Metastatic High-grade Serous Carcinoma Research Articles

Human peritoneal fluid exerts ovulation- and nonovulation-sourced oncogenic activities on transforming fallopian tube epithelial cells

Secretory cells in the fallopian tube fimbria epithelium (FTE) are regarded as the main cells of origin of ovarian high-grade serous carcinoma (HGSC). Ovulation is the main cause of FTE oncogenesis, which proceeds through a sequence of TP53 mutations, chromosomal instability due to Rb/cyclin E aberration, in situ carcinoma (STIC), and metastasis to the ovary and peritoneum (metastatic HGSC). Previously, we have identified multiple oncogenic activities of the ovulatory follicular fluid (FF), which exerts the full spectrum of transforming activity on FTE cells at different stages of transformation. After ovulation, the FF is transfused into the peritoneal fluid (PF), in which the FTE constantly bathes. We wondered whether PF exerts the same spectrum of oncogenic activities as done by FF and whether these activities are derived from FF. By using a panel of FTE cell lines with p53 mutation (FT282-V), p53/CCNE1 aberrations (FT282-CCNE1), and p53/Rb aberrations plus spontaneous transformation, and peritoneal metastasis (FEXT2), we analyzed the changes of different transformation phenotypes after treating with FF and PF collected before or after ovulation. Similar to effects exhibited by FF, we found that, to a lesser extent, PF promoted anchorage-independent growth (AIG), migration, anoikis resistance, and peritoneal attachment in transforming FTE cells. The more transformed cells were typically more affected. Among the transforming activities exhibited by PF treatment, AIG, Matrigel invasion, and peritoneal attachment growth were higher with luteal-phase PF treatment than with the proliferative-phase PF treatment, suggesting an ovulation source. In contrast, changes in anoikis resistance and migration activities were similar in response to treatment with PF collected before and after ovulation, suggesting an ovulation-independent source. The overall transforming activity of luteal-phase PF was verified in an i.p. co-injection xenograft mouse model. Co-injection of Luc-FEXT2 cells with either FF or luteal-phase PF supported early peritoneal implantation, whereas co-injection with follicular-phase PF did not. This study, for the first time, demonstrates that PF from ovulating women can promote different oncogenic phenotypes in FTE cells at different stages of malignant transformation. Most of these activities, other than anoikis resistance and cell migration, are sourced from ovulation.

Claudin-10 is a new candidate prognostic marker in metastatic high-grade serous carcinoma

The objective of this study was to analyze the expression and prognostic role of the tight junction protein claudin-10 in high-grade serous carcinoma (HGSC). Claudin-10 protein expression by immunohistochemistry was analyzed in 588 HGSC (414 effusions, 174 surgical specimens). Expression in mesotheliomas (n = 97; 47 effusions, 50 surgical specimens) was studied for comparative purposes. CLDN10 mRNA expression by quantitative RT-PCR (qRT-PCR) was analyzed in 40 HGSC effusions. Claudin-10 protein expression was found in 360/588 (61%) HGSC vs. 19/97 (20%) mesotheliomas (p < 0.001), and was higher in HGSC surgical specimens compared to effusions (p < 0.001). qRT-PCR confirmed the presence of CLDN10 mRNA in HGSC effusions. High (> 25%) claudin-10 expression in HGSC effusions was significantly associated with shorter overall survival (OS; p = 0.036) and progression-free survival (PFS; p = 0.045) in univariate analysis, and was an independent prognosticator of OS in multivariate analysis (p = 0.045). In conclusion, claudin-10 protein expression is higher in HGSC compared to mesothelioma, although the diagnostic power of this marker appear to be lesser than other claudin family members. Claudin-10 expression in HGSC effusions is marker of more aggressive disease.

Discordance of PD-L1 expression in primary and metastatic ovarian high-grade serous carcinoma and its correlation with CD8 + tumor-infiltrating lymphocytes and patient prognosis.

Differential expression of programmed death-1 ligand (PD-L1) and its clinical significance in primary and metastatic ovarian high-grade serous carcinoma (HGSC) have not been defined. Thus, we investigated the PD-L1 expression of paired ovarian primary and omental metastatic HGSC and its correlation with CD8 + tumor-infiltrating lymphocyte (TILs) and patient survival. A total of 212 cases of ovarian HGSCs with matched primary ovarian and metastatic omental tumors accessioned between 2003 and 2018 were selected for further analysis. Using immunohistochemistry, we evaluated the density of CD8 + TILs and expression of PD-L1 on whole tissue sections. Applying tumor proportion score (TPS, cutoff 1%) and combined positive score (CPS, cutoff 1), the prevalence of PD-L1 expression was similar but with significant discordance in ovarian and omental tumor. Using TPS, patients with PD-L1-positive tumors demonstrated significantly worse recurrence free survival (RFS) and overall survival (OS) than patients with PD-L1-negative tumors. Using CPS, patients with PD-L1-positive ovarian tumors demonstrated significantly worse OS while no significant difference in RFS was found. Patients with PD-L1-positive omental tumors demonstrated significantly worse RFS and OS. Patients with omental PD-L1-positive tumors (TPS) were associated with poorer RFS and OS, while patients with ovarian PD-L1-positive tumors (TPS) were associated with OS not RFS, in COX multivariant analysis. Nonetheless, ovarian and omental high CD8 TILs density was not associated with worse OS in univariant and COX multivariant analysis. PD-L1 expression in ovarian and omental tumor associated with an increased CD8 + TILs density. PD-L1 expression by TPS was better correlated with survival than by CPS, and PD-L1 expression in omental tumors was a stronger prognostic indicator than that in ovarian tumors.

S2362 Paraneoplastic Mucous Membrane Pemphigoid: Not Your Typical Cause of Odynophagia

Introduction: Paraneoplastic Mucous Membrane Pemphigoid (MMP) is a rare inflammatory autoimmune disorder that primarily affects the oral, ocular and aerodigestive mucous membranes and is associated with an underlying malignancy. IgG, IgA, and C3 autoantibodies target basal membrane zones causing subepithelial blisters with erosive lesions in the mucosa. It is rarely seen in the clinical setting, with an incidence of 2-10 cases in 100,000 individuals. High clinical suspicion is needed in order to diagnose Paraneoplastic MMP presenting as odynophagia and dysphagia. Case Description/Methods: A 88 year old female presented with a 5 month history of worsening odynophagia, dysphagia to solids and liquids and a fifty pound weight loss. Physical examination was remarkable for diffuse erosive lesions of the oral mucosa, tense bullae on the soft palate, and bilateral temporal symblepharon along with inflammation of upper and lower eyelids. Laboratory workup demonstrated elevated Cancer Antigen-125 (574.20 U/mL). Immunofluorescence study of biopsies taken from esophageal mucosa, right lateral tongue lesions and the left inferior conjunctiva were remarkable for IgG, IgM, IgA interkeratinocytic deposits at lower level of the epidermis and C3 linear deposits at the dermoepidermal junction consistent with Paraneoplastic Mucous Membrane Pemphigoid. Chest-abdominal-pelvic computed tomography scan demonstrated an irregular enhancing right adnexal mass, intra-abdominal lymphadenopathy, left hemiabdomen omental metastatic deposits and bilateral pulmonary nodules. Computed tomography guided core biopsy of a left omentum deposit was remarkable for primary ovarian metastatic high grade serous carcinoma. Due to refractory odynophagia and dysphagia, intravenous Solumedrol was initiated with subsequent improvement of symptoms. Patient was discharged with multidisciplinary team follow up for chemotherapy initiation and Rituxan induction. Discussion: Paraneoplastic MMP is an uncommon autoimmune mucocutaneous disease diagnosed when there is presence of stomatitis, histologic features of acantholysis or interface dermatitis, demonstration of anti-plakin autoantibodies on biopsy, with an underlying neoplasm. Less than 500 cases have been reported where clinical features, presentation, and autoantibodies profiles have varied widely between patients highlighting the challenge of diagnosis. Early recognition of Paraneoplastic MMP presenting as odynophagia is difficult due to the overlap of symptoms in more prevalent conditions.

Genomic catastrophe, the peritoneal cavity and ovarian cancer prevention.

The current theory of carcinogenesis for the deadliest of 'ovarian' cancers-high-grade serous carcinoma (HGSC)-holds that the malignancy develops first in the fallopian tube and spreads to the ovaries, peritoneum, and/or regional lymph nodes. This is based primarily on the observation of early forms of serous neoplasia (serous tubal intraepithelial lesions [STILs], and serous tubal intraepithelial carcinomas [STICS]) in the fimbria of women undergoing risk reduction surgery. However, these lesions are uncommon in the general population, confer a low risk (5%) of HGSC following their removal in at-risk women with germ-line BRCA1/2 mutations, and require 4 or more years to recur as intraperitoneal HGSC. These features suggest that isolated STILs and STICs behave as precursors, with uncertain cancer risk rather than carcinomas. Their evolution to HGSC within, or after, escape from the tube could proceed stepwise with multiple biologic events; however, it is unclear whether tubal or ovarian HGSCs encountered in the setting of advanced disease evolved in the same fashion. The latter scenario could also be explained by a 'catastrophic' model in which STICs suddenly develop with invasive and metastatic potential, overwhelming or obscuring the site of origin. Moreover, a similar model might explain the sudden emergence of HGSC in the peritoneal cavity following escape of precursor cells years before. Long-term follow-up data from opportunistic or prophylactic salpingectomy should shed light on where malignant transformation occurs, as well as the timeline from precursor to metastatic HGSC. © 2022 The Pathological Society of Great Britain and Ireland.

Robotic assisted cytoreductive surgery, removal of a recurrent disease in the right pericaval lymph node in a patient with ovarian cancer with the robotic Xi platform.

ObjectiveThe standard approach for recurrent ovarian cancer is laparotomy. In this video, we present a cytoreductive surgery using the robotic Xi platform to remove a 2.7 cm pericaval tumor.MethodsA narrative video demonstration of robotic-assisted surgery to remove recurrent ovarian cancer in a pericaval lymph node. A 62-year-old female presented with recurrent carcinoma of the pericaval lymph node. After 40 months of surveillance, the patient was asymptomatic, but a computed tomography (CT) scan showed an isolated mass (2.7×2.3 cm) in the right pericaval lymph node. Her cancer antigen (CA)-125 level increased from 26 to 46 U/mL. The robotic Xi platform was used to remove the metastatic lymph nodes. The first step was diagnostic laparoscopy. The second step was robotic port placement below the umbilicus. The third step was dissection and identification of landmarks, and the last step was removal of the tumor and closure.ResultsThe metastatic lymph nodes were removed. The patient was discharged on postoperative day 1 and had no postoperative complications. Her CA-125 level dropped to 17 U/mL two weeks after surgery. Pathology showed metastatic high-grade serous carcinoma in one lymph node, consistent with the patient’s known primary. Two additional lymph nodes were removed and negative for carcinoma. Pelvic washings were negative for malignancy.ConclusionRobotic-assisted surgery is safe and feasible in selected patients with isolated recurrent disease.

Co-evolution of matrisome and adaptive adhesion dynamics drives ovarian cancer chemoresistance

Due to its dynamic nature, the evolution of cancer cell-extracellular matrix (ECM) crosstalk, critically affecting metastasis and treatment resistance, remains elusive. Our results show that platinum-chemotherapy itself enhances resistance by progressively changing the cancer cell-intrinsic adhesion signaling and cell-surrounding ECM. Examining ovarian high-grade serous carcinoma (HGSC) transcriptome and histology, we describe the fibrotic ECM heterogeneity at primary tumors and distinct metastatic sites, prior and after chemotherapy. Using cell models from systematic ECM screen to collagen-based 2D and 3D cultures, we demonstrate that both specific ECM substrates and stiffness increase resistance to platinum-mediated, apoptosis-inducing DNA damage via FAK and β1 integrin-pMLC-YAP signaling. Among such substrates around metastatic HGSCs, COL6 was upregulated by chemotherapy and enhanced the resistance of relapse, but not treatment-naïve, HGSC organoids. These results identify matrix adhesion as an adaptive response, driving HGSC aggressiveness via co-evolving ECM composition and sensing, suggesting stromal and tumor strategies for ECM pathway targeting.

The phosphatase PTPN1/PTP1B is a candidate marker of better chemotherapy response in metastatic high-grade serous carcinoma.

To analyse the expression and clinical role of the phosphatase PTPN1 (PTP1B) in serous effusions. PTPN1 mRNA expression by quantitative RT-PCR was analysed in 83 high-grade serous carcinoma (HGSC) and 15 malignant mesothelioma (MM) effusions. PTP1B and phospho-PTP1B (pPTP1B) protein expression by immunohistochemistry was analysed in 62 HGSC and 44 MM effusions. PTPN1 mRNA (P=.048), PTP1B protein (P=.047) and pPTP1B protein (P<.001) were overexpressed in HGSC compared to MM effusions. PTPN1 mRNA was additionally overexpressed in post-chemotherapy HGSC effusions compared to chemo-naïve effusions (P=.005). However, pPTP1B protein expression was higher in effusions from patients with FIGO stage III compared to stage IV (P=.006), and higher expressions of both PTPN1 mRNA (P=.041) and PTP1B protein (P=.035) in HGSC effusions were associated with better (complete) chemotherapy response at diagnosis. PTPN1 RNA and protein expression was unrelated to survival in HGSC, whereas a trend for shorter overall survival (P=.06) was found for MM patients whose tumours expressed pPTP1B protein. PTPN1 is overexpressed in HGSC compared to MM effusions, and may be a marker of better chemotherapy response in the former. Whether PTPN1 activation is informative of adverse outcome in MM merits further investigation.

Carcinosarcomas of Ovary/Fallopian Tube: A Rare Entity

Abstract Introduction/Objective Adnexal carcinosarcomas (MMMTs) are rare tumors (1–4% ovarian carcinomas) with worse prognosis than high grade serous carcinomas (HGS) at similar stage. They typically present at age 64–66, often with peritoneal involvement. They are biphasic tumors with stem cells undergoing divergent epithelial and sarcomatous differentiation. The epithelial component is usually HGS and drives progression of the tumor. The mesenchymal component can be homologous with high-grade spindled cells or heterologous with malignant cartilage, bone, muscle or fat. Metastases are mostly epithelial; metastatic sarcomatous components are unusual. We reviewed our single- institutional experience of adnexal MMMTs. Methods We reviewed our pathology database (2001–2019) to find all cases of adnexal MMMTs. We reviewed their histological features, histology of metastases and clinical outcomes. Results Our series consisted of 12 cases. Patients aged 41–82 years. The primary tumor sites were ovary (6 cases, 50%), fallopian tube (4, 33%), 1 each (8%) in paratubal region and infundibular ligament. Fallopian tube was involved in 8/12 cases (4 cases as primary MMMT, 4 cases with STIC or HGS). Epithelial component was serous (75%), endometrioid (17%) and mucinous (8%). Sarcomatous component was homologous in 5 cases (41%), heterologous in 7 cases: cartilage (33%), cartilage/muscle (8%), muscle (8%), cartilage/muscle/fat (8%). 3 cases were FIGO stage I, 9 had peritoneal metastases (8 stage III, 1 stage IV). Six cases had metastatic HGS; 3 had metastatic HGS with sarcomatous component, 2 with heterologous elements. Aberrant p53 pattern was seen in 7/12 and TP53 mutation was noted in 6/12. Ten patients received cytoreductive surgery and chemotherapy. 7 patients are alive with progression free survival ranging 6–59 months, 2 survived for 25 and 29 months, 3 are lost to follow-up. Conclusion Metastatic sarcomatous heterologous elements are rare in uterine carcinosarcomas and may suggest adnexal origin. They may correlate with worse outcome; in our series, 1/2 died after 29 months, the other was lost to follow-up. Fallopian tube involvement (75% of our cases) is of significance as identical TP53 mutation has been identified in a case report of ovarian carcinosarcoma with fallopian tube STIC. Also, our 2 cases of infundibular ligament and paratubal region may indicate seeding from fallopian tube. Further studies are needed to confirm the correlation.

Death-domain-associated protein (DAXX) is a novel prognostic factor in metastatic high-grade serous carcinoma

Death-domain-associated protein (DAXX) is a novel prognostic factor in metastatic high-grade serous carcinoma

Abstract 1237: Biological effects of a FRα-targeting antibody-drug conjugate, IMGN853 (mirvetuximab soravtansine) in high-grade serous ovarian cancer

Abstract Objective: Autophagic cell death is an important mechanism induced by blocking folate receptor (FRα) in inhibiting tumor growth. Here, our objective is to examine the biological effects of IMGN853 (mirvetuximab soravtansine) in preclinical models of ovarian cancer and to identify potential combination therapies. Methods: In vitro, immunoblotting, assays for cell viability, proliferation and cell cycle by fluorescence-activated cell sorting (FACS) were performed in an array of high grade serous carcinoma (HGSC) cell lines. Autophagy flux and activities of autophagy factors were also determined. In vivo, metastasis mouse models were used for testing the therapeutic efficacy of IMGN853 monotherapy or in combination with olaparib or cisplatin. Potential synergy with these drugs was assessed using in vitro assays. The resulting tumors were subjected to immunohistochemistry and reverse phase protein arrays (RPPA). Results: Data from the Cancer Genome Atlas Data (TCGA) revealed that FRα copy-number alterations was significantly correlated with shorter disease-free survival in patients with HGSC. Autophagy marker LC3 was upregulated following monotherapy with IMGN853 as well as in combination of IMGN853 with olaparib or cisplatin in HGSC cell lines such as OVCA8 and OVCA432, which express high-level of FRα. Experiments using metastatic HGSC models showed that IMGN853 monotherapy reduced tumor growth (30% change); the combination of IMGN853 and olaparib was superior to olaparib monotherapy (24% change; p 0.0033). Integrated analysis on RPPA revealed increased expression of ABL1 and PEA15 in the groups treated with IMGN853 monotherapy or in combination with olaparib. We further found reduced FRα expression and increased caspase 3 expression in IMGN853 groups compared with control. Conclusion: Our results point to sustained autophagy in FRα positive cells as a mechanism of effect of IMGN853. These findings could have implications for clinical development of anti-FRα therapies, especially in combination with other drugs such as olaparib. Citation Format: Anca Chelariu-Raicu, Elaine Stur, Cristina Ivan, Robert L. Coleman, Anil K. Sood, Wen Yunfei. Biological effects of a FRα-targeting antibody-drug conjugate, IMGN853 (mirvetuximab soravtansine) in high-grade serous ovarian cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1237.

M2-like macrophages dictate clinically relevant immunosuppression in metastatic ovarian cancer

BackgroundThe immunological microenvironment of primary high-grade serous carcinomas (HGSCs) has a major impact on disease outcome. Conversely, little is known on the microenvironment of metastatic HGSCs and its potential influence...

Abstract B17: Modeling ovarian cancer in mice using in vivo electroporation and CRISPR-mediated genome editing

Abstract Ovarian cancer is the fifth largest cause of cancer-related deaths in women. The vast majority of ovarian cancers are epithelial ovarian cancers, and high-grade serous carcinoma (HGSC) is the most common and most lethal epithelial ovarian cancer. In the last 10 years, it has been recognized that the cell of origin of most HGSCs is within the fallopian tube epithelium, instead of the ovarian surface epithelium. However, the early events in disease progression still remain poorly defined, because HGSC is usually diagnosed at advanced stages and there is a lack of proper animal models recapitulating human disease progression. My group has recently developed a unique strategy for generating mouse ovarian cancer models, which is a combination of in vivo fallopian tube electroporation, Cre-mediated lineage tracing and CRISPR-mediated gene modifications. As proof of principle, we generated a highly metastatic HGSC model by targeting four tumor suppressor genes. The female mice targeted these four genes generated ovarian tumors within 5 months after electroporation and peritoneal metastasis within 6 months. After 6 months, ascites formation was observed in two third of those females. Interestingly, similar to human ovarian cancer patients, we observed two metastatic patterns, miliary and nonmiliary. Our unique strategy has several advantages over the current mouse cancer models: 1) high flexibility permitting many gene combinations/modifications and host genetic backgrounds to be tested; 2) control over the size and area of targeted cells (the low-frequency mosaic transfection pattern better recapitulates the sporadic nature of human tumorigenesis); 3) the ability to track genetically modified cells by fluorescent reporters, permitting analysis of tumor initiation and early metastasis; and 4) highly metastatic mouse models with immune competency. Citation Format: Keerthana Harwalkar, Katie Teng, Jocelyn Arceneau, Yifan Zhao, Dave Farnell, Matt Ford, Tuyet Nhung Tun Nu, David Huntsman, Yojiro Yamanaka. Modeling ovarian cancer in mice using in vivo electroporation and CRISPR-mediated genome editing [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 B17.

Death domain-associated protein (DAXX) expression is associated with poor survival in metastatic high-grade serous carcinoma

The objective of this study was to analyze the expression and clinical role of mitosis regulators α-thalassemia/mental retardation syndrome X-linked (ATRX) and death-domain-associated protein (DAXX) in metastatic high-grade serous carcinoma (HGSC). ATRX and DAXX protein expression by immunohistochemistry was analyzed in 400 HGSC effusions. DAXX expression was additionally studied in 15 cancer cell lines, including 4 ovarian carcinoma lines, and in 81 of the 400 HGSC effusions using Western blotting. ATRX and DAXX were expressed in HGSC cells in 386/400 (96%) and 348/400 (87%) effusions, respectively. Western blotting showed DAXX expression in all 15 cell lines and in 70/81 (86%) HGSC effusions. DAXX expression by immunohistochemistry was higher in pleural compared to peritoneal effusions (p = 0.006) and in post-chemotherapy compared to pre-chemotherapy effusions (p = 0.004), and its expression was significantly associated with poor overall survival in univariate of the entire cohort (p = 0.014), as well as analysis limited to chemo-naïve effusions tapped at diagnosis (p = 0.038). The former association retained its prognostic role in Cox multivariate survival analysis (p = 0.011). ATRX expression was unrelated to clinicopathologic parameters or survival. In conclusion, DAXX is associated with disease progression and could be a prognostic marker in metastatic HGSC. Silencing this molecule may have therapeutic relevance in this cancer.

Expression of the cancer stem cell marker SSEA1 is associated with poor survival in metastatic high-grade serous carcinoma

The objective of the present study was to perform a quantitative analysis of cancer stem cell (CSC) marker expression in ovarian carcinoma effusions. The clinical role of SSEA1 in metastatic high-grade serous carcinoma (HGSC) was additionally analyzed. CD133, Nanog, SOX2, Oct3/4, SSEA1, and SSEA4 protein expressions were quantitatively analyzed using flow cytometry (FCM) in 24 effusions. SSEA1 expression by immunohistochemistry was analyzed in 384 HGSC effusions. Highly variable expression of CSC markers by FCM was observed, ranging from 0 to 78% of Ber-EP4-positive cells in the case of CD133, with the largest number of negative specimens seen for SSEA4. SSEA1 expression by immunohistochemistry was found in HGSC cells in 336/384 (89%) effusions, most commonly focally (< 5% of cells). SSEA1 was overexpressed in post-chemotherapy disease recurrence specimens compared with chemo-naïve HGSC effusions tapped at diagnosis (p = 0.029). In univariate survival analysis, higher SSEA1 expression was significantly associated with poor overall survival (p = 0.047) and progression-free survival (p = 0.018), though it failed to retain its prognostic role in Cox multivariate survival analysis in which it was analyzed with clinical parameters (p = 0.059 and p = 0.111 for overall and progression-free survival, respectively). In conclusion, CSC markers are variably expressed in ovarian carcinoma effusions. SSEA1 expression is associated with disease progression and poor survival in metastatic HGSC. Silencing this molecule may have therapeutic relevance in this cancer.

Expression of Wnt pathway molecules is associated with disease outcome in metastatic high-grade serous carcinoma

The objective of this study was to analyze the expression and clinical role of Wnt pathway molecules in metastatic high-grade serous carcinoma (HGSC). mRNA expression by qPCR of 20 molecules related to Wnt signaling (WNT1, WNT2, WNT3, WNT4, WNT5A, WNT6, WNT7, WNT11, FZD1, FZD4, FZD5, FZD6, FZD7, FZD8, FZD10, LRP5, LRP6, DKK, CCND, RUNX2) was analyzed in 87 HGSC effusions. Thirty-nine surgical specimens (19 ovarian, 20 from otherintra-abdominal sites) were analyzed for comparative purposes. Protein expression of YAP and LRP and their phosphorylated forms by western blotting were analyzed in 52 tumors. Significant differences in mRNA expression as a function of the anatomic site were observed for WNT3 (p = 0.005), WNT5A (p = 0.008), WNT7 (p < 0.001), FRZ5 (p = 0.04), and FRZ6 (p < 0.001). YAP and LRP and their phosphorylated forms were detected in HGSC specimens. FZD10 was overexpressed in effusions from patients who had complete response to chemotherapy compared with those with less favorable response (p = 0.037). WNT4 (p = 0.005), WNT7 (p = 0.047), RUNX2 (p = 0.038), LRP5 (p = 0.022), LRP6 (p = 0.011), FZD6 (p = 0.036), FZD7 (p = 0.004), and FZD10 (p = 0.015) levels were inversely related to primary chemoresistance. High FZD5 levels in pre-chemotherapy effusions tapped at diagnosis and high WNT2 levels in post-chemotherapy disease recurrence effusions were related to shorter overall survival (p = 0.018 and p = 0.011, respectively), whereas high RUNX2 (p = 0.031) and FZD1 (p = 0.029) in post-chemotherapy effusions were associated with longer overall survival. In multivariate analysis of post-chemotherapy cases, WNT2 (p = 0.002), RUNX2 (p = 0.017), FZD1 (p = 0.036), and FZD4 (p = 0.013) were independent prognosticators. In conclusion, expression of Wnt pathway molecules is anatomic site dependent. In HGSC effusions, it is informative of chemoresponse and survival.

A detailed morphological and immunohistochemical comparison of primary endometrial and tubo-ovarian high-grade serous carcinomas and their corresponding omental metastases

Increasingly, high-grade serous carcinomas (HGSCs) of fallopian tube/ovarian origin are managed initially with neoadjuvant chemotherapy (NACT) and pre-treatment diagnosis is often based upon relatively limited core biopsy and/or cytology specimens. Endometrial HGSC can also present with adnexal and peritoneal metastasis, thus mimicking a primary tubo-ovarian neoplasm, but the role of NACT in these cases is less established. Immunohistochemistry has been considered useful in this distinction but with a wide range of reported findings in the literature. In this study we have examined tumour growth patterns and the expression p16, Ki-67, WT1, PAX2, HER2, ER-α, ER-β, PR, and BAF250a in 18 tubo-ovarian and 14 endometrial HGSCs, comparing the findings in primary and omental sites. Metastatic tubo-ovarian carcinomas demonstrated significantly more varied architectural patterns than metastatic endometrial HGSCs (median 2.5 versus 1). None of the immunohistochemical markers proved completely reliable but only endometrial HGSC were WT1 negative (7/14 metastatic tumours) or demonstrated over-expression of HER2 (2/14 cases). Micropapillary tumour elements more often showed retained PAX2 and WT1 expression, low Ki-67 labelling, and (in endometrial tumours) PR staining. Diverse architectural patterns suggest tubo-ovarian origin in a metastatic HGSC. Immunohistochemical results should be cautiously interpreted, particularly in small specimens.

Calreticulin exposure correlates with robust adaptive antitumor immunity and favorable prognosis in ovarian carcinoma patients

BackgroundAdjuvanticity, which is the ability of neoplastic cells to deliver danger signals, is critical for the host immune system to mount spontaneous and therapy-driven anticancer immune responses. One of such signals, i.e., the exposure of calreticulin (CALR) on the membrane of malignant cells experiencing endoplasmic reticulum (ER) stress, is well known for its role in the activation of immune responses to dying cancer cells. However, the potential impact of CALR on the immune contexture of primary and metastatic high-grade serous carcinomas (HGSCs) and its prognostic value for patients with HGSC remains unclear.MethodWe harnessed a retrospective cohort of primary (no = 152) and metastatic (no = 74) tumor samples from HGSC patients to investigate the CALR expression in relation with prognosis and function orientation of the tumor microenvironment. IHC data were complemented with transcriptomic and functional studies on second prospective cohort of freshly resected HGSC samples. In silico analysis of publicly available RNA expression data from 302 HGSC samples was used as a confirmatory approach.ResultsWe demonstrate that CALR exposure on the surface of primary and metastatic HGSC cells is driven by a chemotherapy-independent ER stress response and culminates with the establishment of a local immune contexture characterized by TH1 polarization and cytotoxic activity that enables superior clinical benefits.ConclusionsOur data indicate that CALR levels in primary and metastatic HGSC samples have robust prognostic value linked to the activation of clinically-relevant innate and adaptive anticancer immune responses.

SOX2 and SOX9 are markers of clinically aggressive disease in metastatic high-grade serous carcinoma

ObjectiveThe aim of this study was to analyze the expression, biological role and clinical relevance of cancer stem cell markers in high-grade serous carcinoma (HGSC). MethodsmRNA expression by qRT-PCR of NANOG, OCT4, SOX2, SOX4, SOX9, LIN28A and LIN28B was analyzed in 134 HGSC specimens (84 effusions, 50 surgical specimens). Nanog, OCT3/4, SOX2 and SOX9 protein expression by immunohistochemistry was analyzed in 52 HGSC effusions. Nanog protein expression in exosomes from 80 HGSC effusions was studied by Western Blotting. OVCAR3 cells underwent CRISPR/Cas9 Nanog knockout (KO), and the effect of Nanog KO on migration, invasion, proliferation and proteolytic activity was analyzed in OVCAR3 and OVCAR8 cells. ResultsOCT4 mRNA was overexpressed in effusions compared to solid specimens (p = 0.046), whereas SOX9 was overexpressed in the ovarian tumors compared to effusions and solid metastases (p = 0.003). Higher SOX2 and SOX9 expression was associated with primary (intrinsic) chemoresistance (p = 0.009 and p = 0.02, respectively). Higher SOX9 levels were associated with shorter overall survival in univariate (p = 0.04) and multivariate (p = 0.049) analysis. OCT3/4, SOX2 and SOX9 proteins were found in HGSC cells, whereas Nanog was detected only in exosomes. Higher SOX2 protein expression was associated with shorter overall survival in univariate analysis (p = 0.049). OVCAR cells exposed to OVCAR3 NANOG KO exosomes had reduced migration, invasion and MMP9 activity. ConclusionsSOX2 and SOX9 mRNA levels in HGSC effusions may be markers of clinically aggressive disease. Nanog is secreted in HGSC exosomes in effusions and modulates tumor-promoting cellular processes in vitro.

Cell Origins of High-Grade Serous Ovarian Cancer.

High-grade serous ovarian cancer, also known as high-grade serous carcinoma (HGSC), is the most common and deadliest type of ovarian cancer. HGSC appears to arise from the ovary, fallopian tube, or peritoneum. As most HGSC cases present with widespread peritoneal metastases, it is often not clear where HGSC truly originates. Traditionally, the ovarian surface epithelium (OSE) was long believed to be the origin of HGSC. Since the late 1990s, the fallopian tube epithelium has emerged as a potential primary origin of HGSC. Particularly, serous tubal intraepithelial carcinoma (STIC), a noninvasive tumor lesion formed preferentially in the distal fallopian tube epithelium, was proposed as a precursor for HGSC. It was hypothesized that STIC lesions would progress, over time, to malignant and metastatic HGSC, arising from the fallopian tube or after implanting on the ovary or peritoneum. Many clinical studies and several mouse models support the fallopian tube STIC origin of HGSC. Current evidence indicates that STIC may serve as a precursor for HGSC in high-risk women carrying germline BRCA1 or 2 mutations. Yet not all STIC lesions appear to progress to clinical HGSCs, nor would all HGSCs arise from STIC lesions, even in high-risk women. Moreover, the clinical importance of STIC remains less clear in women in the general population, in which 85–90% of all HGSCs arise. Recently, increasing attention has been brought to the possibility that many potential precursor or premalignant lesions, though composed of microscopically—and genetically—cancerous cells, do not advance to malignant tumors or lethal malignancies. Hence, rigorous causal evidence would be crucial to establish that STIC is a bona fide premalignant lesion for metastatic HGSC. While not all STICs may transform into malignant tumors, these lesions are clearly associated with increased risk for HGSC. Identification of the molecular characteristics of STICs that predict their malignant potential and clinical behavior would bolster the clinical importance of STIC. Also, as STIC lesions alone cannot account for all HGSCs, other potential cellular origins of HGSC need to be investigated. The fallopian tube stroma in mice, for instance, has been shown to be capable of giving rise to metastatic HGSC, which faithfully recapitulates the clinical behavior and molecular aspect of human HGSC. Elucidating the precise cell(s) of origin of HGSC will be critical for improving the early detection and prevention of ovarian cancer, ultimately reducing ovarian cancer mortality.