Prognostic significance of pathogenic variants in BRCA1, BRCA2, ATM and PALB2 genes in men undergoing hormonal therapy for advanced prostate cancer

Prognostic value of germline mutations in metastatic hormone-sensitive prostate cancer (mHSPC)

BACKGROUND

About 8% to 12% of patients presenting with mHSPC exhibit germline pathogenic variants (PV) in cancer predisposition genes. The aim of this study is to assess the presence of germline PV as a prognostic factor in the setting of mHSPC and to determine whether mutational status can predict rapid progression to castration resistance.

METHODS

Genetic analysis using a multigene next-generation sequencing (NGS) panel was performed on 34 patients diagnosed with mHSPC undergoing treatment. We assessed the prevalence of germline PV and examined differences based on clinical-pathological characteristics, family history (FH), prostate-specific antigen (PSA) response, impact on time to castration-resistant prostate cancer (TTCRPC), and overall survival (OS).

RESULTS

Germline PV were identified in 6 patients (17,6%). When comparing the clinical-pathological characteristics of PV carriers (n = 6) to noncarriers (n = 28), no significant associations were observed except for the presence of FH of hereditary breast and ovarian cancer (HBOC) syndrome and/or Lynch syndrome (P = 0.024). At a median follow-up of 33 months, significant differences in OS were observed based on the presence of PV (26 months in carriers vs. 74 months in noncarriers; P < 0.01). Patients who harbored a BRCA2 mutation (n = 3) showed a worse clinical outcome, presenting a shorter TTCRPC (7 months vs. 23 months; P = 0.005) and lower OS (7 months vs. 74 months; P < 0.001) compared to noncarriers (n = 31).

CONCLUSION

mHSPC germline PV carriers had a worse survival outcome. Furthermore, BRCA2 germline mutation was an independent poor prognostic factor for mHSPC disease, associated with earlier progression to castration-resistant prostate cancer, and shorter OS. These results highlight the importance of evaluating germline mutational status in patients with hormone-sensitive prostate cancer.

Prostate cancer and liquid biopsies: Clinical applications and challenges

Liquid biopsy has emerged as a valuable and minimally invasive tool for real-time detection of clinically actionable abnormalities across various cancer types. Its applicability is particularly compelling in the realm of prostate cancer, where novel therapeutic agents, including those targeting DNA repair systems, are under development. Despite these advancements, challenges persist in effectively screening for prostate cancer, enhancing risk stratification, and determining optimal approaches for treating advanced disease. Consequently, there is a pressing need for improved biomarkers to aid clinicians in decision-making within these contexts. Cell-free DNA and extracellular vesicle analysis have demonstrated promise in diagnosis, prognostication, assessment of treatment responses, and identification of emerging mechanisms of resistance. Nevertheless, obstacles must be addressed before liquid biopsies can be integrated into routine clinical practice. These challenges encompass preanalytical considerations such as sample collection and storage, methods of extracellular vesicle isolation and enrichment, and the need for enhanced interpretation of generated sequencing data. This review provides a comprehensive overview of current clinical opportunities in managing prostate cancer through blood-based liquid biopsy, highlighting the progress made, and acknowledging the challenges that remain. Additionally, we discuss the next steps required for the effective implementation of liquid biopsies in guiding personalized treatment strategies for prostate cancer.

Prevalence of germline BRCA1/2 pathogenic variants in Japanese patients treated with castration-resistant prostate cancer and efficacy of CRPC treatment in real-world clinical practice

OBJECTIVE

The companion diagnosis for olaparib, a poly (ADP-ribose) polymerase inhibitor for prostate cancer, aims to detect BRCA1/2 gene variants. In clinical practice, the frequency of germline BRCA1/2 variants in patients receiving castration-resistant prostate cancer treatment is unknown. We aimed to evaluate the prevalence of germline BRCA1/2 variants and their relationship to prognosis and treatment efficacy in castration-resistant prostate cancer.

METHODS

Between June 2021 and 2023, 92 patients receiving castration-resistant prostate cancer treatment were examined for germline BRCA1/2 variants using BRACAnalysis CDx®. Furthermore, the associations between BRCA1/2 pathogenic variants and clinical outcomes were assessed.

RESULTS

Of the 92 patients referred for genetic testing, 6 (6.5%) carried germline pathogenic variants in BRCA1/2. The BRCA2 variant was the most frequent (n = 5), followed by BRCA1 variant (n = 1). Among the five variants in BRCA2, the p.Asp427Thrfs*3 variant was identified for the first time in prostate cancer. Overall survival from castration-resistant prostate cancer for patients with BRCA1/2 variants was significantly shorter than for patients without BRCA1/2 variants (P = 0.043). Progression-free survival of androgen receptor signaling inhibitors for patients with BRCA1/2 variants was significantly shorter than for those without (P = 0.003). Progression-free survival of taxane chemotherapy was significantly shorter in patients with BRCA1/2 variants than in those without (P = 0.0149).

CONCLUSIONS

In clinical practice, 6.5% of patients treated with castration-resistant prostate cancer carried germline BRCA1/2 pathogenic variants. Japanese castration-resistant prostate cancer patients with germline BRCA1/2 mutants have a poor prognosis and may be less responsive to treatment with androgen receptor signaling inhibitors and taxane-based chemotherapy for castration-resistant prostate cancer.

Proteomic-based stratification of intermediate-risk prostate cancer patients

Gleason grading is an important prognostic indicator for prostate adenocarcinoma and is crucial for patient treatment decisions. However, intermediate-risk patients diagnosed in the Gleason grade group (GG) 2 and GG3 can harbour either aggressive or non-aggressive disease, resulting in under- or overtreatment of a significant number of patients. Here, we performed proteomic, differential expression, machine learning, and survival analyses for 1,348 matched tumour and benign sample runs from 278 patients. Three proteins (F5, TMEM126B, and EARS2) were identified as candidate biomarkers in patients with biochemical recurrence. Multivariate Cox regression yielded 18 proteins, from which a risk score was constructed to dichotomize prostate cancer patients into low- and high-risk groups. This 18-protein signature is prognostic for the risk of biochemical recurrence and completely independent of the intermediate GG. Our results suggest that markers generated by computational proteomic profiling have the potential for clinical applications including integration into prostate cancer management.

Molecular Mechanisms of Prostate Cancer Development in the Precision Medicine Era: A Comprehensive Review

The progression of prostate cancer (PCa) relies on the activation of the androgen receptor (AR) by androgens. Despite efforts to block this pathway through androgen deprivation therapy, resistance can occur through several mechanisms, including the abnormal activation of AR, resulting in castration-resistant PCa following the introduction of treatment. Mutations, amplifications, and splicing variants in AR-related genes have garnered attention in this regard. Furthermore, recent large-scale next-generation sequencing analysis has revealed the critical roles of AR and AR-related genes, as well as the DNA repair, PI3K, and cell cycle pathways, in the onset and progression of PCa. Moreover, research on epigenomics and microRNA has increasingly become popular; however, it has not translated into the development of effective therapeutic strategies. Additionally, treatments targeting homologous recombination repair mutations and the PI3K/Akt pathway have been developed and are increasingly accessible, and multiple clinical trials have investigated the efficacy of immune checkpoint inhibitors. In this comprehensive review, we outline the status of PCa research in genomics and briefly explore potential future developments in the field of epigenetic modifications and microRNAs.

Personalized medicine with germline pathogenic variants: Importance of population- and region-wide evidence

Rare germline pathogenic variants in cancer-predisposing genes have a high impact and potential for clinical utility. In the last 30 years, based on evidence of cancer risk associated with germline pathogenic variants, several measures have been suggested for personalized medicine, including the development of novel treatments, treatment stratification, risk reduction by surgical measures, chemoprevention, removal of environmental factors, and surveillance for early detection among specific high-risk individuals. However, this evidence is mainly based on evaluations of European populations. Our large-scale analyses of more than 100,000 individuals, including 14 disease cases and non-cancer controls in the Japanese population, suggest some discrepancies in the associations between cancer-predisposing genes and diseases, expansion of the targeted diseases of BRCA1 and BRCA2, and a potential novel risk-reduction measure for gastric cancer. They are likely to be explained by population and region variations; therefore, more population-wide and region-wide research could provide improved personalized medicine as well as a better understanding of disease mechanisms. This review summarizes current personalized medicine and discusses the potential use of germline pathogenic variants.

Genetic aberrations of homologous recombination repair pathways in prostate cancer: The prognostic and therapeutic implications

Prostate cancer (PC) is the second most common cancer in men worldwide. Homologous recombination repair (HRR) gene defects have been identified in a significant proportion of metastatic castration-resistant PC (mCRPC) and are associated with an increased risk of PC and more aggressive PC. Importantly, it has been well-documented that poly ADP-ribose polymerase (PARP) inhibition in cells with HR deficiency (HRD) can cause cell death. This has been exploited for the targeted treatment of PC patients with HRD by PARP inhibitors. Moreover, it has been shown that platinum-based chemotherapy is more effective in mCRPC patients with HRR gene alterations. This review highlights the prognosis and therapeutic implications of HRR gene alterations in PC.

Investigation of Clinically Significant Molecular Aberrations in Patients with Prostate Cancer: Implications for Personalized Treatment, Prognosis and Genetic Testing

The data on tumor molecular profiling of European patients with prostate cancer is limited. Our aim was to evaluate the prevalence and prognostic and predictive values of gene alterations in unselected patients with prostate cancer. The presence of gene alterations was assessed in patients with histologically confirmed prostate cancer using the ForeSENTIA^® Prostate panel (Medicover Genetics), targeting 36 clinically relevant genes and microsatellite instability testing. The primary endpoint was the prevalence of gene alterations in homologous recombination repair (HRR) genes. Overall, 196 patients with prostate cancer were evaluated (median age 72.2 years, metastatic disease in 141 (71.9%) patients). Gene alterations were identified in 120 (61%) patients, while alteration in HRR genes were identified in 34 (17.3%) patients. The most commonly mutated HRR genes were ATM (17, 8.7%), BRCA2 (9, 4.6%) and BRCA1 (4, 2%). The presence of HRR gene alterations was not associated with advanced stage (p = 0.21), age at diagnosis (p = 0.28), Gleason score (p = 0.17) or overall survival (HR 0.72; 95% CI: 0.41-1.26; p = 0.251). We identified clinically relevant somatic gene alterations in European patients with prostate cancer. These molecular alterations have prognostic significance and therapeutic implications and/or may trigger genetic testing in selected patients. In the era of precision medicine, prospective research on the predictive role of these alterations for innovative treatments or their combinations is warranted.

Combination of C-reactive protein/albumin ratio and time to castration resistance enhances prediction of prognosis for patients with metastatic castration-resistant prostate cancer

Objective

This study aimed to identify the prediction accuracy of the combination of C-reactive protein (CRP) albumin ratio (CAR) and time to castration resistance (TTCR) for overall survival (OS) following development of metastatic castration-resistant prostate cancer (mCRPC).

Methods

Clinical data from 98 mCRPC patients treated at our institution from 2009 to 2021 were retrospectively evaluated. Optimal cutoff values for CAR and TTCR to predict lethality were generated by use of a receiver operating curve and Youden's index. The Kaplan-Meier method and Cox proportional hazard regression models for OS were used to analyze the prognostic capabilities of CAR and TTCR. Multiple multivariate Cox models were then constructed based on univariate analysis and their accuracy was validated using the concordance index.

Results

The optimal cutoff values for CAR at the time of mCRPC diagnosis and TTCR were 0.48 and 12 months, respectively. Kaplan-Meier curves indicated that patients with CAR >0.48 or TTCR <12 months had a significantly worse OS (both p < 0.005). Univariate analysis also identified age, hemoglobin, CRP, and performance status as candidate prognostic factors. Furthermore, a multivariate analysis model incorporating those factors and excluding CRP showed CAR and TTCR to be independent prognostic factors. This model had better prognostic accuracy as compared with that containing CRP instead of CAR. The results showed effective stratification of mCRPC patients in terms of OS based on CAR and TTCR (p < 0.0001).

Conclusion

Although further investigation is required, CAR and TTCR used in combination may more accurately predict mCRPC patient prognosis.

Frequency of Germline and Somatic BRCA1 and BRCA2 Mutations in Prostate Cancer: An Updated Systematic Review and Meta-Analysis

In prostate cancer (PC), the presence of BRCA somatic and/or germline mutation provides prognostic and predictive information. Meta-analysis aims to estimate the frequency of BRCA mutations in patients with PC (PCp). In November 2022, we reviewed literature searching for all articles testing the proportion of BRCA mutations in PCp, without explicit enrichment for familiar risk. The frequency of germline and somatic BRCA1 and/or BRCA2 mutations was described in three stage disease populations (any/metastatic/metastatic castration-resistant PC, mCRPC). Out of 2253 identified articles, 40 were eligible. Here, 0.73% and 1.20% of any stage PCp, 0.94% and 1.10% of metastatic PCp, and 1.21% and 1.10% of mCRPC patients carried germline and somatic BRCA1 mutation, respectively; 3.25% and 6.29% of any stage PCp, 4.51% and 10.26% of metastatic PCp, and 3.90% and 10.52% of mCRPC patients carried germline and somatic BRCA2 mutation, respectively; and 4.47% and 7.18% of any stage PCp, 5.84% and 10.94% of metastatic PCp, and 5.26% and 11.26% of mCRPC patients carried germline and somatic BRCA1/2 mutation, respectively. Somatic mutations are more common than germline and BRCA2 are more common than BRCA1 mutations; the frequency of mutations is higher in the metastatic setting. Despite that BRCA testing in PC is now standard in clinical practice, several open questions remain.

Newly developed MEIS inhibitor selectively blocks MEIS High prostate cancer growth and induces apoptosis

Prostate cancer (PCa) is the second most diagnosed cancer in males. Understanding the molecular mechanism and investigation of novel ways to block PCa growth or metastasis are vital and a medical necessity. In this study, we examined differential expression of MEIS1/2/3 and its associated factors in PCa cell lines. MEIS1/2/3 content, reactive oxygen species, and cell cycle status were analyzed in PCa cells post MEIS inhibitor (MEISi) treatments, which is developed in our laboratory as a first-in-class small molecule inhibitor. A correlation was detected between MEIS content and MEISi IC50 values of PCa cells. MEISi decreased the viability of PC-3, DU145, 22Rv-1 and LNCaP cells, and significantly increased apoptosis in parallel with the increased cellular ROS content. The efficacy of MEISi was shown to positively correlate with the levels of MEIS1/2/3 proteins and the long term exposure to MEISi elevated MEIS1/2/3 protein content in PCa cells. Our findings suggest that MEISi could be used to target PCa with high MEIS expression in order to reduce PCa viability and growth; however, more research is needed before this can be translated into clinical settings.