Maintenance Treatment of Newly Diagnosed Advanced Ovarian Cancer: Time for a Paradigm Shift?

Drug-Resistant Epithelial Ovarian Cancer: Current and Future Perspectives

Epithelial ovarian cancer (EOC) is a complex disease with diverse histological subtypes, which, based on the aggressiveness and course of disease progression, have recently been broadly grouped into type I (low-grade serous, endometrioid, clear cell, and mucinous) and type II (high-grade serous, high-grade endometrioid, and undifferentiated carcinomas) categories. Despite substantial differences in pathogenesis, genetics, prognosis, and treatment response, clinical diagnosis and management of EOC remain similar across the subtypes. Debulking surgery combined with platinum-taxol-based chemotherapy serves as the initial treatment for High Grade Serous Ovarian Carcinoma (HGSOC), the most prevalent one, and for other subtypes, but most patients exhibit intrinsic or acquired resistance and recur in short duration. Targeted therapies, such as anti-angiogenics (e.g., bevacizumab) and PARP inhibitors (for BRCA-mutated cancers), offer some success, but therapy resistance, through various mechanisms, poses a significant challenge. This comprehensive chapter delves into emerging strategies to address these challenges, highlighting factors like aberrant miRNAs, metabolism, apoptosis evasion, cancer stem cells, and autophagy, which play pivotal roles in mediating resistance and disease relapse in EOC. Beyond standard treatments, the focus of this study extends to alternate targeted agents, including immunotherapies like checkpoint inhibitors, CAR T cells, and vaccines, as well as inhibitors targeting key oncogenic pathways in EOC. Additionally, this chapter covers disease classification, diagnosis, resistance pathways, standard treatments, and clinical data on various emerging approaches, and advocates for a nuanced and personalized approach tailored to individual subtypes and resistance mechanisms, aiming to enhance therapeutic outcomes across the spectrum of EOC subtypes.

Side Effects from Cancer Therapies and Perspective of 1044 Long-Term Ovarian Cancer Survivors-Results of Expression VI-Carolin Meets HANNA-Holistic Analysis of Long-Term Survival with Ovarian Cancer: The International NOGGO, ENGOT, and GCIG Survey

The aim of this survey was to increase the knowledge on the characteristics and health concerns of long-term survivors (LTS; survival > 5 years) after ovarian cancer in order to tailor follow-up care. This international survey was initiated by the NOGGO and was made available to members of ENGOT and GCIG. The survey is anonymous and consists of 68 questions regarding sociodemographic, medical (cancer) history, health concerns including distress, long-term side effects, and lifestyle. For this analysis, 1044 LTS from 14 countries were recruited. In total, 58% were diagnosed with FIGO stage III/IV ovarian cancer and 43.4% developed recurrent disease, while 26.0% were receiving cancer treatment at the time of filling in the survey. LTS who survived 5-10 years self-estimated their health status as being significantly worse than LTS who survived more than 10 years (p = 0.034), whereas distress also remained high 10 years after cancer diagnosis. Almost half of the cohort (46.1%) reported still having symptoms, which were mainly lymphedema (37.7%), fatigue (23.9%), pain (21.6%), polyneuropathy (16.9%), gastrointestinal problems (16.6%), and memory problems (15.5%). Almost all patients (94.2%) regularly received follow-up care. Specialized survivorship care with a focus on long-term side effects, lifestyle, and prevention should be offered beyond the typical five years of follow-up care.

Hormone Receptors and Epithelial Ovarian Cancer: Recent Advances in Biology and Treatment Options

Epithelial ovarian cancer (EOC) is a significant cause of cancer-related mortality in women. Despite advances in diagnosis and treatment, EOC remains a challenging disease to manage, and the 5-year survival rate is still poor. The role of hormone receptors (HRs) in EOC carcinogenesis and prognosis has been actively explored; however, the role of hormone therapy (HT) in the treatment of these tumors is not well established. Most available data on HT mainly come from retrospective series and small early clinical trials. Several of these studies suggest that HT may have a role in adjuvant, maintenance therapy, or in the case of recurrent disease, especially for some subtypes of EOC (e.g., low-grade serous EOC). Furthermore, HT has recently been combined with targeted therapies, but most studies evaluating these combinations are still ongoing. The main aim of this review is to provide an overview of the progress made in the last decade to characterize the biological and prognostic role of HRs for EOC and the developments in their therapeutic targeting through HT.

PARP Inhibitors in Ovarian Cancer: A Review

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPis) have transformed the ovarian cancer (OC) treatment landscape. This narrative review provides a comprehensive overview of data for the PARPis olaparib, niraparib, and rucaparib in patients with OC and discusses their role in disease management, with a focus on the use of PARPis as maintenance therapy in the United States (US). Olaparib was the first PARPi to be approved as first-line maintenance monotherapy in the US, with maintenance niraparib subsequently approved in the first-line setting. Data also support the efficacy of rucaparib as first-line maintenance monotherapy. PARPi maintenance combination therapy (olaparib plus bevacizumab) also provides benefit in patients with newly diagnosed advanced OC whose tumors tested positive for homologous recombination deficiency (HRD). Biomarker testing is critical in the newly diagnosed setting to identify patients most likely to benefit from PARPi maintenance therapy and guide treatment decisions. Clinical trial data support the use of PARPis (olaparib, niraparib, rucaparib) as second-line or later maintenance therapy in patients with platinum-sensitive relapsed OC. Although distinct differences in tolerability profile were observed between PARPis, they were generally well tolerated, with the majority of adverse events managed by dose modification. PARPis had no detrimental effect on patients' health-related quality of life. Real-world data support the use of PARPis in OC, although some differences between PARPis are apparent. Data from trials investigating novel combination strategies, such as PARPis plus immune checkpoint inhibitors, are awaited with interest; the optimal sequencing of novel therapies in OC remains to be established.

Poly (ADP-ribose) polymerase inhibitors (PARPi) in ovarian cancer: lessons learned and future directions

Poly (ADP-ribose) polymerase inhibitors (PARPi) represent a new standard of care in the upfront treatment of advanced epithelial ovarian cancer to the point that the vast majority of patients now receive a PARPi, alone or in combination with the anti-angiogenic bevacizumab, as part of their first-line maintenance therapy. The clinical benefit of PARPi is well established; however, much has changed since their introduction and several relevant questions have been raised and remain unresolved in the post-PARPi era. The decision-making process regarding the most appropriate first-line maintenance therapy could be challenging in clinical practice, especially in the homologous recombination-proficient setting, and several other factors need to be considered apart from the mutational status. Concerns regarding post-PARPi progression treatment have emerged, highlighting an unmet need to define a valid algorithm strategy. PARPi may not only compromise the response to further platinum due to cross-resistance mechanisms but the impact on subsequent non-platinum chemotherapy and surgery also remains unclear. Definitive results on the role of PARPi rechallenge are awaited, especially in the case of oligoprogression managed with locoregional treatment. Moreover, the updated overall survival data from the recurrent setting warrant caution in using PARPi as single agents for unselected patients. Several PARPi combination regimens are emerging for overcoming PARPi resistance and may become our new therapeutic armamentarium. This review discusses a set of clinically relevant issues in the PARPi era and provides a glimpse of future challenges and opportunities in ovarian cancer treatment.

Towards Personalized Management of Ovarian Cancer

Despite advances in surgery and chemotherapy, the overall outcomes for patients with advanced ovarian cancer remain poor. Although initial response rates to platinum-based chemotherapy is about 60-80%, most patients will have recurrence and succumb to the disease. However, a DNA repair-directed precision medicine strategy has recently generated real hope in improving survival. The clinical development of PARP inhibitors has transformed lives for many patients with BRCA germline-deficient and/or platinum-sensitive epithelial ovarian cancers. Antiangiogenic agents and intraperitoneal chemotherapy approaches may also improve outcomes in patients. Moreover, evolving immunotherapeutic opportunities could also positively impact patient outcomes. Here we review the current clinical state of PARP inhibitors and other clinically viable targeted approaches in ovarian cancer.

The Potential of Novel Lipid Agents for the Treatment of Chemotherapy-Resistant Human Epithelial Ovarian Cancer

Simple Summary

Disease recurrence and chemotherapy resistance are the major causes of mortality for the majority of epithelial ovarian cancer (EOC) patients. Standard of care relies on cytotoxic drugs that induce a form of cell death called apoptosis. EOC cells can evolve to resist apoptosis. We developed drugs called glycosylated antitumor ether lipids (GAELs) that kill EOC cells by a mechanism that does not involve apoptosis. GAELs most likely induce cell death through a process called methuosis. Importantly, we showed that GAELs are effective at killing chemotherapy-resistant EOC cells in vitro and in vivo. Our work shows that the EOC community should begin to investigate methuosis-inducing agents as a novel therapeutic platform to treat chemotherapy-resistant EOC.

Abstract

Recurrent epithelial ovarian cancer (EOC) coincident with chemotherapy resistance remains the main contributor to patient mortality. There is an ongoing investigation to enhance patient progression-free and overall survival with novel chemotherapeutic delivery, such as the utilization of antiangiogenic medications, PARP inhibitors, or immune modulators. Our preclinical studies highlight a novel tool to combat chemotherapy-resistant human EOC. Glycosylated antitumor ether lipids (GAELs) are synthetic glycerolipids capable of killing established human epithelial cell lines from a wide variety of human cancers, including EOC cell lines representative of different EOC histotypes. Importantly, GAELs kill high-grade serous ovarian cancer (HGSOC) cells isolated from the ascites of chemotherapy-sensitive and chemotherapy-resistant patients grown as monolayers of spheroid cultures. In addition, GAELs were well tolerated by experimental animals (mice) and were capable of reducing tumor burden and blocking ascites formation in an OVCAR-3 xenograft model. Overall, GAELs show great promise as adjuvant therapy for EOC patients with or without chemotherapy resistance.

PARP inhibitors rising as an epoch-making strategy in first-line maintenance therapy of ovarian cancer: A systematic review and meta-analysis

Background To illustrate the accurate location of PARP inhibitor (PARPi) as the first-line maintenance therapy in advanced ovarian cancer (AOC).Methods Search for eligible studies and calculate clinical outcomes.Results PARPi as a first-line maintenance treatment significantly prolonged the BRCAmut population and the HRD positive population.Conclusion PARPi as first-line maintenance therapy significantly improves the PFS in AOC, especially in the BRCAmut and HRD positive populations. PARPi has been becoming the standard first-line maintenance therapy for AOC.

Noncoding RNAs in the Glycolysis of Ovarian Cancer

Energy metabolism reprogramming is the characteristic feature of tumors. The tumorigenesis, metastasis, and drug resistance of ovarian cancer (OC) is dependent on energy metabolism. Even under adequate oxygen conditions, OC cells tend to convert glucose to lactate, and glycolysis can rapidly produce ATP to meet their metabolic energy needs. Non-coding RNAs (ncRNAs) interact directly with DNA, RNA, and proteins to function as an essential regulatory in gene expression and tumor pathology. Studies have shown that ncRNAs regulate the process of glycolysis by interacting with the predominant glycolysis enzyme and cellular signaling pathway, participating in tumorigenesis and progression. This review summarizes the mechanism of ncRNAs regulation in glycolysis in OC and investigates potential therapeutic targets.

ONC206 has anti-tumorigenic effects in human ovarian cancer cells and in a transgenic mouse model of high-grade serous ovarian cancer

ONC206, a dopamine receptor D2 (DRD2) antagonist and imipridone, is a chemically modified derivative of ONC201. Recently, ONC206 and other imipridones were identified as activators of the mitochondrial protease ClpP, inducing downstream pathways that allow them to selectively target cancer cells. Clinical trials showed that ONC201, the first in class imipridone, was well tolerated and exhibited tumor regression in some solid tumors. Our goal was to evaluate the effect of ONC206 on cell proliferation and tumor growth in ovarian cancer cell lines and in a transgenic mouse model of high grade serous ovarian cancer (KpB model). ONC206 was more potent than ONC201 in inhibiting cell proliferation, as evidenced by a 10-fold decrease in IC50 for the SKOV3 and OVCAR5 cell lines. This was accompanied by the results that ONC206 significantly inhibited cellular proliferation, induced cell cycle G1 arrest and apoptosis, caused cellular stress, and inhibited adhesion and invasion in vitro. Treatment of obese and non-obese KpB mice with ONC206 elevated Bip and ClpP expression and reduced KI67, BCL-XL and DRD2 expression in the ovarian tumors. Our findings demonstrate that ONC206 has anti-tumorigenic effects in ovarian cancer as previously demonstrated by ONC201 but appears to be as well tolerated and more potent. Thus, ONC206 deserves further evaluation in clinical trials.

Machine Learning-Based Risk Prediction of Critical Care Unit Admission for Advanced Stage High Grade Serous Ovarian Cancer Patients Undergoing Cytoreductive Surgery: The Leeds-Natal Score

Achieving complete surgical cytoreduction in advanced stage high grade serous ovarian cancer (HGSOC) patients warrants an availability of Critical Care Unit (CCU) beds. Machine Learning (ML) could be helpful in monitoring CCU admissions to improve standards of care. We aimed to improve the accuracy of predicting CCU admission in HGSOC patients by ML algorithms and developed an ML-based predictive score. A cohort of 291 advanced stage HGSOC patients with fully curated data was selected. Several linear and non-linear distances, and quadratic discriminant ML methods, were employed to derive prediction information for CCU admission. When all the variables were included in the model, the prediction accuracies were higher for linear discriminant (0.90) and quadratic discriminant (0.93) methods compared with conventional logistic regression (0.84). Feature selection identified pre-treatment albumin, surgical complexity score, estimated blood loss, operative time, and bowel resection with stoma as the most significant prediction features. The real-time prediction accuracy of the Graphical User Interface CCU calculator reached 95%. Limited, potentially modifiable, mostly intra-operative factors contributing to CCU admission were identified and suggest areas for targeted interventions. The accurate quantification of CCU admission patterns is critical information when counseling patients about peri-operative risks related to their cytoreductive surgery.