Magnetic Resonance Imaging as a Tool for Monitoring Intratibial Growth of Experimental Prostate Cancer Metastases in Mice.

Bone metastases cause morbidity and mortality in several human cancer forms. Experimental models are used to unravel the mechanisms and identify possible treatment targets. The location inside the skeleton complicates accurate assessment. This study evaluates the performance of magnetic resonance imaging (MRI) of prostate cancer tumors growing intratibially in mice. MRI detected intratibial tumor lesions with a sensitivity and specificity of 100% and 89%, respectively, compared to histological evaluation. Location and some phenotypical features could also be readily detected with MRI. Regarding volume estimation, the correlation between MRI and histological assessment was high (p < 0.001, r = 0.936). In conclusion, this study finds MRI to be a reliable tool for in vivo, non-invasive, non-ionizing, real-time monitoring of intratibial tumor growth.

Effect of docetaxel added to bicalutamide in Hormone-Naïve non-metastatic prostate cancer with rising PSA, a randomized clinical trial (SPCG-14).

BACKGROUND: Historically, endocrine therapy was used in a range of scenarios in patients with rising PSA, both as a treatment for locally advanced non-metastatic prostate cancer and PSA recurrence following curative intended therapy. In the present study the objective was to investigate if chemotherapy added to endocrine therapy could improve progression-free survival (PFS). MATERIALS AND METHODS: Patients with hormone-naïve, non-metastatic prostate cancer and rising prostate-specific antigen (PSA), enrolled from Sweden, Denmark, the Netherlands, and Finland, were randomized to long-term bicalutamide (150 mg daily) or plus docetaxel (75 mg/m2, q3w, 8-10 cycles) without prednisone, after stratification for the site, prior local therapy or not, and PSA doubling time. The primary endpoint was 5-year PFS analyzed with a stratified Cox proportional hazards regression model on intention to treat basis. RESULTS: Between 2009 and 2018, a total of 348 patients were randomized; 315 patients had PSA relapse after radical treatment, 33 patients had no prior local therapy. Median follow-up was 4.9 years (IQR 4.0-5.1). Adding docetaxel improved PFS (HR 0.68, 95% CI 0.50-0.93; p = 0.015). Docetaxel showed an advantage for patients with PSA relapse after prior local therapy (HR 0.67, 95% CI 0.49-0.94; p = 0.019). One event of neutropenic infection/fever occurred in 27% of the patients receiving docetaxel. Limitations were slow recruitment, lack of enrolling patients without radical local treatment, and too short follow-up for evaluation of overall survival in patients with PSA relapse. CONCLUSION: Docetaxel improved PFS in patients starting bicalutamide due to PSA relapse after local therapy or localized disease without local therapy. Confirmatory studies of the efficacy of docetaxel in the setting of PSA-only relapse in addition to endocrine therapies may be justified if longer follow-up will show increased metastatic-free survival.

Osteoclasts directly influence castration-resistant prostate cancer cells.

Metastasis to bone is the leading cause of death from prostate cancer. Interaction between tumor cells and bone cells can promote progression and influence tumor phenotype. It is known that prostate cancer cells support osteoclast differentiation, and degradation of bone matrix by osteoclasts releases growth factors stimulating tumor cell proliferation and invasion. In the present study osteolytic (PC-3) and osteoblastic (LNCaP-19) castration-resistant prostate cancer (CRPC) cells were co-cultured with mature osteoclasts or their precursor cells (RAW 264.7) to characterize direct effects of mature osteoclasts on CRPC cells. Osteoclasts increased proliferation and decrease apoptosis of CRPC cells as assessed with flow cytometry. RNA sequencing revealed that osteolytic CRPC cells were more responsive to osteoclast stimulation regarding gene expression, but the overall induced expression patterns were similar between the prostate cancer cell lines. Genes related to DNA repair were upregulated by osteoclasts, while genes related to endoplasmic reticulum stress-induced apoptosis and cholesterol synthesis were downregulated. The results of this study shows that osteoclasts directly influence CRPC cells, increasing proliferation, decreasing apoptosis, and affecting gene expression pathways that can affect sensitivity to DNA damage and endoplasmic reticulum function. This suggests targeting of osteoclasts to be a possible way to affect efficacy of other drugs by combination regimens in treating prostate cancer metastases.

Androgens, aging, and prostate health.

Due to late onset hypogonadism (LOH), there is an increased usage of testosterone replacement therapy (TRT) in the aging male population. Since prostate is a target organ for androgens and anti-androgenic strategies are used to treat and palliate benign prostate hyperplasia (BPH) and prostate cancer (PC), the prevalence of both increases with age, the possible influence of TRT on prostate health becomes highly relevant. The present review summarizes existing data on the associations between endogenous hormone concentrations and prostate growth and concludes that circulating concentrations of androgens do not appear to be associated with the risks of development of BPH or initiation or progression of PC. The explanation for these findings relates to an apparent insensitivity of prostatic tissue to changes of testosterone concentrations within the physiological range.

Clinical and biological relevance of the transcriptomic-based prostate cancer metastasis subtypes MetA-C.

To improve treatment of metastatic prostate cancer, the biology of metastases needs to be understood. We recently described three subtypes of prostate cancer bone metastases (MetA-C), based on differential gene expression. The aim of this study was to verify the clinical relevance of these subtypes and to explore their biology and relations to genetic drivers. Freshly-frozen metastasis samples were obtained as hormone-naive (n = 17), short-term castrated (n = 21), or castration-resistant (n = 65) from a total of 67 patients. Previously published sequencing data from 573 metastasis samples were also analyzed. Through transcriptome profiling and sample classification based on a set of predefined MetA-C-differentiating genes, we found that most metastases were heterogeneous for the MetA-C subtypes. Overall, MetA was the most common subtype, while MetB was significantly enriched in castration-resistant samples and in liver metastases, and consistently associated with poor prognosis. By gene set enrichment analysis, the phenotype of MetA was described by high androgen response, protein secretion and adipogenesis, MetB by high cell cycle activity and DNA repair, and MetC by epithelial-to-mesenchymal transition and inflammation. The MetB subtype demonstrated single nucleotide variants of RB transcriptional corepressor 1 (RB1) and loss of 21 genes at chromosome 13, including RB1, but provided independent prognostic value to those genetic aberrations. In conclusion, a distinct set of gene transcripts can be used to classify prostate cancer metastases into the subtypes MetA-C. The MetA-C subtypes show diverse biology, organ tropism, and prognosis. The MetA-C classification may be used independently, or in combination with genetic markers, primarily to identify MetB patients in need of complementary therapy to conventional androgen receptor-targeting treatments.

Timing of the Pubertal Growth Spurt and Prostate Cancer.

Previous studies of pubertal timing and the risk of prostate cancer have used self-reported markers of pubertal development, recalled in mid-life, and the results have been inconclusive. Our aim was to evaluate the age at the pubertal growth spurt, an objective marker of pubertal timing, and the risk of prostate cancer and high-risk prostate cancer. This population-based cohort study included 31,971 men with sufficient height measurements to calculate age at peak height velocity (PHV). Outcomes were accessed through national registers. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox regressions with follow up starting at 20 years of age. In total, 1759 cases of prostate cancer including 449 high-risk were diagnosed during follow up. Mean follow up was 42 years (standard deviation 10.0). Compared to quintiles 2-4 (Q2-4), men in the highest age at PHV quintile (Q5) had lower risk of prostate cancer (HR 0.83, 95% CI 0.73-0.94), and of high-risk prostate cancer (0.73; 0.56-0.94). In an exploratory analysis with follow up starting at age at PHV, late pubertal timing was no longer associated with reduced risk of prostate cancer. Later pubertal timing was associated with reduced risk of prostate cancer and especially high-risk prostate cancer. We propose that the risk of prostate cancer might be influenced by the number of years with exposure to adult levels of sex steroids.

The roles of RUNX2 and osteoclasts in regulating expression of steroidogenic enzymes in castration-resistant prostate cancer cells.

Intratumoral steroidogenesis is involved in development of castration-resistant prostate cancer (CRPC) as bone metastases. The osteoblast transcription factor RUNX2 influences steroidogenesis and is induced in CRPC cells by osteoblasts. This study investigates osteoclastic influence on RUNX2 in intratumoral steroidogenesis. Steroidogenic enzymes and steroid receptors were detected with immunohistochemistry in xenograft intratibial tumors from CRPC cells. In vitro, expression of RUNX2 was increased by osteoclasts in osteoblastic LNCaP-19 cells, but not in osteolytic PC-3. Silencing of RUNX2 downregulates expression of CYP11A1, CYP17A1 and HSD3B1 in LNCaP-19 cells co-cultured with osteoclasts, leading to inhibition of KLK3 expression. Osteoclasts promoted CYP11A1 and RUNX2 promoted AKR1C3, HSD17B3 and CYP19A1, but suppressed ESR2 in PC-3 cells. This study shows that osteoclasts promote RUNX2 regulated induction of key steroidogenic enzymes, influencing activation of androgen receptor in CRPC cells. The potential of RUNX2 as a target to inhibit progression of skeletal metastases of CRPC needs further investigation.

Inhibition of STAT3 prevents bone metastatic progression of prostate cancer in vivo.

BACKGROUND: Prostate cancer (PC) metastasizes to the skeleton forming predominantly sclerotic lesions, and there is currently no cure for bone metastatic disease. The transcription factor signal transducer and activator of transcription 3 (STAT3) is implicated as a metastatic driver, but its potential as therapeutic target in bone metastasis has not been investigated. In this study, we evaluated for the first time a STAT3 inhibitor, Napabucasin, as a therapeutic option for bone metastatic PC. METHODS: Effects of STAT3 inhibitors, Stattic and Napabucasin, on metastatic potential in PC cells were studied in vitro by assessment of migration capacity, self-renewal potential, and tumorsphere formation. For evaluation of the role of STAT3 in initial skeletal establishment of PC cells as well as in progressed castration-resistant PC (CRPC) in bone, human VCaP prostate cancer cells were inoculated in the tibia of mice which subsequently were treated with the STAT3 inhibitor Napabucasin. Bone specimens were analyzed using computed tomography (CT), immunohistochemistry, and quantitative polymerase chain reaction. RESULTS: The small molecule STAT3 inhibitors Stattic and Napabucasin both effectively impaired metastatic potential of PC cells in vitro. Furthermore, treatment with Napabucasin prevented metastatic establishment in tibial bones in vivo and thereby also the tumor-induced sclerotic bone response seen in vehicle-treated VCaP xenografts. In addition, treatment with Napabucasin of established bone CRPC significantly decreased both tumor burden and tumor-induced trabecular bone volume compared with effects seen in vehicle-treated animals. Anti-mitotic effects were confirmed by decreased Ki67 staining in Napabucasin-treated xenografts compared with vehicle-treated xenografts. Alterations of gene expression in the femoral bone marrow (BM) niche toward the maintenance of hematopoietic stem cells and the myeloid lineage were demonstrated by quantitative real-time polymerase chain reaction and were further reflected by a substantial increase in the number of erythrocytes in BM of Napabucasin-treated mice. Furthermore, a unique pattern of STAT3 phosphorylation in osteoblasts/stromal cells surrounding the areas of tumor cells was demonstrated immunohistochemically in bone xenograft models using several different PC cell lines. CONCLUSION: Inhibition of STAT3 activity disrupts the bone metastatic niche and targets both the skeletal establishment of PC and advanced bone metastatic CRPC in mice, suggesting STAT3 as a candidate for molecular targeted therapies of skeletal metastatic disease.

RGS2 is prognostic for development of castration resistance and cancer-specific survival in castration-resistant prostate cancer.

BACKGROUND: Regulator of G-protein signaling 2 (RGS2) is a multifaceted protein with a prognostic value in hormone-naïve prostate cancer (PC). It has previously been associated with the development of castration resistance. However, RGS2 expression in clinical specimens of castration-resistant prostate cancer (CRPC) and its clinical relevance has not been explored. In the present study, RGS2 was assessed in CRPC and in relation to the development of castration resistance. METHODS: In the present study, RGS2 expression was evaluated with immunohistochemistry in patient materials of hormone-naïve and castration-resistant primary tumors, also in matched specimens before and after 3 months of androgen deprivation therapy (ADT). Cox regression and Kaplan-Meier curves were used to evaluate the clinical significance of RGS2 expression. RGS2 expression in association to castration-resistant growth was assessed experimentally in an orthotopic xenograft mouse model of CRPC. In vitro, hormone depletion of LNCaP and enzalutamide treatment of LNCaP, 22Rv1, and VCaP was performed to evaluate the association between RGS2 and the androgen receptor (AR). Stable RGS2 knockdown was used to evaluate the impact of RGS2 in association to PC cell growth under hormone-reduced conditions. Gene and protein expression were evaluated with quantitative polymerase chain reaction and Western blot analysis, respectively. RESULTS: RGS2 expression is increased in CRPC and enriched under ADT. Furthermore, a high RGS2 level is prognostic for poor cancer-specific survival for CRPC patients and significantly reduced failure-free survival (FFS) after an initiated ADT. Additionally, the prognostic value of RGS2 outperforms prostate-specific antigen (PSA) in terms of FFS. The present study furthermore suggests that RGS2 expression is reflective of AR activity. Moreover, low RGS2-expressing cells display hampered growth under hormone-reduced conditions, in line with the poor prognosis associated with high RGS2 expression. CONCLUSIONS: High levels of RGS2 are associated with aggressive forms of castration-resistant PC. The results demonstrate that a high level of RGS2 is associated with poor prognosis in association with castration-resistant PC growth. RGS2 alone, or in association with PSA, has the potential to identify patients that require additional treatment at an early stage during ADT.

Targeted alpha therapy with astatine-211-labeled anti-PSCA A11 minibody shows antitumor efficacy in prostate cancer xenografts and bone microtumors.

PURPOSE: Targeted alpha therapy (TAT) is a promising treatment for micrometastatic and minimal residual cancer. We evaluated systemic α-radioimmunotherapy (α-RIT) of metastatic castration-resistant prostate cancer (mCRPC) using the α-particle emitter 211At-labeled to the anti-PSCA A11 minibody. A11 is specific for prostate stem cell antigen (PSCA), a cell surface glycoprotein which is overexpressed in more than 90% of both localized prostate cancer and bone metastases. METHODS: PC3-PSCA cells were implanted subcutaneously (s.c.) and intratibially (i.t) in nude mice. Efficacy of α-RIT (two fractions-14-day interval) was studied on s.c. macrotumors (0, 1.5 and 1.9 MBq) and on i.t. microtumors (~100-200 µm; 0, 0.8 or 1.5 MBq) by tumor-volume measurements. The injected activities for therapies were estimated from separate biodistribution and myelotoxicity studies. RESULTS: Tumor targeting of 211At-A11 was efficient and the effect on s.c. macrotumors was strong and dose-dependent. At 6 weeks, the mean tumor volumes for the treated groups, compared with controls, were reduced by approximately 85%. The separate myelotoxicity study following one single fraction showed reduced white blood cells (WBC) for all treated groups on day 6 after treatment. For the 0.8 and 1.5 MBq, the WBC reductions were transient and followed by recovery at day 13. For 2.4 MBq, a clear toxicity was observed and the mice were sacrificed on day 7. In the long-term follow-up of the 0.8 and 1.5 MBq-groups, blood counts on day 252 were normal and no signs of radiotoxicity observed. Efficacy on i.t. microtumors was evaluated in two experiments. In experiment 1, the tumor-free fraction (TFF) was 95% for both treated groups and significantly different (p < 0.05) from the controls at a TFF of 66%). In experiment 2, the difference in TFF was smaller, 32% for the treated group versus 20% for the controls. However, the difference in microtumor volume in experiment 2 was highly significant, 0.010 ± 0.003 mm3 versus 3.79 ± 1.24 mm3 (treated versus controls, respectively), i.e., a 99.7% reduction (p < 0.001). The different outcome in experiment 1 and 2 is most likely due to differences in microtumor sizes at therapy, or higher tumor-take in experiment 2 (where more cells were implanted). CONCLUSION: Evaluating fractionated α-RIT with 211At-labeled anti-PSCA A11 minibody, we found clear growth inhibition on both macrotumors and intratibial microtumors. For mice treated with multiple fractions, we also observed radiotoxicity manifested by progressive loss in body weight at 30 to 90 days after treatment. Our findings are conceptually promising for a systemic TAT of mCRPC and warrant further investigations of 211At-labeled PSCA-directed vectors. Such studies should include methods to improve the therapeutic window, e.g., by implementing a pretargeted regimen of α-RIT or by altering the size of the targeting vector.

Temporal changes in survival in men with de novo metastatic prostate cancer: nationwide population-based study.

Background: There have been large changes in the pattern of detection, work-up and treatment of men with prostate cancer during the last two decades. Therefore, we aimed to investigate temporal changes in survival in men with metastatic prostate cancer.Methods: Population-based cohort study in Prostate Cancer data Base Sweden of 13,709 men with de novo metastatic prostate cancer diagnosed between 1998 and 2015. Overall survival in four calendar periods were compared by the use of Kaplan-Meier analyses and Cox regression models including age at diagnosis, T stage and serum levels of prostate-specific antigen (PSA).Results: Between 1998-2001 and 2010-2015, median survival increased with 6 months for all men. The largest increase in survival was 14 months in men age 60-69 at diagnosis and in multivariable analysis risk of death decreased for men diagnosed in 2010-2015 compared to 1998-2001, hazard ratio (HR) 0.77 (95% CI: 0.68-0.86). The median PSA at date of diagnosis decreased with 46% from 181 ng/mL in 1998 to 98 ng/mL in 2015.Conclusions: There was an increase in survival among men with de novo metastatic prostate cancer in Sweden between 1998 and 2015. This increase was due to a decreased cancer extent indicated by lower PSA levels with ensuing longer lead times and speculatively also due to an increased use of chemotherapy in the latest time period. Given the increasing use of systemic treatment for advanced prostate cancer, our results are likely heralding larger increases in survival in men with metastatic prostate cancer in the near future.

Gene Expression Alterations during Development of Castration-Resistant Prostate Cancer Are Detected in Circulating Tumor Cells.

Development of castration-resistant prostate cancer (CRPC) is associated with alterations in gene expression involved in steroidogenesis and androgen signaling. This study investigates whether gene expression changes related to CRPC development can be identified in circulating tumor cells (CTCs). Gene expression in paired CTC samples from 29 patients, before androgen deprivation therapy (ADT) and at CRPC relapse, was compared using a panel including 47 genes related to prostate cancer progression on a qPCR platform. Fourteen genes displayed significantly changed gene expression in CTCs at CRPC relapse compared to before start of ADT. The genes with increased expression at CRPC relapse were related to steroidogenesis, AR-signaling, and anti-apoptosis. In contrast, expression of prostate markers was downregulated at CRPC. We also show that midkine (MDK) expression in CTCs from metastatic hormone-sensitive prostate cancer (mHSPC) was associated to short cancer-specific survival (CSS). In conclusion, this study shows that gene expression patterns in CTCs reflect the development of CRPC, and that MDK expression levels in CTCs are prognostic for cancer-specific survival in mHSPC. This study emphasizes the role of CTCs in exploring mechanisms of therapy resistance, as well as a promising biomarker for prognostic and treatment-predictive purposes in advanced mHSPC.

Triple treatment of high-risk prostate cancer. A matched cohort study with up to 19 years follow-up comparing survival outcomes after triple treatment and treatment with hormones and radiotherapy.

Purpose: To evaluate the efficacy of a triple treatment strategy, including surgery, on high risk prostate cancer comparing long-term survival outcome with a cohort receiving standard radiotherapy with endocrine therapy. Materials and methods: This study compared two cohorts in survival outcomes, matched on the year of diagnosis and age. In both groups there was a curative intention to treat localized high-risk prostate cancer (one or more of Gleason score 8-10, PSA 20-50 or stage T3), diagnosed between 1995-2010, follow-up at the end of 2014. Triple treatment group: 153 patients treated primarily with radical prostatectomy with neoadjuvant endocrine treatment, and a majority with adjuvant radiotherapy. Standard radiotherapy group: 702 patients with a treatment of either external radiotherapy or high dose brachytherapy combined with external beam therapy, both modalities in combination with neoadjuvant endocrine therapy. Results: The prostate-cancer-specific mortality was 10% for the triple treatment group and 15% for the standard radiotherapy group during the period, HR = 2.01 (1.17-3.43), p = 0.011. The corresponding overall mortality was 26% vs 29%, HR = 1.54 (1.09-2.17), p = 0.015. High Gleason score was the dominating risk factor for early death due to the disease. Clinical T-stage was not an independent risk factor for death in this population. Conclusion: Adding surgery in a multimodal treatment model in high-risk prostate cancer showed significantly better survival outcome compared with the current standard of radiotherapy. Surgery in this group is, therefore, compelling and that also includes a clinical T3-stage of the disease. The study is limited by possible selection bias for the two treatment models.

Androgen deprivation therapy for prostate cancer and risk of dementia.

OBJECTIVES: To study whether androgen deprivation therapy (ADT), the mainstay treatment for advanced and disseminated prostate cancer, is associated with risk of dementia. METHODS: Risk of dementia in men with prostate cancer primarily managed with ADT or watchful waiting (WW) in the Prostate Cancer Database Sweden, PCBaSe, was compared with that in prostate cancer-free men, matched on birth year and county of residency. We used Cox regression to calculate the hazard ratios (HRs) for Alzheimer's and non-Alzheimer's dementia (vascular dementia, dementia secondary to other diseases or unspecified dementias) for different types and duration of ADT and oral antiandrogens (AAs) as well as for men managed with WW. RESULTS: A total of 25 967 men with prostate cancer and 121 018 prostate cancer-free men were followed for a median of 4 years. In both groups 6% of the men were diagnosed with dementia. In men with prostate cancer, gonadotropin-releasing hormone agonist treatment ( HR 1.15, 95% confidence interval [CI] 1.07-1.23) and orchiectomy (HR 1.60, 95% CI 1.32-1.93) were associated with an increased risk of dementia, as compared to no treatment in prostate cancer-free men; however, this increase in risk was only observed for non-Alzheimer's dementia and occurred from year 1-4 after start of ADT. No increase in risk for any type of dementia was observed for men treated with AAs or for men on WW. CONCLUSION: This population-based cohort study does not support previous observations of an increased risk of Alzheimer's dementia for men on ADT; however, there was a small increase in risk of non-Alzheimer's dementia.

Analysis of regulator of G-protein signalling 2 (RGS2) expression and function during prostate cancer progression.

Prostate cancer (PC) represents the second highest cancer-related mortality among men and the call for biomarkers for early discrimination between aggressive and indolent forms is essential. Downregulation of Regulator of G-protein signaling 2 (RGS2) has been shown in PC, however the underlying mechanism has not been described. Aberrant RGS2 expression has also been reported for other carcinomas in association to both positive and negative prognosis. In this study, we assessed RGS2 expression during PC progression in terms of regulation and impact on tumour phenotype and evaluated its prognostic value. Our experimental data suggest that the RGS2 downregulation seen in early PC is caused by hypoxia. In line with the common indolent phenotype of a primary PC, knockdown of RGS2 induced epithelial features and impaired metastatic properties. However, increased STAT3, TWIST1 and decreased E-cadherin expression suggest priming for EMT. Additionally, improved tumour cell survival and increased BCL-2 expression linked decreased RGS2 levels to fundamental tumour advantages. In contrast, high RGS2 levels in advanced PC were correlated to poor patient survival and a positive metastatic status. This study describes novel roles for RGS2 during PC progression and suggests a prognostic potential discriminating between indolent and metastatic forms of PC.

Work-up and treatment of prostate cancer before and after publication of the first national guidelines on prostate cancer care in Sweden.

BACKGROUND AND OBJECTIVES: In 2007, the Swedish National Board of Health and Welfare published the first Swedish guidelines on prostate cancer (PCa) to improve care and decrease geographical and social inequalities. The aim of this analysis was to assess how these guidelines affected PCa care. MATERIALS AND METHODS: Work-up and treatment for men diagnosed with PCa between 1998 and 2014 were assessed by use of data in the Prostate Cancer data Base Sweden (PCBaSe) with information from the National Prostate Cancer Register (NPCR) and other healthcare registries and demographic databases. RESULTS: Overall, there were modest improvements in the performance for 14 selected quality indicators, with some notable exceptions. There was a strong increase in the use of active surveillance for very low-risk PCa, up from 56% in 2009 to 92% in 2014, and use of bone imaging for high-risk PCa up from 50% in 2008 to 77% in 2014. There were large differences in work-up and treatment of PCa between healthcare providers with modest decreases over time. The differences between counties were larger than differences according to socioeconomic status with one exception: use of curative treatment for high-risk PCa was more common in men with high income, highest versus lowest tertile, OR 2.74 (95% CI, 1.85-4.06). CONCLUSION: The modest improvements in PCa care after the publications of national guidelines indicate that if these are to make an impact on care, feedback to each point of care on their performance as well as local quality improvement programs implementing the guidelines are needed.

Circulating tumor cells mirror bone metastatic phenotype in prostate cancer.

Circulating tumor cells (CTCs) are promising biomarkers in prostate cancer (PC) because they derive from primary tumor and metastatic tissues. In this study, we used quantitative real-time PCR (qPCR) to compare the expression profiles of 41 PC-related genes between paired CTC and spinal column metastasis samples from 22 PC patients that underwent surgery for spinal cord compression. We observed good concordance between the gene expression profiles in the CTC and metastasis samples in most of the PC patients. Expression of nine genes (AGR2, AKR1C3, AR, CDH1, FOLH1, HER2, KRT19, MDK, and SPINK1) showed a significant correlation between the CTC and metastasis samples. Hierarchical clustering analysis showed a similar grouping of PC patients based on the expression of these nine genes in both CTC and metastasis samples. Our findings demonstrate that CTCs mirror gene expression patterns in tissue metastasis samples from PC patients. Although low detection frequency of certain genes is a limitation in CTCs, our results indicate the potential for CTC phenotyping as a tool to improve individualized therapy in metastatic prostate cancer.

A stage-dependent link between metabolic syndrome components and incident prostate cancer.

Metabolic syndrome is associated with increased cancer risk and progression at almost all sites, including the prostate in high-stage prostate cancer. However, several reports have described an inverse relationship between metabolic syndrome and its components and low-stage incident prostate cancer. Such anomalies in cancer research hamper efforts to fight cancer. Evidence suggests that metabolic syndrome and its components have two distinct effects in prostate cancer, concealing prostate cancer in low-stage disease and promoting progression to high-stage incident, nonlocalized, and lethal prostate cancer. The concealment of prostate cancer by metabolic syndrome and its components might be related to bias mechanisms that reduce PSA level and lead to a delayed diagnosis of low-stage prostate cancer, meaning that fewer men with metabolic syndrome are diagnosed with low-stage disease. The inverse link between metabolic syndrome and its components and low-stage incident prostate cancer might simply be the result of such bias and the shortcomings of the diagnostic procedure rather than being related to prostate cancer biology itself. The evidence summarized here supports the hypothesis that the link between metabolic syndrome and its components and incident prostate cancer is a two-way and stage-dependent one, a theory that requires further research.