Olaparib for Metastatic Castration-Resistant Prostate Cancer

Cost-Effectiveness of PARP Inhibitors for Patients with BRCA1/2-Positive Metastatic Castration-Resistant Prostate Cancer-The Canadian Perspective

BACKGROUND/OBJECTIVES

Through phase III clinical trials, PARP inhibitors have demonstrated outcome improvements in mCRPC patients with alterations in BRCA1/2 genes who have progressed on a second-generation androgen receptor pathway inhibitor (ARPI). While improving outcomes, PARP inhibitors contribute to the ever-growing economic burden of PCa. The objective of this project is to evaluate the cost-effectiveness of PARP inhibitors (olaparib, rucaparib, or talazoparib) versus the SOC (docetaxel or androgen receptor pathway inhibitors (ARPI)) for previously progressed mCRPC patients with BRCA1/2 mutations from the Canadian healthcare system perspective.

METHODS

Partitioned survival models were created to represent mCRPC disease after progression until death. Survival inputs for BRCA1/2-mutated patients were extracted from the PROfound, TRITON3, and TALAPRO-1 clinical trials, while Canadian-specific costs are presented in 2023 dollars. Upon progression, patients were treated with chemotherapy. The considered time horizon was 5 years and outcomes were discounted at 1.5% per year.

RESULTS

PARP inhibitors provide an additional survival of 0.19 quality-adjusted life years (QALY) when compared to the current standard of care, with additional costs of CAD 101,679 resulting in an incremental cost-utility ratio (ICUR) of CAD 565,383/QALY. The results were most sensitive to PARP inhibitors' acquisition costs and health-state utilities. PARP inhibitors required price reductions of up to 83% to meet the CAD 50,000/QALY willingness-to-pay threshold (WTP).

CONCLUSIONS

While providing survival benefits to previously progressed mCRPC patients presenting deleterious BRCA1/2 gene mutations, PARP inhibitors are not cost-effective and require major price reductions to reach local WTP thresholds.

Homologous recombination deficiency (HRD) diagnostics: underlying mechanisms and new perspectives

Homologous recombination deficiency (HRD) is considered a universal and effective sign of a tumor's sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors. HRD diagnostics have undergone several stages of transformations: from detection of point mutations in HR-related genes and large regions with loss of heterozygosity detected using single-nucleotide polymorphism arrays to whole-genome signatures of single-nucleotide variants, large genomic rearrangements (LGRs), and copy number alterations. All these methods have their own advantages and limitations. HRD tests, based on signatures of LGRs and copy number alterations, show in hindsight that some progenitor cells have possessed HRD status but not the current state of the genome. The aim of this review was to compare different methods of HRD detection and mechanisms of formation of HRD-specific LGRs. In the last several years, new data appeared implying a crucial role of proteins BRCA1 and BRCA2 in the resolution of stalled replication forks that may be associated with at least some of LGRs observed in HRD-positive tumors. Reviewing current knowledge on these mechanisms, distributions of different LGR types, and limitations of sequencing technologies and algorithms of data analysis, we offer some new perspectives on HRD diagnostics. We hope that this review will help to accelerate the development of new diagnostic approaches in this important field of molecular oncology.

Hematopoietic adverse events associated with PARP inhibitors: A FAERS database study

OBJECTIVES

Analyze hematopoietic ADR signals of PARP inhibitors (Olaparib, Niraparib, Rucaparib, Talazoparib) using FAERS data to inform clinical practice.

METHODS

Extracted ASCII data for these drugs from Q1 2019 to Q2 2024. Employed SMQ and PT for standardization. Screened ADR signals via ROR, PRR, and MHRA method, comparing SMQ ratios.

RESULTS

Hematopoietic ADRs peaked within 30 days post-treatment, with cytopenia and leukopenia most prevalent. Niraparib showed the highest adverse event count and signal intensity. Olaparib and Talazoparib also indicated strong hematotoxicity.

CONCLUSION

PARP inhibitors vary in ADR incidence and duration, necessitating personalized treatment plans for optimized safety and rational use.

BRCA and Beyond: Impact on Therapeutic Choices Across Cancer

BACKGROUND

Identifying patients with gBRCAm is crucial to facilitate screening strategies, preventive measures and the usage of targeted therapeutics in their management. This review examines the evidence for the latest predictive and therapeutic approaches in BRCA-associated cancers.

CLINICAL DESCRIPTION

Data supports the use of adjuvant olaparib in patients with gBRCAm high-risk HER2-negative breast cancer. In advanced gBRCAm HER2-negative breast cancer, the PARPis talazoparib and olaparib have demonstrated benefit over standard chemotherapy. In ovarian cancer, olaparib, niraparib or rucaparib can be used as monotherapy in frontline maintenance. Olaparib and bevacizumab as a combination can also be used as frontline maintenance. In the relapsed platinum-sensitive setting, olaparib, niraparib and rucaparib are effective maintenance options in BRCAm patients who are PARPi naive. Both olaparib and rucaparib are effective options in BRCAm metastatic castrate-resistant prostate cancer (mCRPC). Evidence also exists for the benefit of PARPi combinations in mCRPC. In metastatic pancreatic cancer, olaparib can be used in gBRCAm patients who are responding to platinum chemotherapy. However, there may be a development of PARPi resistance. Understanding the pathophysiology that contributes to such resistance may allow the development of novel therapeutics. Combination therapy appears to have promising results in emerging trials. Seeking avenues for subsidised genetic testing can reduce the total costs of cancer management, leading to improve detection rates.

CONCLUSION

Identifying breast, ovarian, pancreatic and prostate cancer patients with gBRCAm plays a crucial predictive role in selecting those who will benefit significantly from PARPi therapy. The use of PARPi in gBRCAm HBOC-related cancers has resulted in significant survival benefits. Beyond BRCA1/2, HRR gene assessment and the consideration of other cancer predisposition syndromes may allow more patients to be eligible for and benefit from targeted therapies.

Isolation of Plasma Extracellular Vesicles for High-Depth Analysis of Proteomic Biomarkers in Metastatic Castration-Resistant Prostate Cancer Patients

Introduction: Prostate cancer treatment has been revolutionized by targeted therapies, including PARP inhibitors, checkpoint immunotherapies, and PSMA-targeted radiotherapies. Despite such advancements, accurate patient stratification remains a challenge, with current methods relying on genomic markers, tissue staining, and imaging. Extracellular vesicle (EV)-derived proteins offer a novel non-invasive alternative for biomarker discovery, holding promise for improving treatment precision. However, the characterization of plasma-derived EVs in prostate cancer patients remains largely unexplored. Methods: We conducted proteomic analyses on EVs isolated from plasma in 27 metastatic castration-resistant prostate cancer (mCRPC) patients. EVs were purified using ultracentrifugation and analyzed via mass spectrometry. Proteomic data were correlated with clinical markers such as serum prostate-specific antigen (PSA) and bone lesion counts. Statistical significance was assessed using Mann-Whitney t-tests and Spearman correlation. Results: The median age of patients was 74 (range: 44-94) years. At the time of blood collection, the median PSA level was 70 (range: 0.5-1000) ng/mL. All patients had bone metastasis. A total of 5213 proteins were detected, including EV-related proteins (CD9, CD81, CD63, FLOT1, TSG101) and cancer-related proteins (PSMA, B7-H3, PD-L1). Proteomic profiling of plasma EVs revealed a significant correlation between specific EV-derived proteins and clinical prognostic markers. B7-H3, LAT1, and SLC29A1 showed a strong association with serum PSA levels and number of bone lesions, indicating potential for these proteins to serve as biomarkers of disease burden and therapy response. Conclusions: Our findings demonstrate the potential of EV-based proteomics for identifying biomarkers in mCRPC patients. Proteins such as B7-H3 and LAT1 could guide precision oncology approaches, improving patient stratification. Future research incorporating outcomes data and EV subpopulation analysis is needed to establish clinical relevance.

Implementation of Universal Germline Genetic Testing Into Standard of Care for Patients With Prostate Cancer: The Time Is Now

Indications for and implications of germline genetic testing (GGT) in patients with prostate cancer have expanded over the past decade, particularly related to precision therapies and management. GGT has become the standard of care for many cancers such as breast, ovarian, colorectal, pancreatic, and metastatic prostate cancer, and it is imperative that patients be offered timely and equitable access to testing as it can inform patient-physician shared decision making for management of the current cancer as well as anticipatory guidance for disease progression. Additionally, GGT guides screening for and prevention of secondary malignancies for the patient and cascade testing for at-risk family members. Here, we present data supporting the notion that clinicians should offer all patients with prostate cancer the opportunity to undergo comprehensive GGT for pathogenic germline variants known to be associated with familial cancer and/or known to have implications for treatment and management.

The oncogenic lncRNA MIR503HG suppresses cellular senescence counteracting supraphysiological androgen treatment in prostate cancer

BACKGROUND

The androgen receptor (AR), a ligand-dependent transcription factor, plays a key role in regulating prostate cancer (PCa) growth. The novel bipolar androgen therapy (BAT) uses supraphysiological androgen levels (SAL) that suppresses growth of PCa cells and induces cellular senescence functioning as a tumor suppressive mechanism. The role of long non-coding RNAs (lncRNAs) in the regulation of SAL-mediated senescence remains unclear. This study focuses on the SAL-repressed lncRNA MIR503HG, examining its involvement in androgen-controlled cellular senescence in PCa.

METHODS

Transcriptome and ChIP-Seq analyses of PCa cells treated with SAL were conducted to identify SAL-downregulated lncRNAs. Expression levels of MIR503HG were analyzed in 691 PCa patient tumor samples, mouse xenograft tumors and treated patient-derived xenografts. Knockdown and overexpression experiments were performed to assess the role of MIR503HG in cellular senescence and proliferation using senescence-associated β-Gal assays, qRT-PCRs, and Western blotting. The activity of MIR503HG was confirmed in PCa tumor spheroids.

RESULTS

A large patient cohort analysis shows that MIR503HG is overexpressed in metastatic PCa and is associated with reduced patient survival, indicating its potential oncogenic role. Notably, SAL treatment suppresses MIR503HG expression across four different PCa cell lines and patient-derived xenografts but interestingly not in the senescence-resistant LNCaP Abl EnzaR cells. Functional assays reveal that MIR503HG promotes PCa cell proliferation and inhibits SAL-mediated cellular senescence, partly through miR-424-5p. Mechanistic analyses and rescue experiments indicate that MIR503HG regulates the AKT-p70S6K and the p15INK4b-pRb pathway. Reduced expression of MIR503HG by SAL or knockdown resulted in decreased BRCA2 levels suggesting a role in DNA repair mechanisms and potential implications for PARP inhibitor sensitivity by SAL used in BAT clinical trial.

CONCLUSIONS

The lncRNA MIR503HG acts as an oncogenic regulator in PCa by repressing cellular senescence. SAL-induced suppression of MIR503HG enhances the tumor-suppressive effects of AR signaling, suggesting that MIR503HG could serve as a biomarker for BAT responsiveness and as a target for combination therapies with PARP inhibitors.

Altered TP53, CDKN2A, ATM, EPHA7, POT1, CHEK1, GRIN2A, and EGFR Predict Shorter Survival in Penile Squamous Cell Carcinoma

Penile squamous cell carcinoma (pSCC) represents an uncommon malignancy characterized by stagnant mortality, psychosexual distress, and a highly variable prognosis. Currently, the World Health Organization distinguishes between human papillomavirus (HPV)-related and HPV-independent pSCC. Recently, there has been an evolving line of research documenting the enrichment of HPV-independent pSCC with a high tumor mutational burden (TMB) and programmed death ligand-1 expression, as well as clusters of genes associated with HPV status. In this study, we conducted comprehensive next-generation sequencing DNA profiling of 146 pSCC samples using a panel consisting of 355 genes associated with tumors. This profiling was correlated with immunohistochemical markers and prognostic clinical data. A survival analysis of recurrent genomic events (found in ≥10 cases) was performed. TP53, CDKN2A, ATM, EPHA7, POT1, CHEK1, GRIN2A, and EGFR alterations were associated with significantly shortened overall survival in univariate and multivariate analysis. HPV positivity, diagnosed through both p16 immunohistochemistry and HPV DNA analysis, displayed no impact on survival but was associated with high-grade, lymphatic invasion, programmed death ligand-1 negativity/weak expression, and low TMB. FAT1, TP53, CDKN2A, CASP8, and HRAS were more often mutated in HPV-independent pSCC. In contrast, HPV-associated pSCCs were enriched by EPHA7, ATM, GRIN2A, and CHEK1 mutations. PIK3CA, FAT1, FBXW7, and KMT2D mutations were associated with high TMB. NOTCH1, TP53, CDKN2A, POT1, KMT2D, ATM, CHEK1, EPHA3, and EGFR alterations were related to adverse clinicopathologic signs, such as advanced stage, high tumor budding, and lymphovascular invasion. We detected 160 alterations with potential treatment implications, with 21.2% of samples showing alterations in the homologous recombination repair pathway. To the best of our knowledge, this study describes the largest cohort of pSCC with complex molecular pathologic, clinical, and prognostic analysis correlating with prognosis.

Impact of molecular diagnostics and targeted cancer therapy on patient outcomes (MODIFY): a retrospective study of the implementation of precision oncology

High-throughput genomic analyses are being implemented in clinical practice. MODIFY is a retrospective study of the first introduction of genomic profiling and molecular tumor boards in the country of Luxembourg. The primary objective was to assess whether patients derived a clinical benefit by measuring the percentage of patients who presented a progression-free survival (PFS) on matched therapy (PFS2) 1.3-fold longer than PFS on previous therapy (PFS1). A total of 94 patients were included. In total, 45 patients (53.57% of patients with successful next-generation sequencing [NGS] analysis) were found to have an actionable mutation. Of these, 11 patients received the treatment recommended by the molecular tumor board, another 12 received best-supportive care, and 20 were treated with conventional therapy. PFS2 and PFS1 data were available for eight patients. The PFS2/PFS1 ratio was ≥ -1.3 in 62.5% (n = 5/8; CI [30.38, 86.51]) of patients; three patients showed a partial response, and median overall survival (OS) was 7.3 months. Although the examined population was small, this study further supports evidence indicating that patients with advanced cancer benefit from molecular profiling and targeted therapy.

Improved survival of patients with newly diagnosed oligometastatic prostate cancer through intensified multimodal treatment

Background and objectives

The standard of care for patients with metastatic hormone-sensitive prostate cancer (mHSPC) includes androgen deprivation therapy (ADT), novel antihormonal therapies (NHT) and/or chemotherapy. Patients with newly diagnosed oligometastatic prostate cancer (omPCa) represent a distinct subgroup of mHSPC, for which the optimal treatment, particularly the role of radical prostatectomy (RP) and metastasis-directed therapy (MDT), is currently under debate.

Materials and methods

In this single center, retrospective analysis, 43 patients with newly diagnosed omPCa were included. All patients underwent RP as part of a multimodal, personalized treatment approach. Other treatments included ADT, NHT, MDT (surgery or radiotherapy), adjuvant radiotherapy (prostatic fossa and/or pelvic lymph nodes) or chemotherapy in various combinations. Clinical endpoints were progression free and cancer specific survival (PFS, CSS).

Results

No patient with omPCa died from prostate cancer during an up to ten years follow-up period after intensified multimodal treatment i.e., RP, ADT, adjuvant radiation therapy and MDT (n=13). In contrast, patients requiring chemotherapy (n=10) showed a significantly worse PFS (p<0.001) and CSS (p<0.001). Patients receiving various combinations (<4 therapeutic modalities; n=20) showed a more favorable outcome than patients receiving chemotherapy, but differences in PFS and CSS were not statistically significant compared to patients receiving an intensified multimodal treatment.

Conclusions

An intensified, multimodal treatment approach including RP can lead to excellent survival outcomes in patients with newly diagnosed omPCa. Patients requiring chemotherapy have most likely a more aggressive disease and therefore a more rapid tumor progression. Future studies to identify markers for risk stratification in patients with omPCa are therefore needed.

Elucidating acquired PARP inhibitor resistance in advanced prostate cancer

PARP inhibition (PARPi) has anti-tumor activity against castration-resistant prostate cancer (CRPC) with homologous recombination repair (HRR) defects. However, mechanisms underlying PARPi resistance are not fully understood. While acquired mutations restoring BRCA genes are well documented, their clinical relevance, frequency, and mechanism of generation remain unclear. Moreover, how resistance emerges in BRCA2 homozygously deleted (HomDel) CRPC is unknown. Evaluating samples from patients with metastatic CRPC treated in the TOPARP-B trial, we identify reversion mutations in most BRCA2/PALB2-mutated tumors (79%) by end of treatment. Among reversions mediated by frameshift deletions, 60% are flanked by DNA microhomologies, implicating POLQ-mediated repair. The number of reversions and time of their detection associate with radiological progression-free survival and overall survival (p < 0.01). For BRCA2 HomDels, selection for rare subclones without BRCA2-HomDel is observed following PARPi, confirmed by single circulating-tumor-cell genomics, biopsy fluorescence in situ hybridization (FISH), and RNAish. These data support the need for restored HRR function in PARPi resistance.

Real-world efficacy and safety of combined first-line treatment with PARP inhibitors and novel hormonal therapy in mCRPC patients with HRR gene mutations

Objective

This study evaluated the real-world efficacy and safety of combining PARP inhibitors with novel hormonal therapy (NHT) as a first-line treatment in Chinese patients with metastatic castration-resistant prostate cancer (mCRPC) harboring homologous recombination repair (HRR) gene mutations.

Methods

We enrolled 41 mCRPC patients who received at least 1 month of combined treatment with PARP inhibitors and NHT. Patients were divided into two groups: Cohort A (mutations in BRCA1, BRCA2, or ATM genes) and Cohort B (mutations in other HRR genes). The primary endpoint was imaging-based progression-free survival (PFS), with secondary endpoints including objective response rate (ORR), disease control rate (DCR), overall survival (OS), PSA50 response, and adverse events (AEs). To ensure accurate research results and control confounding factors, we will employ multivariate Cox proportional hazards models to evaluate key variables affecting mCRPC patient survival outcomes.

Results

This study enrolled 41 patients, 22 in Cohort A and 19 in Cohort B. The median PFS for all patients was 21.8 months, and the median OS had yet to be reached. The overall ORR was 48.8%, and the DCR was 61.0%. Specifically, the median PFS for Cohort A was 21.8 months compared to 14.5 months for Cohort B. The median OS had yet to be reached for either cohort. Regarding efficacy, 81.8% of patients in Cohort A and 73.7% in Cohort B achieved a PSA50 response. Imaging assessments showed ORRs of 54.6% for Cohort A and 42.1% for Cohort B, with DCRs of 72.7% and 47.4%, respectively. 85.4% of patients experienced grade 1 or 2 adverse events, and 51.2% encountered grade 3 or 4. In the multivariate Cox regression analysis focusing on PFS, the Gleason score was identified as a significant predictor (HR = 5.8, 95% CI: 1.65-20.2, p = 0.006).

Conclusion

Combined first-line treatment with PARP inhibitors and NHT is effective and well-tolerated in mCRPC patients with HRR gene mutations, particularly those with BRCA1, BRCA2, or ATM mutations. These findings underscore the potential of this therapeutic combination in managing mCRPC in the Chinese population, suggesting a favorable outcome for those with specific genetic backgrounds.

Experience of urologists, oncologists and nurse practitioners with mainstream genetic testing in metastatic prostate cancer

BACKGROUND

International guidelines recommend germline genetic testing for men with metastatic prostate cancer. If offered to all patients by genetic healthcare professionals, there will be insufficient capacity to cope with the high patient numbers. In a mainstreaming pathway, non-genetic healthcare professionals (ngHCPs) discuss and order germline genetic testing instead of referring patients to genetic healthcare professionals. We aimed to evaluate the experience of ngHCPs with pre-test genetic counselling and to explore the feasibility from the ngHCPs' perspective.

METHODS

We carried out a prospective cohort study in 15 hospitals in the Netherlands. All participating ngHCPs (i.e. urologists, medical oncologists, specialist nurses and nurse practitioners) completed an online training module of 45 min. The ngHCPs completed a questionnaire both before the training and at three and nine months after it. Paired analyses were used to compare the first with the last questionnaires on attitude, confidence in the ability to discuss and order germline genetic testing, and perceived and actual knowledge of genetics and genetic testing.

RESULTS

167 ngHCPs were invited to participate of whom 69 completed the first questionnaire and started or completed the last one. They had a positive attitude towards offering genetic testing themselves. After nine months of providing pre-test genetic counselling, significantly more ngHCPs considered mainstreaming helpful (94% after versus 81% before, p = 0.01). Both perceived and actual knowledge increased significantly. Pre-test genetic counselling took less than 10 minutes for 82% of ngHCPs and the majority (88%) were in favour of continuing the mainstream pathway. Only six participating ngHCPs considered mainstreaming possible without completing a training module beforehand.

CONCLUSIONS

After completing a short online training module, ngHCPs feel well-prepared to discuss germline genetic testing with metastatic prostate cancer patients.

DTX3L-mediated TIRR nuclear export and degradation regulates DNA repair pathway choice and PARP inhibitor sensitivity

53BP1 plays an important role in DNA double-strand break (DSB) repair and this activity is negatively regulated by its interaction with Tudor interacting repair regulator (TIRR). However, how the TIRR-53BP1 repair axis is regulated in response to DNA damage remains elusive. Here, we demonstrate that TIRR is translocated to the cytoplasm and degraded upon DNA damage. Ubiquitination of TIRR at lysine 187 by DTX3L is a critical process that regulates NHEJ pathway activity and PARP inhibitor sensitivity by facilitating XPO1-mediated TIRR nuclear export and degradation after DNA damage. We show that DTX3L is overexpressed in prostate cancers in patients and that decreased expression of TIRR due to DTX3L overexpression impairs the negative regulatory effect of TIRR on 53BP1, which consequently induces HR deficiency and chromosomal instability and sensitizes prostate cancer cells to poly (ADP-ribose) polymerase (PARP) inhibitors. Our work reveals a dual action of DTX3L on TIRR degradation and nuclear exportation and identifies DTX3L as an upstream regulator of the TIRR-53BP1 axis that governs DNA repair pathway choice and PARP inhibitor sensitivity. These findings suggest that TIRR ubiquitination and DTX3L overexpression could be viable biomarkers predicting PARP inhibitor sensitivity in cancers.

Recent and Future Developments in the Use of Poly (ADP-ribose) Polymerase Inhibitors for Prostate Cancer

BACKGROUND AND OBJECTIVE

Advanced prostate cancer (PCa) is enriched for alterations in DNA damage repair genes; poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) are a class of drugs that have demonstrated effectiveness in PCa, particularly in tumors with alterations in BRCA1/2 and other homologous recombination repair (HRR) genes, acting through a synthetic lethal mechanism. To prevent or delay drug resistance, and to expand the patient population that can benefit from this class of drug, combination treatment strategies have been developed in preclinical and clinical studies.

METHODS

This review examines the latest developments in clinical trials testing PARPi for advanced PCa and their emerging role in earlier disease settings. Furthermore, it discusses the critical role of careful patient selection and identification of additional biomarkers to enhance treatment efficacy.

KEY FINDINGS AND LIMITATIONS

Two PARPi (olaparib and rucaparib) have been approved as monotherapy in metastatic castration-resistant PCa, thereby establishing the first biomarker-guided drug indications in PCa. Several combinations of PARPi with androgen receptor pathway inhibitors have now also been approved. Anemia and fatigue are the main adverse events associated with this drug class in clinical trials; gastrointestinal toxicities are common but usually manageble.

CONCLUSIONS AND CLINICAL IMPLICATIONS

PARPi are active against PCa with HRR mutations, especially in those with germline or somatic BRCA1/2 mutations.  There is still a need to further optimize patient stratification strategies, particularly for combination approaches. Future research should focus on refining predictive biomarkers, improving treatment delivery strategies, and exploring the potential benefits of PARPi in earlier stages of the disease.

PATIENT SUMMARY

Here, we summarize the results from clinical trials testing different poly (ADP-ribose) polymerase inhibitors (PARPi), a novel targeted drug class, in prostate cancer. Overall, the data from these trials confirm the efficacy of this drug class in those metastatic prostate cancers that show specific gene alterations, such as mutations in the BRCA1/2 genes. Several studies combining PARPi with other standard drugs for prostate cancer suggest that there may be efficacy in larger patient populations, but some of these data still need validation in longer follow-up analyses.

Therapeutic Exploitation of Neuroendocrine Transdifferentiation Drivers in Prostate Cancer

Neuroendocrine prostate cancer (NEPC), an aggressive and lethal subtype of prostate cancer (PCa), often arises as a resistance mechanism in patients undergoing hormone therapy for prostate adenocarcinoma. NEPC is associated with a significantly poor prognosis and shorter overall survival compared to conventional prostate adenocarcinoma due to its aggressive nature and limited response to standard of care therapies. This transdifferentiation, or lineage reprogramming, to NEPC is characterised by the loss of androgen receptor (AR) and prostate-specific antigen (PSA) expression, and the upregulation of neuroendocrine (NE) biomarkers such as neuron-specific enolase (NSE), chromogranin-A (CHGA), synaptophysin (SYP), and neural cell adhesion molecule 1 (NCAM1/CD56), which are critical for NEPC diagnosis. The loss of AR expression culminates in resistance to standard of care PCa therapies, such as androgen-deprivation therapy (ADT) which target the AR signalling axis. This review explores the drivers of NE transdifferentiation. Key genetic alterations, including those in the tumour suppressor genes RB1, TP53, and PTEN, and changes in epigenetic regulators, particularly involving EZH2 and cell-fate-determining transcription factors (TFs) such as SOX2, play significant roles in promoting NE transdifferentiation and facilitate the lineage switch from prostate adenocarcinoma to NEPC. The recent identification of several other key novel drivers of NE transdifferentiation, including MYCN, ASCL1, BRN2, ONECUT2, and FOXA2, further elucidates the complex regulatory networks and pathways involved in this process. We suggest that, given the multifactorial nature of NEPC, novel therapeutic strategies that combine multiple modalities are essential to overcome therapeutic resistance and improve patient outcomes.

Synthetic Lethal Targeting of CDK12-Deficient Prostate Cancer with PARP Inhibitors

PURPOSE

The cyclin-dependent kinase (CDK), CDK12, is mutated or amplified in multiple cancers. We previously described a subtype of prostate cancer characterized predominantly by frameshift, loss-of-function mutations in CDK12. This subtype exhibits aggressive clinical features.

EXPERIMENTAL DESIGN

Using isogenic prostate cancer models generated by CRISPR/Cas9-mediated inactivation of CDK12, we conducted a chemical library screen of ∼1,800 FDA-approved drugs. We inhibited cyclin K and CDK13 and evaluated the effects on PARP inhibitor (PARPi) sensitivity. CDK12 truncation and kinase domain mutations were expressed in cell lines to determine the effects on PARPi sensitivity. Mice bearing control and CDK12-mutant prostate tumors were treated with rucaparib. Finally, we evaluated PSA responses in patients with CDK12 mutations treated with rucaparib on the TRITON2 trial.

RESULTS

Cancer cells lacking CDK12 are more sensitive to PARPi than isogenic wild-type cells, and sensitivity depends on the degree of CDK12 inhibition. Inhibiting cyclin K, but not CDK13, also led to PARPi sensitivity and suppressed homologous recombination. CDK12 truncation mutants remained sensitive to PARPi, whereas kinase domain mutants exhibited intermediate sensitivity. The PARPi rucaparib suppressed tumor growth in mice bearing CDK12-mutated tumors. Finally, 6 of 11 (55%) patients with prostate cancer with biallelic CDK12 mutations had reductions in serum PSA levels when treated with rucaparib on the TRITON2 clinical trial.

CONCLUSIONS

In prostate cancer, sensitivity to PARPi is dependent on the specific type and zygosity of the CDK12 mutation. PARPi monotherapy may have some activity in patients with prostate cancer with biallelic inactivating CDK12 alterations.

Nivolumab in Patients with Metastatic Castration-Resistant Prostate Cancer with and without DNA Repair Defects

PURPOSE

Despite the success of immune checkpoint inhibitors (ICI) across various cancers, their efficacy in metastatic castration-resistant prostate cancer (mCRPC) is modest, except for a subset of patients who experience significant, yet unpredictable, benefits. DNA repair defects (DRD) are associated with higher neoantigen load, which may predict response. Our study explored the potential of DRD for enhanced responsiveness to the ICI nivolumab.

PATIENTS AND METHODS

We conducted a phase II, multicenter, single-arm trial evaluating nivolumab in patients with mCRPC with prior docetaxel therapy. The DRD were assessed using ctDNA. The primary endpoint was PSA50 response. Secondary endpoints included the objective response rate, radiographic progression-free survival (rPFS), and overall survival. Also, exploratory comprehensive genomic profiling was performed via whole-exome sequencing of tumor samples and matched normal tissues, alongside PD-L1 expression evaluation.

RESULTS

Among the 38 enrolled patients, DRD was identifiable in 30.5% (11/36) through ctDNA and/or whole-exome sequencing analyses. The overall PSA50 response rate was 10.5% (4/38). The PSA50 and objective response rates did not significantly differ between patients with and without DRD (18.2% vs. 8%; P = 0.57 and 50% vs. 17.6%; P = 0.27, respectively). The median PSA-PFS (1.9 vs. 2.8 months; P = 0.52) and rPFS (3.4 vs. 5.5 months; P = 0.7) were not statistically different between patients with and without DRD. Grade ≥ 3 adverse events were reported in 47.3% of participants.

CONCLUSIONS

Nivolumab has clinical activity in a subset of patients with mCRPC; however, DRD does not predict response. These results highlight the necessity of identifying new biomarkers to more accurately determine patients with mCRPC who might respond to ICIs.

UQCRB and LBH are correlated with Gleason score progression in prostate cancer: Spatial transcriptomics and experimental validation

Prostate cancer (PCa) is a multifocal disease characterized by genomic and phenotypic heterogeneity within a single gland. In this study, Visium spatial transcriptomics (ST) analysis was applied to PCa tissues with different histological structures to infer the molecular events involved in Gleason score (GS) progression. The spots in tissue sections were classified into various groups using Principal Component Analysis (PCA) and Louvain clustering analysis based on transcriptome data. Anotation of the spots according to GS revealed notable similarities between transcriptomic profiles and histologically identifiable structures. The accuracy of macroscopic GS determination was bioinformatically verified through malignancy-related feature analysis, specifically inferred copy number variation (inferCNV), as well as developmental trajectory analyses, such as diffusion pseudotime (DPT) and partition-based graph abstraction (PAGA). Genes related to GS progression were identified from the differentially expressed genes (DEGs) through pairwise comparisons of groups along a GS gradient. The proteins encoded by the representative oncogenes UQCRB and LBH were found to be highly expressed in advanced-stage PCa tissues. Knockdown of their mRNAs significantly suppressed PCa cell proliferation and invasion. These findings were validated using The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) dataset, as well as through histological and cytological experiments. The results presented here establish a foundation for ST-based evaluation of GS progression and provide valuable insights into the GS progression-related genes UQCRB and LBH.

Phase II Trial of the PARP Inhibitor, Niraparib, in BAP1 and Other DNA Damage Response Pathway-Deficient Neoplasms

PURPOSE

BRCA1-associated protein 1 (BAP1) is a critical cell cycle and DNA damage response (DDR) regulator with mutations (mBAP1) causing a functional protein loss. PARP inhibitors (PARPis) demonstrate synthetic lethality in mBAP1 preclinical models, independent of underlying BRCA status. This study aimed to explore the clinical activity of niraparib in patients with advanced tumors likely to harbor mBAP1.

METHODS

This was a phase II multicenter trial in which refractory solid tumor patients were assigned to cohort A (histology-specific tumors likely to harbor mBAP1) or cohort B (histology-agnostic tumors with other known non-BRCA-confirmed DDR mutations). All patients received niraparib 300 mg orally once daily on a 28-day cycle. The primary end point was objective response rate, and secondary end points included progression-free survival (PFS) and overall survival.

RESULTS

From August 2018 through December 2021, 37 patients were enrolled with 31 evaluable for response (cohort A, n = 18; cohort B, n = 13). In cohort A, the best response was one partial response (PR; 6%), eight stable disease (SD; 44%), and nine progressive disease (PD; 50%). This cohort stopped at the first stage following the prespecified Simon's design. mBAP1 was confirmed in 7/9 patients (78%) with PR or SD but in only 3/9 (33%) in those with PD. The median PFS in patients with mBAP1 (n = 10) was 6.7 months (95% CI, 1.0 to 9.2) versus 1.8 months (95% CI, 0.9 to 4.5) for wild-type (n = 8; P = .020). In cohort B, the best response was six SD (46%) and seven PD (54%), with SD in those with ATM, CHEK2, PTEN, RAD50, and ARID1A mutations.

CONCLUSION

Niraparib failed to meet the prespecified efficacy end point for response. However, clinical benefit was suggested in a proportion of patients who had a confirmed mBAP1, supporting further investigation.

Circulating Biomarkers Predictive of Treatment Response in Patients with Hormone-sensitive or Castration-resistant Metastatic Prostate Cancer: A Systematic Review

BACKGROUND AND OBJECTIVE

Metastatic prostate cancer (mPCa) harbors genomic alterations that may predict targeted therapy efficacy. These alterations can be identified not only in tissue but also directly in biologic fluids (ie, liquid biopsies), mainly blood. Liquid biopsies may represent a safer and less invasive alternative for monitoring patients treated for mPCa. Current research focuses on the description and validation of novel predictive biomarkers to improve precision medicine in mPCa. Our aim was to systematically review the current evidence on liquid biopsy biomarkers for predicting treatment response in mPCa.

METHODS

We systematically searched Medline, Web of Science, and evidence-based websites for publications on circulating biomarkers in mPCa between March 2013 and February 2024 for review. Endpoints were: prediction of overall survival, biochemical or radiographic progression-free survival after treatment (chemotherapy, androgen deprivation therapy, androgen receptor pathway inhibitors [ARPIs], immunotherapy, or PARP inhibitors [PARPIs]). For each biomarker, the level of evidence (LOE) for clinical validity was attributed: LOE IA and IB, high level of evidence; LOE IIB and IIC, intermediate level; and LOE IIIC and LOE IV-VD, weak level.

KEY FINDINGS AND LIMITATIONS

The predictive value of each biomarker for the response to several therapies was evaluated in both metastatic hormone-sensitive (mHSPC) and castration-resistant prostate cancer (mCRPC). In patients with mCRPC, BRCA1/2 or ATM mutations predicted response to ARPIs (LOE IB) and PARPIs (LOE IIB), while AR-V7 transcripts or AR-V7 protein levels in circulating tumor cells (CTCs) predicted response to ARPIs and taxanes (LOE IB). CTC quantification predicted response to cabazitaxel, abiraterone, and radium-223 (LOE IIB), while TP53 alterations predicted response to 177Lu prostate-specific membrane antigen radioligand treatment (LOE IIB). AR copy number in circulating tumor DNA before the first treatment line and before subsequent lines predicted response to docetaxel, cabazitaxel, and ARPIs (LOE IIB). In mHSPC, DNA damage in lymphocytes was predictive of the response to radium-223 (LOE IIB).

CONCLUSIONS AND CLINICAL IMPLICATIONS

BRCA1/2, ATM, and AR alterations detected in liquid biopsies may help clinicians in management of patients with mPCa. The other circulating biomarkers did not reach the LOE required for routine clinical use and should be validated in prospective independent studies.

PATIENT SUMMARY

We reviewed studies assessing the value of biomarkers in blood or urine for management of metastatic prostate cancer. The evidence indicates that some biomarkers could help in selecting patients eligible for specific treatments.

Tolerability of Olaparib Combined with Abiraterone in Patients with Metastatic Castration-resistant Prostate Cancer: Further Results from the Phase 3 PROpel Trial

BACKGROUND

The PROpel study (NCT03732820) demonstrated a statistically significant progression-free survival benefit with olaparib plus abiraterone versus placebo plus abiraterone in the first-line metastatic castration-resistant prostate cancer (mCRPC) setting, irrespective of homologous recombination repair mutation status.

OBJECTIVE

We report additional safety analyses from PROpel to increase clinical understanding of the adverse-event (AE) profiles of olaparib plus abiraterone versus placebo plus abiraterone.

DESIGN, SETTING, AND PARTICIPANTS

A randomised (1:1), double-blind, placebo-controlled trial was conducted at 126 centres in 17 countries (October 2018-January 2020). Patients had mCRPC and no prior systemic mCRPC treatment.

INTERVENTION

Olaparib (300 mg bid) or placebo with abiraterone (1000 mg od) plus prednisone/prednisolone (5 mg bid).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The data cut-off date was July 30, 2021. Safety was assessed by AE reporting (Common Terminology Criteria for Adverse Events v4.03) and analysed descriptively.

RESULTS AND LIMITATIONS

The most common AEs (all grades) for olaparib plus abiraterone versus placebo plus abiraterone were anaemia (46.0% vs 16.4%), nausea (28.1% vs 12.6%), and fatigue (27.9% vs 18.9%). Grade ≥3 anaemia occurred in 15.1% versus 3.3% of patients in the olaparib plus abiraterone versus placebo plus abiraterone arm. The incidences of the most common AEs for olaparib plus abiraterone peaked early, within 2 mo, and were managed typically by dose modifications or standard medical practice. Overall, 13.8% versus 7.8% of patients discontinued treatment with olaparib plus abiraterone versus placebo plus abiraterone because of an AE; 3.8% versus 0.8% of patients discontinued because of anaemia. More venous thromboembolism events were observed in the olaparib plus abiraterone arm (any grade, 7.3%; grade ≥3, 6.8%) than in the placebo plus abiraterone arm (any grade, 3.3%; grade ≥3, 2.0%), most commonly pulmonary embolism (6.5% vs 1.8% for olaparib plus abiraterone vs placebo plus abiraterone).

CONCLUSIONS

Olaparib plus abiraterone has a manageable and predictable safety profile.

PATIENT SUMMARY

The PROpel trial showed that in patients who had not received any previous treatment for metastatic castration-resistant prostate cancer, olaparib combined with abiraterone was more effective in delaying progression of the disease than abiraterone alone. Most side effects caused by combining olaparib with abiraterone could be managed with supportive care methods, by pausing olaparib administration for a short period of time and/or by reducing the dose of olaparib.

Neurosurgical application of olaparib from a thermo-responsive paste potentiates DNA damage to prolong survival in malignant glioma

BACKGROUND

There is increased pan-cancer specific interest in repurposing the poly adenosine diphosphate-ribose polymerase-1 (PARP-1) inhibitor, olaparib, for newly diagnosed or recurrent isocitrate dehydrogenase wild type glioblastoma. We explore whether intra-cavity delivery of olaparib confers a survival benefit in a pre-clinical high-grade glioma model.

METHODS

Primary tumor RNA sequencing data was used to determine PARP-1 as a target in the glioblastoma infiltrative margin. We assessed radiosensitization conferred by olaparib alone and concomitant to genotoxic insults in vitro using clonal growth assays, cell cycle analysis and immunocytochemistry, and in vivo upon post-surgical delivery from a temperature-sensitive polymeric paste.

RESULTS

RNA-sequencing confirmed PARP-1 as a viable therapy target in glioblastoma infiltrative disease. Acute exposure of glioma cells to olaparib impaired proliferation and induced late-stage apoptosis associated with DNA damage in vitro, potentiated by radiation. Using high-grade glioma orthotopic allografts, a long-term overall survival benefit was observed upon interstitial olaparib delivery concomitant with radiotherapy, compared to systemic olaparib and standard glioblastoma treatment. Combined delivery of olaparib with either temozolomide or etoposide increased long-term survival, suggestive of olaparib functioning as DNA damage sensitizer.

CONCLUSIONS

Collectively, our data support a rationale for localized olaparib delivery concomitant with the current clinical regimen for malignant glioma treatment.

Guidelines for genetic testing in prostate cancer: a scoping review

BACKGROUND

Genetic testing, to identify pathogenic or likely pathogenic variants in prostate cancer, is valuable in guiding treatment decisions for men with prostate cancer and to inform cancer prevention and early detection options for their immediate blood relatives. There are various guidelines and consensus statements for genetic testing in prostate cancer. Our aim is to review genetic testing recommendations across current guidelines and consensus statements and the level of evidence supporting those recommendations.

METHODS

A scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review (PRISMA-ScR) guidelines. Electronic database searches and manual searches of grey literature, including websites of key organisations were conducted. Using the Population, Concept, Context (PCC) framework, this scoping review included: men with prostate cancer or men at high risk of prostate cancer and their biological families; existing guidelines and consensus statements with supporting evidence for genetic testing of men with prostate cancer from any geographical location worldwide.

RESULTS

Of the 660 citations identified, 23 guidelines and consensus statements met the inclusion criteria for the scoping review. Based on different levels of evidence about who should be tested and how, a diverse range of recommendations were identified. There was general consensus among the guidelines and consensus statements that men with metastatic disease be offered genetic testing; however, there was less consensus in relation to genetic testing in localised prostate cancer. While there was some consensus in relation to which genes to test, recommendations varied regarding who to test, testing methods and implementation.

CONCLUSION

While genetic testing in prostate cancer is routinely recommended and numerous guidelines exist, there is still considerable lack of consensus regarding who should be tested and how they should be tested. Further evidence is needed to inform value-based genetic testing strategies for implementation in practice.

Real-world prevalence of homologous recombination repair mutations in advanced prostate cancer: an analysis of two clinico-genomic databases

BACKGROUND

Homologous recombination repair mutation (HRRm) status may guide risk-stratification and treatment decisions, including polyadenosine diphosphate-ribose polymerase inhibitor use, in advanced prostate cancer. Although HRRm prevalence has been reported in single-institution studies or clinical trials, real-world HRRm prevalence in diverse populations is unknown. We describe HRRm in the clinical setting using two real-world clinicogenomic databases: the Flatiron Health and Foundation Medicine, Inc. Clinico-Genomic Database (CGDB), a national electronic health record-derived database, and the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange (GENIE).

METHODS

This cross-sectional analysis included 3757 individuals diagnosed with prostate cancer who had next generation sequencing (NGS) as standard of care. The CGDB included men with advanced/metastatic prostate cancer and genetic data included both germline and somatic pathogenic mutations. The GENIE analysis included men with prostate cancer whose received NGS as standard of care, but the data were filtered to include somatic mutations only. Due to key differences among databases, direct comparisons were not possible. Overall prevalence of HRRm was calculated and stratified by demographic and clinical characteristics.

RESULTS

HRRm prevalence (combined germline and somatic) in CGDB (n = 487) was 24.6% (95% CI 20.9-28.7%), with no major differences across demographic and disease characteristic subgroups. HRRm prevalence (somatic) in GENIE (n = 3270) was 11.0% (95% CI 10.0-12.1%), which varied between 9.5% and 18.4% across treatment centers.

CONCLUSIONS

Approximately one-quarter of patients with advanced/metastatic prostate cancer in the CGDB had germline and/or somatic HRRm, which is consistent with clinical trials such as the PROfound study that used a similar NGS platform and algorithm to define HRRm. In the GENIE database, HRRm prevalence varied by treatment center or NGS platform. More research is needed to understand real-world HRRm prevalence variations.

A panel-based mutational signature of homologous recombination deficiency associates with response to PARP inhibition in metastatic castration-resistant prostate cancer

BACKGROUND

The PARP inhibitor (PARPi) olaparib is approved for homologous recombination repair (HRR) gene-altered metastatic castration-resistant prostate cancer (mCRPC). However, there is significant heterogeneity in response to PARPi in patients with mCRPC. Better clinical biomarkers are needed to identify patients likely to benefit from PARPi.

METHODS

Patients with prostate adenocarcinoma and panel sequencing at Dana-Farber Cancer Institute were identified. Mutational signature analysis was performed using SigMA to characterize tumors as HRR deficient (HRD). The validity of SigMA to identify patients likely to benefit from olaparib was compared to the current FDA label (presence of a deleterious alteration in one of 14 HRR genes).

RESULTS

546 patients were identified, of which 34% were HRD. Among patients with HRR gene alterations, only patients with BRCA2 two-copy loss (2CL) were more likely to be HRD compared to patients without HRR gene alterations (74% vs 31%; P = 9.1 × 10-7). 28 patients with mCRPC received olaparib, of which 13 were HRD and 9 had BRCA2 2CL. SigMA improved upon the current FDA label for predicting PSA50 (sensitivity: 100% vs 90%; specificity: 83% vs 44%; PPV: 77% vs 47%; NPV: 100% vs 89%) and rPFS > 6 months (sensitivity: both 92%; specificity: 93% vs 53%; PPV: 92% vs 63%; NPV: 93% vs 89%). On multivariate analysis, incorporating prognostic clinical factors and HR gene alterations, SigMA-predicted HRD independently associated with improved PSA-PFS (HR = 0.086, p = 0.00082) and rPFS (HR = 0.078, p = 0.0070).

CONCLUSIONS

SigMA-predicted HRD may better identify patients likely to benefit from olaparib as compared to the current FDA label. Larger studies are needed for further validation.

Hot topics in genitourinary cancers: A multidisciplinary discussion on state-of-the-art and latest developments among international experts and patient advocacy

Genitourinary cancers present significant challenges to oncologists, necessitating innovative approaches for improved patient outcomes. The 'Controversies in Genitourinary Cancers' congress, held in January 2024, convened international experts to address the complexities of prostate, bladder, renal and rare genitourinary cancers. Sessions explored current trends, novel treatments, and unmet needs, emphasizing collaborative efforts to advance knowledge and patient care. Through multidisciplinary engagement and patient advocacy, the congress underscored the imperative of collective action in navigating the complexities of genitourinary cancers, ultimately aiming to transform clinical practice and improve patient outcomes.

Progression-directed Therapy in Oligoprogressive Castration-resistant Prostate Cancer: Final Results from the Prospective, Single-arm, Phase 2 MEDCARE Trial

BACKGROUND AND OBJECTIVE

Next-line systemic treatment (NEST) is the standard of care for patients presenting with progressive metastatic castration-resistant prostate cancer (mCRPC). Progression-directed therapy (PDT), defined as a lesion-directed approach in patients with a limited number of progressive and/or new lesions, could postpone the need for NEST in these patients with so-called oligoprogressive mCRPC. Our aim was to investigate the feasibility of postponing NEST initiation in oligoprogressive mCRPC by using PDT.

METHODS

MEDCARE was a prospective, single-arm, nonrandomized phase 2 trial. Eligible patients had oligoprogressive mCRPC and were treated with PDT while their ongoing systemic therapy was continued. The primary endpoint was NEST-free survival (NEST-FS). Secondary endpoints were prostate-specific antigen response, clinical progression-free survival (cPFS), prostate cancer-specific survival (PCSS), overall survival (OS), and PDT-induced toxicity.

KEY FINDINGS AND LIMITATIONS

Twenty patients underwent PDT for 38 oligoprogressive lesions. At median follow-up of 28 mo, median NEST-FS was 17 mo and the 2-yr NEST-FS rate was 35%. Median PCSS and median OS were not reached. The PCSS and OS rates at 2 yr were 80% and 70%, respectively. The 2-yr local control rate was 95%. No patient experienced early or late grade ≥3 toxicity. NEST-FS was longer for patients who received PDT to all lesions visible on 18F-PSMA positron emission tomography/computed tomography (30 vs 13 mo; p = 0.002).

CONCLUSIONS AND CLINICAL IMPLICATIONS

This single-center, single-arm, phase 2 trial demonstrated that PDT in oligoprogressive mCRPC resulted in median NEST-FS of 17 mo without any early or late grade ≥3 toxicity.

PATIENT SUMMARY

For patients with metastatic prostate cancer no longer responding to hormone therapy, we investigated radiotherapy targeted at progressive cancer lesions while continuing their ongoing systemic treatment. The results show that this targeted therapy had very low toxicity and delayed the need to start a new line of systemic treatment by 17 months.

Precision medicine for prostate cancer: An international perspective

Greater personalization of cancer medicine continues to shape therapy development and patient selection accordingly. The treatment of prostate cancer has evolved considerably since the discovery of androgen deprivation therapy. The comprehensive profiling of the prostate cancer genome has mapped the targetable molecular landscape of the disease and identified opportunities for the implementation of novel and combination therapies. In this review, we provide an overview of the molecular biology of prostate cancer and tools developed to aid prognostication and prediction of therapy benefit. Modern treatment of advanced prostate cancer is reviewed as a paradigm of increasing precision-informed approach to patient care, and must be considered on a global scale with respect to the state of science and care delivery.

Germline BRCA pathogenic variants and hematologic adverse events in patients with ovarian carcinoma receiving PARP inhibitors: a retrospective cohort study

BACKGROUND

Patients with a germline BRCA pathogenic variant (gBRCA-PV) and advanced high grade ovarian carcinoma (aHGOC) experience higher hematologic adverse events (HAEs) when receiving platinum salts and ionizing radiations, compared to non-carriers, due to a possible higher susceptibility of the hemopoietic stem cells to DNA targeting agents. However, the incidence of PARP inhibitor (PARPi)-related HAEs according to the gBRCA-PV status is currently unknown.

PATIENTS AND METHODS

We conducted a single-center retrospective cohort study to describe the occurrence of HAEs in patients with aHGOC receiving ≥8 weeks of maintenance PARPi in any line of therapy, comparing gBRCA-PVs carriers to non-carriers. HAEs were manually identified by searching the patients' electronic medical records and classified by CTCAE v5.0. The main endpoint was the incidence rate of any HAE (ie, anaemia, neutropenia, or thrombocytopenia) of grade 2 or more (G ≥ 2).

RESULTS

One hundred and sixty-six patients were included; 95 (57%) had a gBRCA-PV. In total, 162 incident cases of G ≥ 2 HAEs were reported over 255.3 person-years. The incidence rates of G ≥ 2 HAEs were 1003/1000 person-years in gBRCA-PV carriers and 993/1000 person-years in non-carriers. No difference in the incidence rate of G ≥ 2 HAEs emerged comparing gBRCA-PV carriers to non-carriers (crude-incidence rate ratio [IRR]: 1.01; 95% CI: 0.72, 1.43; P = .96), even after adjusting for the type of PARPi (Mantel-Haenszel IRR: 0.99; 95% CI: 0.67, 1.46).

CONCLUSION

Patients with aHGOC and a gBRCA-PV do not experience higher PARPi-related HAEs compared to non-gBRCA-PV carriers, unlike platinum salt-related HAEs.

CRISPR/Cas9 Technology Providing the Therapeutic Landscape of Metastatic Prostate Cancer

Prostate cancer (PCa) is the most prevalent malignancy and the second leading cause of cancer-related death in men. Although current therapies can effectively manage the primary tumor, most patients with late-stage disease manifest with metastasis in different organs. From surgery to treatment intensification (TI), several combinations of therapies are administered to improve the prognosis of patients with metastatic PCa. Due to the high frequency of the mutation during the metastatic phase, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated nuclease 9 (Cas9) genetic engineering tool can accelerate the effects of TI by enhancing targeted gene therapy or immunotherapy. This review describes the genetic background of metastatic PCa and how CRISPR/Cas9 technology can contribute to the field of PCa treatment development. It also discusses the current limitations of conventional PCa therapy and the potential of CRISPR-based PCa therapy.

Triple-Action Therapy: Combining Machine Learning, Docking, and Dynamics to Combat BRCA1-Mutated Breast Cancer

Breast cancer dominates women's mortality, and among other factors, mutations in the BRCA1 gene are significant risk factors. Several approaches are followed to treat the BRCA1 affected cancer patients. However, specific BRCA1 inhibitors are not available till date due to its structural complexity. In addition, there are several limitations associated with the existing drugs used to treat BRCA1-related breast cancer and some side effects. The side effects include symptoms such as hot flashes, joint pain, nausea, fatigue, hair loss, diarrhea, chills, fever, and others. Therefore, advanced approaches needed that can overcome all the limitations and side effects of the current inhibitors. In this study, we adopted a multistep approach to identify potential inhibitors for BRCA1-mutated breast cancer. We used our developed machine learning models to screen potential inhibitors. Molecular docking approach was carried out for the screened hit compounds with BRCA1 and its mutated forms. Two ligands, β-amyrin and Narirutin, has shown significant performance in multiple scoring schemes such as molecular docking and RF score calculations. Molecular dynamics simulations demonstrated the stability of the complexes formed by β-amyrin and Narirutin with BRCA1, with lower RMSD values and less RMSF fluctuations at the binding site locations. Principal component analysis (PCA) and free energy landscape (FEL) further confirmed the compactness and favorable binding of β-Amyrin and Narirutin to BRCA1. These findings suggest that β-amyrin and Narirutin have potential as therapeutic agents against BRCA1-mutated breast cancer.

Application and research progress of synthetic lethality in the development of anticancer therapeutic drugs

With the tremendous success of the PARP inhibitor olaparib in clinical practice, synthetic lethality has become an important field for the discovery and development of anticancer drugs. More and more synthetic lethality targets have been discovered with the rapid development of biotechnology in recent years. Currently, many drug candidates that were designed and developed on the basis of the concept of synthetic lethality have entered clinical trials. Taking representative synthetic lethal targets Poly ADP-ribose polymerase 1 (PARP1), Werner syndrome helicase (WRN) and protein arginine methyltransferase 5 (PRMT5) as examples, this article briefly discusses the application and research progress of synthetic lethality in the development of anticancer drugs.

A phase II study evaluating safety and efficacy of niraparib in patients with previously treated homologous recombination defective metastatic esophageal/gastroesophageal junction/proximal gastric adenocarcinoma

Introduction

Esophageal adenocarcinoma (EAC) remains a devastating disease and second line treatment options in the metastatic space are limited. Homologous recombination (HR) defects have been described in EAC in up to 40% of patients. Poly (ADP-ribose) polymerase (PARP)1 and PARP2 inhibitors have shown efficacy in HR defective prostate and ovarian cancers. Here, we describe the activity of the PARP inhibitor niraparib in metastatic EAC with HR defects.

Methods

In this single arm Simon two-stage Phase II study, we assessed the safety and efficacy of niraparib in patients with metastatic EAC previously treated with platinum containing chemotherapy harboring defective HR. Defective HR was defined as deleterious alterations in the following HR genes: BRCA1/2, PALB2, ATM, BARD1, BRIP1, CDK12, CHEK2, FANCA, RAD51, RAD51B, RAD51C, RAD51D, RAD54L, NBN, ARID1A and GEN1.

Results

14 patients were enrolled in this study. The trial was stopped early due to slow accrual. 3 patients did not have post-treatment scans because of rapid clinical decline. The overall response rate (ORR) (95% exact CI) was 0/11 = 0% (0%, 28.49%). The disease control rate (DCR) (95% exact CI) was 2/11 = 18.2% (2.3%, 51.8%). The median PFS was 1.8 months (95% CI = 1.0-3.7). The median OS for evaluable patients was 6.6 months (95% CI =2.7-11.4) and 5.7 months for all patients (95% CI =2.7-10.1). The most common adverse events seen were anemia, fatigue, and thrombocytopenia.

Conclusion

In patients with metastatic EAC, single agent niraparib as second line therapy is not an effective option.

Genetic and clinical characteristics of genetic tumor syndromes in the central nervous system cancers: Implications for clinical practice

Recognizing individuals with Genetic tumor syndromes (GTS) in the primary central nervous system (CNS) tumors is crucial for optimizing proper genetic counseling and improving therapeutics and clinical care. We retrospectively analyzed the GTS in a Chinese CNS tumor cohort and examined the molecular characteristics and their clinical significance for diagnostic and therapeutic purposes. Our study identified 34 categories of GTS in 258 patients with CNS tumors. The gene with the highest germline pathogenic or likely pathogenic mutation frequency was TP53, followed by MSH2, NF1, and BRCA2. The top five GTS in CNS tumors showed high genetic heterogeneity GTS analysis reclassifies CNS tumors as "NEC." 53.88% of patients diagnosed with GTS harbor potential precision oncology therapy target mutations. The results of our study deepen our understanding of CNS tumors, provide a reference direction for the future design of clinical trials, and further expect to improve disease entire process management in CNS tumors.

Real-World Comparison of Cabazitaxel Versus 177Lu-PSMA Radiopharmaceutical Therapy in Metastatic Castration-Resistant Prostate Cancer

177Lu-vipivotide tetraxetan prostate-specific membrane antigen (177Lu-PSMA) therapy is under current scientific investigation and aims to become established in the treatment of metastatic castration-resistant prostate cancer (mCRPC). However, real-world evidence in treatment comparison is scant. Methods: We relied on the FRAMCAP database and compared cabazitaxel versus 177Lu-PSMA therapy in mCRPC patients regarding progression-free survival (PFS) and overall survival (OS). Sensitivity analyses addressed second- to fourth-line mCRPC treatment to approximate current phase III patient selection criteria. Results: Of 373 patients, 14% received cabazitaxel, 65% received 177Lu-PSMA, and 21% received both. Patients undergoing 177Lu-PSMA therapy were significantly older than cabazitaxel patients (median, 72 y vs. 66 y; P < 0.01), and a higher proportion had an Eastern Cooperative Oncology Group score of 2 or more (12% vs. 5.0%, P = 0.1). Rates of a prostate-specific antigen decline of at least 50% were 32% versus 0% for 177Lu-PSMA versus cabazitaxel. In outcome analyses, significant superior median PFS was observed for 177Lu-PSMA versus cabazitaxel (13.4 mo vs. 7.1 mo, P < 0.001), even after multivariable adjustment (hazard ratio, 0.38; P < 0.001). Regarding OS, rates also significantly differed, with median OS of 14.7 mo versus 16.5 mo versus 29.6 mo for cabazitaxel versus 177Lu-PSMA versus both treatments (P < 0.01). In sensitivity analyses of second- to fourth-line mCRPC treatment, PFS rates and median OS rates for cabazitaxel versus 177Lu-PSMA versus both therapies qualitatively remained the same as for the entire cohort. Conclusion: In a real-world setting, 177Lu-PSMA provides significantly better PFS and qualitatively better OS rates than does cabazitaxel chemotherapy and should therefore be considered a valuable treatment option for advanced mCRPC patients according to the European Medicines Agency approval.

Olaparib enhancing radiosensitization and anti-metastatic effect of oral cancer by targeting IL-17A signal

PURPOSE

We tested whether the PARP inhibitor, Olaparib, can effectively enhance radiosensitivity while inhibiting OSCC growth and metastasis in vitro and in vivo. Patient samples were used for survival validation.

METHODS

The present study investigated the effect of Olaparib and ionizing radiation (IR) on clonogenic, migratory, and invasive ability in human IR-sensitive (OML1) and IR-resistant (OML1-R) OSCC cell lines. We next explored the underlying mechanism with ELISA and a Western blotting assay. Two in vivo mouse models were established to investigate the efficacy of Olaparib combined with radiotherapy (RT) on local tumor growth and lung metastasis. IL-17 A expression was confirmed in tissue specimens of OSCC patients by immunohistochemistry.

RESULTS

We found that Olaparib, in combination with IR, substantially inhibited cell growth, migration, and invasion in vitro. Mechanistically, the Olaparib treatment significantly reduced the secretion of IL-17 A in irradiated OSCC cells by attenuating NF-κB and p38 activity. Consistently, Olaparib enhanced the radiosensitivity and, with RT, synergistically reduced both tumor growth and lung metastasis in mice. In addition, OSCC patients with high IL-17 A expression were substantially associated with an increased risk of lymph node involvement and worse survival.

CONCLUSIONS

This study has highlighted that Olaparib displays radiosensitizing and antimetastatic effects by inhibiting the IL-17 A-dependent signal. Remarkably, Olaparib could provide a remarkable anticancer efficacy to improve treatment response in OSCC patients with recurrent/metastatic disease after RT.

Acute BRCAness Induction and AR Signaling Blockage through CDK12/7/9 Degradation Enhances PARP Inhibitor Sensitivity in Prostate Cancer

Current treatments for advanced prostate cancer (PCa) primarily target the androgen receptor (AR) pathway. However, the emergence of castration-resistant prostate cancer (CRPC) and resistance to AR pathway inhibitors (APSIs) remains ongoing challenges. Here, we present BSJ-5-63, a novel proteolysis-targeting chimera (PROTAC) targeting cyclin-dependent kinases (CDKs) CDK12, CDK7, and CDK9, offering a multi-pronged approach to CRPC therapy. BSJ-5-63 degrades CDK12, diminishing BRCA1 and BRCA2 expression and inducing a sustained "BRCAness" state. This sensitizes cancer cells to PARP inhibitors (PARPis) regardless of their homologous recombination repair (HRR) status. Furthermore, CDK7 and CDK9 degradation attenuates AR signaling, enhancing its therapeutic efficacy. Preclinical studies, including both in vitro and in vivo CRPC models, demonstrate that BSJ-5-63 exerts potent anti-tumor activity in both AR-positive and AR-negative setting. This study introduces BSJ-5-63 as a promising therapeutic agent that addresses both DNA repair and AR signaling mechanisms, with potential benefits for a board patient population.

Comprehensive review of cardiovascular disease in prostate cancer: epidemiology, risk factors, therapeutics and prevention strategies

BACKGROUND

The prevalence of cardiovascular risk factors and disease is high in patients with newly diagnosed prostate cancer (PC). Survivorship of PC patients is often determined by cardiovascular disease (CVD). Our review synthesizes the most recent literature exploring the dynamics between PC and CVD across the disease trajectory and treatments. We review key ongoing clinical trials in the field and highlight avenues for future study.

METHODS

We conducted a comprehensive narrative review of the literature using various search strategies in three databases (PubMed, Web of Science, ClinicalTrials.gov), focusing on literature published between 2000 and 2024.

RESULTS

We discuss the significance of CVD-related mortality in PC, review the risk factors, and highlight potential mechanisms for accelerated CVD in the androgen-deprivation setting. Furthermore, we summarize key literature of CVD and cardiotoxicity for various therapeutic approaches in PC, including orchiectomy, taxane-based chemotherapy, GnRH-axis targets, and next-generation hormonal agents and PARP inhibitors. Lastly, we discuss prevention strategies and the importance of multi-disciplinary care in this setting.

CONCLUSION

CVD is a major cause of death in men with PC. Various novel therapeutic approaches have been pivotal in improving oncologic outcomes, but emerging data demonstrate a complex interplay between the androgen axis and CVD that is likely affected by modern treatment strategies. Given the prolonged PC survivorship, unraveling non-oncologic related causes of death and investigating prevention strategies are imperative (Fig. 1). Fig. 1 LANDSCAPE OF PROSTATE CANCER.: Spectrum of prostate cancer disease states (red) and interventions (yellow) with the potential role for optimization (green) to improve cardiovascular outcomes in the future (blue).

Reduced penetrance BRCA1 and BRCA2 pathogenic variants in clinical germline genetic testing

Prior studies have suggested the existence of reduced penetrance pathogenic variants (RPPVs) in BRCA1 and BRCA2 (BRCA) which pose challenges for patient counseling and care. Here, we sought to establish RPPVs as a new category of variants. Candidate BRCA RPPVs provided by two large clinical diagnostic laboratories were compiled to identify those with the highest likelihood of being a RPPV, based on concordant interpretations. Sixteen concordant candidate BRCA RPPVs across both laboratories were systematically assessed. RPPVs included missense, splice site, and frameshift variants. Our study establishes RPPVs as a new class of variants imparting a moderately increased risk of breast cancer, which impacts risk-informed cancer prevention strategies, and provides a framework to standardize interpretation and reporting of BRCA RPPVs. Further work to define clinically meaningful risk thresholds and categories for reporting BRCA RPPVs is needed to personalize cancer risks in conjunction with other risk factors.

Exploring the impact of BRCA1 and BRCA2 mutation type and location on Olaparib maintenance therapy in platinum-sensitive relapsed ovarian Cancer patients: A single center report

OBJECTIVE

In patients with platinum-sensitive relapsed ovarian cancer (PSROC) harboring pathogenic/likely pathogenic variants (PV) in BRCA1 and BRCA2 genes, olaparib maintenance monotherapy (OMT) is a viable option. Our study aimed to evaluate the impact of different BRCA1/2 PV in survival outcomes and safety of OMT in BRCA1/2-mutated PSROC patients, focusing on the type and location of PV.

METHODS

We assessed the outcomes of 100 BRCA1/2-mutated PSROC patients treated at our institute, analyzing progression-free survival (PFS) and overall survival (OS). Germline and tumor BRCA1/2 genotyping was conducted using Illumina's next-generation sequencing (NGS).

RESULTS

PFS and OS were significantly shorter in PSROC patients with PV in BRCA1 compared to those with PV in BRCA2 (PFS:14.0 vs. 38.8 months, p = 0.007, OS: 21.8 vs. 62.0 months, p = 0.011). Notably, there was a significant difference in PFS based on the intragenic location of BRCA1 PV, with shorter PFS in patients with 1st/2nd relapse, harboring PV in BRCA1 RING domain compared to those with PV in the DNA binding domain (DBD) and BRCT domains (12.4 vs. 23.0 months, p = 0.046). No differences in PFS and OS were observed between patients with germline versus somatic BRCA1/2 PV (PFS:14.9 vs.19.3, p = 0.316, OS: not reached vs. 25.8 months; p = 0.224). However, there were significant differences in the reasons for OMT discontinuation between patients with germline and somatic BRCA1/2 PV, primarily due to adverse side effects.

CONCLUSIONS

In summary, the type and location of BRCA1 and BRCA2 PV provide additional insight into the expected survival outcomes of olaparib MT in PSROC patients.

TRIAL REGISTRATION NUMBER

ISRCTN42408038, Name of registry: ISRCTN registry, Date of registration: 24/11/2015.

PROTAC as a novel anti-cancer strategy by targeting aging-related signaling

Aging and cancer share common cellular hallmarks, including cellular senescence, genomic instability, and abnormal cell death and proliferation, highlighting potential areas for therapeutic interventions. Recent advancements in targeted protein degradation technologies, notably Proteolysis-Targeting Chimeras (PROTACs), offer a promising approach to address these shared pathways. PROTACs leverage the ubiquitin-proteasome system to specifically degrade pathogenic proteins involved in cancer and aging, thus offering potential solutions to key oncogenic drivers and aging-related cellular dysfunction. This abstract summarizes the recent progress of PROTACs in targeting critical proteins implicated in both cancer progression and aging, and explores future perspectives in integrating these technologies for more effective cancer treatments.

Japanese clinical practice guidelines for prostate cancer 2023

This fourth edition of the Japanese Clinical Practice Guidelines for Prostate Cancer 2023 is compiled. It was revised under the leadership of the Japanese Urological Association, with members selected from multiple academic societies and related organizations (Japan Radiological Society, Japanese Society for Radiation Oncology, the Department of EBM and guidelines, Japan Council for Quality Health Care (Minds), Japanese Society of Pathology, and the patient group (NPO Prostate Cancer Patients Association)), in accordance with the Minds Manual for Guideline Development (2020 ver. 3.0). The most important feature of this revision is the adoption of systematic reviews (SRs) in determining recommendations for 14 clinical questions (CQs). Qualitative SRs for these questions were conducted, and the final recommendations were made based on the results through the votes of 24 members of the guideline development group. Five algorithms based on these results were also created. Contents not covered by the SRs, which are considered textbook material, have been described in the general statement. In the general statement, a literature search for 14 areas was conducted; then, based on the general statement and CQs of the Japanese Clinical Practice Guidelines for Prostate Cancer 2016, the findings revealed after the 2016 guidelines were mainly described. This article provides an overview of these guidelines.

Hereditary and Familial Traits in Urological Cancers and Their Underlying Genes

Early recognition of hereditary urological cancers may influence diagnostic and therapeutic decision-making, and potentially alter the fate of patients and family members. Here, we introduce readers to the current knowledge on germline genetic testing and clinical practice in prostate, bladder, renal, and testicular carcinoma. Considering all urological cancer patients, routine inquiries about familial cancer history should become a standard practice in clinical settings. If suspicion arises, patients can opt for two avenues: referral to genetic counseling or undergoing genetic tests after consultation with the treating urologist.

Patient summary

Tumors of the urogenital tract (prostate, kidney, bladder, and testes) can sometimes be related to genetic mutations that are present in all the cells of the body. Such mutations can be inherited and run in families. Therefore, it is relevant to obtain information on the incidence of all cancers in the family history. The information obtained may initiate genetic testing, leading to the identification of mutations that are related to cancer in the current or next generation. In addition, these mutations may offer alternative treatment options for patients.

Polθ: emerging synthetic lethal partner in homologous recombination-deficient tumors

The most remarkable finding in synthetic lethality (SL) is the hypersensitivity to PARP inhibitors (PARPis) of the tumors harboring defects in genes involved in homologous repair (HR) such as BRCA1/2. Despite initial responsiveness to PARPi, the penetrance of the synthetic lethal interactions between BRCA1/2 genes and PARPi is incomplete. Thus, a significant proportion of HR-defective tumors experience intrinsic or acquired resistance, representing a key challenge of clinical research. An expanded concept of SL is opening new ways and includes novel forms of genetic interactions, investigating not only traditional SL of pairs genes but also SL between biological pathways that regulate the same essential survival cell function. In this context, recent research showed that HR and theta-mediated end-joining (TMEJ) pathways exhibit SL. DNA polymerase theta (Polθ) is encoded by the POLQ gene and is a key component of the TMEJ, an essential backup pathway, intrinsically mutagenic, to repair resected double-strand breaks (DSBs) when the non-homologous end joining (NHEJ) and HR are impaired. Polθ is broadly expressed in normal tissues, overexpressed in several cancers, and typically associated with poor outcomes and shorter relapse-free survival. Notably, HR-deficient tumor cells present the characteristic mutational signatures of the error-prone TMEJ pathway. According to this observation, the loss of HR proteins, such as BRCA1 or BRCA2, contributes to increasing the TMEJ-specific genomic profile, suggesting synthetic lethal interactions between loss of the POLQ and HR genes, and resulting in the emerging interest for Polθ as a potential therapeutic target in BRCA1/2-associated tumors.This review summarizes the converging roles of the POLQ and HR genes in DNA DSB repair, the early-stage clinical trials using Polθ inhibitor to treat HR-defective tumors and to overcome BRCA-reversion mutations responsible for therapeutic resistance, and the novel pleiotropic effects of Polθ, paving the way for the development of unexplored synthetic lethality strategies.

Single-Hit and Multi-hit PIK3CA Short Variant Genomic Alterations in Clinically Advanced Prostate Cancer: A Genomic Landscape Study

BACKGROUND

Tumors harboring two or more PIK3CA short variant (SV) ("multi-hit") mutations have been linked to improved outcomes with anti-PIK3CA-targeted therapies in breast cancer. The landscape and clinical implications of multi-hit PIK3CA alterations in clinically advanced prostate cancer (CAPC) remains elusive.

OBJECTIVE

To evaluate the genomic landscape of single-hit and multi-hit PIK3CA genomic alterations in CAPC.

PATIENTS AND METHODS

The Foundation Medicine FoundationCore database was used to identify 19,978 CAPC tumors that underwent hybrid capture-based comprehensive genomic profiling to evaluate all classes of genomic alterations (GA) and determine tumor mutational burden (TMB), microsatellite instability (MSI), genomic ancestry, single-base substitution mutational signatures, and homologous recombination deficiency signature (HRDsig). Tumor cell PD-L1 expression was determined by IHC (Dako 22C3).

RESULTS

18,741 (93.8%) tumors were PIK3CA wild type (WT), 1155 (5.8%) featured single PIK3CA SV, and 82 (0.4%) featured multi-hit PIK3CA SVs. Single-hit (6.6 versus 3.8; p < 0.0001) and multi-hit (12.8 versus 3.8; p < 0.0001) featured more driver GA per tumor than PIK3CA WT CAPC, as well as higher prevalence of MMR mutational signature, MSI high status, and TMB levels versus PIK3CA WT (p < 0.0001). Other differences in GA included higher frequencies of GA in BRCA2 in multi-hit versus WT (18.3% versus 8.5%; p = 0.0191), ATM in multi-hit versus WT (13.4% versus 5.6%; p = 0.02) and PTEN in single-hit versus WT (40.2% versus 30.1%; p < 0.0001). Homologous recombination deficiency signatures were higher in PIK3CA WT versus single-hit (11.2% versus 7.6%; p = 0.0002). There were no significant differences in PD-L1 expression among the three groups.

CONCLUSIONS

Identification of multi-hit PIK3CA GA in CAPC highlights a potentially unique phenotype that may be associated with response to anti-PIK3CA targeted therapy and checkpoint inhibition, supporting relevant clinical trial designs.

Efficacy and safety of rechallenge [177Lu]Lu-PSMA-617 RLT after initial partial remission in patients with mCRPC: evaluation of a prospective registry (REALITY study)

AIM

Rechallenge of [177Lu]Lu-PSMA-617 radioligand therapy (RLT) was proposed for patients who initially responded to PSMA-RLT experiencing partial remission, but relapsed into progression after a certain period of remission. However, only limited data is available regarding this approach. In this study, we analyzed the efficacy and safety profile of one or more series of [177Lu]Lu-PSMA-617 RLT rechallenge in patients from a prospective registry (REALITY Study, NCT04833517) after they initially benefited from PSMA-RLT.

METHODS

Forty-seven patients with metastatic castration-resistant prostate cancer (mCRPC) who had biochemical response to initial [177Lu]Lu-PSMA-617 RLT followed by disease progression received at least one (up to three) series of [177Lu]Lu-PSMA-617 RLT rechallenge. Biochemical response rates based on prostate-specific antigen (PSA) serum value, PSA-based progression-free survival (PFS) and overall survival (OS) were calculated. Adverse events of the treatment were assessed according to 'common terminology criteria for adverse events' (CTCAE).

RESULTS

After one series of RLT rechallenge, a PSA decline of at least 50% was achieved in 27/47 patients (57.4%). The median PFS of all patients was 8.7 mo and the median OS was 22.7 mo, each calculated from the administration of the first rechallenge series. Patients who responded (PSA decline > 50%) to the rechallenge showed a median OS of 27.3 mo. Regarding PFS, a significant correlation (r = 0.4128, p = 0.0323) was found for these patients comparing initial and rechallenge RLT. Ten patients received a second and 3 patients received a third rechallenge series with 8/10 and 3/3 patients responding to repeated RLT rechallenge. No severe deterioration of adverse events rated by CTCAE criteria was observed.

CONCLUSION

[177Lu]Lu-PSMA-617 RLT rechallenge is associated with significant PSA response and encouraging survival outcome as well as a very favourable safety profile and should therefore be considered as a straight-forward treatment option in mCRPC patients, who previously benefited from PSMA-RLT.

Real-world genome profiling in Japanese patients with pancreatic ductal adenocarcinoma focusing on HRD implications

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges due to its high mortality, making it a critical area of research. This retrospective observational study aimed to analyze real-world data from comprehensive genome profiling (CGP) of Japanese patients with PDAC, mainly focusing on differences in gene detection rates among panels and the implications for homologous recombination deficiency (HRD) status. This study enrolled 2568 patients with PDAC who had undergone CGP between June 2019 and December 2021 using data from the nationwide Center for Cancer Genomics and Advanced Therapeutics database. Two types of CGP assays (tissue and liquid biopsies) were compared and a higher detection rate of genetic abnormalities in tissue specimens was revealed. HRD-related gene alterations were detected in 23% of patients, with BRCA1/2 mutations accounting for 0.9% and 2.9% of patients, respectively. Treatment outcome analysis indicated that patients with BRCA1/2 mutations had a longer time to treatment discontinuation with FOLFIRINOX than gemcitabine plus nab-paclitaxel as first-line therapy (9.3 vs. 5.6 months, p = 0.028). However, no significant differences were observed in the treatment response among the other HRD-related genes. Logistic regression analysis identified younger age and family history of breast, prostate, and ovarian cancers as predictive factors for HRD-related gene alterations. Despite the lack of progression-free survival data and the inability to discriminate between germline and somatic mutations, this study provides valuable insights into the clinical implications of CGP in Japanese patients with PDAC. Further research is warranted to optimize panel selection and elucidate the efficacy of platinum-based therapies depending on the HRD status.

The Cost-Effectiveness of Germline BReast CAncer Gene Testing in Metastatic Prostate Cancer Followed by Cascade Testing of First-Degree Relatives of Mutation Carriers

OBJECTIVES

Patients with metastatic prostate cancer (mPCa) with BReast CAncer gene (BRCA) mutations benefit from targeted treatments (eg, olaparib). In addition, family members of affected patients have increased risk of hereditary cancers and benefit from early detection and prevention. International guidelines recommend genetic testing in mPCa; however, the value for money of testing patients with mPCa and cascade testing of blood-related family members has not been assessed. In this context, we evaluated the cost-effectiveness of germline BRCA testing in patients with mPCa followed by cascade testing of first-degree relatives (FDRs) of mutation carriers.

METHODS

We conducted a cost-utility analysis of germline BRCA testing using 2 scenarios: (1) testing patients with mPCa only and (2) testing patients with mPCa and FDRs of those who test positive. A semi-Markov multi-health-state transition model was constructed using a lifetime time horizon. The analyses were performed from an Australian payer perspective. Decision uncertainty was characterized using probabilistic analyses.

RESULTS

Compared with no testing, BRCA testing in mPCa was associated with an incremental cost of AU$3731 and a gain of 0.014 quality-adjusted life-years (QALYs), resulting in an incremental cost-effectiveness ratio of AU$265 942/QALY. Extending testing to FDRs of variant-positive patients resulted in an incremental cost-effectiveness ratio of AU$16 392/QALY. Probability of cost-effectiveness at a willingness-to-pay of AU$75 000/QALY was 0% in the standalone mPCa analysis and 100% in the cascade testing analysis.

CONCLUSION

BRCA testing when performed as a standalone strategy in patients with mPCa may not be cost-effective but demonstrates significant value for money after the inclusion of cascade testing of FDRs of mutation carriers.