Advanced Stage Serous Ovarian Cancer Research Articles

Single-arm phase II trial of carboplatin and mirvetuximab soravtansine as neoadjuvant chemotherapy (NACT) for advanced- stage ovarian, fallopian tube or primary peritoneal cancer (EOC) who are folate receptor α positive (NCT04606914) (578)

Objectives: The primary objective is to assess the feasibility and safety of obtaining tissue, assessing alpha-folate receptor status, and initiating treatment based on this data using a 21-day schedule in the advanced-stage ovarian, fallopian tube, or peritoneal cancer patients, without an unacceptable interval debulking surgery (IDS) delay. Secondary objectives include assessing progression-free survival, percentage of disease-free survival at two years, ORR prior to IDS per iRECIST 1.1 and GCIG CA-125 criteria, and percentage of optimal cytoreduction and pathological complete response (pCR) at IDS. Methods: This is a phase II study design with carboplatin and mirvetuximab (FRa receptor monoclonal antibody.) Patients with biopsy-confirmed, newly diagnosed, advanced-stage serous epithelial ovarian cancer appropriate for NACT will have centralized tumor evaluation via immunohistochemistry for FRa receptor overexpression. IHC staining is 2+ in 75% of cells will define eligibility. Patients will receive NACT with one lead-in cycle of single-agent carboplatin AUC 5/6, physician’s choice), followed by AUC 5 carboplatin and Mirvetuximab 6mg/kg adjusted to ideal body weight every 21days for three cycles prior to interval cytoreductive surgery (iCRS.) Patients eligible for surgery will undergo an iCRS no sooner than three weeks but no later than six weeks following the completion of cycle 3. Postoperatively, patients will complete three additional cycles of carboplatin-mirvetuximab for a total of 6 intended cycles. A total of 70 patients will be included. Patients with BRCA mutations are not excluded from this trial and may receive standard of care maintenance therapy, including bevacizumab and/or PARP inhibitors per physician’s choice in the adjuvant setting. After completion of adjuvant treatment, participants will be assessed approximately every 12 weeks by radiologic imaging to monitor disease status using RECIST 1.1 criteria. Objectives: The primary objective is to assess the feasibility and safety of obtaining tissue, assessing alpha-folate receptor status, and initiating treatment based on this data using a 21-day schedule in the advanced-stage ovarian, fallopian tube, or peritoneal cancer patients, without an unacceptable interval debulking surgery (IDS) delay. Secondary objectives include assessing progression-free survival, percentage of disease-free survival at two years, ORR prior to IDS per iRECIST 1.1 and GCIG CA-125 criteria, and percentage of optimal cytoreduction and pathological complete response (pCR) at IDS. Methods: This is a phase II study design with carboplatin and mirvetuximab (FRa receptor monoclonal antibody.) Patients with biopsy-confirmed, newly diagnosed, advanced-stage serous epithelial ovarian cancer appropriate for NACT will have centralized tumor evaluation via immunohistochemistry for FRa receptor overexpression. IHC staining is 2+ in 75% of cells will define eligibility. Patients will receive NACT with one lead-in cycle of single-agent carboplatin AUC 5/6, physician’s choice), followed by AUC 5 carboplatin and Mirvetuximab 6mg/kg adjusted to ideal body weight every 21days for three cycles prior to interval cytoreductive surgery (iCRS.) Patients eligible for surgery will undergo an iCRS no sooner than three weeks but no later than six weeks following the completion of cycle 3. Postoperatively, patients will complete three additional cycles of carboplatin-mirvetuximab for a total of 6 intended cycles. A total of 70 patients will be included. Patients with BRCA mutations are not excluded from this trial and may receive standard of care maintenance therapy, including bevacizumab and/or PARP inhibitors per physician’s choice in the adjuvant setting. After completion of adjuvant treatment, participants will be assessed approximately every 12 weeks by radiologic imaging to monitor disease status using RECIST 1.1 criteria.

Prolongation of Neoadjuvant Chemotherapy before Surgery: Seeking the Optimal Number of Cycles in Serous Ovarian Cancer

Aim: The optimal number of neoadjuvant chemotherapy (NACT) cycles is unclear in epithelial ovarian cancer. Our study aimed to evaluate the effect of the number of NACT cycles before interval debulking surgery on survival. Methods: Data of 221 patients with advanced-stage serous epithelial ovarian cancer (EOC) were retrospectively evaluated. The patients were divided into groups as who received 3 cycles of NACT (group A), 4-5 cycles of NACT (group B), and 6 cycles of NACT (group C). Results: There were 67 (30%) patients in group A, 70 (32%) in group B, and 84 (38%) in group C. Median overall survival (OS) was 61 (range 43–79) months for group A, 44 (range 36–52) months for group B, and 39 (range 27–50) months for group C. In addition, median disease-free survival (DFS) was 23.1 (range 8.5–32.1) months for group A, 19.2 (range 10.1–28.4) months for group B, and 21.5 (range 16–27) months for group C. Patients receiving >3 NACT cycles had worse OS than patients who received 3 NACT cycles (for group A vs. B, p = 0.018; for group A vs. C, p = 0.049). However, in terms of DFS, patients receiving 3 NACT cycles had no statistically significant difference compared to patients who received >3 NACT cycles. Conclusions: Patients with advanced-stage serous EOC who received more than 3 cycles of NACT had poor OS. However, there was no statistical difference in terms of DFS. In addition, >3 cycles of NACT did not increase the probability of achieving complete cytoreduction at the time of surgery.

Omental Macrophagic "Crown-like Structures" Are Associated with Poor Prognosis in Advanced-Stage Serous Ovarian Cancer.

The tumor microenvironment is a well-recognized framework in which immune cells present in the tumor microenvironment promote or inhibit cancer formation and development. A crown-like structure (CLS) has been reported as a dying or dead adipocyte surrounded by a ‘crown’ of macrophages within adipose tissue, which is a histologic hallmark of the inflammatory process in this tissue. CLSs have also been found to be related to formation, progression and prognosis of some types of cancer. However, the presence of CLSs in the omentum of advanced-stage high-grade serous ovarian carcinoma (HGSOC) has not been thoroughly investigated. By using CD68, a pan-macrophage marker, and CD163, an M2-like polarization macrophage marker, immunohistochemistry (IHC) was performed to identify tumor-associated macrophages (TAMs) and CLSs. This retrospective study analyzed 116 patients with advanced-stage HGSOC who received complete treatment and had available clinical data from July 2008 through December 2016 at National Cheng Kung University Hospital (NCKUH) (Tainan, Taiwan). Based on multivariate Cox regression analysis, patients with omental CD68+ CLSs had poor OS (median survival: 24 vs. 38 months, p = 0.001, hazard ratio (HR): 2.26, 95% confidence interval (CI): 1.41–3.61); patients with omental CD163+ CLSs also had poor OS (median survival: 22 vs. 36 months, HR: 2.14, 95%CI: 1.33–3.44, p = 0.002). Additionally, patients with omental CD68+ or CD163+ CLSs showed poor PFS (median survival: 11 vs. 15 months, HR: 2.28, 95%CI: 1.43–3.64, p = 0.001; median survival: 11 vs. 15 months, HR: 2.17, 95%CI: 1.35–3.47, respectively, p = 0.001). Conversely, the density of CD68+ or CD163+ TAMs in ovarian tumors was not associated with patient prognosis in advanced-stage HGSOC in our cohort. In conclusion, we, for the first time, demonstrate that the presence of omental CLSs is associated with poor prognosis in advanced-stage HGSOC.

Identification of a Novel Tumor Microenvironment Prognostic Signature for Advanced-Stage Serous Ovarian Cancer.

Simple SummaryThe expression of tumor microenvironment-related genes is known to be correlated with ovarian cancer patients’ prognosis. Immunotherapeutic targets are in part located in this complex cluster of cells and soluble factors. In our study, we constructed a prognostic 11-gene signature for advanced serous ovarian cancer from tumor microenvironment-related genes through lasso regression. The established risk score can quantify the prognosis of ovarian cancer patients more accurately and is able to predict the putative biological response of cancer samples to a programmed death ligand 1 blocking immunotherapy. This might empower the role of immunotherapy in ovarian cancer through its usage in future study protocols.(1) Background: The tumor microenvironment is involved in the growth and proliferation of malignant tumors and in the process of resistance towards systemic and targeted therapies. A correlation between the gene expression profile of the tumor microenvironment and the prognosis of ovarian cancer patients is already known. (2) Methods: Based on data from The Cancer Genome Atlas (379 RNA sequencing samples), we constructed a prognostic 11-gene signature (SNRPA1, CCL19, CXCL11, CDC5L, APCDD1, LPAR2, PI3, PLEKHF1, CCDC80, CPXM1 and CTAG2) for Fédération Internationale de Gynécologie et d’Obstétrique stage III and IV serous ovarian cancer through lasso regression. (3) Results: The established risk score was able to predict the 1-, 3- and 5-year prognoses more accurately than previously known models. (4) Conclusions: We were able to confirm the predictive power of this model when we applied it to cervical and urothelial cancer, supporting its pan-cancer usability. We found that immune checkpoint genes correlate negatively with a higher risk score. Based on this information, we used our risk score to predict the biological response of cancer samples to an anti-programmed death ligand 1 immunotherapy, which could be useful for future clinical studies on immunotherapy in ovarian cancer.

Transcriptome-based stemness indices analysis reveals platinum-based chemo-theraputic response indicators in advanced-stage serous ovarian cancer

ABSTRACT Serous ovarian cancer (SOC) is a main histological subtype of ovarian cancer, in which cancer stem cells (CSC) are responsible for its chemoresistance. However, the underlying modulation mechanisms of chemoresistance led by cancer stemness are still undefined. We aimed to investigate potential drug-response indicators among stemness-associated biomarkers in advanced SOC samples. The mRNA expression-based stemness index (mRNAsi) of The Cancer Genome Atlas (TCGA) was evaluated and corrected by tumor purity. Weighted gene co-expression network analysis (WGCNA) was utilized to explore the gene modules and key genes involved in stemness characteristics. We found that mRNAsi and corrected mRNAsi scores were both greater in tumors of Grade 3 and 4 than that of Grade 1 and 2. Forty-two key genes were obtained from the most significant mRNAsi-related gene module. Functional annotation revealed that these key genes were mainly involved in the mitotic division. Thirteen potential platinum-response indicators were selected from the genes enriched to platinum-response associated pathways. Among them, we identified 11 genes with prognostic value of progression-free survival (PFS) in advanced SOC patients treated with platinum and 7 prognostic genes in patients treated with a combination of platinum and taxol. The expressions of the 13 key genes were also validated between platinum-resistant and -sensitive SOC samples of advanced stages in two Gene Expression Omnibus (GEO) datasets. The results revealed that CDC20 was a potential platinum-sensitivity indicator in advanced SOC. These findings may provide a new insight for chemotherapies in advanced SOC patients clinically.

Abstract IA06: The Long-Term Ovarian Cancer Survivor Project: A Department of Defense initiative

Abstract In 2019 there will be 22,500 new cases of ovarian cancer, resulting in approximately 14,000 deaths. Ovarian cancer remains the highest case fatality rate of any gynecologic cancer. Despite significant improvement in the surgical and chemotherapeutic managements of ovarian cancer patients, the overall survival has not changed in 30 years. However, these new therapies have resulted in a significant improvement in median survival, resulting in increasing numbers of patients surviving greater than 10 years with disease. The clinical and molecular features of these unique patients remain uncharacterized. The Department of Defense Ovarian Cancer Research Program (DOD OCRP) funded the creation of our interdisciplinary Long-term Survivor Consortium (LTSC), composed of 6 research sites including MDACC, UAB, IU, UCI, Ludwig Cancer Research, and University Hospitals of Canton Vaud (CHUV) and INOVA, a bioinformatic center at DFCI, and administrative centers at UCI and UAB. The purpose of the consortium is to identify characteristics and predictors of long-term survival in advanced ovarian cancer patients. The consortium is overseen by both a scientific and advocacy advisory board to guide direction and efforts. 285 specimens of advanced-stage high-grade serous ovarian cancers with full clinical annotation including greater than 12 years of follow-up were analyzed for this project. In addition, 340 early-stage high-grade ovarian cancers were available for one of the AIMs of the project. These latter samples were obtained through the creation of an international consortium funded by the DOD OCRP. All specimens were first reviewed for tumor context by H&E staining to determine percentage of tumor. The scientific platforms include whole transcriptome, microRNAs, global proteomics, immune profiling, and methylation. All specimens were analyzed on each individual platform and the results will be integrated in a global process. In parallel with these efforts, a systematic analysis of quality of life of patients at the time of diagnosis and later during the course of their disease based upon patient-reported outcome surveys has been undertaken. These data will also be integrated with genomic results to produce signatures that can further characterize long-term survivors of ovarian cancer. Citation Format: Michael J. Birrer, Lari Wenzel, Austin Miller, Heather Lankes, Nilsa Ramirez, Giovanni Parmigiani, Samuel Mok, Kenneth Nephew, Thomas Conrads, George Coukos, George L. Maxwell, Giulia Fulci, Mary Scroggins. The Long-Term Ovarian Cancer Survivor Project: A Department of Defense initiative [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr IA06.

Abstract AP26: CANCER STEM CELLS: DISTINCT SEEDS FOR RECURRENT OVARIAN CANCER

Abstract PURPOSE: The treatment of ovarian cancer (OC) with chemotherapy leaves resistant cancer cells which in a short time re-grow as recurrent cancer. A diverse array of resistance mechanisms for chemotherapy has been described but none have proven as viable targets in a clinical setting. Cancer stem cells (CSCs) are increasingly accepted as the putative mediators of chemoresistance and relapse of cancer. This study aimed to understand the molecular mechanisms involved with chemoresistance and recurrence by investigating the proteomic profile of ascites-derived tumor cells obtained from OC patients prior to (chemonaive, CN) and after chemotherapy treatments (recurrent, CR). METHODS: Ascites collected from CN and CR OC patients diagnosed with advanced-stage serous OC were cultured using a novel in vitro method to obtain a distinct population of epithelial tumor cells. Flow cytometry and immunofluorescence were used to characterize the tumor population. High-resolution label-free quantitative proteomic profiling was used to define significantly differentially expressed proteins between CN and CR tumor cells. KEGG and DAVID software's were used to determine pathways associated with CR cells. The mechanisms of survival of cisplatin and paclitaxel-treated OC cancer cells were determined in vitro by mRNA analysis and in vivo mouse xenograft models by immunohistochemistry. RESULTS: Proteomic profiling of CN and CR tumor cells showed significant differences in proteins encoding for CSC, immune surveillance, DNA repair mechanisms, cytoskeleton rearrangement, cell-cell adhesion, cell cycle pathways, cellular transport, and proteins involved with glycine/proline/arginine synthesis in tumor cells isolated from CR relative to CN patients. Pathway analyses revealed enrichment of chemoresistance markers, energy metabolism, DNA repair mechanisms and immune surveillance pathways in recurrent CR tumor cells. Validation of these pathways in OC cell lines and nude mice treated with chemotherapy demonstrated increased expression of CSC and chemoresistant markers, enhancement in glycolytic pathway and oxidative phosphorylation, suppression of immune surveillance in chemotherapy treated cell lines and recurrent mice xenografts compared to untreated control. CONCLUSION: These findings unravel some of the molecular mechanisms by which chemoresistance and relapse occur in OC patients' post-chemotherapy treatment; and may be important in designing novel therapeutic options for advanced-stage OC patients. Citation Format: Nuzhat Ahmed, Ruth Escalona, Elif Kadife, Dilys Leung and George Kannourakis. CANCER STEM CELLS: DISTINCT SEEDS FOR RECURRENT OVARIAN CANCER [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr AP26.

Correlation of differential ascites volume with primary cytoreductive surgery outcome, lymph node involvement, and disease recurrence in advanced ovarian cancer.

High-grade serous ovarian cancer accounts for a disproportionate number of deaths from gynecologic malignancies. It typically presents at an advanced stage and with a high volume of ascites a common presenting feature. The aims of this study is to evaluate the association between ascites volume at the time of primary surgery for advanced stage ovarian cancer with surgical outcomes and patterns of recurrence. A retrospective review of stage III/IV high-grade serous ovarian cancer patients who underwent primary surgery at two centers between March 2003 to June 2016. Patients were categorized as low-volume ascites (≤ 200 mL) vs high-volume (≥ 1 L). Patients with an unknown volume of ascites or neoadjuvant chemotherapy were excluded. Patients' characteristics were compared for the two groups. Probability of recurrence over time and the HR from a proportional hazards model for sub-distribution were calculated. A total of 210 patients were included, 90 (42.9%) patients in the low-volume and 120 (57.1%) patients in the high-volume group. Patients in the low-volume group were older with a median age of 60.2 years vs 56.8 years in the high-volume group and had lower serum CA-125 levels (mean 223 vs 971.5 U/mL). The low-volume group had better surgical outcome with suboptimal debulking (> 1 cm residual disease) in only 17.8 % vs 39.2 % in the high-volume group and had longer median time to recurrence (2.8 years in low-volume vs 1.6 years high-volume group). At the time of recurrence, the low-volume group had a less disseminated pattern of recurrence, lower rates of ascites (20 % in the low-volume group vs 37.2 % in the high-volume group), and a trend toward lower serum CA125 levels (mean 352.8 vs 596.9 U/mL). Advanced stage serous ovarian cancer patients who present with low-volume ascites have lower serum CA125 levels, more optimal cytoreduction rates, and longer disease-free interval. The low-volume group had less ascites, less disseminated disease, and a trend toward lower serum CA125 levels at the time of recurrence.

Interactions of Omentin and Lactotransferrin in the Progression of Metastatic Ovarian Cancer

Advanced stage serous ovarian cancer metastasizes preferentially to the omentum, which is a major site of intra‐abdominal fat accumulation and is covered by a layer of mesothelial cells (mesothelium). Ovarian cancer cells first adhere to and then penetrate through the mesothelium. It was previously shown the expression of adipokine omentin (ITLN1) in mesothelial cells was down‐regulated when mesothelial cells were co‐cultured with ovarian cancer cells. Survival correlation studies demonstrated that patients with serum ITLN1 levels of >350 ng/mL at the time of first treatment experienced longer survival times than those with lower levels of ITLN1. In addition, wound‐healing assay and invasion assay demonstrated that ovarian cancer cells (SKOV3 and A224) treated with physiological levels of ITLN1 showed a significant decrease in motility and invasion potential. However, the molecular mechanism by which ITLN1 modulates these malignant phenotypes remains unknown. Cancer cells migrate using cell‐matrix mechanocoupling mechanisms through paths generated by the degradation and remodeling of the extracellular matrix (ECM) and by force‐mediated deformation (powered by cell traction force from cancer cells). To explore whether omentin suppresses ovarian cancer invasion potential via inhibiting ECM proteolysis, RNA sequencing and pathway analyses were performed on ITLN1 treated cancer cells. Significantly lower levels of MMP1 (matrix metalloproteinase‐1) was found in cancer cells treated with ITLN1 than untreated cells, which was confirmed by qRT‐PCR analysis. Since ITLN1 has been shown to interact with LTF (lactotransferrin), and binding of LTF to its receptors LRP1 (low‐intensity lipoprotein‐receptor‐related protein 1) can transcriptionally upregulate MMP1, an in vitro pull‐down assay on purified LTF and recombinant ITLN1 in serum‐free media was first performed to confirm that ITLN1 interacts and binds with LTF. To determine whether ITLN1 can interfere with the binding of LTF to LRP1 on ovarian cancer cells, a Duolink proximity ligation assay was performed using both anti‐LTF and anti‐LRP1 antibodies. There was a significant decrease in fluorescent signals in cells that were treated with ITLN1 compared to the control. The results suggested that ITLN1 interacts with LTF and prevents LTF from binding to its receptor LRP1 on ovarian cancer cells. Furthermore, ITLN1 abrogated the effects of LTF on MMP1 expression in a dose‐dependent manner in ovarian cancer cells. LTF not only induced MMP1 expression, but also triggered an increase of cytosolic Ca2+ and cell traction force in ovarian cancer cells, which were attenuated by pre‐incubation with ITLN1. Taken together, these data suggest that ITLN1 suppressed LTF's effect on the motility and invasion potential of ovarian cancer cells by decreasing MMP1 expression and cell traction force generation through modulating a calcium dependent LTF‐LRP1 signaling pathway.Support or Funding InformationDepartment of Defense: grant W81XWH‐17‐1‐0146This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Downregulated Salt-inducible Kinase 3 Expression Promotes Chemoresistance in Serous Ovarian Cancer via the ATP-binding Cassette Protein ABCG2.

Background: Epithelial ovarian cancer (EOC) has a high tumor-associated mortality rate among gynecological cancers. Although CA125 is a well-studied biomarker for ovarian cancer, it is also elevated under numerous conditions, resulting in decreased specificity. Recently, we identified a novel tumor-associated antigen, salt-inducible kinase 3 (SIK3), during tumorigenesis in ovarian cancer. However, the association between SIK3 expression and patient outcomes in ovarian cancer remains unclear.Materials and Methods: We collected EOC samples from 204 patients and examined tumor SIK3 expression by immunohistochemistry (IHC) and CA125 expression in tumors and serum. The expression levels of SIK3 and CA125 were correlated with patient survival. SIK3 expression was silenced with SIK3-specific shRNAs to investigate the possible mechanisms related to chemoresistance in serous-type ovarian cancer cell lines OVCAR4 and SKOV3.Results: In advanced-stage serous ovarian cancer, patients with low SIK3 expression have poorer overall survival (OS) and progression-free survival (PFS) than patients with high SIK3 expression. Ovarian cancer cells with SIK3 knockdown display increased chemoresistance to Taxol plus cisplatin treatment, which is associated with the upregulation of the ABCG2 transporter. In addition, in serous ovarian cancer, SIK3 expression is inversely correlated to ABCG2 expression, and patients with low SIK3 and high ABCG2 expression have worse prognosis than patients with high SIK3 and low ABCG2 expression.Conclusion: Our results demonstrated that serous EOC patients with low SIK3 expression have poor prognosis, which is associated with chemoresistance mediated by ABCG2 upregulation. SIK3 and ABCG2 expression levels may be potential prognostic markers to predict the outcome in serous EOC patients.

The road to long-term survival: Surgical approach and longitudinal treatments of long-term survivors of advanced-stage serous ovarian cancer

ObjectiveIt is unclear if the types of surgical procedures performed on long-term survivors (LTS) of high-grade serous ovarian carcinoma (HGSOC) contribute to prolonged survival. In this case-control study we review the surgical procedures performed on LTS and describe their individual longitudinal disease courses. MethodsWomen with FIGO stage III–IV high-grade serous cancer of the ovary, fallopian tube or peritoneum were selected from the University of Chicago ovarian cancer database. LTS were those surviving >7 years and controls were short-term survivors (STS) living 1–2 years. Patients with non-serous histology, low grade, and low malignant potential tumors were excluded. ResultsWe identified 450 women with stage III/IV HGSOC including 45 LTS and 78 STS. LTS showed a trend towards lower disease burden, yet underwent more aggressive surgical treatment. Interestingly, only 15 LTS (34%) were debulked to microscopic disease and 9 LTS (21%) underwent suboptimal debulking. Two LTS (5%) recurred within 12 months. LTS had heterogeneous clinical courses with 13 (29%) never experiencing a recurrence with 143 months median follow-up and 32 (71%) experiencing a recurrence with 115 months median follow-up. Of the women who recurred, 19 (59%) underwent at least one surgery for recurrence. ConclusionsAggressive surgical treatment intended to achieve microscopic disease, primary debulking surgery, preservation of sensitivity to chemotherapy, and recurrence amenable to secondary debulking are associated with long-term survival. However, clinicopathologic data are insufficient to predict long-term survival of HGSOC. Biologic characterization of these patient's tumors likely holds the key to understanding their unusually favorable courses.

Abstract 639: Salt-inducible kinase 3 expression identifies long-term survivors of serous ovarian cancer

Abstract Background: Epithelial ovarian cancer (EOC) has a high tumor-associated mortality rate among the gynecological cancers because EOC is usually diagnosed during the advanced stage. Cancer antigen (CA) 125 is the most well-studied biomarker for ovarian cancer screening. However, CA125 is also elevated in numerous conditions, resulting in decreased specificity. Materials and Method: We collected ovarian cancer specimens from 204 patients and examined the SIK3 and CA125 expression levels. The expression percentage of SIK3 or CA125 in the tumor cells, pre-surgery serum CA125 was divided into two groups and compared with patient overall survival, progression-free survival, cancer stage, cancer type and chemotherapeutic resistance. Results: A total of 30.9% of the patients had stage I disease, 7.8% had stage II disease, 52.4% had stage III disease, and 8.9% had stage IV disease. The median OS and PFS were 49.5 months (range 0.25-205 months) and 28.4 months (0.25-182.4), respectively. The mean age of the patients was 52.8 years (range 25-82 years). The histological classification was based on the four main ovarian cancer types: serous (51.5%), endometrioid (14.2%), clear cell (20.6%), and mucinous (9.3%). In all stages of the disease, high expression of SIK3 (SIK3-H) was associated with a markedly better OS, compared with low expression of SIK3 (SIK3-L) (127.0 months and 46.0 months, respectively; hazard ratio [HR] for death, 0.59; 95% confidence interval [CI], 0.41 to 0.86; P=0.005). SIK3-H had a markedly better PFS rate than SIK3-L (66.0 months and 26.0 months, respectively; HR for disease progression or recurrence, 0.68; 95% CI, 0.47 to 0.99; P=0.04). The same results were evident for serous ovarian cancer, where SIK3-H had a better OS rate than SIK3-L (75.0 months and 34.0 months, respectively; HR for death, 0.57; 95% CI, 0.36 to 0.91; P=0.02) and a better PFS rate than SIK3-L (44 and 13 months, respectively; HR, 0.52; 95% CI, 0.32 to 0.83; P=0.006). Notably, for advanced stage serous ovarian cancer, Only SIK3-H had a better OS rate than SIK3-L (48.0 months and 28.0 months, respectively; HR for death, 0.56; 95% CI, 0.33 to 0.96; P=0.03) and PFS rate (32 and 13 months, respectively; HR, 0.57; 95% CI, 0.34 to 0.95; P=0.03). Tissue CA125 expression and the pre-surgery serum CA125 level did not show significant differences in OS and PFS. Our results demonstrated that high SIK3 expression correlated with better OS and PFS rates in ovarian cancer patients, especially in patients with advanced serous ovarian cancer. Conclusion: High expression of SIK3 indicates a better prognosis in primary ovarian cancer and serous disease, especially in advanced serous disease. Citation Format: Keng-Fu Hsu, Yu-Ling Liang, Chin-Han Wu, Neng-Yao Shih. Salt-inducible kinase 3 expression identifies long-term survivors of serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 639.

The role of α2,3-linked sialylation on clear cell type epithelial ovarian cancer

ObjectiveOur previous study has shown that high expression of α2,3-sialytransferase type I was associated with advanced stage serous type epithelial ovarian cancer (EOC). The aim of the current study further attempts to evaluate the altered α 2,3-sialylation on the behavior of clear cell type EOC (C-EOC). Materials and methodsImmunohistochemistry staining, bioinformatics analysis and tissue array were used to disclose the clinical significance of over α2,3-sialylation in C-EOC. An α2,3 sialylation inhibitor, soyasaponin I (SsaI) was used to investigate the behavior change of the C-EOC cell line. ResultsWe reconfirmed that α2,3-sialylation, instead of α2,6- sialylation, was associated with late-stage C-EOC. Soyasaponin I could inhibit α2,3-sialylation of C-EOC cell lines and increase E-cadherin expression with subsequently suppressing migration of C-EOC cells. ConclusionsThe current study demonstrated the important role of α2,3-linked sialylation in C-EOC and targeting of α2,3-linked sialylation might offer as a potential therapeutic strategy in the future.

Single-gene prognostic signatures for advanced stage serous ovarian cancer based on 1257 patient samples.

We sought to identify stable single-gene prognostic signatures based on a large collection of advanced stage serous ovarian cancer (AS-OvCa) gene expression data and explore their functions. The empirical Bayes (EB) method was used to remove the batch effect and integrate 8 ovarian cancer datasets. Univariate Cox regression was used to evaluate the association between gene and overall survival (OS). The Database for Annotation, Visualization and Integrated Discovery (DAVID) tool was used for the functional annotation of genes for Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The batch effect was removed by the EB method, and 1257 patient samples were used for further analysis. We selected 341 single-gene prognostic signatures with FDR < 0.05, in which 110 and 231 genes were positively and negatively associated with OS, respectively. The functions of these genes were mainly involved in extracellular matrix organization, focal adhesion and DNA replication which are closely associated with cancer. We used the EB method to remove the batch effect of 8 datasets, integrated these datasets and identified stable prognosis signatures for AS-OvCa.

Peritoneal cancer index as a predictor of survival in advanced stage serous epithelial ovarian cancer: a prospective study.

ObjectiveA numerical score, the peritoneal cancer index (PCI), was developed to reflect the extent of tumor growth in gastric and colorectal cancers and to tailor treatment. This study aimed to examine the value of the PCI score in advanced epithelial ovarian cancer (EOC) regarding completeness of surgical cytoreduction and survival.MethodsThis was a prospective observational cohort study. Patients with primary serous EOC at International Federation of Gynecology and Obstetrics (FIGO) stages IIIB or higher were included. Patients with FIGO stage IVB as well as those assigned to receive neoadjuvant treatment were excluded from the study. The PCI was obtained and registered intraoperatively.ResultsIn the study period we recruited 96 patients with serous EOC stage IIIB–IVA. A PCI score cut-off value of 13 was calculated using a receiver operator characteristic (ROC) curve, above which worse survival is expected (area under the curve [AUC]=0.641; 95% confidence interval [CI]=0.517–0.765; sensitivity and specificity 80.6%, 45.0%, respectively; p=0.050). A multivariate analysis determined that suboptimal surgical cytoreduction was the only independent predictive factor for recurrence (odds ratio [OR]=7.548; 95% CI=1.473–38.675; p=0.015). A multivariate analysis determined that only suboptimal surgical cytoreduction (hazard ratio [HR]=2.33; 95% CI=0.616–8.795; p=0.005), but not PCI score >13 (HR=1.289; 95% CI=0.329–5.046; p=0.716), was an independent predictive factor for death.ConclusionWe conclude from this study that the PCI score is a reliable tool helping to assess the extent of disease in advanced serous EOC patients and may help predicting complete surgical cytoreduction but cannot qualify as a predictor of survival.

Expression of Placenta Growth Factor Is Associated with Unfavorable Prognosis of Advanced-Stage Serous Ovarian Cancer.

Ovarian cancer is the fourth leading cause of cancer death in women and the most fatal gynecologic malignancy. Placenta growth factor (PGF), a member of the vascular endothelial growth factor, plays an important role in angiogenesis. The overexpression of PGF was observed in several types of cancers, but the clinical significance of PGF in epithelial ovarian cancer (EOC) is still unknown. To explore the prognostic value of PGF among patients with serous EOC, we analyzed the expression of PGF in 89 EOC specimens by immunohistochemistry. The scoring system of immunohistochemistry was based on the staining intensity and the percentage of PGF-positive cells in each EOC tissue. According to the immunohistochemical score, 34 patients with score ≥ 6 were defined as high PGF expression, and other 55 patients were the group with low PGF expression. The prognostic significance of PGF expression was analyzed. EOC patients with higher IHC scores of PGF expression are significantly associated with positive lymphatic invasion and poorer response to chemotherapy. Patients with higher IHC scores of PGF expression had poorer response to chemotherapy and lower overall survival rate. Additionally, the positive lymph node metastasis, advanced TNM stage, and poorer response to chemotherapy were all remarkably correlated to poorer prognosis. In conclusion, patients with higher PGF in EOC tissues were more predisposed to positive lymphatic invasion, poorer response to chemotherapy and unfavorable prognosis of patients with serous EOC. We propose that PGF expression may be predictive of chemoresistance and poor prognosis of serous EOC.

A multiplex platform for the identification of ovarian cancer biomarkers

BackgroundCurrently, there are no FDA approved screening tools for detecting early stage ovarian cancer in the general population. Development of a biomarker-based assay for early detection would significantly improve the survival of ovarian cancer patients.MethodsWe used a multiplex approach to identify protein biomarkers for detecting early stage ovarian cancer. This new technology (Proseek® Multiplex Oncology Plates) can simultaneously measure the expression of 92 proteins in serum based on a proximity extension assay. We analyzed serum samples from 81 women representing healthy, benign pathology, early, and advanced stage serous ovarian cancer patients.ResultsPrinciple component analysis and unsupervised hierarchical clustering separated patients into cancer versus non-cancer subgroups. Data from the Proseek® plate for CA125 levels exhibited a strong correlation with current clinical assays for CA125 (correlation coefficient of 0.89, 95% CI 0.83, 0.93). CA125 and HE4 were present at very low levels in healthy controls and benign cases, while higher levels were found in early stage cases, with highest levels found in the advanced stage cases. Overall, significant trends were observed for 38 of the 92 proteins (p < 0.001), many of which are novel candidate serum biomarkers for ovarian cancer. The area under the ROC curve (AUC) for CA125 was 0.98 and the AUC for HE4 was 0.85 when comparing early stage ovarian cancer versus healthy controls. In total, 23 proteins had an estimated AUC of 0.7 or greater. Using a naïve Bayes classifier that combined 12 proteins, we improved the sensitivity corresponding to 95% specificity from 93 to 95% when compared to CA125 alone. Although small, a 2% increase would have a significant effect on the number of women correctly identified when screening a large population.ConclusionsThese data demonstrate that the Proseek® technology can replicate the results established by conventional clinical assays for known biomarkers, identify new candidate biomarkers, and improve the sensitivity and specificity of CA125 alone. Additional studies using a larger cohort of patients will allow for validation of these biomarkers and lead to the development of a screening tool for detecting early stage ovarian cancer in the general population.

Genome-wide association study evaluating single-nucleotide polymorphisms and outcomes in patients with advanced stage serous ovarian or primary peritoneal cancer: An NRG Oncology/Gynecologic Oncology Group study.

This study evaluated single nucleotide polymorphisms (SNPs) associated with progression free (PFS) and overall survival (OS) in patients with advanced stage serous EOC. Patients enrolled in GOG-172 and 182 who provided specimens for translational research and consent were included. Germline DNA was evaluated with the Illumina's HumanOMNI1-Quad beadchips and scanned using Illumina's iScan optical imaging system. SNPs with allele frequency>0.05 and genotyping rate>0.98 were included. Analysis of SNPs for PFS and OS was done using Cox regression. Statistical significance was determined using Bonferroni corrected p-values with genomic control adjustment. The initial GWAS analysis included 1,124,677 markers in 396 patients. To obtain the final data set, quality control checks were performed and limited to serous tumors and self-identified Caucasian race. In total 636,555 SNPs and 289 patients passed all the filters. The pre-specified statistical level of significance was 7.855e-08. No SNPs met this criteria for PFS or OS, however, two SNPs were close to significance (rs10899426 p-2.144e-08) (rs6256 p-9.774e-07) for PFS and 2 different SNPs were identified (rs295315 p-7.536e-07; rs17693104 p-7.734e-07) which were close to significance for OS. Using the pre-specified level of significance of 1×10-08, we did not identify any SNPs of statistical significance for OS or PFS, however several were close. The SNP's identified in this GWAS study will require validation and these preliminary findings may lead to identification of novel pathways and biomarkers.

A clinical prediction model for chemoresponse in advanced-stage serous ovarian cancer

Objective: Nearly one- third of patients with advanced-stage serous ovarian cancer will not respond to initial chemotherapy and experience very poor survival. To date, there are no diagnostic tools to identify these patients. Identifying nonresponders before initial chemotherapy would allow us to offer potentially more effective alternative targeted therapies. Our aim was to construct a prediction model of chemoresponse with clinical variables.

Abstract DPOC-001: CANCER STEM CELLS: THE SEEDS FOR RECURRENT OVARIAN CANCER

Abstract PURPOSE: The treatment of ovarian cancer (OC) with chemotherapy leaves resistant cancer cells which in a short time re–grow as recurrent cancer. A diverse array of resistance mechanisms for chemotherapy in tumor cells has been described but none has proven to be a viable target in a clinical setting. Cancer stem cells (CSCs) are increasingly accepted as the putative mediators of chemoresistance and relapse of cancer. This study aimed to understand the molecular mechanisms involved with chemoresistance and recurrence by investigating the roles of CSCs and their associated pathways in OC cell lines and tumor cells isolated from the ascites of OC patients. METHODS: Tumor cells were collected from chemonaive (CN) and recurrent (CR) OC patients diagnosed with advanced–stage serous OC using a novel in vitro method to obtain a distinct population of epithelial tumor cells. Flow cytometry and immunofluorescence were used to characterize the tumor population. High–resolution label–free quantitative proteomic profiling was used to define significantly differentially expressed proteins between CN and CR tumor cells. KEGG and DAVID software's were used to determine pathways associated with CR cells. The mechanisms of survival of in vitro cisplatin or paclitaxel treated ascites–derived tumor cells as well as cultured OC cell lines were determined by in vitro assays and in mouse xenografts. In another approach, the expression of embryonic stem cell factor Oct4A was determined in primary ovarian tumors and its functional role was investigated using in vitro assays and in vivo mouse models with stable knockdown (shRNA) of Oct4A in OC cell lines. RESULTS: Proteomic profiling of CN and CR tumor cells showed significant differences in proteins encoding for immune surveillance, DNA repair mechanisms, cytoskeleton rearrangement, cell–cell adhesion, cell cycle pathways, cellular transport, and proteins involved with glycine/proline/arginine synthesis in tumor cells isolated from CR relative to CN patients. Pathway analyses revealed enrichment of metabolic pathways, DNA repair mechanisms and energy metabolism in CR tumor cells. The treatment of ascites–derived OC cells with chemotherapy in vitro resulted in a CSC–like residual population with increased activation of JAK2/STAT3 pathway. Both JAK2/STAT3 activation and CSC–like characteristics were suppressed by a low dose JAK2 specific inhibitor, Momelotinib, in vitro and in vivo. This also resulted in a significantly reduced tumor burden and increased disease–free survival periods in mice in vivo. In another approach, stable knockdown of Oct4A resulted in the decreased expression of CSCs in OC cells and was consistent with decreased cell proliferation, migration and chemoresistance in vitro. In vivo Oct4A knockdown cells produced a significantly reduced tumor burden in mice resulting in a significantly increased disease–free survival periods compared to vector control cells. CONCLUSION: The above studies suggest that targeting the CSCs may prove a therapeutic option for advanced–stage OC patients. Citation Format: Nuzhat Ahmed, Emily Chan, Chantel Samardzija, Khalid Abubaker, Ardian Latifi, George Kannourakis &amp; Jock Findlay. CANCER STEM CELLS: THE SEEDS FOR RECURRENT OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr DPOC-001.