Surgical management of high-risk, localized prostate cancer

Nanotherapeutics for prostate cancer treatment: A comprehensive review

Prostate cancer (PCa) is the most prevalent solid organ malignancy and seriously affects male health. The adverse effects of prostate cancer therapeutics can cause secondary damage to patients. Nanotherapeutics, which have special targeting abilities and controlled therapeutic release profiles, may serve as alternative agents for PCa treatment. At present, many nanotherapeutics have been developed to treat PCa and have shown better treatment effects in animals than traditional therapeutics. Although PCa nanotherapeutics are highly attractive, few successful cases have been reported in clinical practice. To help researchers design valuable nanotherapeutics for PCa treatment and avoid useless efforts, herein, we first reviewed the strategies and challenges involved in prostate cancer treatment. Subsequently, we presented a comprehensive review of nanotherapeutics for PCa treatment, including their targeting methods, controlled release strategies, therapeutic approaches and mechanisms. Finally, we proposed the future prospects of nanotherapeutics for PCa treatment.

Molecular features of prostate cancer after neoadjuvant therapy in the phase 3 CALGB 90203 trial

BACKGROUND

The phase 3 CALGB 90203 (Alliance) trial evaluated neoadjuvant chemohormonal therapy for high-risk localized prostate cancer before radical prostatectomy. We dissected the molecular features of post-treated tumors with long-term clinical outcomes to explore mechanisms of response and resistance to chemohormonal therapy.

METHODS

We evaluated 471 radical prostatectomy tumors, including 294 samples from 166 patients treated with 6 cycles of docetaxel plus androgen deprivation therapy before radical prostatectomy and 177 samples from 97 patients in the control arm (radical prostatectomy alone). Targeted DNA sequencing and RNA expression of tumor foci and adjacent noncancer regions were analyzed in conjunction with pathologic changes and clinical outcomes.

RESULTS

Tumor fraction estimated from DNA sequencing was significantly lower in post-treated tumor tissues after chemohormonal therapy compared with controls. Higher tumor fraction after chemohormonal therapy was associated with aggressive pathologic features and poor outcomes, including prostate-specific antigen-progression-free survival. SPOP alterations were infrequently detected after chemohormonal therapy, while TP53 alterations were enriched and associated with shorter overall survival. Residual tumor fraction after chemohormonal therapy was linked to higher expression of androgen receptor-regulated genes, cell cycle genes, and neuroendocrine genes, suggesting persistent populations of active prostate cancer cells. Supervised clustering of post-treated high-tumor-fraction tissues identified a group of patients with elevated cell cycle-related gene expression and poor clinical outcomes.

CONCLUSIONS

Distinct recurrent prostate cancer genomic and transcriptomic features are observed after exposure to docetaxel and androgen deprivation therapy. Tumor fraction assessed by DNA sequencing quantifies pathologic response and could be a useful trial endpoint or prognostic biomarker. TP53 alterations and high cell cycle transcriptomic activity are linked to aggressive residual disease, despite potent chemohormonal therapy.

Surgical Management and Considerations for Patients with Localized High-Risk Prostate Cancer

OPINION STATEMENT

Localized high-risk (HR) prostate cancer (PCa) is a heterogenous disease state with a wide range of presentations and outcomes. Historically, non-surgical management with radiotherapy and androgen deprivation therapy was the treatment option of choice. However, surgical resection with radical prostatectomy (RP) and pelvic lymph node dissection (PLND) is increasingly utilized as a primary treatment modality for patients with HRPCa. Recent studies have demonstrated that surgery is an equivalent treatment option in select patients with the potential to avoid the side effects from androgen deprivation therapy and radiotherapy combined. Advances in imaging techniques and biomarkers have also improved staging and patient selection for surgical resection. Advances in robotic surgical technology grant surgeons various techniques to perform RP, even in patients with HR disease, which can reduce the morbidity of the procedure without sacrificing oncologic outcomes. Clinical trials are not only being performed to assess the safety and oncologic outcomes of these surgical techniques, but to also evaluate the role of surgical resection as a part of a multimodal treatment plan. Further research is needed to determine the ideal role of surgery to potentially provide a more personalized and tailored treatment plan for patients with localized HR PCa.

Androgen deprivation therapy plus abiraterone or docetaxel as neoadjuvant therapy for very-high-risk prostate cancer: a pooled analysis of two phase II trials

Objective: The study aimed to compare the efficacy and safety of androgen deprivation therapy (ADT) with abiraterone or docetaxel versus ADT alone as neoadjuvant therapy in patients with very-high-risk localized prostate cancer. Methods: This was a pooled analysis of two single-center, randomized, controlled, phase II clinical trials (ClinicalTrials.gov: NCT04356430 and NCT04869371) conducted from December 2018 to March 2021. Eligible participants were randomly assigned to the intervention (ADT plus abiraterone or docetaxel) and control (ADT alone) groups at a 2:1 ratio. Efficacy was evaluated by pathological complete response (pCR), minimal residual disease (MRD), and 3-year biochemical progression-free survival (bPFS). Safety was also analyzed. Results: The study included 42 participants in the ADT group, 47 in the ADT plus docetaxel group, and 48 in the ADT plus abiraterone group. A total of 132 (96.4%) participants had very-high-risk prostate cancer, and 108 (78.8%) had locally advanced disease. The ADT plus docetaxel group (28%) and ADT plus abiraterone group (31%) had higher rates of pCR or MRD (p = 0.001 and p < 0.001) compared with the ADT group (2%). The 3-year bPFS was 41.9% (95% CI: 26.6-57.2), 51.1% (95% CI: 36.8-65.4), and 61.2% (95% CI: 45.5-76.9), respectively. Significant difference was found among groups in terms of bPFS (p = 0.037). Conclusion: Compared with ADT alone, neoadjuvant therapy with ADT plus docetaxel or abiraterone could achieve better pathological outcomes (pCR or MRD) for very-high-risk localized prostate cancer. The ADT plus abiraterone group showed longer bPFS than ADT alone. The combination regimens were tolerable.

In Response to Precision Medicine: Current Subcellular Targeting Strategies for Cancer Therapy

Emerging as a potent anticancer treatment, subcellular targeted cancer therapy has drawn increasing attention, bringing great opportunities for clinical application. Here, two targeting strategies for four main subcellular organelles (mitochondria, lysosome, endoplasmic reticulum, and nucleus), including molecule- and nanomaterial (inorganic nanoparticles, micelles, organic polymers, and others)-based targeted delivery or therapeutic strategies, are summarized. Phototherapy, chemotherapy, radiotherapy, immunotherapy, and "all-in-one" combination therapy are among the strategies covered in detail. Such materials are constructed based on the specific properties and relevant mechanisms of organelles, enabling the elimination of tumors by inducing dysfunction in the corresponding organelles or destroying specific structures. The challenges faced by organelle-targeting cancer therapies are also summarized. Looking forward, a paradigm for organelle-targeting therapy with enhanced therapeutic efficacy compared to current clinical approaches is envisioned.

Prevalence of tumour-infiltrating CD103+ cells identifies therapeutic-sensitive prostate cancer with poor clinical outcome

BACKGROUND

The clinical significance and immune correlation of CD103+ cells in prostate cancer (PCa) remain explored.

METHODS

In total, 1080 patients with PCa underwent radical prostatectomy from three cohorts were enrolled for retrospective analysis. Tumour microarrays were constructed and fresh tumour samples were analysed by flow cytometry.

RESULTS

High CD103+ cell infiltration correlated with reduced biochemical recurrence (BCR)-free survival in PCa. Adjuvant hormone therapy (HT) prolonged the BCR-free survival for high-risk node-negative diseases with CD103+ cell abundance. CD103+ cell infiltration correlated with less cytotoxic expression and increased infiltration of CD8+ and CD4+ T cells, M1 macrophages and mast cells in PCa. Intratumoral CD8+ T cell was the predominant source of CD103, and the CD103+ subset of CD8+ T cells was featured with high IL-10, PD-1 and CTLA-4 expression. Tumour-infiltrating CD103+ CD8+ T cells exerted anti-tumour function when treated with HT ex vivo.

DISCUSSION

CD103+ cell infiltration predicted BCR-free survival and response to adjuvant HT in PCa. CD103+ cell infiltration correlated with an enriched but immune-evasive immune landscape. The study supported a model that CD103 expression conferred negative prognostic impact and immunosuppressive function to tumour-infiltrating CD8+ T cells, while the CD103+ CD8+ T cells exhibited a powerful anti-tumour immunity with response to HT.

Modular Smart Molecules for PSMA-Targeted Chemotherapy

New targeted chemotherapeutics are urgently needed to minimize off-target toxicity and reduce the high-mortality rate associated with metastatic prostate cancer. Herein, we report on the modular synthesis, pharmacokinetics, and efficacy of two small-molecule-drug conjugates (SMDC) targeted to prostate-specific membrane antigen (PSMA) incorporating either: (i) a cathepsin-B-cleavable valine-citrulline (Val-Cit), or (ii) an acid-cleavable phosphoramidate linker. Crucial components used in the design of the conjugates include: (i) CTT1298, a nanomolar affinity ligand that binds irreversibly to PSMA and has proven in past studies to rapidly internalize and shuttle payloads into PSMA-expressing prostate cancer cells, (ii) MMAE, a known potent cytotoxic payload, and (iii) an albumin-binder, proven to improve residence time of drug conjugates. At dose of 0.8 mg/kg (∼250 nmol/kg), the two SMDCs showed significant efficacy in a PSMA(+) PC3-PIP mouse model of human prostate cancer compared with controls, without inducing systemic toxicity. Though localization of the SMDCs was observed in tissues apart from the tumor, release of MMAE was observed predominantly in tumor tissue, at levels that were 2-3 orders of magnitude higher than non-target tissues. Furthermore, SMDC2, which incorporated a novel pH-responsive phosporamidate linker, demonstrated significantly improved efficacy over SMDC1 that has a Val-Cit linker, with a 100% survival over 90 days and 4 out of 8 mice showing complete tumor growth inhibition after 6 weekly doses of 0.8 mg/kg (244 nmol/kg). Our findings demonstrate the potential of irreversible PSMA inhibitors combined with pH-responsive linkers as a way to specifically deliver chemotherapeutic drugs to prostate cancer tumors with minimal toxicity.

Frailty Assessment for Outcome Prediction of Patients With Prostate Cancer Receiving Radical Prostatectomy: A Meta-Analysis of Cohort Studies

A meta-analysis was conducted to investigate the association between frailty and postoperative complications in patients with prostate cancer following radical prostatectomy. A systematic search of PubMed, Embase, and Web of Science was conducted for relevant cohort studies. A random-effect model was chosen to combine the results. Five cohort studies including 171,929 patients were included. Results showed that patients with frailty had higher risk of severe postoperative complications (Clavien-Dindo IV complications, risk ratio [RR]: 1.87, 95% confidence interval [CI]: 1.67 to 2.10, p < .001; I² = 18%) and all-cause mortality (RR: 2.89, 95% CI: 1.86 to 4.50, p < 0.001; I² = 18%). Subgroup analyses showed consistent results in patients receiving open and robot-assisted radical prostatectomy, and also in studies with univariate and multivariate analyses. In conclusion, preoperative frailty may be a predictor of severe postoperative complications and all-cause mortality of patients with prostate cancer following radical prostatectomy.

Precision Targets for Intercepting the Lethal Progression of Prostate Cancer: Potential Avenues for Personalized Therapy

Organ-confined prostate cancer of low-grade histopathology is managed with radiation, surgery, active surveillance, or watchful waiting and exhibits a 5-year overall survival (OS) of 95%, while metastatic prostate cancer (PCa) is incurable, holding a 5-year OS of 30%. Treatment options for advanced PCa-metastatic and non-metastatic-include hormone therapy that inactivates androgen receptor (AR) signaling, chemotherapy and genome-targeted therapy entailing synthetic lethality of tumor cells exhibiting aberrant DNA damage response, and immune checkpoint inhibition (ICI), which suppresses tumors with genomic microsatellite instability and/or deficient mismatch repair. Cancer genome sequencing uncovered novel somatic and germline mutations, while mechanistic studies are revealing their pathological consequences. A microRNA has shown biomarker potential for stratifying patients who may benefit from angiogenesis inhibition prior to ICI. A 22-gene expression signature may select high-risk localized PCa, which would not additionally benefit from post-radiation hormone therapy. We present an up-to-date review of the molecular and therapeutic aspects of PCa, highlight genomic alterations leading to AR upregulation and discuss AR-degrading molecules as promising anti-AR therapeutics. New biomarkers and druggable targets are shaping innovative intervention strategies against high-risk localized and metastatic PCa, including AR-independent small cell-neuroendocrine carcinoma, while presenting individualized treatment opportunities through improved design and precision targeting.

Association Between Pre-Treatment and Post-Treatment 3-Month Red Cell Distribution Width with Three-Year Prognosis of Prostate Cancer

Purpose

Red cell distribution width (RDW), an inflammation biomarker, has been linked to poor outcomes in patients with different types of cancers. The present study aimed to investigate the relationship between pre-/post-treatment 3-month RDW levels and changes in RDW with 3-year prognosis of prostate cancer.

Patients and Methods

A total of 348 patients with prostate cancer were recruited between June 1, 2012 and June 1, 2017 and were followed up for at least 3 years. RDW was measured with the Mindray BC-6800Plus automatic blood counting system at pre- and post-treatment 3-month. Demographic and clinical information of the participants were also collected. The overall survival (OS) and cancer-specific survival (CSS) were analyzed using the Kaplan–Meier method. Cox regression and competing risk regression analyses were performed.

Results

During the follow-up period, 51 (14.66%) deaths occurred. The levels of pre- and post-treatment RDW levels were significantly higher in the death group than in the survival group (p<0.001). In the death group, the level of RDW continued to rise in most subjects, and the mean level of RDW was significantly higher at post-treatment than pre-treatment, contrary to the results observed in the survival group. Multivariate Cox regression analysis revealed that high pre-treatment RDW, high post-treatment RDW, and persistently higher RDW were independently associated with OS and CSS (p<0.001). Similar results were observed in the competing risk regression analysis. Kaplan–Meier analysis revealed that patients with higher pre-treatment RDW levels, higher post-treatment RDW levels, and persistently higher RDW levels had poorer 3-year OS and CSS rates (p<0.05).

Conclusion

The levels of and changes in RDW before and after treatment were associated with the 3-year prognosis of prostate cancer, suggesting that RDW might be an efficient prognostic predictor in patients with prostate cancer.

The role of liquid biopsies in prostate cancer management

Liquid biopsy has emerged as a complement to invasive tissue biopsy to guide cancer diagnosis and treatment. The common liquid biopsy biomarkers are circulating tumor cells (CTCs), extracellular vesicles (EVs), and circulating tumor DNA (ctDNA). Each biomarker provides specific information based on its intrinsic characteristics. Prostate cancer is the second most common cancer in males worldwide. In men with low-grade localized prostate cancer, the disease can often be managed by active surveillance. For men who require treatment, the 5-year survival rate of localized prostate cancer is the highest among all cancer types, but the metastatic disease remains incurable. Metastatic prostate cancer invariably progresses to involve multiple bone sites and develops into a castration-resistant disease that leads to cancer death. The need to appropriately diagnose and guide the serial treatment of men with prostate cancer has led to the implementation of many studies to apply liquid biopsies to prostate cancer management. This review describes recent advancements in isolation and detection technology and the strength and weaknesses of the three circulating biomarkers. The clinical studies based on liquid biopsy results are summarized to depict the future perspective in the role of liquid biopsy on prostate cancer management.

Occupational radiation exposure of radiopharmacy-, nuclear medicine-, and surgical personnel during use of [99mTc]Tc-PSMA-I&S for prostate cancer surgery

Aim: The aim of this study was to estimate and subsequently measure the occupational radiation exposure for all personnel involved in the production, administration, imaging, or surgery with [^99mTc]Tc-PSMA-I&S, which has been introduced for identification of tumor-positive lymph nodes during salvage prostate cancer surgery Materials and Methods: The effective dose was estimated and subsequently measured with electronic personal dosimeters for the following procedures and personnel: labeling and quality control by the radiopharmacy technician, syringe preparation by the nuclear medicine laboratory technician, patient administration by the nuclear medicine physician, patient imaging by the nuclear medicine imaging technician, and robot-assisted laparoscopic salvage lymph node dissection attended by an anesthesiology technician, scrub nurse, surgical nurse, and surgeon. The dose rate of the patient was measured immediately after administration of [^99mTc]Tc-PSMA-I&S, after imaging, and after surgery. Results: The estimated dose per procedure ranged from 1.59x10-10 µSv (imaging technician) to 9.74 µSv (scrub nurse). The measured effective dose ranged from 0 to 5 µSv for all personnel during one procedure with [^99mTc]Tc-PSMA-I&S. The highest effective dose was received by the scrub nurse (3.2±1.3 µSv), whilst the lowest dose was measured for the surgical nurse (0.2±0.5 µSv). If a single scrub nurse would perform as much as 100 procedures with [^99mTc]Tc-PSMA-I&S in a year, the total effective dose would be 3.2x10-1 mSv/year. Immediately after administration, the dose rate at 50 cm from the patient was 18.5±1.6 µSv/h, which dropped to 1.8±0.3 µSv/h after imaging the following day and reducing even further to 0.56±0.33 µS/h after surgery. Conclusion: The effective dose for personnel involved in handling [^99mTc]Tc-PSMA-I&S is comparable to that of other ^99mTc-radiopharmaceuticals and therefore safe for imaging and radioguided surgery.

Isoalantolactone Increases the Sensitivity of Prostate Cancer Cells to Cisplatin Treatment by Inducing Oxidative Stress

Prostate cancer is the most common malignancy among men worldwide. Platinum (II)-based chemotherapy has been used to treat a number of malignancies including prostate cancer. However, the potential of cisplatin for treating prostate cancer is restricted owing to its limited efficacy and toxic side effects. Combination therapies have been proposed to increase the efficacy and reduce the toxic side effects. In the present study, we investigated how isoalantolactone (IATL), a sesquiterpene lactone extracted from the medicinal plant Inula helenium L., acts synergistically with cisplatin on human prostate cancer cells. We show that IATL significantly increased cisplatin-induced growth suppression and apoptosis in human prostate cancer cells. Mechanistically, the combined treatment resulted in an excessive accumulation of intracellular reactive oxygen species (ROS), which leads to the activation of endoplasmic reticulum (ER) stress and the JNK signaling pathway in human prostate cancer cells. Pretreatment of cells with the ROS scavenger N-acetylcysteine (NAC) significantly abrogated the combined treatment-induced ROS accumulation and cell apoptosis. In addition, the activation of ER stress and the JNK signaling pathway prompted by IATL and cisplatin was also reversed by NAC pretreatment. In vivo, we found that IATL combined with cisplatin showed the strongest antitumor effects compared with single agents. These results support the notion that IATL and cisplatin combinational treatment may be more effective for treating prostate cancer than cisplatin alone.

Upregulation of ATP Binding Cassette Subfamily C Member 5 facilitates Prostate Cancer progression and Enzalutamide resistance via the CDK1-mediated AR Ser81 Phosphorylation Pathway

The treatment of advanced prostate cancer, castration-resistant prostate cancer, remains challenging. The mechanisms of action of ATP binding cassette subfamily C member 5 (ABCC5) in prostate cancer and its relationship with drug resistance are still unclear. Expression and prognostic analyses of ABCC5 were performed through bioinformatic methods and immunohistochemistry analyses in multiple public databases as well as in our own prostate cancer cohort. The biological function of ABCC5 in prostate cancer cells was evaluated by in vitro and in vivo cell proliferation and migration and invasion assays. The regulation of CDK1 by ABCC5 was determined via RT-qPCR, western blots, and immunofluorescence. ABCC5 was significantly overexpressed in prostate cancer and positively associated with unfavorable clinicopathological features and prognosis. Upregulation of ABCC5 could enhance the cell proliferation, migration, and invasion of prostate cancer in vitro and in vivo. Mechanistically, ABCC5 exerts a protumor effect by binding to and inhibiting the protein degradation of CDK1, which promotes the phosphorylation of AR at Ser81 by CDK1 and activates the transcriptional activity of AR on target genes. Moreover, the addition of a CDK1 inhibitor or knockdown of CDK1 significantly improved the efficacy of enzalutamide on prostate cancer cells. The ABCC5-CDK1-AR regulatory pathway could be a potential therapeutic target for advanced prostate cancer, especially castration-resistant prostate cancer (CRPC), to enhance the therapeutic effect of enzalutamide.

Non-coding RNAs regulating androgen receptor signaling pathways in prostate cancer

Prostate cancer (PCa) is one of the most common malignancies for men worldwide, and abnormal activation of the androgen receptor (AR) signaling plays an important role in the progression of PCa. However, in the androgen deprivation therapy (ADT), AR signaling inevitably recovered, as a result, exploring novel regulating mechanisms is of great importance. Recently, non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs, circular RNAs, could be involved in the progression of PCa, and participate in the regulatory network of AR signaling in a variety of ways. This will help to identify novel molecular mechanisms to promote the development of PCa and find new potential therapeutic targets. In this review, we provide a synopsis of the latest research relating to ncRNAs and associated AR signaling in PCa.