[Metastatic castration-resistant prostate cancer and PARP inhibitors: From tumor genomics to new therapeutic combinations]. / Cancer de prostate métastatique résistant à la castration et inhibiteurs de PARP : de la génomique tumorale aux nouvelles associations thérapeutiques.

Castration-resistant metastatic prostate cancer remains lethal and a therapeutic challenge. Current strategies are geared towards the personalization of treatments based on the identification of relevant molecular targets, including genomic alterations involved in tumoral processes. Among these novel targeted therapies, poly-ADP-ribose polymerase inhibitors (PARPi), by blocking the action of enzymes involved in deoxyribonucleic acid (DNA) repair, induce the destruction of cells carrying defects in homologous recombination repair, often associated with alterations in genes involved in this mechanism. Thus, determining the presence of a molecular anomaly, particularly alterations in the BRCA1/2 genes, is a prerequisite for initiating PARPi monotherapy. In patients with metastatic castration-resistant prostate cancer , around 20-30 % carry this type of mutation. In this population, single-agent studies have demonstrated PARPi ability to prolong overall survival, and to improve symptom control, including pain. Other studies are underway to assess their effectiveness in combination with other therapies, and it already appears that association with new-generation hormone therapy can further prolong radiological progression-free survival, regardless of the mutation status of the genes involved in DNA repair, indicating a synergistic action between PARPi and new-generation hormone therapy.

Current HRD assays in ovarian cancer: differences, pitfalls, limitations, and novel approaches.

Ovarian carcinoma (OC) still represents an insidious and fatal malignancy, and few significant results have been obtained in the last two decades to improve patient survival. Novel targeted therapies such as poly (ADP-ribose) polymerase inhibitors (PARPi) have been successfully introduced in the clinical management of OC, but not all patients will benefit, and drug resistance almost inevitably occurs. The identification of patients who are likely to respond to PARPi-based therapies relies on homologous recombination deficiency (HRD) tests, as this condition is associated with response to these treatments. This review summarizes the genomic and functional HRD assays currently used in clinical practice and those under evaluation, the clinical implications of HRD testing in OC, and their current pitfalls and limitations. Special emphasis will be placed on the functional HRD assays under development and the use of machine learning and artificial intelligence technologies as novel strategies to overcome the current limitations of HRD tests for a better-personalized treatment to improve patient outcomes.

Recent Advances in Immunotherapy and Targeted Therapy of Triple Negative Breast Cancer.

The truancy of representation of the estrogen, progesterone, and human epidermal growth factor receptors occurs during TNBC. TNBC is recognized for the upper reappearance and has a poorer diagnosis compared with rest breast cancer (BC) types. Presently, as such, no targeted therapy is approved for TNBC and treatment options are subjected to chemotherapy and surgery, which have high mortality rates. Hence, the current article focuses on the scenario of TNBC vital pathways and discusses the latest advances in TNBC treatment, including immune checkpoint inhibitors (ICIs), PARP suppressors, and cancer vaccines. Immunotherapy and ICIs, like PD 1 and PD L1 suppressors, displayed potential in clinical trials (CTs). These suppressors obstruct the mechanisms which allow tumor cells to evade the system thereby boosting the body's defense against TNBC. Immunotherapy, either alone or combined with chemotherapy has demonstrated patient outcomes such as increased survival rates and reduced treatment-related side effects. Additionally, targeted therapy approaches include BRCA/2 mutation poly ribose polymerase inhibitors, Vascular Endothelial Growth Factor Receptor (VEGFR) inhibitors, Epidermal growth factor receptor inhibitors, Fibroblast growth factor inhibitors, Androgen Receptor inhibitors, PIK3/AKT/mTOR pathway inhibitors, Cyclin-dependent kinase (CDK) inhibitors, Notch signaling pathway inhibitors, Signal transducer and activator of transcription 3 (STAT3) signaling pathway inhibitors, Chimeric antigen receptor T (CAR-T) cell therapy, Transforming growth factor (TGF) -ß inhibitors, Epigenetic modifications (EPM), Aurora Kinase inhibitors and antibody-drug conjugates. We also highlight ongoing clinical trials and potential future directions for TNBC therapy. Despite the challenges in treating TNBC, recent developments in understanding the molecular and immune characteristics of TNBC have opened up new opportunities for targeted therapies, which hold promise for improving outcomes in this aggressive disease.

Homologous recombination deficiency (HRD) is associated with better prognosis and possibly causes a non-inflamed tumour microenvironment in nasopharyngeal carcinoma.

Homologous recombination deficiency (HRD) score is a reliable indicator of genomic instability. The significance of HRD in nasopharyngeal carcinoma (NPC), particularly its influence on prognosis and the immune microenvironment, has yet to be adequately explored. Understanding HRD status comprehensively can offer valuable insights for guiding precision treatment. We utilised three cohorts to investigate HRD status in NPC: the Zhujiang cohort from local collection and the Hong Kong (SRA288429) and Singapore (SRP035573) cohorts from public datasets. The GATK (genome analysis toolkit) best practice process was employed to investigate germline and somatic BRCA1/2 mutations and various bioinformatics tools and algorithms to examine the association between HRD status and clinical molecular characteristics. We found that individuals with a negative HRD status (no-HRD) exhibited a higher risk of recurrence [hazard ratio (HR), 1.43; 95% confidence interval (CI), 2.03-333.76; p = 0.012] in the Zhujiang cohort, whereas, in the Singapore cohort, they experienced a higher risk of mortality (HR, 26.04; 95% CI, 1.43-34.21; p = 0.016) compared with those in the HRD group. In vitro experiments demonstrated that NPC cells with BRCA1 knockdown exhibit heightened sensitivity to chemoradiotherapy. Furthermore, the HRD group showed significantly higher tumour mutational burden and tumour neoantigen burden levels than the no-HRD group. Immune infiltration analysis indicated that HRD tissues tend to have a non-inflamed tumour microenvironment. In conclusion, patients with HRD exhibit a comparatively favourable prognosis in NPC, possibly associated with a non-inflammatory immune microenvironment. These findings have positive implications for treatment stratification, enabling the selection of more precise and effective therapeutic approaches and aiding in the prediction of treatment response and prognosis to a certain extent.

Talazoparib enhances resection at DSBs and renders HR-proficient cancer cells susceptible to Polθ inhibition.

BACKGROUND AND PURPOSE: The PARP inhibitor (PARPi), Talazoparib (BMN673), effectively and specifically radiosensitizes cancer cells. Radiosensitization is mediated by a shift in the repair of ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) toward PARP1-independent, alternative end-joining (alt-EJ). DNA polymerase theta (Polθ) is a key component of this PARP1-independent alt-EJ pathway and we show here that its inhibition can further radiosensitize talazoparib-treated cells. The purpose of the present work is to explore mechanisms and dynamics underpinning enhanced talazoparib radiosensitization by Polθ inhibitors in HR-proficient cancer cells. METHODS AND MATERIALS: Radiosensitization to PARPis, talazoparib, olaparib, rucaparib and veliparib was assessed by clonogenic survival. Polθ-proficient and -deficient cells were treated with PARPis and/or with the Polθ inhibitors ART558 or novobiocin. The role of DNA end-resection was studied by down-regulating CtIP and MRE11 expression using siRNAs. DSB repair was assessed by scoring γH2AX foci. The formation of chromosomal abnormalities was assessed as evidence of alt-EJ function using G2-specific cytogenetic analysis. RESULTS: Talazoparib exerted pronounced radiosensitization that varied among the tested cancer cell lines; however, radiosensitization was undetectable in normal cells. Other commonly used PARPis, olaparib, veliparib, or rucaparib were ineffective radiosensitizers under our experimental conditions. Although genetic ablation or pharmacological inhibition of Polθ only mildly radiosensitized cancer cells, talazoparib-treated cells were markedly further radiosensitized. Mechanistically, talazoparib shunted DSBs to Polθ-dependent alt-EJ by enhancing DNA end-resection in a CtIP- and MRE11-dependent manner - an effect detectable at low, but not high IR doses. Chromosomal translocation analysis in talazoparib-treated cells exposed to Polθ inhibitors suggested that PARP1- and Polθ-dependent alt-EJ pathways may complement, but also back up each other. CONCLUSION: We propose that talazoparib promotes low-dose, CtIP/MRE11-dependent resection and increases the reliance of irradiated HR-proficient cancer cells, on Polθ-mediated alt-EJ. The combination of Polθ inhibitors with talazoparib suppresses this option and causes further radiosensitization. The results suggest that Polθ inhibition may be exploited to maximize talazoparib radiosensitization of HR-proficient tumors in the clinic.

Strategies for the prevention or reversal of PARP inhibitor resistance.

INTRODUCTION: Advances in our understanding of tumor biology shed light on hallmarks of cancer development and progression that include dysregulated DNA damage repair (DDR) machinery. Leveraging the underlying tumor genomic instability and tumor-specific defects in DDR, Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) induced DNA damage emerges as a novel non-chemotherapy therapeutic opportunity. PARPis are currently approved in multiple tumor types, with the largest benefit seen in tumors with homologous recombination repair (HRR) deficiency, including germline and somatic mutations in BRCA1/2 genes (BRCA) and other pathway members such as PALB2 and Rad51c. AREAS COVERED: This review article summarizes the current approval landscape and known and proposed mechanisms of resistance to PARPi. Further, therapeutic strategies to overcome PARPi resistance are discussed, including ongoing clinical trials. EXPERT OPINION: PARPi have proven to be a safe and effective therapy and represents a cornerstone treatment across multiple solid tumor types. Elucidating innate and acquired mechanisms of resistance, coupled with the emergence of novel therapeutic options to capitalize on the activity of PARPi and prevent or reverse the acquisition of resistance, provides an opportunity to further expand the role of PARPi in cancer therapy.

Leveraging PARP-1/2 to Target Distant Metastasis.

Poly (ADP-Ribose) Polymerase (PARP) inhibitors have changed the outcomes and therapeutic strategy for several cancer types. As a targeted therapeutic mainly for patients with BRCA1/2 mutations, PARP inhibitors have commonly been exploited for their capacity to prevent DNA repair. In this review, we discuss the multifaceted roles of PARP-1 and PARP-2 beyond DNA repair, including the impact of PARP-1 on chemokine signalling, immune modulation, and transcriptional regulation of gene expression, particularly in the contexts of angiogenesis and epithelial-to-mesenchymal transition (EMT). We evaluate the pre-clinical role of PARP inhibitors, either as single-agent or combination therapies, to block the metastatic process. Efficacy of PARP inhibitors was demonstrated via DNA repair-dependent and independent mechanisms, including DNA damage, cell migration, invasion, initial colonization at the metastatic site, osteoclastogenesis, and micrometastasis formation. Finally, we summarize the recent clinical advancements of PARP inhibitors in the prevention and progression of distant metastases, with a particular focus on specific metastatic sites and PARP-1 selective inhibitors. Overall, PARP inhibitors have demonstrated great potential in inhibiting the metastatic process, pointing the way for greater use in early cancer settings.

Cardiovascular adverse events associated with PARP inhibitors for ovarian cancer: a real world study (RWS) with Bayesian disproportional analysis based on the FDA adverse event reporting system (FAERS).

BACKGROUND: To investigate the pharmacovigilance (PV) and make pairwise comparisons on reporting proportion, seriousness, and severity of outcomes of major adverse cardiovascular events (MACE) among poly(ADP-ribose) polymerase-inhibitors (PARPis) in treating ovarian cancer, fallopian tube carcinoma, and primary peritoneal cancer (collectively named EOC) from the US Food and Drug Administration Adverse Event Reporting System (FAERS). RESEARCH DESIGN AND METHODS: Data on adverse cardiovascular events reports related to EOC treatment submitted to FAERS from the first quarter of 2015 to the second quarter of 2023 were harvested. Three PARPis were identified: olaparib, niraparib, and rucaparib. RESULTS: Eventually, a total of 258,596 eligible records were enrolled with 12,331 reports including 5,292 reports of MACE and 7,039 reports of other cardiovascular events. For the primary composite endpoint, a PV signal associated with MACE was detected in niraparib (ROR = 1.12; IC025 = 0.03), whereas it was not detected in olaparib and rucaparib; For the secondary endpoint, PV signals associated with other cardiovascular events were detected in niraparib (ROR = 1.17;IC025 = 0.04), but not in olaparib and rucaparib. CONCLUSIONS: For EOC patients, close monitoring of blood pressure, heart rate, and coagulation function should be conducted when selecting niraparib for treatment.

Poly (ADP-ribose) polymerase inhibitor therapy and mechanisms of resistance in epithelial ovarian cancer.

Advanced epithelial ovarian cancer is the commonest cause of gynaecological cancer deaths. First-line treatment for advanced disease includes a combination of platinum-taxane chemotherapy (post-operatively or peri-operatively) and maximal debulking surgery whenever feasible. Initial response rate to chemotherapy is high (up to 80%) but most patients will develop recurrence (approximately 70-90%) and succumb to the disease. Recently, poly-ADP-ribose polymerase (PARP) inhibition (by drugs such as Olaparib, Niraparib or Rucaparib) directed synthetic lethality approach in BRCA germline mutant or platinum sensitive disease has generated real hope for patients. PARP inhibitor (PARPi) maintenance therapy can prolong survival but therapeutic response is not sustained due to intrinsic or acquired secondary resistance to PARPi therapy. Reversion of BRCA1/2 mutation can lead to clinical PARPi resistance in BRCA-germline mutated ovarian cancer. However, in the more common platinum sensitive sporadic HGSOC, the clinical mechanisms of development of PARPi resistance remains to be defined. Here we provide a comprehensive review of the current status of PARPi and the mechanisms of resistance to therapy.

Germline BRCA pathogenic variants in patients with ovarian cancer and post-poly (ADP-ribose) polymerase inhibitor myeloid neoplasms.

BACKGROUND: Among patients with advanced high-grade ovarian carcinoma (aHGOC) treated with poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis), the presence of a germline BRCA pathogenic variant (gBRCA-PV) may increase the risk of bone marrow mutagenesis resulting in postcytotoxic therapy myelodysplastic neoplasms (MDS-pCT) or acute myeloid leukemia (AML-pCT), as it is expressed in heterozygosity also by hematopoietic progenitors. We aimed to investigate the occurrence of post-PARPi MDSs/AMLs-pCTs according to gBRCA-PV status. PATIENTS AND METHODS: We conducted a retrospective single-center study to evaluate MDS/AML-pCT in patients with aHGOC and a known gBRCA-PV status receiving at least 8 weeks of maintenance PARPi, in any line of therapy, from February 2017 to December 2022. The endpoint was the proportion of patients who experienced MDSs-pCT and AMLs-pCT during and after treatment with PARPi, in gBRCA-PV carriers and non-carriers. RESULTS: A total of 166 patients were included: 95 (57%) had a gBRCA-PV and 72% received PARPi for recurrent disease. The number of lines of chemotherapies before and after PARPi, median overall survival, and median follow-up were comparable between gBRCA-PV carriers and non-carriers. After a median follow-up of 40.0 (95% confidence interval: 35.7-44.3) months, 10 (6%) patients were diagnosed with an MDS-pCT and 4 (2%) with an AML-pCT. A higher proportion of MDSs/AMLs-pCT (10% versus 2%; P = 0.16) and, in particular, of MDSs-pCT (9% versus 1%; P = 0.04) was observed among gBRCA-PV carriers. CONCLUSIONS: The presence of a gBRCA-PV is associated with a higher risk of MDS-pCT and possibly of myeloid neoplasms after PARPi in patients with aHGOC who received PARPi, especially in the setting of recurrent disease.

PARP inhibitor resistance mechanisms and PARP inhibitor derived imaging probes.

INTRODUCTION: Poly(ADP-ribose) polymerase 1 (PARP1) inhibition has become a major target in anticancer therapy. While PARP inhibitors (PARPi) are approved for homologous recombination (HR) deficient cancers, therapeutic resistance is a challenge and PARPi are now being investigated in cancers lacking HR deficiencies. This creates a need to develop molecular and imaging biomarkers of PARPi response to improve patient selection and circumvent therapeutic resistance. AREAS COVERED: PubMed and clinicaltrials.gov were queried for studies on PARPi resistance and imaging. This review summarizes established and emerging resistance mechanisms to PARPi, and the current state of imaging and theragnostic probes for PARPi, including fluorescently labeled and radiolabeled probes. EXPERT OPINION: While progress has been made in understanding PARPi therapeutic resistance, clinical evidence remains lacking and relatively little is known regarding PARPi response outside of HR deficiencies. Continued research will clarify the importance of known biomarkers and resistance mechanisms in patient cohorts and the broader utility of PARPi. Progress has also been made in PARPi imaging, particularly with radiolabeled probes, and both imaging and theragnostic probes have now reached clinical validation. Reducing abdominal background signal from probe clearance will broaden their applicability, and improvements to molecular synthesis and radiation delivery will increase their utility.

PARP enzymes and mono-ADP-ribosylation: advancing the connection from interferon-signalling to cancer biology.

ADP-ribosyltransferases of the PARP family encompass a group of enzymes with variegated regulatory functions in cells, ranging from DNA damage repair to the control of cell-cycle progression and immune response. Over the years, this knowledge has led to the use of PARP1/2 inhibitors as mainstay pharmaceutical strategies for the treatment of ovarian, pancreatic, prostate and breast cancers, holding mutations in genes encoding for proteins involved in the DNA repair mechanisms (synthetic lethality). Meanwhile, the last decade has witnessed significant progress in comprehending cellular pathways regulated by mono-ADP-ribosylation, with a huge effort in the development of novel selective compounds to inhibit those PARPs endowed with mono-ADP-ribosylation activity. This review focuses on the progress achieved in the cancer field, delving into most recent findings regarding the role of a subset of enzymes - the interferon-stimulated PARPs - in cancer progression.

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.

Application of PARP inhibitors combined with immune checkpoint inhibitors in ovarian cancer.

The advent of polyadenosine diphosphate ribose polymerase inhibitors (PARPi) has brought about significant changes in the field of ovarian cancer treatment. However, in 2022, Rucaparib, Olaparib, and Niraparib, had their marketing approval revoked for third-line and subsequent therapies due to an increased potential for adverse events. Consequently, the exploration of new treatment modalities remains imperative. Recently, the integration of PARPi with immune checkpoint inhibitors (ICIs) has emerged as a potential remedy option within the context of ovarian cancer. This article offers a comprehensive examination of the mechanisms and applications of PARPi and ICIs in the treatment of ovarian cancer. It synthesizes the existing evidence supporting their combined use and discusses key considerations that merit attention in ongoing development efforts.

GPX4 Inhibition Enhances the Antitumor Effect of PARP Inhibitor on Homologous Recombination Proficient Ovarian Cancer Cells.

BACKGROUND: Poly (ADP-ribose) polymerase inhibitors (PARPi) are now widely used in BRCA1/2 mutation or homologous recombination (HR) deficiency ovarian cancer but have limited efficacy in HR-proficient patients. GPX4 is a key regulator of ferroptosis and has been proven to be associated with multiple drug sensitivities. As a molecule that regulates the sensitivity of multiple drugs, the relationship between GPX4 and the efficacy of PARPi in HR-proficient ovarian cancer has not been elucidated. METHODS: In this study, siRNA transfection was used to regulate the expression of GPX4. The effect of GPX4 inhibition on HR-proficient ovarian cancer was determined by CCK-8 assay and flow cytometry. Immunofluorescence and comet assays were used to reflect DNA dam-age. ROS production was measured using DCFH-DA and flow cytometry. The combination index of PARP inhibitors and RSL3 was calculated using CompuSyn software based on Chou-Talalay methodology. RESULTS: GPX4 inhibition confers HR-proficient ovarian cancer cells sensitive to PARPi due to ROS generation and oxidative stress caused by DNA double-strand breakage. The combina-tion of olaparib and niraparib with GPX4 inhibitor RSL3 also showed a synergistic effect. CONCLUSION: Combining GPX4 inhibition with PARP inhibitors resulted in a notable increase in DNA damage, ultimately causing the death of cancer cells with proficient HR pathways. Our findings may provide new therapeutic options for HR-proficient patients to benefit from PARP inhibitors and improve outcomes.

The PARP1 selective inhibitor saruparib (AZD5305) elicits potent and durable antitumor activity in patient-derived BRCA1/2-associated cancer models.

BACKGROUND: Poly (ADP-ribose) polymerase 1 and 2 (PARP1/2) inhibitors (PARPi) are targeted therapies approved for homologous recombination repair (HRR)-deficient breast, ovarian, pancreatic, and prostate cancers. Since inhibition of PARP1 is sufficient to cause synthetic lethality in tumors with homologous recombination deficiency (HRD), PARP1 selective inhibitors such as saruparib (AZD5305) are being developed. It is expected that selective PARP1 inhibition leads to a safer profile that facilitates its combination with other DNA damage repair inhibitors. Here, we aimed to characterize the antitumor activity of AZD5305 in patient-derived preclinical models compared to the first-generation PARP1/2 inhibitor olaparib and to identify mechanisms of resistance. METHODS: Thirteen previously characterized patient-derived tumor xenograft (PDX) models from breast, ovarian, and pancreatic cancer patients harboring germline pathogenic alterations in BRCA1, BRCA2, or PALB2 were used to evaluate the efficacy of AZD5305 alone or in combination with carboplatin or an ataxia telangiectasia and Rad3 related (ATR) inhibitor (ceralasertib) and compared it to the first-generation PARPi olaparib. We performed DNA and RNA sequencing as well as protein-based assays to identify mechanisms of acquired resistance to either PARPi. RESULTS: AZD5305 showed superior antitumor activity than the first-generation PARPi in terms of preclinical complete response rate (75% vs. 37%). The median preclinical progression-free survival was significantly longer in the AZD5305-treated group compared to the olaparib-treated group (> 386 days vs. 90 days). Mechanistically, AZD5305 induced more replication stress and genomic instability than the PARP1/2 inhibitor olaparib in PARPi-sensitive tumors. All tumors at progression with either PARPi (39/39) showed increase of HRR functionality by RAD51 foci formation. The most prevalent resistance mechanisms identified were the acquisition of reversion mutations in BRCA1/BRCA2 and the accumulation of hypomorphic BRCA1. AZD5305 did not sensitize PDXs with acquired resistance to olaparib but elicited profound and durable responses when combined with carboplatin or ceralasertib in 3/6 and 5/5 models, respectively. CONCLUSIONS: Collectively, these results show that the novel PARP1 selective inhibitor AZD5305 yields a potent antitumor response in PDX models with HRD and delays PARPi resistance alone or in combination with carboplatin or ceralasertib, which supports its use in the clinic as a new therapeutic option.

Expanding the Perspective on PARP1 and Its Inhibitors in Cancer Therapy: From DNA Damage Repair to Immunomodulation.

The emergence of PARP inhibitors as a therapeutic strategy for tumors with high genomic instability, particularly those harboring BRCA mutations, has advanced cancer treatment. However, recent advances have illuminated a multifaceted role of PARP1 beyond its canonical function in DNA damage repair. This review explores the expanding roles of PARP1, highlighting its crucial interplay with the immune system during tumorigenesis. We discuss PARP1's immunomodulatory effects in macrophages and T cells, with a particular focus on cytokine expression. Understanding these immunomodulatory roles of PARP1 not only holds promise for enhancing the efficacy of PARP inhibitors in cancer therapy but also paves the way for novel treatment regimens targeting immune-mediated inflammatory diseases.

Case report of two long term ovarian cancer survivors with brain metastases following multimodal treatment including chemotherapy, radiotherapy and maintenance olaparib: An institutional case series and literature review.

Brain metastasis from ovarian cancer is a very rare condition with a poor prognosis. However, due to its rarity, there is no established treatment strategy. We present a case series of brain metastasis with ovarian cancer, focusing on two long-term survivors treated with multimodal therapy. Among the nine cases, the median survival time after brain metastases was six months (range: 0-58 months). Eight patients had high-grade serous carcinoma (HGSC). Three of the four patients who underwent genetic testing tested positive for germline BRCA2 (gBRCA2) mutation. Two patients survived longer than 4 years after the diagnosis of brain metastases. Both of these patients received chemotherapy, radiation therapy, and olaparib, a molecularly targeted drug, as maintenance therapy. This case series suggests that patients with gBRCA2 mutation-positive HGSC may be at a high risk of developing brain metastases. A multidisciplinary approach, including PARP inhibitors, may improve the prognosis of patients with brain metastases from ovarian cancer.

Shifting Paradigms in TNBC Treatment: Emerging Alternatives to Capecitabine in the Post-Neoadjuvant Setting.

BACKGROUND: Triple-negative breast cancer (TNBC) remains a clinically challenging subtype due to its aggressive nature and limited treatment options post-neoadjuvant failure. Historically, capecitabine has been the cornerstone of adjuvant therapy for TNBC patients not achieving a pathological complete response (pCR). However, the integration of new modalities such as immunotherapy and PARP inhibitors has prompted a re-evaluation of traditional post-neoadjuvant approaches. METHODS: This review synthesizes data from pivotal clinical trials and meta-analyses to evaluate the efficacy of emerging therapies in the post-neoadjuvant setting. We focus on the role of immune checkpoint inhibitors (ICIs), PARP inhibitors (PARPis), and antibody-drug conjugates (ADCs) alongside or in place of capecitabine in TNBC treatment paradigms. RESULTS: The addition of ICIs like pembrolizumab to neoadjuvant regimens has shown increased pCR rates and improved event-free survival, posing new questions about optimal post-neoadjuvant therapies. Similarly, PARPis have demonstrated efficacy in BRCA-mutated TNBC populations, with significant improvements in disease-free survival (DFS) and overall survival (OS). Emerging studies on ADCs further complicate the adjuvant landscape, offering potentially efficacious alternatives to capecitabine, especially in patients with residual disease after neoadjuvant therapy. DISCUSSION: The challenge remains to integrate these new treatments into clinical practice effectively, considering factors such as drug resistance, patient-specific characteristics, and socio-economic barriers. This review discusses the implications of these therapies and suggests a future direction focused on personalized medicine approaches in TNBC. CONCLUSIONS: As the treatment landscape for TNBC evolves, the role of capecitabine is being critically examined. While it remains a viable option for certain patient groups, the introduction of ICIs, PARPis, and ADCs offers promising alternatives that could redefine adjuvant therapy standards. Ongoing and future trials will be pivotal in determining the optimal therapeutic strategies for TNBC patients with residual disease post-neoadjuvant therapy.