Understanding and overcoming resistance to immunotherapy in genitourinary cancers

The introduction of novel immunotherapies has significantly transformed the treatment landscape of genitourinary (GU) cancers, even becoming the standard of care in some settings. One such type of immunotherapy, immune checkpoint inhibitors (ICIs) like nivolumab, ipilimumab, pembrolizumab, and atezolizumab play a pivotal role by disturbing signaling pathways that limit the immune system's ability to fight tumor cells. Despite the profound impact of these treatments, not all tumors are responsive. Recent research efforts have been focused on understanding how cancer cells manage to evade the immune response and identifying the possible mechanisms behind resistance to immunotherapy. In response, ICIs are being combined with other treatments to reduce resistance and attack cancer cells through multiple cellular pathways. Additionally, novel, targeted strategies are currently being investigated to develop innovative methods of overcoming resistance and treatment failure. This article presents a comprehensive overview of the mechanisms of immunotherapy resistance in GU cancers as currently described in the literature. It explores studies that have identified genetic markers, cytokines, and proteins that may predict resistance or response to immunotherapy. Additionally, we review current efforts to overcome this resistance, which include combination ICIs and sequential therapies, novel insights into the host immune profile, and new targeted therapies. Various approaches that combine immunotherapy with chemotherapy, targeted therapy, vaccines, and radiation have been studied in an effort to more effectively overcome resistance to immunotherapy. While each of these combination therapies has shown some efficacy in clinical trials, a deeper understanding of the immune system's role underscores the potential of novel targeted therapies as a particularly promising area of current research. Currently, several targeted agents are in development, along with the identification of key immune mediators involved in immunotherapy resistance. Further research is necessary to identify predictors of response.

Association between the apoptotic effect of Cabazitaxel and its pro-oxidant efficacy on the redox adaptation mechanisms in prostate cancer cells with different resistance phenotypes

Redox adaptation causes poor prognosis by adapting cancer cells to excessive oxidative stress. Previously, we introduced an oxidative stress-resistant metastatic prostate cancer (mPC) model (LNCaP-HPR) that redox adaptation reduced the effect of Cabazitaxel (Cab), the last taxane-derivative for metastatic castration-resistant PC (mCRPC). Whereas, we investigated for the first time whether there is an association between the altered apoptotic effect and pro-oxidant efficacy of Cab on the redox adaptation in PC cells with different phenotypes, including LNCaP mPC, LNCaP-HPR, C4-2 mCRPC, and RWPE-1 cells. Cab was shown pro-oxidant efficacy proportionally with the apoptotic effect, more prominent in the less aggressive LNCaP cells, by increasing the endogenous ROS, mitochondrial damage, and inhibiting nuclear ROS scavengers, p-Nrf2 and HIF-1α. However, the pro-oxidant and apoptotic effect was lower in the LNCaP-HPR and C4-2 cells, indicating that the drug sensitivity of the cells adapted to survive with more ROS was reduced via altered regulation of redox adaptation. Additionally, unlike LNCaP, Cab caused an increase in the p-NF-κB activation, suggesting that the p-NF-κB might accompany maintaining survival with the increased ROS in the aggressive PC cells. Moreover, the cytotoxic and apoptotic effects of Cab were less on RWPE-1 cells compared to LNCaP but were closer to those on the more aggressive LNCaP-HPR and C4-2 cells, except for the changing pro-oxidant effect of Cab. Consequently, this study indicates the variable pro-oxidant effects of Cab on redox-sensitive proteins, which could be a target for improving Cab's apoptotic effect more in aggressive PC cells.

Gastrin-releasing peptide receptor (GRPR) as a novel biomarker and therapeutic target in prostate cancer

Aim: This comprehensive review aims to explore the potential applications of Gastrin-releasing peptide receptor (GRPR) in the diagnosis and treatment of prostate cancer. Additionally, the study investigates the role of GRPR in prognostic assessment for individuals afflicted with prostate cancer.Methods: The review encompasses a thorough examination of existing literature and research studies related to the upregulation of GRPR in various tumor types, with a specific focus on prostate. The review also evaluates the utility of GRPR as a molecular target in prostate cancer research, comparing its significance to the well-established Prostate-specific membrane antigen (PSMA). The integration of radionuclide-targeted therapy with GRPR antagonists is explored as an innovative therapeutic approach for individuals with prostate cancer.Results: Research findings suggest that GRPR serves as a promising molecular target for visualizing low-grade prostate cancer. Furthermore, it is demonstrated to complement the detection of lesions that may be negative for PSMA. The integration of radionuclide-targeted therapy with GRPR antagonists presents a novel therapeutic paradigm, offering potential benefits for individuals undergoing treatment for prostate cancer.Conclusions: In conclusion, this review highlights the emerging role of GRPR in prostate cancer diagnosis and treatment. Moreover, the integration of radionuclide-targeted therapy with GRPR antagonists introduces an innovative therapeutic approach that holds promise for improving outcomes in individuals dealing with prostate cancer. The potential prognostic value of GRPR in assessing the disease's progression adds another dimension to its clinical significance in the realm of urology.

[Corrigendum] Cripto‑1 promotes epithelial‑mesenchymal transition in prostate cancer via Wnt/β‑catenin signaling

Following the publication of the above article, an interested reader drew to the authors' attention that the β‑actin control blots featured in Figs. 5A and 6A appeared to be strikingly similar. Upon examining their original data, the authors have realized that the β‑actin blots for Fig. 5A were inadvertently chosen incorrectly. The corrected version of Fig. 5 is shown opposite. Note that the error made in uploading the incorrect version of this figure did not affect the overall conclusions reported in the paper. All the authors agree with the publication of this corrigendum, and are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish this. They also apologize to the readership for any inconvenience caused. [Oncology Reports 1521‑1528, 2017; DOI: 10.3892/or.2017.5378].

Icariin‑curcumol promotes ferroptosis in prostate cancer cells through Nrf2/HO‑1 signaling

Ferroptosis is a form of regulatory cell death that relies on iron and reactive oxygen species (ROS) to inhibit tumors. The present study aimed to investigate whether icariin-curcumol could be a novel ferroptosis inducer in tumor inhibition. Various concentrations of icariin-curcumol were used to stimulate prostate cell lines (RWPE-2, PC-3, VCAP and DU145). Small interfering negative control (si-NC) and si-nuclear factor erythroid 2-related factor 2 (Nrf2) were used to transfect DU145 cells. Cell viability was determined by using cell counting kit-8. Ferroptosis-related factor levels were analyzed using western blotting and reverse transcription-quantitative PCR. Enzyme-linked immunosorbent assays were used to assess the ferrous (Fe2+), glutathione and malondialdehyde (MDA) content. The ROS fluorescence intensity was assessed using flow cytometry. DU145 cells were most sensitive to icariin-curcumol concentration. The Fe2+ content, ROS fluorescence intensity and MDA level gradually increased, while solute carrier family 7 member 11 (SLC7A11) level, glutathione peroxidase 4 (GPX4) level, GSH content, Nrf2 and heme oxygenase-1 (HO-1) decreased with icariin-curcumol in a dose-dependent manner. After si-Nrf2 was transfected, the cell proliferation ability, SLC7A11 and GPX4 levels declined compared with the si-NC group. In contrast to the control group, the icariin + curcumol group showed reductions in Nrf2 and HO-1 levels, cell proliferation, SLC7A11 and GPX4 levels, with an increase in Fe2+ content and ROS fluorescence intensity. Overexpression of Nrf2 reversed the regulation observed in the icariin + curcumol group. Icariin-curcumol induced ferroptosis in PCa cells, mechanistically by inhibiting the Nrf2/HO-1 signaling pathway. Icariin-curcumol could be used as a new type of ferroptosis inducer to treat PCa effectively.

Prostate and gut: Any relationship? A narrative review on the available evidence and putative mechanisms

BACKGROUND

Gut microbiome is a community of microorganisms that lives in the human intestine and exerts various functions on the host, including metabolic, immunoregulatory, and control over cell proliferation. Gut microbiome alterations have been associated with various pathological conditions, such as diabetes mellitus, obesity, and cardiovascular diseases. Gut-prostate axis is explained by the association between gut microbiome quantitative and functional alterations along with increased intestinal epithelial permeability with prostatediseases. However, the pathophysiological mechanisms and clinical importance of this association are not completely clarified yet.

METHODS

We conducted a narrative review of the most relevant articles in the Medline (US National Library of Medicine, Bethesda, MD, USA), Scopus (Elsevier, Amsterdam, The Netherlands) and Web of Science Core Collection (Thomson Reuters, Toronto, ON, Canada) databases. No chronological restrictions were applied, and the most related papers published until December 2023 were included.

RESULTS

Gut microbiota (GM) and its metabolites are capable of modifying host androgen level, as well as prostate cancer (PCa) therapy response. Moreover, patients with inflammatory bowel disease have higher rates of prostatitis-like symptoms and a potential risk of developing PCa.

CONCLUSIONS

There is evidence that interventions on the GM and its metabolites have a high potential to serve as diagnostic and therapeutic tools for prostate diseases, including PCa.

Metastasis-directed therapy in oligometastatic prostate cancer

PURPOSE OF REVIEW

To summarize the recent findings on the subject of metastasis-directed therapy (MDT) in the treatment of oligometastatic prostate cancer (omPCa).

RECENT FINDINGS

Evidence from two randomized clinical trials (RCTs) and a meta-analysis show favorable toxicity profiles, and the potential to delay androgen-deprivation therapy (ADT) for up to two years in nearly half of patients with metachronous hormone-sensitive omPCa. Another RCT showed promising results of MDT as treatment-escalation method combined with androgen receptor signaling inhibitors (ARSI) in first-line treatment for castration-resistant omPCa.Surveys by radiation oncologists and consensus guidelines advocate for MDT across various omPCa scenarios. Multiple single-arm trials present encouraging results; however, the evidence for the benefit of MDT is still weak requiring further investigation to assess its impact on pivotal endpoints, such as survival and quality of life.

SUMMARY

MDT is a promising approach in omPCa, and can be used to defer ADT in newly diagnosed metachronous omPCa patients, or to add to ARSI treatment at first diagnosis of castration-resistance. Ongoing prospective trials are needed to guide its optimal utilization in other settings, and patients should be informed about the evolving landscape of systemic therapies with proven survival benefits alongside MDT options.

Prevalence and predictors of colon and prostate cancer screening among volunteer firefighters: The United States Firefighter Cancer Assessment and Prevention Study

BACKGROUND

Although firefighters have increased risk for colon and prostate cancer, limited information exists on screening practices for these cancers in volunteer firefighters who compose two-thirds of the US fire service. We estimated the prevalence of colon and prostate cancer screening among volunteer firefighters using eligibility criteria from 4 evidence-based screening recommendations and evaluated factors influencing screening.

METHODS

We evaluated colon (n = 569) and prostate (n = 498) cancer screening prevalence in a sample of US volunteer firefighters using eligibility criteria from the US Preventive Services Taskforce (USPSTF), National Fire Protection Association, American Cancer Society, and National Comprehensive Cancer Network. We assessed associations with fire service experience, demographics, and cancer risk perception based on USPSTF guidelines.

RESULTS

For those eligible based on USPSTF guidelines, colon and prostate cancer screening prevalence was 51.7% (95% CI: 45.7, 57.8) and 48.8% (95% CI: 40.0, 57.6), respectively. Higher odds of colon and prostate cancer screening were observed with older age and with some college education compared to those with less education. Fire service experience and cancer risk perception were not associated with screening practices.

CONCLUSION

This is the first large study to assess colon and prostate cancer screening among US volunteer firefighters based on different screening guidelines. Our findings suggest gaps in cancer prevention efforts in the US volunteer fire service. Promoting cancer screening education and opportunities for volunteer firefighters by their fire departments, healthcare professionals, and public health practitioners, may help to address the gaps.

Preanalytical stability of molecular forms of prostate-specific antigen in serum samples (PSA, free PSA, [-2]proPSA) and their impact on fPSA/tPSA ratio and PHI

BACKGROUND

Prostate cancer is a common cancer in men. Detection methods include the measurement of biomarkers: prostate-specific antigen (PSA), free PSA, [-2]proPSA, and the calculated indices: fPSA/tPSA ratio and Prostate Health Index (PHI). Proper preanalytical conditions are crucial for precise measurement and failure to adhere to protocols or regulations can influence the diagnostic algorithm. We assessed the stability of the above-mentioned biomarkers, fPSA/tPSA ratio and PHI, under various pre-analytical conditions.

METHODS

Serum samples from 45 males were collected and stored under specific conditions before tPSA, fPSA, and [-2]proPSA were measured. Subsequently, the fPSA/tPSA and PHI were calculated.

RESULTS

tPSA, fPSA, and [-2]proPSA remained stable during the two freeze-thaw cycles. Storage at 4°C and 22°C resulted in stable tPSA concentrations. However, fPSA levels decreased and [-2]proPSA levels increased over time. The fPSA/tPSA ratio remained stable for 72 h, at which point a decrease was observed in the samples kept at 4°C and 22°C. A gradual increase in PHI was observed in the samples kept at 4°C and 22°C.

CONCLUSIONS

All biomarkers remained stable during two freeze-thaw cycles. tPSA was the most stable analyte when stored at 4°C, as well as at RT. A gradual increase of [-2]proPSA and a slight decrease in fPSA were observed during the storage test. This led to a decrease in the fPSA/tPSA ratio and an elevation in the PHI. We therefore recommend measuring prostate biomarkers promptly following blood collection.

IMPACT

Understanding the pre-analytical stability of prostate biomarkers helps prevent false positive results and improve the accuracy of diagnostics for prostate cancer.

Unveiling hormone-stimulated gene mechanisms in prostate cancer: A prognostic model, immune infiltration analysis, and drug sensitivity study

Hormones promote the progression of prostate cancer (PRCA) through the activation of a complex regulatory network. Inhibition of hormones or modulation of specific network nodes alone is insufficient to suppress the entire oncogenic network. Therefore, it is imperative to elucidate the mechanisms underlying the occurrence and development of PRCA in order to identify reliable diagnostic markers and therapeutic targets. To this end, we used publicly available data to analyze the potential mechanisms of hormone-stimulated genes in PRCA, construct a prognostic model, and assess immune infiltration and drug sensitivity. The single-cell RNA-sequencing data of PRCA were subjected to dimensionality reduction clustering and annotation, and the cells were categorized into two groups based on hormone stimulus-related scores. The differentially expressed genes between the two groups were screened and incorporated into the least absolute shrinkage and selection operator machine learning algorithm, and a prognostic model comprising six genes (ZNF862, YIF1A, USP22, TAF7, SRSF3, and SPARC) was constructed. The robustness of the model was validation through multiple methods. Immune infiltration scores in the two risk groups were calculated using three different algorithms. In addition, the relationship between the model genes and immune cell infiltration, and that between risk score and immune cell infiltration were analyzed. Drug sensitivity analysis was performed for the model genes and risk score using public databases to identify potential candidate drugs. Our findings provide novel insights into the mechanisms of hormone-stimulated genes in PRCA progression, prognosis, and drug screening.

Prostate cancer therapy outcome prediction: are miRNAs a suitable guide for therapeutic decisions?

BACKGROUND

Radical prostatectomy, radiotherapy, chemotherapy, and androgen-deprivation therapy are among the most common treatment options for different forms of prostate cancer (PCa). However, making therapeutic decisions is difficult due to the lack of reliable prediction markers indicating therapy outcomes in clinical practice. The involvement of miRNAs in all mechanisms of the PCa development and their easy detection characterize them as attractive PCa biomarkers. Although there are extensive data on the role of miRNAs in PCa therapy resistance and sensitivity development, the issues of whether they could be used as a guide for therapy choice and, if so, how we can progress toward this goal, remain unclear. Thus, generalizable reviews and studies which summarize, compare, and analyze data on miRNA involvement in responses to different types of PCa therapies are required.

OBJECTIVES

Data on the involvement of miRNAs in therapy responses, on the role of cross-miRNA expression in different therapies, and on miRNA targets were analyzed in order to determine the miRNA-related factors which can lend perspective to the future development of personalized predictors of PCa sensitivity/resistance to therapies.

MATERIALS AND METHODS

The data available on the miRNAs associated with different PCa therapies (resistance and sensitivity therapies) are summarized and analyzed in this study, including analyses using bioinformatics resources. Special attention was dedicated to the mechanisms of the development of therapy resistance.

RESULTS AND DISCUSSION

A comprehensive combined analysis of the current data revealed a panel of miRNAs that were shown to be most closely associated with the PCa therapy response and were found to regulate the genes involved in PCa development via cell proliferation regulation, epithelial-mesenchymal transition (EMT), apoptosis, cell-cycle progression, angiogenesis, metastasis and invasion regulation, androgen-independent development, and colony formation.

CONCLUSION

The selected miRNA-based panel has the potential to be a guide for therapeutic decision making in the effective treatment of PCa.

Development of depression in patients using androgen deprivation therapy: A systemic review and meta-analysis

BACKGROUND

Androgen deprivation therapy (ADT) is an effective treatment for advanced prostate cancer (PCa). Multiple studies have highlighted serious consequences this therapy poses to mental health, particularly depression. We aimed to review the incidence and association between ADT in men with PCa and the risk of depression.

METHODS

We systematically searched multiple databases, including MEDLINE, Scopus till August 2023 for studies that compared ADT versus control for treating PCa reporting depression as outcome. Meta-analysis was performed using random-effects models and results presented as odds ratios (ORs) with 95% confidence interval (CI). Quality assessment of the included studies was conducted using Joanna Briggs Institute critical appraisal checklists.

RESULTS

A total of 38 studies (17 retrospective studies, 16 prospective studies, two cross-sectional studies and two randomized trials) with 360,650 subjects met the inclusion criteria and were included in this meta-analysis. The estimated pooled incidence of depression among ADT patients is 209.5 (95% CI = 122.3; 312.2) per 1000 patients. There is statistically significant relationship between ADT treatment and depression (OR = 1.46, 95% CI = 1.28, 1.67; p = 0, I2 = 86.4%). The results remained consistent across various subgroups. No risk of publication bias was detected by funnel plot and Eggers's test (p > 0.05).

CONCLUSION

There is a higher risk of depression for men receiving ADT. Further studies evaluating optimal treatments for depression in men on ADT are warranted.

Effect of Pelvic External Beam Radiation Therapy on Bone Mineral Density: A Secondary Analysis of a Phase 3 Randomized Controlled Trial

PURPOSE

Pelvic radiation therapy may lead to decreased bone mineral density (BMD) and increased risk of fracture that could be of particular concern in patients with prostate cancer who also receive androgen deprivation therapy (ADT). We performed an exploratory analysis of a randomized, double-masked, placebo-controlled trial to determine whether exposure to prior pelvic external beam radiation therapy (XRT) affects BMD and risk of fracture in patients with prostate cancer treated with ADT.

METHODS AND MATERIALS

Patients with nonmetastatic prostate cancer aged ≥70 years or <70 years with low BMD (T-score < -1) or osteoporotic fracture who had been receiving ADT for ≥12 months were randomly assigned to receive densoumab or placebo every 6 months for 3 years. BMD was measured at baseline and at months 1, 3, 6, 12, 24, and 36. We applied multivariable linear mixed-effects models with an interaction term between the treatment arm and exposure to prior pelvic XRT to evaluate differential XRT effect on percent BMD change between the 2 treatment arms.

RESULTS

Among 1407 eligible patients, 31% (n = 447) received prior pelvic XRT. There was no significant difference in any clinical fractures among patients with (5.8%, 26 of 447) or without (5.2%, 50 of 960) prior pelvic XRT (P = .42). Prior pelvic XRT was associated with a significant (0.54%) improvement in BMD (95% CI, 0.05-1.02) in the placebo group and a nonsignificant (0.04%) decline in BMD (95% CI, -0.47 to -0.35) in the denosumab group (interaction P = .007). There was no significant difference in pelvic XRT effect on percent BMD change in the lumbar spine (P = .65) or total hip (P = .39) between the 2 treatment groups.

CONCLUSIONS

We did not find sufficient evidence to suggest any detrimental effect of pelvic XRT on the treatment effect from denosumab on percent BMD change, with only an approximately 5% incidence of clinical fractures.

Racial and Ethnic Variation in Receipt and Intensity of Active Surveillance for Older Patients With Localized Prostate Cancer

INTRODUCTION

The use of active surveillance (AS) for prostate cancer is increasing, and racial disparities have been identified in its implementation. We investigated differences by race and ethnicity in the utilization and intensity of AS by race and ethnicity among older men with low- and favorable intermediate-risk prostate cancer, with particular focus on the integration of multiparametric MRI (mpMRI) into AS protocols.

METHODS

Using the Surveillance, Epidemiology, and End Results and Medicare fee-for-service linked database, we identified a cohort of men diagnosed between 2010 and 2017 with low- or favorable intermediate-risk prostate cancer. The odds of receiving AS were compared by patient race and ethnicity using multivariable logistic regression models, while the rates of usage of PSA tests, biopsy, and mpMRI within 2 years of diagnosis among men on AS were assessed using multivariable Poisson regression models.

RESULTS

Our cohort included 33,542 men. The proportion of men with low-risk disease who underwent AS increased from 29.5% in 2010 to 51.7% in 2017, while the proportion among men with favorable intermediate disease grew from 11.4% to 17.2%. Hispanic (odds ratio [OR] = 0.68, 95% CI 0.58-0.79) and non-Hispanic Black men (OR = 0.78, 95% CI 0.68-0.89) were less likely to receive AS than non-Hispanic White men for low-risk disease, while non-Hispanic Black men were more likely to receive AS for favorable intermediate disease (OR = 1.21, 95% CI 1.04-1.39). Non-Hispanic Black men receiving AS underwent prostate MRI at a lower rate compared to non-Hispanic White men, regardless of whether they had low-risk (incidence rate ratio = 0.77, 95% CI 0.61-0.97) or favorable intermediate-risk (incidence rate ratio = 0.61, 95% CI 0.44-0.83) disease, respectively.

CONCLUSIONS

The overall adoption of AS for low-risk prostate cancer increased among Medicare fee-for-service beneficiaries. However, a significant disparity exists for non-Hispanic Black men, as they exhibit lower rates of AS utilization. Moreover, non-Hispanic Black men are less likely to have access to novel technologies, such as mpMRI, as part of their AS protocols.

Postradical prostatectomy prostate-specific antigen outcomes after 6 versus 18 months of perioperative androgen-deprivation therapy in men with localized, unfavorable intermediate-risk or high-risk prostate cancer: Results of part 2 of a randomized phase 2 trial

BACKGROUND

Patients with localized, unfavorable intermediate-risk and high-risk prostate cancer have an increased risk of relapse after radical prostatectomy (RP). The authors previously reported on part 1 of this phase 2 trial testing neoadjuvant apalutamide, abiraterone, prednisone, plus leuprolide (AAPL) or abiraterone, prednisone, and leuprolide (APL) for 6 months followed by RP. The results demonstrated favorable pathologic responses (tumor <5 mm) in 20.3% of patients (n = 24 of 118). Herein, the authors report the results of part 2.

METHODS

For part 2, patients were randomized 1:1 to receive either AAPL for 12 months (arm 2A) or observation (arm 2B), stratified by neoadjuvant therapy and pathologic tumor classification. The primary end point was 3-year biochemical progression-free survival. Secondary end points included safety and testosterone recovery (>200 ng/dL).

RESULTS

Overall, 82 of 118 patients (69%) enrolled in part 1 were randomized to part 2. A higher proportion of patients who were not randomized to adjuvant therapy had a favorable prostatectomy pathologic response (32.3% in nonrandomized patients compared with 17.1% in randomized patients). In the intent-to-treat analysis, the 3-year biochemical progression-free survival rate was 81% for arm 2A and 72% for arm 2B (hazard ratio, 0.81; 90% confidence interval, 0.43-1.49). Of the randomized patients, 81% had testosterone recovery in the AAPL group compared with 95% in the observation group, with a median time to recovery of <12 months in both arms.

CONCLUSIONS

In this study, because 30% of patients declined adjuvant treatment, part B was underpowered to detect differences between arms. Future perioperative studies should be biomarker-directed and include strategies for investigator and patient engagement to ensure compliance with protocol procedures.

Testosterone bounce predicts favorable prognoses for prostate cancer patients treated with degarelix

BACKGROUND

To clarify the clinical roles of changes in testosterone (T) levels with a cut-off level of 20 ng/dL as predictive factors for prostate cancer patients treated with degarelix acetate.

METHODS

A total of 120 prostate cancer patients who received hormone therapies with gonadotropin-releasing hormone antagonist degarelix acetate were retrospectively analyzed. The predictive values of nadir T levels, max T levels, T bounce, and other clinical factors were evaluated for overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS). T bounce was defined as satisfying both nadir serum T levels of <20 ng/dL and max serum T levels of ≥20 ng/dL during hormone therapies.

RESULTS

In 120 prostate cancer patients, 16 (13%) patients did not achieve nadir T < 20 ng/dL, and 76 (63%) patients had max T ≥ 20 ng/dL. The median times to nadir T and max T are 108 and 312 days, respectively. T bounce was shown in 60 (50%) patients and is associated with favorable prognoses both for OS (p = 0.0019) and CSS (p = 0.0013) but not for PFS (p = 0.92). While in the subgroup analyses of the patients with the progression of the first-line hormone therapies, T bounce predicts favorable OS (p = 0.0015) and CSS (p = 0.0013) after biochemical recurrence.

CONCLUSIONS

The present study revealed that T bounce with cut-off levels of 20 ng/dL is a promising biomarker that predicts OS and CSS for prostate cancer patients treated with degarelix acetate.

Butyrate increases methylglyoxal production through regulation of the JAK2/Stat3/Nrf2/Glo1 pathway in castration‑resistant prostate cancer cells

Cancer cells are characterized by increased glycolysis, known as the Warburg effect, which leads to increased production of cytotoxic methylglyoxal (MGO) and apoptotic cell death. Cancer cells often activate the protective nuclear factor erythroid 2‑related factor2 (Nrf2)/glyoxalase1 (Glo1) system to detoxify MGO. The effects of sodium butyrate (NaB), a product of gut microbiota, on Nrf2/Glos/MGO pathway and the underlying mechanisms in prostate cancer (PCa) cells were investigated in the present study. Treatment with NaB induced the cell death and reduced the proliferation of PCa cells (DU145 and LNCap). Moreover, the protein kinase RNA-like endoplasmic reticulum kinase/Nrf2/Glo1 pathway was greatly inhibited by NaB, thereby accumulating MGO-derived adduct hydroimidazolone (MG-H1). In response to a high amount of MGO, the expression of Nrf2 and Glo1 was attenuated, coinciding with an increased cellular death. NaB also markedly inhibited the Janus kinase 2 (JAK2)/Signal transducer and activator of transcription 3 (Stat3) pathway. Conversely, co‑treatment with Colivelin, a Stat3 activator, significantly reversed the effects of NaB on Glo1 expression, MG-H1 production, and the cell migration and viability. As expected, overexpression of Stat3 or Glo1 reduced NaB‑induced cell death. The activation of calcium/calmodulin dependent protein kinase II gamma and reactive oxygen species production also contributed to the anticancer effect of NaB. The present study, for the first time, demonstrated that NaB greatly increases MGO production through suppression of the JAK2/Stat3/Nrf2/Glo1 pathway in DU145 cells, a cell line mimicking castration‑resistant PCa (CRPC), suggesting that NaB may be a potential agent for PCa therapy.

Patterns of Care for Medicare Beneficiaries With Metastatic Prostate Cancer

INTRODUCTION

Therapeutic options for men with metastatic prostate cancer have increased in the past decade. We studied recent treatment patterns for men with metastatic prostate cancer and how treatment patterns have changed over time.

METHODS

Using the Surveillance, Epidemiology, and End Results‒Medicare database, we identified fee-for-service Medicare beneficiaries who either were diagnosed with metastatic prostate cancer or developed metastases following diagnosis, as indicated by the presence of claims with diagnoses codes for metastatic disease, between 2007 and 2017. We evaluated treatment patterns using claims.

RESULTS

We identified 29,800 men with metastatic disease, of whom 4721 (18.8%) had metastatic disease at their initial diagnosis. The mean age was 77 years, and 77.9% of patients were non-Hispanic White. The proportion receiving antineoplastic agents within 3 years of the index date increased over time (from 9.7% in 2007 to 25.9% in 2017; P < .001). Opioid use within 3 years of prostate cancer diagnosis was stable during 2007 to 2013 (around 73%) but decreased through 2017 to 65.5% (P < .001). Patients diagnosed during 2015 to 2017 had longer median survival (32.6 months) compared to those diagnosed during 2007 to 2010 (26.6 months; P < .001).

CONCLUSIONS

Most metastatic prostate cancer patients do not receive life-prolonging antineoplastic therapies. Improved adoption of effective cancer therapies when appropriate may increase length and quality of survival among metastatic prostate cancer patients.

Capivasertib combines with docetaxel to enhance anti-tumour activity through inhibition of AKT-mediated survival mechanisms in prostate cancer

BACKGROUND/OBJECTIVE

To explore the anti-tumour activity of combining AKT inhibition and docetaxel in PTEN protein null and WT prostate tumours.

METHODS

Mechanisms associated with docetaxel capivasertib treatment activity in prostate cancer were examined using a panel of in vivo tumour models and cell lines.

RESULTS

Combining docetaxel and capivasertib had increased activity in PTEN null and WT prostate tumour models in vivo. In vitro short-term docetaxel treatment caused cell cycle arrest in the majority of cells. However, a sub-population of docetaxel-persister cells did not undergo G2/M arrest but upregulated phosphorylation of PI3K/AKT pathway effectors GSK3β, p70S6K, 4E-BP1, but to a lesser extent AKT. In vivo acute docetaxel treatment induced p70S6K and 4E-BP1 phosphorylation. Treating PTEN null and WT docetaxel-persister cells with capivasertib reduced PI3K/AKT pathway activation and cell cycle progression. In vitro and in vivo it reduced proliferation and increased apoptosis or DNA damage though effects were more marked in PTEN null cells. Docetaxel-persister cells were partly reliant on GSK3β as a GSK3β inhibitor AZD2858 reversed capivasertib-induced apoptosis and DNA damage.

CONCLUSION

Capivasertib can enhance anti-tumour effects of docetaxel by targeting residual docetaxel-persister cells, independent of PTEN status, to induce apoptosis and DNA damage in part through GSK3β.

Medium-term follow up of active surveillance for early prostate cancer at a non-academic institution

OBJECTIVES

To report oncological outcomes of active surveillance (AS) at a single non-academic institution adopting the standardised Prostate Cancer Research International Active Surveillance (PRIAS) protocol.

PATIENTS AND METHODS

Competing risk analyses estimated the incidence of overall mortality, metastases, conversion to treatment, and grade reclassification. The incidence of reclassification and adverse pathological findings at radical prostatectomy were compared between patients fulfilling all PRIAS inclusion criteria vs those not fulfilling at least one.

RESULTS

We analysed 341 men with Grade Group 1 prostate cancer (PCa) followed on AS between 2010 and 2022. There were no PCa deaths, two patients developed distant metastases and were alive at the end of the study period. The 10-year cumulative incidence of metastases was 1.9% (95% confidence interval [CI] 0.33-6.4%). A total of 111 men were reclassified, and 127 underwent definitive treatment. Men not fulfilling at least one PRIAS inclusion criteria (n = 43) had a higher incidence of reclassification (subdistribution hazards ratio 1.73, 95% CI 1.07-2.81; P = 0.03), but similar rates of adverse pathological findings at radical prostatectomy.

CONCLUSION

Metastases in men on AS at a non-academic institution are as rare as those reported in established international cohorts. Men followed without stringent inclusion criteria should be counselled about the higher incidence of reclassification and reassured they can expect rates of adverse pathological findings comparable to those fulfilling all criteria. Therefore, AS should be proposed to all men with low-grade PCa regardless of whether they are followed at academic institutions or smaller community hospitals.

Estimating disparities of prostate cancer burden and its attributable risk factors for males across the BRICS-plus, 1990-2019: A comparable study of key nations with emerging economies

BACKGROUNDS

The study aimed to analyze epidemiology burden of male prostate cancer across the BRICS-plus, and identify potential risk factors by assessing the associations with age, period, birth cohorts and sociodemographic index (SDI).

METHODS

Data were extracted from the Global Burden of Disease Study 2019. The average annual percent change (AAPC) was calculated to assess long-term trends, and age-period-cohort analysis was used to analyze these three effects on prostate cancer burden. Quantile regression was used to investigate the association between SDI and health outcomes.

RESULTS

The higher incidence and mortality were observed in Mercosur and SACU regions, increasing trends were observed in prostate cancer incidence in almost all BRICS-plus countries (AAPC > 0), and EEU's grew by 24.31% (%AAPC range: -0.13-3.03). Mortality had increased in more than half of countries (AAPC > 0), and SACU grew by 1.82% (%AAPC range: 0.62-1.75). Incidence and mortality risk sharply increased with age across all BRICS-plus countries and globally, and the peak was reached in the age group 80-84 years. Rate ratio (RR) of incidence increased with birth cohorts in all BRICS-plus countries except for Kazakhstan where slightly decrease, while mortality RR decreased with birth cohort in most of BRICS-plus countries. SDI presented significantly positive associations with incidence in 50 percentiles. The deaths attributable to smoking declined in most of BRICS-plus nations, and many countries in China-ASEAN-FTA and EEU had higher values.

CONCLUSION

Prostate cancer posed a serious public health challenge with an increasing burden among most of BRICS-plus countries. Age had significant effects on prostate cancer burden, and recent birth cohorts suffered from higher incidence risk. SDI presented a positive relationship with incidence, and the smoking-attributable burden was tremendous in China-ASEAN-FTA and EEU region. Secondary prevention should be prioritized in BRICS-plus nations, and health policies targeting important populations should be strengthened based on their characteristics and adaptability.

Current clinical application of lutetium‑177 in solid tumors (Review)

Radionuclide-based therapy represents a novel treatment regimen for tumors. Among these therapies, lutetium-177 (177Lu) has gained significant attention due to its stability and safety, as well as its ability to emit both γ and β rays, allowing for both imaging with single photon emission computed tomography and tumor treatment. As a result, 177Lu can be used for both diagnosis and treatment for diseases such as prostatic and gastric cancer. Therefore, based on the available data, the present review provides a brief overview of the clinical applications of 177Lu-targeted radionuclide therapy in metastatic prostate cancer, neuroendocrine tumors and other types of solid tumors, and highlights the current therapeutic effect, reduction in damage to normal tissues and future research directions, including the development of new nuclides and the application of more nuclides in different tumors. In the future, such treatments could be used in more tumors.

Plant-based diet associated with better quality of life in prostate cancer survivors

BACKGROUND

Plant-based diets have many health benefits, including a lower risk of fatal prostate cancer, and greater environmental sustainability. However, less is known regarding the impact of plant-based diets on quality of life among individuals diagnosed with prostate cancer. The authors' objective was to examine the relationship between plant-based diet indices postdiagnosis with quality of life.

METHODS

This prospective cohort study included 3505 participants in the Health Professionals Follow-Up Study (1986-2016) with nonmetastatic prostate cancer. Food-frequency questionnaires were used to calculate overall and healthful plant-based diet indices. Quality-of-life scores were calculated using the Expanded Prostate Cancer Index Composite. Generalized estimating equations were used to examine associations over time between plant-based diet indices and quality-of-life domains (sexual functioning, urinary irritation/obstruction, urinary incontinence, bowel functioning, hormonal/vitality), adjusted for demographics, oncologic history, body mass index, caloric intake, health-related behaviors, and comorbidities.

RESULTS

The median age at prostate cancer diagnosis was 68 years; 48% of patients underwent radical prostatectomy, and 35% received radiation as primary therapy. The median time from diagnosis/treatment to first the quality-of-life questionnaire was 7.0 years. A higher plant-based diet index was associated with better scores for sexual function, urinary irritation/obstruction, urinary incontinence, and hormonal/vitality. Consuming more healthful plant-based foods was also associated with better sexual and bowel function, as well as urinary incontinence and hormonal/vitality scores in the age-adjusted analysis, but not in the multivariable analysis.

CONCLUSIONS

This prospective study provides supportive evidence that greater consumption of healthful plant-based foods is associated with modestly higher scores in quality-of-life domains among patients with prostate cancer.

Impact of presentation timing in metastatic hormone-sensitive prostate cancer: Characterization of patients and identification of prognostic factors

BACKGROUND

The treatment and surveillance of metastatic hormone-sensitive prostate cancer (mHSPC) has evolved since the introduction of several treatment intensification options associated with hormonal blockade and classifications based on the timing of metastatic disease presentation and disease volume. Using a hospital-based registry, we aimed to assess whether these new classifications are applicable to our population, as few studies have demonstrated their prognostic value for overall survival (OS) and time to development of castration-resistant prostate cancer (CRPC), and to establish prognostic factors in our population.

METHODS

A retrospective cohort of mHSPC patients who were attended at an oncology referral hospital in Bogota between 2017 and 2021 were included in this study. The primary and secondary endpoints were OS and time to CRPC. The distribution of outcome measures was estimated using the Kaplan-Meier method. Proportional hazard models were constructed using the Cox regression approach and stratified according to risk factors.

RESULTS

The study cohort included 373 patients. The median castration resistance-free survival was 48 months (CI: 32-73 months), and OS was 43 months (CI: 37-48 months). In multivariate analysis, nodal staging, ECOG status, and surgical castration were independent prognostic factors.

CONCLUSION

In our hospital-based registry, the independent impact of the time of presentation on castration-resistant-free survival or OS could not be demonstrated, nor could the grouping of prognostic categories based on metastatic presentation temporality and volume. Other independent prognostic factors have been proposed.

Prior male sling does not affect outcomes of artificial urinary sphincter

OBJECTIVE

To investigate the outcomes of artificial urinary sphincter (AUS) placement in patients with post-prostatectomy urinary incontinence (PPUI) with or without a prior male sling.

PATIENTS AND METHODS

We performed a retrospective chart review of patients who underwent AUS for PPUI from 2007 to 2022. The primary endpoint was to determine the proportion of patients who achieved social continence, defined as self-reported use of 0-1 pad/day. The secondary endpoints were device failure rates and device failure-free survival.

RESULTS

The analysis included 210 patients, with 30 (14.3%) having had prior slings and 180 (85.7%) without prior slings. After AUS insertion, 80.0% of patients with prior slings and 76.7% of those without prior slings achieved continence (0-1 pad/day). There were six (20.0%) and 53 (29.4%) device failures in patients with and without prior slings, respectively. The median device failure-free survival was not reached in patients with prior slings and was 8.9 years in patients without prior slings (P = 0.048). Limitations include retrospective nature and small sample size.

CONCLUSIONS

The efficacy and safety of AUS in patients with prior slings are similar to those without. Prior sling is associated with a longer device failure-free survival. AUS remains a viable option in patients who have persistent PPI after prior slings.

A prospective study of birth weight and prostate cancer risk and mortality in the Health Professionals Follow-up Study

BACKGROUND

Previous studies have observed inconsistent associations between birth weight and aggressive prostate cancer risk. This study aimed to prospectively analyse this association in the Health Professionals Follow-up Study (HPFS).

METHODS

Birth weight was self-reported in 1994, and prostate cancer diagnoses were assessed biennially through January 2017 and confirmed by medical record review. Multivariable Cox proportional hazards regression was used to evaluate the association between birth weight and prostate cancer risk and mortality.

RESULTS

Among 19,889 eligible men, 2520 were diagnosed with prostate cancer, including 643 with higher-grade/advanced stage, 296 with lethal, and 248 with fatal disease. Overall, no association was observed for increasing birth weight with risk of overall prostate cancer, lower-grade, and organ-confined disease. However, a borderline statistically significant positive trend was observed for increasing birth weight with risk of higher-grade and/or advanced-stage prostate cancer (adjusted hazard ratio [HRadj] per pound: 1.05; 95% confidence interval [CI]: 0.99-1.11; P-trend = 0.08), but no associations were observed with risk of lethal or fatal disease (HRadj: 0.99, 95% CI: 0.91-1.08; P-trend = 0.83; and HRadj: 0.99, 95% CI: 0.90-1.08; P-trend = 0.82, respectively).

CONCLUSION

No consistent associations were observed between birth weight and prostate cancer risk or mortality in this 22-year prospective cohort study.

Challenges in clinical trials for high-risk but curable prostate cancer

Clinical trials studying neoadjuvant and adjuvant therapy around prostatectomy for patients with high‐risk prostate cancer have faced multiple challenges. Patients who have a very good response to neoadjuvant therapy may not wish to continue to adjuvant treatment, and prostate‐specific antigen–based end points are difficult to interpret because of variations in testosterone recovery.

Added value of randomised biopsy to multiparametric magnetic resonance imaging-targeted biopsy of the prostate in a contemporary cohort

OBJECTIVE

To assess the added value of concurrent systematic randomised ultrasonography-guided biopsy (SBx) to multiparametric magnetic resonance imaging (mpMRI)-targeted biopsy and the additional rate of overdiagnosis of clinically insignificant prostate cancer (ciPCa) by SBx in a large contemporary, real-world cohort.

PATIENTS AND METHODS

A total of 1552 patients with positive mpMRI and consecutive mpMRI-targeted biopsy and SBx were enrolled. Added value and the rate of overdiagnosis by SBx was evaluated.

PRIMARY OUTCOME

added value of SBx, defined as detection rate of clinically significant PCa (csPCa; International Society of Urological Pathology [ISUP] Grade ≥2) by SBx, while mpMRI-targeted biopsy was negative or showed ciPCa (ISUP Grade 1).

SECONDARY OUTCOME

rate of overdiagnosis by SBx, defined as detection of ciPCa in patients with negative mpMRI-targeted biopsy and PSA level of <10 ng/mL.

RESULTS

Detection rate of csPCa by mpMRI-targeted biopsy and/or SBx was 753/1552 (49%). Added value of SBx was 145/944 (15%). Rate of overdiagnosis by SBx was 146/656 (22%). Added value of SBx did not change when comparing patients with previous prostate biopsy and biopsy naïve patients. In multivariable analysis, a Prostate Imaging-Reporting and Data System (PI-RADS) 4 index lesion (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.66-6.78; P = 0.001), a PI-RADS 5 index lesion (OR 2.89, 95% CI 1.39-6.46; P = 0.006) and age (OR 1.05, 95% CI 1.03-1.08; P < 0.001) were independently associated with added value of SBx.

CONCLUSIONS

In our real-world analysis, we saw a significant impact on added value and added rate of overdiagnosis by SBx. Subgroup analysis showed no significant decrease of added value in any evaluated risk group. Therefore, we do not endorse omitting concurrent SBx to mpMRI-guided biopsy of the prostate.

Efficacy, tolerability, and safety of teverelix DP in patients with advanced prostate cancer: A multicenter, open-label, phase 2 trial

BACKGROUND

Teverelix drug product (DP) is a novel injectable gonadotropin-releasing hormone antagonist.

METHODS

An adaptive phase 2, open-label, multicenter trial was conducted in patients with advanced prostate cancer to evaluate the efficacy and safety of a combined subcutaneous (SC) and intramuscular (IM) loading dose regimen of teverelix DP of 120 mg SC + 120 mg IM (Group 1; N = 9) or 180 mg SC + 180 mg IM (Group 2; N = 41) administered at a single visit, followed by 6-weekly SC maintenance doses of 120 mg (Group 1) or 180 mg (Group 2), up to Day 168. The primary endpoint was the proportion of patients achieving castration levels with serum testosterone <0.5 ng/mL at Day 28 with a target castration rate of 90%. Injection sites were inspected by the investigator at every visit and reactions (ISRs) were proactively recorded.

RESULTS

The target castration rate was reached in Group 2 (97.5%) but not in Group 1 (62.5%). The castration rates were not maintained to Day 42 (Group 2: 82.5%; Group 1: 50.0%). Suppression of testosterone to castrate levels occurred rapidly (median time: 2 days for both groups). Suppression of testosterone, prostate-specific antigen, follicle-stimulating hormone, and luteinizing hormone was sustained throughout the treatment period, being more prominent with the higher dose. The adverse event (AE) profile was similar between groups. The most common AEs were injection-site induration (n = 40: 80.0%), injection-site erythema (n = 35: 70.0%), and hot flush (n = 21: 42.0%). Most ISRs were Grade 1.

CONCLUSION

Overall, the teverelix DP doses were generally well-tolerated but did not adequately maintain castration levels.

Utilization trend of prebiopsy multiparametric magnetic resonance imaging and its impact on prostate cancer detection: Real-world insights from a high-volume center in southwest China

BACKGROUND

Data on the utilization and effects of prebiopsy prostate multiparametric magnetic resonance imaging (mpMRI) to support its routine use in real-world setting are still scarce.

OBJECTIVE

To evaluate the change of clinical practice of prebiopsy mpMRI over time, and assess its diagnostic accuracy.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively analyzed data from 6168 patients who underwent primary prostate biopsy (PBx) between January 2011 and December 2021 and had prostate-specific antigen (PSA) values ranging from 3 to 100 ng/mL.

INTERVENTION

Prebiopsy MRI at the time of PBx.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We performed general linear regression and to elucidate trends in the annual use of prebiopsy mpMRI and conducted multivariable logistic regression to evaluate the potential benefits of incorporating prebiopsy mpMRI for prostate cancer (PCa) detection.

RESULTS AND LIMITATIONS

The utilization of prebiopsy mpMRI significantly increased from 9.2% in 2011 to 75.0% in 2021 (p < 0.001). In addition, prebiopsy mpMRI significantly reduced negative PBx by 8.6% while improving the detection of clinically significant PCa (csPCa) by 7.0%. Regression analysis showed that the utilization of prebiopsy mpMRI was significantly associated with a 48% (95% confidence interval [CI]: 1.19-1.84) and 36% (95% CI: 1.12-1.66) increased PCa detection rate in the PSA 3-10 ng/mL and 10-20 ng/mL groups, respectively; and a 34% increased csPCa detection rate in the PSA 10-20 ng/mL group (95% CI: 1.09-1.64). The retrospective design and the single center cohort constituted the limitations of this study.

CONCLUSIONS

Our study demonstrated a notable rise in the utilization of prebiopsy mpMRI in the past decade. The adoption of this imaging technique was significantly associated with an increased probability of detecting prostate cancer.

PATIENT SUMMARY

From 2011 to 2021, we demonstrated a steady increase in the utilization of prebiopsy mpMRI among biopsy-naïve men. We also confirmed the positive impact of prebiopsy mpMRI utilization on the detection of prostate cancer.

Cancer cells employ lipid droplets to survive toxic stress

BACKGROUND

Lipid reprogramming is a known mechanism to increase the energetic demands of proliferating cancer cells to drive and support tumorigenesis and progression. Elevated lipid droplets (LDs) are a well-known alteration of lipid reprogramming in many cancers, including prostate cancer (PCa), and are associated with high tumor aggressiveness as well as therapy resistance. The mechanism of LD accumulation and specific LD functions are still not well understood; however, it has been shown that LDs can form as a protective mechanism against lipotoxicity and lipid peroxidation in the cell.

METHODS

This study investigated the significance of LDs in PCa. This was done by staining, imaging, image quantification, and flow cytometry analysis of LDs in PCa cells. Additionally, lipidomics and metabolomics experiments were performed to assess the difference of metabolites and lipids in control and treatment surviving cancer cells. Lastly, to assess clinical significance, multiple publicly available datasets were mined for LD-related data.

RESULTS

Our study demonstrated that prostate and breast cancer cells that survive 72 h of chemotherapy treatment have elevated LDs. These LDs formed in tandem with elevated reactive oxygen species levels to sequester damaged and excess lipids created by oxidative stress, which promoted cell survival. Additionally, by inhibiting diacylglycerol O-acyltransferase 1 (DGAT1) (which catalyzes triglyceride synthesis into LDs) and treating with chemotherapy simultaneously, we were able to decrease the overall amount of LDs and increase cancer cell death compared to treating with chemotherapy alone.

CONCLUSIONS

Overall, our study proposes a potential combination therapy of DGAT1 inhibitors and chemotherapy to increase cancer cell death.

Translation and validation of a lifestyle questionnaire related to prostate cancer

BACKGROUND

Valid and reliable instruments are needed to measure prostate cancer-related lifestyle changes, plan evidence-based interventions to modify lifestyle, and improve treatment outcomes. Due to the lack of appropriate instruments, this study was conducted to translate the Effects of Prostate Cancer upon Lifestyle Questionnaire (EPCLQ) into Persian and examine its psychometric properties in a sample of Iranian older adults with prostate cancer.

METHODS

This methodological study was carried out between 2021 and 2022. Initially, the EPCLQ, comprising 36 items, was translated into Persian through a meticulous translation and back-translation procedure. Subsequent steps involved the assessment of face validity, qualitative content validity, content validity index, content validity ratio, construct validity via confirmatory factor analysis, and reliability testing of the Persian version of the EPCLQ.

RESULTS

The psychometric evaluation led to the exclusion of 4 items from the EPCLQ. The refined model demonstrated satisfactory fit indices (PCFI = 0.732, PNFI = 0.696, CMIN/DF = 2.29, RMSEA = 0.072, IFI = 0.920, CFI = 0.919, and GFI = 0.971), indicating an appropriate fit of the final model. The internal consistency, as measured by Cronbach's alpha, was 0.67, and the intraclass correlation coefficient for the questionnaire was 0.938, reflecting high reliability.

CONCLUSIONS

The Persian version of the EPCLQ, now consisting of 32 items, has been validated and is reliable for assessing the impact of prostate cancer on lifestyle among older adults. Its simplicity and the clarity of the items make it suitable for use in clinical settings or during home visits for follow-up assessments.

Association of PARP inhibitor treatment on the prevalence and progression of clonal hematopoiesis in patients with advanced prostate cancer

BACKGROUND

Poly ADP-ribose polymerase (PARP) inhibitors are approved for the treatment of some men with advanced prostate cancer. Rare but serious side effects include myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The impact of PARP inhibitors on clonal hematopoiesis (CH), a potential precursor lesion associated with MDS and AML, is incompletely understood in prostate cancer. We hypothesized that PARP inhibitors would increase CH prevalence and abundance.

METHODS

We prospectively enrolled participants with advanced prostate cancer treated with PARP inhibitors. The presence of CH was assessed from leukocytes using an ultra-deep error-corrected dual unique molecular identifiers sequencing method targeting 49 genes most commonly mutated in CH and myeloid malignancies. Variant allele frequencies (VAF) of ≥0.5% were considered clinically significant. Blood samples were collected before and after PARP inhibitor treatment.

RESULTS

Ten men were enrolled; mean age of 67 years. Six patients had Gleason 7 disease, and four had Gleason ≥8 disease at diagnosis. Nine had localized disease at diagnosis, and eight had prior treatment with radiation. The mean time between pre- and post-treatment blood samples was 11 months (range 2.6-31 months). Six patients (60%) had CH identified prior to PARP inhibitor treatment, three with multiple clones. Of 11 CH clones identified in follow-up, 5 (45%) appeared or increased after treatment. DNMT3A, TET2, and PPM1D were the most common CH alterations observed. The largest post-treatment increase involved the PPM1D gene.

CONCLUSION

CH alterations are frequently found after treatment with PARP inhibitors in patients with prostate cancer and this may be one mechanism by which PARP inhibitors lead to increased risk of MDS/AML.

The Role of Extracellular Vesicles in the Treatment of Prostate Cancer

Prostate cancer (PCa) has become a public health concern in elderly men due to an ever-increasing number of estimated cases. Unfortunately, the available treatments are unsatisfactory because of a lack of a durable response, especially in advanced disease states. Extracellular vesicles (EVs) are lipid-bilayer encircled nanoscale vesicles that carry numerous biomolecules (e.g., nucleic acids, proteins, and lipids), mediating the transfer of information. The past decade has witnessed a wide range of EV applications in both diagnostics and therapeutics. First, EV-based non-invasive liquid biopsies provide biomarkers in various clinical scenarios to guide treatment; EVs can facilitate the grading and staging of patients for appropriate treatment selection. Second, EVs play a pivotal role in pathophysiological processes via intercellular communication. Targeting key molecules involved in EV-mediated tumor progression (e.g., proliferation, angiogenesis, metastasis, immune escape, and drug resistance) is a potential approach for curbing PCa. Third, EVs are promising drug carriers. Naïve EVs from various sources and engineered EV-based drug delivery systems have paved the way for the development of new treatment modalities. This review discusses the recent advancements in the application of EV therapies and highlights EV-based functional materials as novel interventions for PCa.

A practical guide for the use of apalutamide for non-metastatic castration-resistant prostate cancer in Australia

Studies of patients with castrate-resistant prostate cancer at high risk of developing overt metastases but with no current evidence of evaluable disease on computed tomography or bone scan non-metastatic castrate-resistant prostrate cancer have demonstrated increased metastasis-free survival and overall survival following treatment with the next-generation oral anti-androgen apalutamide (in addition to therapies that aim to lower testosterone to castrate levels) or luteinizing hormone-releasing hormone antagonist or surgical castration. Patients receiving apalutamide can be managed by medical oncologists, radiation oncologists, or urologists, preferably as part of a multidisciplinary team. However, the importance of additional safety monitoring for significant adverse effects and drug interactions should not be underestimated. The toxicities of apalutamide are manageable with experience and should be managed proactively to minimize their impact on patients. Monitoring of patients for apalutamide-specific toxicities, including skin rash, hypothyroidism, and QT prolongation should be carried out regularly, particularly in the first few months following initiation. Monitoring should continue alongside monitoring for toxicities of androgen deprivation, including cardiovascular risk, hot flashes, weight gain, bone health, muscle wasting, and diabetic risk. This review is a practical guide to the use of apalutamide describing the management of patients including dosing and administration, toxicities, potential drug interactions, and safety monitoring requirements.

AAT resistance-related AC007405.2 and AL354989.1 as novel diagnostic and prognostic markers in prostate cancer

OBJECTIVE

Prostate cancer (PCa) is the second disease threatening men's health, and anti-androgen therapy (AAT) is a primary approach for treating this condition. Increasing evidence suggests that long non-coding RNAs (lncRNAs) play crucial roles in the development of PCa and the process of AAT resistance. The objective of this study is to utilize bioinformatics methods to excavate lncRNAs association with AAT resistance and investigate their biological functions.

METHODS

AAT resistance-related risk score model (ARR-RSM) was established by multivariate Cox analysis. Paired clinical tissue samples of 36 PCa patients and 42 blood samples from patients with PSA over 4 ng/ml were collected to verify the ARR-RSM. In vitro, RT-qPCR, CCK-8 and clone formation assays were displayed to verify the expression and function of AL354989.1 and AC007405.2.

RESULTS

Pearson correlation analysis identified 996 lncRNAs were associated with AAT resistance (ARR-LncRs). ARR-RSM was established using multivariate Cox regression analysis, and PCa patients were divided into high-risk and low-risk groups. High-risk patients showed increased expression of AL354989.1 and AC007405.2 had poorer prognoses. The high-risk score correlated with advanced T-stage and N-stage. The AUC of ARR-RSM outperformed tPSA in diagnosing PCa. Silencing of AC007405.2 and AL354989.1 inhibited PCa cells proliferation and AAT resistance.

CONCLUSIONS

In this study, we have discovered the clinical significance of AC007405.2 and AL354989.1 in predicting the prognosis and diagnosing PCa patients. Furthermore, we have confirmed their correlation with various clinical features. These findings provide potential targets for PCa treatment and a novel diagnostic and predictive indicator for precise PCa diagnosis.

A Systematic Review on the Diagnostic Value of Fibroblast Activation Protein Inhibitor PET/CT in Genitourinary Cancers

In contemporary oncologic diagnostics, molecular imaging modalities are pivotal for precise local and metastatic staging. Recent studies identified fibroblast activation protein as a promising target for molecular imaging across various malignancies. Therefore, we aimed to systematically evaluate the current literature on the utility of fibroblast activation protein inhibitor (FAPI) PET/CT for staging patients with genitourinary malignancies. Methods: A systematic Embase and Medline search was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) process, on August 1, 2023. Relevant publications reporting on the diagnostic value of FAPI PET/CT in genitourinary malignancies were identified and included. Studies were critically reviewed using a modified version of a tool for quality appraisal of case reports. Study results were summarized using a narrative approach. Results: We included 22 retrospective studies with a cumulative total of 69 patients, focusing on prostate cancer, urothelial carcinoma of the bladder and of the upper urinary tract, renal cell carcinoma, and testicular cancer. FAPI PET/CT was able to visualize both local and metastatic disease, including challenging cases such as prostate-specific membrane antigen (PSMA)-negative prostate cancer. Compared with radiolabeled 18F-FDG and PSMA PET/CT, FAPI PET/CT showed heterogeneous performance. In selected cases, FAPI PET/CT demonstrated superior tumor visualization (i.e., better tumor-to-background ratios and visualization of small tumors or metastatic deposits visible in no other way) over 18F-FDG PET/CT in detecting local or metastatic disease, whereas comparisons with PSMA PET/CT showed both superior and inferior performances. Challenges in FAPI PET/CT arise from physiologic urinary excretion of most FAPI radiotracers, hindering primary-lesion visualization in the bladder and upper urinary tract, despite generally providing high tumor-to-background ratios. Conclusion: The current findings suggest that FAPI PET/CT may hold promise as a future tool to aid clinicians in detecting genitourinary malignancies. Given the substantial heterogeneity among the included studies and the limited number of patients, caution in interpreting these findings is warranted. Subsequent prospective and comparative investigations are anticipated to delve more deeply into this innovative imaging modality and elucidate its role in clinical practice.

Development of a Visually Calculated SUVmean (HIT Score) on Screening PSMA PET/CT to Predict Treatment Response to 177Lu-PSMA Therapy: Comparison with Quantitative SUVmean and Patient Outcomes

177Lu-PSMA therapy is an effective treatment in patients with metastatic castration-resistant prostate cancer. SUVmean is a valuable screening biomarker to assess the suitability for 177Lu-PSMA therapy but requires quantitative software. This study aims to develop a simple, clinically applicable prostate-specific membrane antigen PET/CT score that encompasses the elements of SUVmean without requiring additional quantification. Methods: Datasets from ethics-approved trials of patients with metastatic castration-resistant prostate cancer after androgen receptor signaling inhibition and taxane chemotherapy (or unfit for taxane), who were treated with 177Lu-PSMA-617 and 177Lu-PSMA I&T with a pretreatment screening with 68Ga-PSMA-11 PET/CT, and clinical outcome data, including a prostate-specific antigen (PSA) 50% response rate (PSA50), PSA progression-free survival (PSA-PFS), and overall survival (OS), were included. The screening 68Ga-PSMA-11 PET/CT of all participants was analyzed both semiquantitatively and visually. Semiquantitative analysis was used to derive the SUVmean Visual analysis of the 68Ga-PSMA-11 PET/CT images involved a binary visual heterogeneity assessment (homogeneous or heterogeneous), allocating a tumor SUVmax range (<15, 15-29, 30-49, 50-79, or ≥80). A 4-category score incorporating both heterogeneity and intensity of tumors (HIT) was then developed as a combination of heterogeneity and intensity (SUVmax range). The SUVmax was less than 15 for score 1, 15-79 with heterogeneous intensity for score 2, 15-79 with homogeneous intensity for score 3, and 80 or greater for score 4. This score was evaluated according to clinical outcomes (PSA50, PSA-PFS, and OS) and compared with SUVmean Results: Data from 139 participants were analyzed. In total, 75 (54%) patients achieved a PSA50 with a median PSA-PFS of 5.5 mo (95% CI, 4.1-6.0 mo) and an OS of 13.5 mo (95% CI, 11.1-17.9 mo). SUVmean was associated with PSA50 and survival outcomes when analyzed as a continuous variable or as quartiles. The PSA50 for HIT scores 1-4 was 0%, 39%, 65%, and 76%, respectively. The HIT score was strongly related to PSA-PFS and OS (log-rank test, P < 0.001 and P = 0.002). The median PSA-PFS for HIT scores 1-4 was 1.0, 4.1, 6.0, and 8.5, respectively, and the median OS was 7.6, 12.0, 18.5, and 16.9 mo, respectively. Cohen κ between readers for the HIT score was 0.71. Conclusion: A prostate-specific membrane antigen PET/CT score incorporating HIT derived from tools on a standard PET workstation is comparable with quantitative SUVmean as a prognostic tool following 177Lu-PSMA therapy.

Carboplatin in Patients With Metastatic Castration-Resistant Prostate Cancer Harboring Somatic or Germline Homologous Recombination Repair Gene Mutations: Phase II Single-Arm Trial

BACKGROUND

Approximately 20%-25% of patients with metastatic castration-resistant prostate cancer (mCRPC) harbor a deleterious germline or somatic mutation in the homologous recombination repair (HRR) pathway genes, which is involved in the repair of double-stranded DNA damage. Half of these mutations are germline, while the remaining are exclusively somatic. While polyadenosine 5'diphosphoribose [poly (ADP-ribose)] polymerase inhibitors, such as olaparib and rucaparib, are effective in this subgroup, their widespread use is limited due to the associated high cost, especially in resource-constrained settings. Notably, platinum agents like carboplatin have exquisite sensitivity to cells with defective DNA repair machinery. Carboplatin, a conventional, inexpensive chemotherapeutic agent, offers a potential alternative treatment in such patients. Several retrospective small case series support this hypothesis. However, there are no prospective clinical trials of carboplatin in patients with mCRPC with HRR mutations.

OBJECTIVE

The primary objective is to assess the objective response rate of 3 weekly carboplatin treatments in patients with mCRPC harboring deleterious mutations in the HRR pathway genes and previously treated with a taxane or a novel antiandrogen agent. The secondary objectives include progression-free survival, health-related quality of life, and safety profile of carboplatin.

METHODS

Patients diagnosed with mCRPC harboring HRR pathway mutations previously treated with docetaxel or novel antiandrogen agents (abiraterone, enzalutamide, apalutamide, or darolutamide) or both will be eligible. Genes involved directly or indirectly in the HRR pathway will be tested. In this single-arm phase II study, we will screen approximately 200 patients to enroll 49 patients, and carboplatin (dosing at the area under curve=5) will be administered every 3 weeks until progression or intolerable side effects. The primary end point will be assessed as the proportion of patients with a reduction of serum prostate-specific antigen by more than 50% from enrollment. Secondary outcomes include progression-free survival-soft-tissue disease progression (by response evaluation criteria in solid tumors, version 1.1, and bone lesion progression using Prostate Cancer Clinical Trials Working Group 3 criteria), health-related quality of life during carboplatin treatment using the Functional Assessment of Cancer Therapy-Prostate questionnaire and the European Organisation for Research and Treatment of Cancer questionnaire and safety profile of carboplatin (National Cancer Institute's Common Terminology Criteria for Adverse Events version 5.0).

RESULTS

The trial started enrollment in September 2023. This trial is ongoing, and 12 patients have been recruited to date. All 49 participants will be enrolled according to plan.

CONCLUSIONS

This prospective phase II trial represents a critical step toward addressing the therapeutic gap in patients with mCRPC harboring HRR pathway mutations, particularly in demographic regions with limited access to poly (ADP-ribose) polymerase inhibitors. Outcomes from this study will inform clinical practice and guide future phase III randomized trials, ultimately improving patient outcomes globally.

TRIAL REGISTRATION

Clinical Trials Registry of India CTRI/2023/04/051507; https://ctri.nic.in/Clinicaltrials/pmaindet2.php?EncHid=Njc0NjU=&Enc=&userName=.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54086.

FOXA1 regulates ribosomal RNA transcription in prostate cancer

BACKGROUND

Ribosome biogenesis is excessively activated in tumor cells, yet it is little known whether oncogenic transcription factors (TFs) are involved in the ribosomal RNA (rRNA) transactivation.

METHODS

Nucleolar proteomics data and large-scale immunofluorescence were re-analyzed to jointly identify the proteins localized at nucleolus. RNA-Seq data of five prostate cancer (PCa) cohorts were combined and integrated with multi-dimensional data to define the upregulated nucleolar TFs in PCa tissues. Then, ChIP-Seq data of PCa cell lines and two PCa clinical cohorts were re-analyzed to reveal the TF binding patterns at ribosomal DNA (rDNA) repeats. The TF binding at rDNA was validated by ChIP-qPCR. The effect of the TF on rRNA transcription was determined by rDNA luciferase reporter, nascent RNA synthesis, and global protein translation assays.

RESULTS

In this study, we reveal the role of oncogenic TF FOXA1 in regulating rRNA transcription within nucleolar organization regions. By analyzing human TFs in prostate cancer clinical datasets and nucleolar proteomics data, we identified that FOXA1 is partially localized in the nucleolus and correlated with global protein translation. Our extensive FOXA1 ChIP-Seq analysis provides robust evidence of FOXA1 binding across rDNA repeats in prostate cancer cell lines, primary tumors, and castration-resistant variants. Notably, FOXA1 occupancy at rDNA repeats correlates with histone modifications associated with active transcription, namely H3K27ac and H3K4me3. Reducing FOXA1 expression results in decreased transactivation at rDNA, subsequently diminishing global protein synthesis.

CONCLUSIONS

Our results suggest FOXA1 regulates aberrant ribosome biogenesis downstream of oncogenic signaling in prostate cancer.

Current state of theranostics in metastatic castrate-resistant prostate cancer

Prostate cancer remains one of the leading causes of cancer-related death in the world. There have been significant advances in chemotherapy, hormonal therapy and targeted therapy options for patients with castrate-resistant disease. However, these systemic treatments are often associated with unwanted toxicities. Targeted therapy with radiopharmaceuticals has become of key interest to limit systemic toxicity and provides a more precision oncology approach to treatment. Strontium-89, Samarium-153 EDTMP and Radium-223 have been trialled with mixed results. Strontium-89 and Samarium-153 EDTMP have shown benefits in palliating metastatic bone pain but with no impact on survival outcomes. Early therapeutic radiopharmaceuticals targeting PSMA that were developed were beta-emitting agents, but recently alpha-emitting agents are being investigated as potentially superior options. Radium-223 is the first alpha-particle emitter therapeutic agent approved by the FDA, with phase III trial evidence showing benefits in overall survival and delay in symptomatic skeletal events for patients. Recently, 177-Lutetium-PSMA-617 has demonstrated significant survival advantages in pre-treated metastatic castrate-resistant cancer patients in a number of phase II and III studies. Furthermore, 225-Actinium-PSMA-617 also showed promise even in patients pre-treated with 177-Lutetium-PSMA-617. Hence, there has been an explosion of radiopharmaceutical treatment options for patients with prostate cancer. This review explores past and current theranostic capacities in the radiopharmaceutical treatment of metastatic castrate-resistant prostate cancer.

Androgen Receptor and Estrogen Receptor Variants in Prostate and Breast Cancers

The androgen receptor (AR) and estrogen receptor alpha (ERα) are steroid receptor transcription factors with critical roles in the development and progression of prostate and breast cancers. Advances in the understanding of mechanisms underlying the ligand-dependent activation of these transcription factors have contributed to the development of small molecule inhibitors that block AR and ERα actions. These inhibitors include competitive antagonists and degraders that directly bind the ligand binding domains of these receptors, luteinizing hormone releasing hormone (LHRH) analogs that suppress gonadal synthesis of testosterone or estrogen, and drugs that block specific enzymes required for biosynthesis of testosterone or estrogen. However, resistance to these therapies is frequent, and is often driven by selection for tumor cells with alterations in the AR or ESR1 genes and/or alternatively spliced AR or ESR1 mRNAs that encode variant forms AR or ERα. While most investigations involving AR have been within the context of prostate cancer, and the majority of investigations involving ERα have been within the context of breast cancer, important roles for AR have been elucidated in breast cancer, and important roles for ERα have been elucidated in prostate cancer. Here, we will discuss the roles of AR and ERα in breast and prostate cancers, outline the effects of gene- and mRNA-level alterations in AR and ESR1 on progression of these diseases, and identify strategies that are being developed to target these alterations therapeutically.

Tumor promoting effect of spheroids in an orthotopic prostate cancer mouse model

In this study, we aimed to establish a technique for intraprostatic implantation of prostate cancer (PCa) spheroids and to identify the impact of three-dimensional organization of PCa cells on tumor progression and metastasis in a representative in vivo model. 40,000 LNCaP cells were implanted into the prostate of immunodeficient SCID mice either as single cells (n = 8) or as preformed 3D spheroids (n = 8). For a follow up of 20 weeks, tumor growth was monitored by serum PSA and high-resolution 3D ultrasonography. Eventually, animals were sacrificed and autopsied. The organ dissects were analyzed for the presence of metastases by histology (H&E) and immunohistochemistry (AMACR, AR, Ki-67, CK5, CK8, E-Cadherin, Vimentin). Solid intraprostatic tumors developed in 50% of mice after spheroid implantation and in 50% of mice after implantation of a single cells. Primary tumors of LNCaP spheroids evolved earlier, exhibiting a shorter tumor doubling time whilst developing larger tumor volumes, which was reflected by a higher immunohistochemical expression of Ki-67 and AR, too. Spheroid tumors established lung and lymph node metastases in 75% of mice, in contrast to 50% of mice after single cell implantation. Our technique enables a variety of studies regarding the influence of the tumor microenvironment on PCa progression.

Harnessing artificial intelligence for prostate cancer management

Prostate cancer (PCa) is a common malignancy in males. The pathology review of PCa is crucial for clinical decision-making, but traditional pathology review is labor intensive and subjective to some extent. Digital pathology and whole-slide imaging enable the application of artificial intelligence (AI) in pathology. This review highlights the success of AI in detecting and grading PCa, predicting patient outcomes, and identifying molecular subtypes. We propose that AI-based methods could collaborate with pathologists to reduce workload and assist clinicians in formulating treatment recommendations. We also introduce the general process and challenges in developing AI pathology models for PCa. Importantly, we summarize publicly available datasets and open-source codes to facilitate the utilization of existing data and the comparison of the performance of different models to improve future studies.

Population-based study of disease trajectory after radical treatment for high-risk prostate cancer

OBJECTIVES

To investigate long-term disease trajectories among men with high-risk localized or locally advanced prostate cancer (HRLPC) treated with radical radiotherapy (RT) or radical prostatectomy (RP).

MATERIAL AND METHODS

Men diagnosed with HRLPC in 2006-2020, who received primary RT or RP, were identified from the Prostate Cancer data Base Sweden (PCBaSe) 5.0. Follow-up ended on 30 June 2021. Treatment trajectories and risk of death from prostate cancer (PCa) or other causes were assessed by competing risk analyses using cumulative incidence for each event.

RESULTS

In total, 8317 men received RT and 4923 men underwent RP. The median (interquartile range) follow-up was 6.2 (3.6-9.5) years. After RT, the 10-year risk of PCa-related death was 0.13 (95% confidence interval [CI] 0.12-0.14) and the risk of death from all causes was 0.32 (95% CI 0.31-0.34). After RP, the 10-year risk of PCa-related death was 0.09 (95% CI 0.08-0.10) and the risk of death from all causes was 0.19 (95% CI 0.18-0.21). The 10-year risks of androgen deprivation therapy (ADT) as secondary treatment were 0.42 (95% CI 0.41-0.44) and 0.21 (95% CI 0.20-0.23) after RT and RP, respectively. Among men who received ADT as secondary treatment, the risk of PCa-related death at 10 years after initiation of ADT was 0.33 (95% CI 030-0.36) after RT and 0.27 (95% CI 0.24-0.30) after RP.

CONCLUSION

Approximately one in 10 men with HRLPC who received primary RT or RP had died from PCa 10 years after diagnosis. Approximately one in three men who received secondary ADT, an indication of PCa progression, died from PCa 10 years after the start of ADT. Early identification and aggressive treatment of men with high risk of progression after radical treatment are warranted.

Dietary Fiber Intake and Risk of Advanced and Aggressive Forms of Prostate Cancer: A Pooled Analysis of 15 Prospective Cohort Studies

BACKGROUND

Evidence of an association between dietary fiber intake and risk of advanced and aggressive forms of prostate cancer (PC) and PC mortality is limited.

OBJECTIVE

To examine associations between intakes of dietary fiber overall and by food source and risk of advanced and aggressive forms of PC.

DESIGN

Pooled analysis of the primary data in 15 cohorts in three continents. Baseline dietary fiber intake was assessed using a validated food frequency questionnaire or diet history in each study.

PARTICIPANTS/SETTING

842,149 men were followed for up to 9-22 years between 1985-2009 across studies.

MAIN OUTCOME MEASURES

The primary outcome measures were advanced (stage T4, N1, or M1 or PC mortality), advanced restricted (excluded men with missing stage and those with localized PC who died of PC), high grade (Gleason score ≥8 or poorly differentiated/undifferentiated) PC, and PC mortality.

STATISTICAL ANALYSIS

Study-specific multivariable hazard ratios (MVHR) were calculated using Cox proportional hazards regression and pooled using random effects models.

RESULTS

Intake of dietary fiber overall, from fruits, and from vegetables was not associated with risk of advanced (n=4,863), advanced restricted (n=2,978), or high-grade PC (n=9,673) or PC mortality (n=3,097). Dietary fiber intake from grains was inversely associated with advanced PC (MVHR comparing the highest vs. lowest quintile=0.84, 95% confidence interval [CI] 0.76-0.93), advanced restricted PC (MVHR=0.85, 95%CI 0.74-0.97), and PC mortality (MVHR=0.78, 95%CI 0.68-0.89); statistically significant trends were noted for each of these associations (p≤0.03), while a null association was observed for high grade PC for the same comparison (MVHR=1.00, 95%CI 0.93-1.07). The comparable results were 1.06 (95%CI 1.01-1.10, p-value, test for trend=0.002) for localized (n=35,199) and 1.05 (95%CI 0.99-1.11, , p-value, test for trend=0.04) for low/intermediate grade (n=34,366) PC.

CONCLUSIONS

Weak nonsignificant associations were observed between total dietary fiber intake and risk of advanced forms of PC, high grade PC, and PC mortality. High dietary fiber intake from grains was associated with a modestly lower risk of advanced forms of PC and PC mortality.

Updates on Overcoming Bicalutamide Resistance: A Glimpse into Resistance to a Novel Antiandrogen

The standard androgen deprivation therapy for advanced prostate cancer includes the use of bicalutamide, which is a well-known antagonist of androgen receptors. Despite numerous benefits of the drugs in prostate cancer treatment, there is always a risk of developing a resistant phenotype, which paves the way for a more aggressive and low-survival type of prostate cancer. Over the years, many studies have investigated the candidate mechanisms of such resistance and have managed to find possible therapeutic solutions. In this Review, we shed light on the heterogeneous dynamics of progression to resistance against bicalutamide treatment, referring to the most recent studies and the approaches that have been so far discussed. This Review tries to offer a deep and comprehensive understanding about how the resistant cells become sensitive to the drug and what corresponding pathways lead to an appropriate solution for the antiandrogen resistance challenge.

An orthotopic prostate cancer model for new treatment development using syngeneic or patient-derived tumors

BACKGROUND

There are limited preclinical orthotopic prostate cancer models due to the technical complexity of surgical engraftment and tracking the tumor growth in the mouse prostate gland. Orthotopic xenografts recapitulate the tumor microenvironment, tumor stromal interactions, and clinical behavior to a greater extent than xenografts grown at subcutaneous or intramuscular sites.

METHODS

This study describes a novel micro-surgical technique for orthotopically implanting intact tumors pieces from cell line derived (transgenic adenocarcinoma mouse prostate [TRAMP]-C2) or patient derived (neuroendocrine prostate cancer [NEPC]) tumors in the mouse prostate gland and monitoring tumor growth using magnetic resonance (MR) imaging.

RESULTS

The TRAMP-C2 tumors grew rapidly to a predetermined endpoint size of 10 mm within 3 weeks, whereas the NEPC tumors grew at a slower rate over 7 weeks. The tumors were readily detected by MR and confidently identified when they were approximately 2-3 mm in size. The tumors were less well-defined on CT. The TRAMP-C2 tumors were characterized by amorphous sheets of poorly differentiated cells similar to a high-grade prostatic adenocarcinoma and frequent macroscopic peritoneal and lymph node metastases. In contrast, the NEPC's displayed a neuroendocrine morphology with polygonal cells arranged in nests and solid sheets and high count. There was a local invasion of the bladder and other adjacent tissues but no identifiable metastases. The TRAMP-C2 tumors were more hypoxic than the NEPC tumors.

CONCLUSIONS

This novel preclinical orthotopic prostate cancer mouse model is suitable for either syngeneic or patient derived tumors and will be effective in developing and advancing the current selection of treatments for patients with prostate cancer.

Manzamine A reduces androgen receptor transcription and synthesis by blocking E2F8-DNA interactions and effectively inhibits prostate tumor growth in mice

The androgen receptor (AR) is the main driver in the development of castration-resistant prostate cancer, where the emergence of AR splice variants leads to treatment-resistant disease. Through detailed molecular studies of the marine alkaloid manzamine A (MA), we identified transcription factor E2F8 as a previously unknown regulator of AR transcription that prevents AR synthesis in prostate cancer cells. MA significantly inhibited the growth of various prostate cancer cell lines and was highly effective in inhibiting xenograft tumor growth in mice without any pathophysiological perturbations in major organs. MA suppressed the full-length AR (AR-FL), its spliced variant AR-V7, and the AR-regulated prostate-specific antigen (PSA; also known as KLK3) and human kallikrein 2 (hK2; also known as KLK2) genes. RNA sequencing (RNA-seq) analysis and protein modeling studies revealed E2F8 interactions with DNA as a potential novel target of MA, suppressing AR transcription and its synthesis. This novel mechanism of blocking AR biogenesis via E2F8 may provide an opportunity to control therapy-resistant prostate cancer over the currently used AR antagonists designed to target different parts of the AR gene.