Patients with castration-resistant prostate cancer (CRPC), who progress after docetaxel therapy, had until very recently, only a few therapeutic options. Recent advances in this field brought about new perspectives in the treatment of this disease. Molecular, basic, and translational research has given us a better understanding on the mechanisms of CRPC. This great investment has turned into a more rational approach to the development of new drugs. Some of the new treatments are already available to our patients outside clinical trials and may include inhibitors of androgen biosynthesis; new chemotherapy agents; bone-targeted therapy; and immunotherapy. This paper aims to review the mechanisms of prostate cancer resistance, possible therapeutic targets, as well as new options to treat CRPC.

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Inflammation is one of the most important causes of the majority of cancer symptoms, including pain, fatigue, cachexia, and anorexia. Cancer pain affects 17 million people worldwide and can be caused by different mediators which act in primary efferent neurons directly or indirectly. Cytokines can be aberrantly produced by cancer and immune system cells and are of particular relevance in pain. Currently, there are very few strategies to control the release of cytokines that seems to be related to cancer pain. Nevertheless, in some cases, targeted drugs are available and in use for other diseases. In this paper, we aim to review the importance of cytokines in cancer pain and targeted strategies that can have an impact on controlling this symptom.

YB-1 (Y-box binding protein 1) is a multifunctional cold-shock protein that has been implicated in all hallmarks of cancer. Elevated YB-1 protein level was associated with poor prognosis in several types of cancers, including breast cancer (BC), where it is a marker of decreased overall survival (OS) and distant metastasis-free survival across all subtypes. YB-1 is also secreted by different cell types and may act as an extracellular mitogen; however the pathological implications of the secreted form of YB-1 (sYB-1) are unknown. Our purpose was to retrospectively evaluate the association between YB-1 measured by ELISA in serum and disease characteristics and outcomes in patients with BC and bone metastases (BM). In our cohort, sYB-1 was detected in the serum of 22 (50%) patients, and was associated with the presence of extra-bone metastases (p=0.044). Positive sYB-1 was also associated with faster bone disease progression (HR 3.1, 95% CI 1.09–8.95, P=0.033), but no significant differences were observed concerning OS, and time to development of skeletal-related events. Moreover, patients with positive sYB-1 also had higher levels of IL-6, a known osteoclastogenic inducer. Therefore, detection of sYB-1 in patients with BC and BM may indicate a higher tumor burden, in bone and extra-bone locations, and is a biomarker of faster bone disease progression.

Colorectal cancer (CRC) is one of the most lethal malignancies. The extreme heterogeneity in survival rate is driving the need for new prognostic biomarkers. Human endogenous retroviruses (hERVs) have been suggested to influence tumor progression, oncogenesis and elicit an immune response. We examined multiple next-generation sequencing (NGS)-derived biomarkers in 114 CRC patients with paired whole-exome and whole-transcriptome sequencing (WES and WTS, respectively). First, we demonstrate that the median expression of hERVs can serve as a potential biomarker for prognosis, relapse, and resistance to chemotherapy in stage II and III CRC. We show that hERV expression and CD8+ tumor-infiltrating T-lymphocytes (TILs) synergistically stratify overall and relapse-free survival (OS and RFS): the median OS of the CD8-/hERV+ subgroup was 29.8 months compared with 37.5 months for other subgroups (HR = 4.4, log-rank P < 0.001). Combing NGS-based biomarkers (hERV/CD8 status) with clinicopathological factors provided a better prediction of patient survival compared to clinicopathological factors alone. Moreover, we explored the association between genomic and transcriptomic features of tumors with high hERV expression and establish this subtype as distinct from previously described consensus molecular subtypes of CRC. Overall, our results underscore a previously unknown role for hERVs in leading to a more aggressive subtype of CRC.

Colorectal cancer (CRC) is a highly diverse disease, where different genomic instability pathways shape genetic clonal diversity and tumor microenvironment. Although intra-tumor heterogeneity has been characterized in primary tumors, its origin and consequences in CRC outcome is not fully understood. Therefore, we assessed intra- and inter-tumor heterogeneity of a prospective cohort of 136 CRC samples. We demonstrate that CRC diversity is forged by asynchronous forms of molecular alterations, where mutational and chromosomal instability collectively boost CRC genetic and microenvironment intra-tumor heterogeneity. We were able to depict predictor signatures of cancer-related genes that can foresee heterogeneity levels across the different tumor consensus molecular subtypes (CMS) and primary tumor location. Finally, we show that high genetic and microenvironment heterogeneity are associated with lower metastatic potential, whereas late-emerging copy number variations favor metastasis development and polyclonal seeding. This study provides an exhaustive portrait of the interplay between genetic and microenvironment intra-tumor heterogeneity across CMS subtypes, depicting molecular events with predictive value of CRC progression and metastasis development.

The fibroblast growth factor (FGF) signaling pathway plays a key role in tumorigenesis and is recognized as a potential therapeutic target. In this study, the authors aimed to assess the impact of serum FGF23 levels in the prognosis of patients with cancer and bone metastases from solid tumors. A cohort of 112 patients with cancer and metastatic bone disease were treated with bone-targeted agents (BTA). Serum baseline FGF23 was quantified by ELISA and dichotomized in FGF23high and FGF23low groups. Additionally, the association between FGF23 and overall survival (OS) and time to skeletal-related events (TTSRE) was investigated. Baseline characteristics were balanced between groups, except for the median urinary N-terminal telopeptide (uNTX) level. After a median follow-up of 26.0 months, a median OS of 34.4 and 12.2 months was found in the FGF23low and FGF23high groups, respectively (multivariate HR 0.18, 95% CI 0.07–0.44, p = 0.001; univariate HR 0.27, p = 0.001). Additionally, TTSRE was significantly longer for patients with FGF23low (13.0 vs 2.0 months, p = 0.04). Overall, this study found that patients with FGF23low at baseline had longer OS and TTSRE. Further studies are warranted to define its role as a prognostic biomarker and in the use of drugs targeting the FGF axis.

Receptor activator of NF-kB (RANK) pathway regulates bone remodeling and is involved in breast cancer (BC) progression. Genetic polymorphisms affecting RANK-ligand (RANKL) and osteoprotegerin (OPG) have been previously associated with BC risk and bone metastasis (BM)-free survival, respectively. In this study we conducted a retrospective analysis of the association of five missense RANK SNPs with clinical characteristics and outcomes in BC patients with BM. SNP rs34945627 had an allelic frequency of 12.5% in BC patients, compared to 1.2% in the control group (P = 0.005). SNP rs34945627 was not associated with any clinicopathological characteristics, but patients presenting SNP rs34945627 had decreased disease-free survival (DFS) (log-rank P = 0.039, adjusted HR 2.29, 95% CI 1.04–5.08, P = 0.041), and overall survival (OS) (log-rank P = 0.019, adjusted HR 4.32, 95% CI 1.55–12.04, P = 0.005). No differences were observed regarding bone disease-free survival (log-rank P = 0.190, adjusted HR 1.68, 95% CI 0.78–3.66, P = 0.187), time to first skeletal-related event (log-rank P = 0.753, adjusted HR 1.28, 95% CI 1.42–3.84; P = 0.665), or time to bone progression (log-rank P = 0.618, adjusted HR 0.511, 95% CI 0.17–1.51; P = 0.233). Our analysis shows that RANK SNP rs34945627 has a high allelic frequency in patients with BC and BM, and is associated with decreased DFS and OS.