Bioinformatic analysis of dysregulated proteins in prostate cancer patients reveals putative urinary biomarkers and key biological pathways

Prostate cancer (PCa) is one of the most common cancer types among men. The quantification of prostate-specific antigen used for PCa detection has revealed limited applicability. Thus, it is crucial to identify new minimally invasive biomarkers for PCa. It is believed that the integration of proteomics data from different studies is vital for identifying new biomarkers for PCa, but studies carried out in this regard have few converging results. Using a different approach, this study aimed to unveil molecular features consistently dysregulated in PCa and potential urinary biomarkers for PCa. The novelty of this analysis relies on the comparison of urinary and tissue proteomes from PCa patients and consequent exclusion of kidney and bladder cancer interference. The conducted bioinformatic analysis revealed molecular processes dysregulated in urine from PCa patients that mirror the alterations in prostate tumor tissue. To identify putative urinary biomarkers, proteins previously detected in kidney and bladder tissues were eliminated from the final list of potential urinary biomarkers for PCa. After a detailed analysis, MSMB, KLK3, ITIH4, ITIH2, HPX, GP2, APOA2 and AZU1 proteins stood out as candidate urinary biomarkers for PCa.

Enzalutamide (Xtandi) for patients with metastatic, resistant prostate cancer

OBJECTIVE

To review the pharmacology and pharmacokinetics, and to evaluate the clinical efficacy, safety, and place in therapy of enzalutamide for the treatment of castration-resistant prostate cancer (CRPC).

DATA SOURCES

A literature search through PubMed (1984 to November 2013; English language) was performed using the following keywords: MDV3100, androgen deprivation therapy, enzalutamide, CRPC, and androgen receptor antagonist. Searches were limited to published studies in humans.

STUDY SELECTION AND DATA EXTRACTION

All articles in English identified from reviews, abstracts, presentations, and clinical trials of enzalutamide in humans were selected and included.

DATA SYNTHESIS

Enzalutamide is an oral, nonsteroidal second-generation androgen receptor antagonist that is Food and Drug Administration-approved for the treatment of metastatic CRPC in men who were previously treated with docetaxel. Enzalutamide was superior to placebo for increasing median survival from 13.6 months to 18.4 months. Enzalutamide was well tolerated at a dose of 160 mg, with minor adverse events such as fatigue, diarrhea, musculoskeletal pain, and hot flashes. Patients with increased risk of seizure should not take enzalutamide.

CONCLUSIONS

Enzalutamide is effective to slow progression of metastatic CRPC, to reduce prostate-specific antigen (PSA) levels, to decrease time to progression of PSA, to increase time to first skeletal-related events, and to increase quality of response rate. Enzalutamide was given at 160 mg/d for a median of 8 cycles of administration. Clinical trials are currently being conducted to observe if enzalutamide will be useful for treatment of other cancers and for early administration in prostate cancer.

Progress in emerging therapies for advanced prostate cancer

The landscape of prostate cancer treatment is rapidly changing as extensive research into potential therapies yields new options. In this article, the literature is reviewed to identify emerging therapies for advanced prostate cancer. Emphasis is placed on agents that have been approved in the United States of America (USA) and the European Union, or that have reached phase III clinical studies. Several new therapies have been approved in recent years across different stages of the natural history of the disease. Degarelix, a luteinizing hormone-releasing hormone antagonist, has been approved for reducing testosterone to castrate levels in hormone-sensitive disease. No new agents have been approved for use in combination with docetaxel chemotherapy, the current standard of care for metastatic castration-resistant prostate cancer. One immunotherapy, sipuleucel-T, has been approved (USA only) in the pre-docetaxel setting. Cabazitaxel, a next-generation taxane, and abiraterone acetate, an inhibitor of androgen biosynthesis, have both been approved as second-line agents following chemotherapy. Enzalutamide (MDV3100), an androgen receptor antagonist, has been shown to increase overall survival in the post-chemotherapy setting in metastatic disease. Denosumab, an antibody-based bone-targeted agent, has been approved for the prevention of skeletal-related events in patients with bone metastases. Radium-223 chloride, an α-emitting radiopharmaceutical, is likely to gain approval soon following promising results in a phase III trial. Clinical studies involving other promising agents are ongoing. The emergence of these therapies adds to the growing armamentarium against prostate cancer.