Exploratory biomarker analysis in the phase III L-MOCA study of olaparib maintenance therapy in patients with platinum-sensitive relapsed ovarian cancer.

BACKGROUND: The prospective phase III multi-centre L-MOCA trial (NCT03534453) has demonstrated the encouraging efficacy and manageable safety profile of olaparib maintenance therapy in the Asian (mainly Chinese) patients with platinum-sensitive relapsed ovarian cancer (PSROC). In this study, we report the preplanned exploratory biomarker analysis of the L-MOCA trial, which investigated the effects of homologous recombination deficiency (HRD) and programmed cell death ligand 1 (PD-L1) expression on olaparib efficacy. METHODS: HRD status was determined using the ACTHRD assay, an enrichment-based targeted next-generation sequencing assay. PD-L1 expression was assessed by SP263 immunohistochemistry assay. PD-L1 expression positivity was defined by the PD-L1 expression on ≥ 1% of immune cells. Kaplan-Meier method was utilised to analyse progression-free survival (PFS). RESULTS: This exploratory biomarker analysis included 225 patients and tested HRD status [N = 190; positive, N = 125 (65.8%)], PD-L1 expression [N = 196; positive, N = 56 (28.6%)], and BRCA1/2 mutation status (N = 219). The HRD-positive patients displayed greater median PFS than the HRD-negative patients [17.9 months (95% CI: 14.5-22.1) versus 9.2 months (95% CI: 7.5-13.8)]. PD-L1 was predominantly expressed on immune cells. Positive PD-L1 expression on immune cells was associated with shortened median PFS in the patients with germline BRCA1/2 mutations [14.5 months (95% CI: 7.4-18.2) versus 22.2 months (95% CI: 18.3-NA)]. Conversely, positive PD-L1 expression on immune cells was associated with prolonged median PFS in the patients with wild-type BRCA1/2 [20.9 months (95% CI: 13.9-NA) versus 8.3 months (95% CI: 6.7-13.8)]. CONCLUSIONS: HRD remained an effective biomarker for enhanced olaparib efficacy in the Asian patients with PSROC. Positive PD-L1 expression was associated with decreased olaparib efficacy in the patients with germline BRCA1/2 mutations but associated with improved olaparib efficacy in the patients with wild-type BRCA1/2. TRIAL REGISTRATION: NCT03534453. Registered at May 23, 2018.

Supragastric lesser sac: an insidious site for surgical exploration during the debulking surgery in advanced ovarian cancer.

OBJECTIVE: Metastases in the supragastric lesser sac (SGLS) are not only occult but are also barriers to complete resection of ovarian cancer. We describe a cohort of patients with SGLS disease undergoing debulking surgery. METHODS: We identified all patients who underwent evaluation and eventual resection of SGLS disease as part of cytoreductive surgery for stage IIIC-IVB high-grade epithelial ovarian cancer at our institution from January 2018 to August 2022. RESULTS: Thirty-three of 286 patients (11.5%) underwent resection of SGLS disease. Metastases in the SGLS were identified by preoperative imaging in 4 of 33 patients (12.1%). The median peritoneal cancer index score was 22 (range, 9-33). Through surgical exploration, metastases were frequently seen in the right diaphragm (100%), hepatorenal recess (97%), lesser omentum (81.8%), left diaphragm (78.8%), supracolic omentum (75.8%), anterior transverse mesocolon (72.7%), splenic hilum (63.6%), ligamentum teres hepatis (60.6%), and gallbladder fossa (51.5%). The lesser omentum was normal in 6 of 33 (18.2%) patients, despite metastases within the SGLS. A total of 54.5% of patients underwent complex surgery (surgical complexity scores; median, 8; range, 3-14). Complete resections were achieved in 19 (57.6%) patients. No complications were related to the resection of SGLS disease. The median length of progression-free survival was 24.8 months (95% confidence interval=16.6-32.9). CONCLUSION: Metastases to the SGLS are not uncommon in advanced ovarian cancer, particularly those with widely disseminated disease. Disease in this recess is rarely identified by preoperative imaging and deserves systematic surgical exploration to attain complete cytoreduction.

Therapeutic targeting of CPSF3-dependent transcriptional termination in ovarian cancer.

Transcriptional dysregulation is a recurring pathogenic hallmark and an emerging therapeutic vulnerability in ovarian cancer. Here, we demonstrated that ovarian cancer exhibited a unique dependency on the regulatory machinery of transcriptional termination, particularly, cleavage and polyadenylation specificity factor (CPSF) complex. Genetic abrogation of multiple CPSF subunits substantially hampered neoplastic cell viability, and we presented evidence that their indispensable roles converged on the endonuclease CPSF3. Mechanistically, CPSF perturbation resulted in lengthened 3'-untranslated regions, diminished intronic polyadenylation and widespread transcriptional readthrough, and consequently suppressed oncogenic pathways. Furthermore, we reported the development of specific CPSF3 inhibitors building upon the benzoxaborole scaffold, which exerted potent antitumor activity. Notably, CPSF3 blockade effectively exacerbated genomic instability by down-regulating DNA damage repair genes and thus acted in synergy with poly(adenosine 5'-diphosphate-ribose) polymerase inhibition. These findings establish CPSF3-dependent transcriptional termination as an exploitable driving mechanism of ovarian cancer and provide a promising class of boron-containing compounds for targeting transcription-addicted human malignancies.

Impact of Nitrite Supplementation on Bioactive Peptides during Sausage Processing.

The goal of this investigation was to examine the impact of nitrite supplementation on the concentration, antioxidant properties, and species of antioxidant peptides in fermented sausages. The polypeptide concentration in nitrite-supplemented sausages was markedly elevated during sausage processing compared to the blank control (p < 0.05). Moreover, nitrite supplementation in fermented sausages markedly enhanced the DPPH, as well as the ABTS, hydroxyl radical, and superoxide anion free radical scavenging abilities (FRSA) of polypeptides (p < 0.05). The ferrous ion chelating ability was also significantly enhanced (p < 0.05). Based on the liquid chromatograph-mass spectrometer (LC-MS) analysis of the sausage, LPGGGHGDL, TKYRVP, FLKMN, SAGNPN, GLAGA, LPGGGT, DLEE, GKFNV, GLAGA, AEEEYPDL, HCNKKYRSEM, TSNRYHSYPWG, and other polypeptides exhibited antioxidant properties. Moreover, the number of species of antioxidant polypeptides in the nitrite-supplemented sausage was greater in comparison to the controls. Based on this evidence, it may be concluded that nitrite supplementation positively modulated antioxidant polypeptide formation in fermented sausages, thereby providing strong evidence that nitrite supplementation significantly enhances sausage quality.

Establishment of a mouse model for ovarian cancer-associated venous thromboembolism.

Patients with ovarian cancer are at increased risk of venous thromboembolism (VTE), and the cumulative incidence is high, particularly at advanced stages of this disease. Nevertheless, it is challenging to investigate the molecular mechanisms of ovarian cancer-associated VTE (OC-VTE), mainly due to the lack of a well-developed animal model for this disease. We generated a mouse model for developing OC-VTE using ovarian cancer cell injection in combination with the inferior vena cava stenosis method. The rate of thrombosis in the OC-VTE group was 50%, compared with 0 in the control group. Moreover, we conducted a proteomic analysis using platelets from these models and revealed differentially expressed proteins between the OC-VTE and control groups, including upregulated and downregulated proteins. Gene Ontology analysis revealed that these differentially expressed proteins were mostly enriched in the biological process of negative regulation of fibrinolysis and the cellular component of the fibrinogen complex, both of which play key roles in thrombosis. In conclusion, this study lays the foundation for further investigation of the underlying mechanisms of how ovarian cancer promotes VTE formation.

Who really benefits from intraperitoneal chemotherapy for advanced ovarian cancer? A treatment-free survival analysis of the AICE trial.

OBJECTIVE: To investigate whether peritoneal disease extent can predict the survival benefit of intraperitoneal/intravenous (IP/IV) chemotherapy in ovarian cancer. DESIGN: A treatment-free survival (TFS) analysis. SETTING: Five-centre trial. POPULATION: An extended follow-up of the Additional Intraperitoneal Cisplatin and Etoposide in ovarian cancer (AICE) trial (NCT01669226), with data cut-off on 27 August 2020. Patients were categorised into subgroups with high tumour burden (HTB) and low tumour burden (LTB). METHODS: Overall survival (OS) was divided into time on protocol treatment exposure (T), time free of subsequent treatment or death (TFS) and time after the first subsequent therapy (REL). TFS analyses and quality-adjusted OS were calculated by multiplying the mean time in each health state by its assigned utility: quality-adjusted OS = ut  × T + TFS + urel  × REL. MAIN OUTCOME MEASURES: The area under each Kaplan-Meier curve was estimated using the 96-month restricted mean time, with threshold utility analyses used to illustrate quality-adjusted OS comparisons. RESULTS: In the HTB subgroup, the restricted mean TFS was 33.9 months and 18.7 months in the IP/IV and IV groups, respectively (p = 0.005), with a significant quality-adjusted OS gain (13.2-16.0 months). In the LTB subgroup, IP/IV therapy yielded no survival benefit in either TFS (p = 0.268) or quality-adjusted OS (range: 1.4-6.3 months). CONCLUSIONS: Both TFS and quality-adjusted OS was longer across all utility weight values with IP/IV than with standard IV therapy in the HTB subgroup, whereas patients in the LTB subgroup did not benefit from the therapy. The tumour burden of ovarian cancer should be assessed before deciding on IP/IV versus IV treatment.

Clinical research in ovarian cancer: consensus recommendations from the Gynecologic Cancer InterGroup.

The Gynecologic Cancer InterGroup (GCIG) sixth Ovarian Cancer Conference on Clinical Research was held virtually in October, 2021, following published consensus guidelines. The goal of the consensus meeting was to achieve harmonisation on the design elements of upcoming trials in ovarian cancer, to select important questions for future study, and to identify unmet needs. All 33 GCIG member groups participated in the development, refinement, and adoption of 20 statements within four topic groups on clinical research in ovarian cancer including first line treatment, recurrent disease, disease subgroups, and future trials. Unanimous consensus was obtained for 14 of 20 statements, with greater than 90% concordance in the remaining six statements. The high acceptance rate following active deliberation among the GCIG groups confirmed that a consensus process could be applied in a virtual setting. Together with detailed categorisation of unmet needs, these consensus statements will promote the harmonisation of international clinical research in ovarian cancer.

Investigation of the Potential Mechanisms Underlying Nuclear F-Actin Organization in Ovarian Cancer Cells by High-Throughput Screening in Combination With Deep Learning.

Increasing evidence supports the notion that filamentous actin (F-actin) and globular actin exist in the nuclei of somatic cells, and are involved in chromatin remodeling, gene transcription regulation and DNA damage repair. However, the underlying mechanisms of how nuclear F-actin are polymerized in cells remain incompletely understood. Here, we identify potential kinase targets that participate in nuclear F-actin polymerization in ovarian cancer cells using small-molecule inhibitor library screening in combination with a deep learning approach. The analysis of the targets of the inhibitors used in this study suggest that the PI3K-AKT pathway are involved in regulating nuclear F-actin organization in ovarian cancer cells. Our work lays the foundation for uncovering the important roles of nuclear F-actin in the context of ovarian cancer, and for understanding how nuclear F-actin structures are organized.

Mutation profiles in circulating cell-free DNA predict acquired resistance to olaparib in high-grade serous ovarian carcinoma.

Although resistance to poly(ADP-ribose) polymerase inhibitors (PARPi) has gradually become a major challenge in the maintenance therapy for high-grade serous ovarian carcinoma (HGSOC), there are no universal indicators for resistance monitoring in patients. A key resistance mechanism to PARPi is the restoration of homologous recombination repair (HRR), including BRCA reversion mutations and changes in DNA damage repair proteins. To explore mutation profiles associated with PARPi resistance, we undertook targeted 42-gene deep sequencing of circulating cell-free DNA (cfDNA) extracted from HGSOC patients pre- and post-treatment with olaparib maintenance therapy. We found that pathogenic germline mutations in the HRR pathway, including BRCA1/2, were strongly associated with improved clinical outcomes, and newly acquired MRE11A mutations significantly shortened the progression-free survival (PFS) of patients. Furthermore, dynamic fluctuations of somatic mutation sites in CHEK2:p.K373E and CHEK2:p.R406H can be used for evaluating the therapeutic efficacy of patients. MRE11A:p.K464R might be a vital driving factor of olaparib resistance, as patients with newly acquired MRE11A:p.K464R in post-treatment cfDNA had significantly shorter PFS than those without it. These findings provide potential noninvasive biomarkers for efficacy evaluation and resistance monitoring of olaparib treatment, and lay the foundation for developing combination treatment after olaparib resistance.

MS: Wip1 suppresses angiogenesis through the STAT3-VEGF signalling pathway in serous ovarian cancer.

Multifaceted functions of the so-called "oncogene" Wip1 have been reported in a previous study, while its actual role remains to be explored in serous ovarian cancer (SOC). In this study, by performing bioinformatic analysis with a public database and immunohistochemical staining of Wip1 in tumour tissue from SOC, we concluded that decreased expression of Wip1 was associated with a higher rate of tumour metastasis and platinum-based therapy resistance and increased ascites volume, which led to poorer prognosis in SOC patients. We also found that overexpression of Wip1 in SKOV3 cells decreased the levels of several cytokines, including VEGF, by secretome profiling analysis, and Wip1 overexpression suppressed angiogenesis both in vitro and in vivo. Mechanistic studies indicated that overexpression of Wip1 decreased the expression of VEGF at both the protein and mRNA levels and that the inhibitory effect was mediated by dephosphorylation of STAT3 at Ser727. Our study uncovered the role of Wip1 in SOC and provides a novel therapeutic strategy for suppressing angiogenesis.

SOX17 and PAX8 constitute an actionable lineage-survival transcriptional complex in ovarian cancer.

Müllerian tissue-specific oncogenes, prototyped by PAX8, underlie ovarian tumorigenesis and represent unique molecular vulnerabilities. Further delineating such lineage-dependency factors and associated therapeutic implications would provide valuable insights into ovarian cancer biology and treatment. In this study, we identified SOX17 as a new lineage-survival master transcription factor, which shared co-expression pattern with PAX8 in epithelial ovarian carcinoma. Genetic disruption of SOX17 or PAX8 analogously inhibited neoplastic cell viability and downregulated a spectrum of lineage-related transcripts. Mechanistically, we showed that SOX17 physically interacted with PAX8 in cultured cell lines and clinical tumor specimens. The two nuclear proteins bound to overlapping genomic regions and regulated a common set of downstream genes, including those involved in cell cycle and tissue morphogenesis. In addition, we revealed that small-molecule inhibitors of transcriptional cyclin-dependent kinases (CDKs) effectively reduced SOX17 and PAX8 expression. ZSQ1722, a novel orally bioavailable CDK12/13 covalent antagonist, exerted potent anti-tumor activity in xenograft models. These findings shed light on an actionable lineage-survival transcriptional complex in ovarian cancer, and facilitated drug discovery by generating a serial of candidate compounds to pharmacologically target this difficult-to-treat malignancy.

Olaparib Maintenance Monotherapy in Asian Patients with Platinum-Sensitive Relapsed Ovarian Cancer: Phase III Trial (L-MOCA).

PURPOSE: In patients with platinum-sensitive relapsed (PSR) ovarian cancer, olaparib maintenance monotherapy significantly improves progression-free survival (PFS) versus placebo. However, evidence in the Asian population is lacking. This is the first study to evaluate olaparib efficacy and tolerability exclusively in Asian patients with PSR ovarian cancer. PATIENTS AND METHODS: Considering the limited placebo effect and significant clinical benefit of olaparib in previous trials, and the rapid approval of olaparib in China, this phase III study was designed as an open-label, single-arm trial. Patients with high-grade epithelial PSR ovarian cancer were enrolled from country-wide clinical centers across China and Malaysia. Patients received oral olaparib (300 mg) twice daily until disease progression or unacceptable toxicity. Primary endpoint was median PFS (mPFS). Primary analysis of PFS using the Kaplan-Meier method was performed when data reached 60% maturity (clinicaltrials.gov NCT03534453). RESULTS: Between 2018 and 2020, 225 patients were enrolled, and 224 received olaparib; 35.7% had received ≥3 lines of chemotherapy, 35.3% had achieved complete response to their last line of platinum-based chemotherapy, and 41.1% had a platinum-free interval ≤12 months. At primary data cut-off (December 25, 2020), overall mPFS was 16.1 months; mPFS was 21.2 and 11.0 months in BRCA-mutated and wild-type BRCA subgroups, respectively. Adverse events (AE) occurred in 99.1% of patients (grade ≥3, 48.7%); 9.4% discontinued therapy due to treatment-related AEs. CONCLUSIONS: Olaparib maintenance therapy was highly effective and well tolerated in Asian patients with PSR ovarian cancer, regardless of BRCA status. This study highlights the promising efficacy of olaparib in this Asian population. See related commentary by Nicum and Blagden, p. 2201.

Randomized Trial of Cytoreductive Surgery for Relapsed Ovarian Cancer.

BACKGROUND: Treatment for patients with recurrent ovarian cancer has been mainly based on systemic therapy. The role of secondary cytoreductive surgery is unclear. METHODS: We randomly assigned patients with recurrent ovarian cancer who had a first relapse after a platinum-free interval (an interval during which no platinum-based chemotherapy was used) of 6 months or more to undergo secondary cytoreductive surgery and then receive platinum-based chemotherapy or to receive platinum-based chemotherapy alone. Patients were eligible if they presented with a positive Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) score, defined as an Eastern Cooperative Oncology Group performance-status score of 0 (on a 5-point scale, with higher scores indicating greater disability), ascites of less than 500 ml, and complete resection at initial surgery. A positive AGO score is used to identify patients in whom a complete resection might be achieved. The primary end point was overall survival. We also assessed quality of life and prognostic factors for survival. RESULTS: A total of 407 patients underwent randomization: 206 were assigned to cytoreductive surgery and chemotherapy, and 201 to chemotherapy alone. A complete resection was achieved in 75.5% of the patients in the surgery group who underwent the procedure. The median overall survival was 53.7 months in the surgery group and 46.0 months in the no-surgery group (hazard ratio for death, 0.75; 95% confidence interval, 0.59 to 0.96; P = 0.02). Patients with a complete resection had the most favorable outcome, with a median overall survival of 61.9 months. A benefit from surgery was seen in all analyses in subgroups according to prognostic factors. Quality-of-life measures through 1 year of follow-up did not differ between the two groups, and we observed no perioperative mortality within 30 days after surgery. CONCLUSIONS: In women with recurrent ovarian cancer, cytoreductive surgery followed by chemotherapy resulted in longer overall survival than chemotherapy alone. (Funded by the AGO Study Group and others; DESKTOP III ClinicalTrials.gov number, NCT01166737.).

Cancer-Associated Fibroblast-Derived Interleukin-8 Promotes Ovarian Cancer Cell Stemness and Malignancy Through the Notch3-Mediated Signaling.

As a significant component in ovarian cancer microenvironment, cancer-associated fibroblasts (CAFs) contribute to cancer progression through interaction with cancer cells. Recent studies demonstrate that interleukin-8 (IL-8) is overexpressed in multiple cancer types and is essential for tumor development. Nonetheless, the underlying mechanism that the CAF-derived IL-8 promotes ovarian tumorigenesis is unknown. Here, we show that IL-8 secreted from CAFs could activate normal ovarian fibroblasts (NFs) through multiple signaling and that IL-8 stimulated malignant growth of ovarian cancer cells in animals and increased the IC50 of cisplatin (CDDP) in ovarian cancer cells. Further study showed that IL-8 induced cancer cell stemness via the activation of Notch3 and that the high level of IL-8 in ascites was positively correlated with the expression of Notch3 in ovarian cancer tissues. Collectively, IL-8 secreted from CAFs and cancer cells promotes stemness in human ovarian cancer via the activation of the Notch3-mediated signaling, which may provide a novel strategy for ovarian cancer treatment.