which provides helpful information for exploring the significance of TMB in prostate cancer.

Reliability and validity test of VES-13 and analysis of influencing factors for the vulnerable condition of patients with advanced castration-resistant prostate cancer

Objectives:

To study the relationship between the reliability and validity of VES-13 and the influencing factors of the vulnerable condition of patients with advanced castration-resistant prostate cancer, so as to provide a reference for the health management and nursing of elderly inpatients.

Methods:

By means of convenience sampling, 150 vulnerable patients with advanced castration-resistant prostate cancer who were admitted to the Department of Oncology of the Affiliated Hospital of Hebei University from April 2019 to March 2020 were selected. General data questionnaire, simple mental state checklist, anxiety self-assessment scale, and the vulnerable elders 13 survey (VES-13) were used in this study. The reliability and validity were tested by SPSS 20.0.

Results:

For this group of patients, VES-13 Cronbach’s α was 0.832, living function was 0.778, body function was 0.846, and the correlation coefficient between items was between 0.401 and 0.823 (P<0.01); the retest reliability was 0.831 (P<0.05), and the correlation coefficient was0.504 (P<0.05). The average time to fill in each scale was 4.53±1.32 Minutes, and general indicators such as economic status and education level were significantly correlated with vulnerability. The clinical indicators of prostate-specific antigen levels, multiple bone metastases, and bone pain were significantly correlated with vulnerability.

Conclusion:

VES-13 scale had high level of reliability and operability, and was straight forward to understand and use; it can be used as an effective tool for the assessment of vulnerability in patients with advanced prostate cancer. The vulnerability of patients with castration-resistant prostate cancer showed significant correlation with economic status, education level, prostate-specific antigen level, multiple bone metastases, bone pain and other indicators. Nursing staff should pay close attention to the relevant factors of inpatients and give targeted advance intervention measures to facilitate rapid recovery of elderly inpatients.