Primary High-grade Serous Carcinoma Research Articles

Concurrent RB1 Loss and BRCA-Deficiency Predicts Enhanced Immunological Response and Long-Term Survival in Tubo-Ovarian High-Grade Serous Carcinoma.

To evaluate RB1 expression and survival across ovarian carcinoma histotypes, and how co-occurrence of BRCA1 or BRCA2 (BRCA) alterations and RB1 loss influences survival in tubo-ovarian high-grade serous carcinoma (HGSC). RB1 protein expression was classified by immunohistochemistry in ovarian carcinomas of 7436 patients from the Ovarian Tumor Tissue Analysis consortium. We examined RB1 expression and germline BRCA status in a subset of 1134 HGSC, and related genotype to overall survival (OS), tumor-infiltrating CD8+ lymphocytes and transcriptomic subtypes. Using CRISPR-Cas9, we deleted RB1 in HGSC cells with and without BRCA1 alterations to model co-loss with treatment response. We performed whole-genome and transcriptome data analyses on 126 primary HGSC to characterize tumors with concurrent BRCA-deficiency and RB1 loss. RB1 loss was associated with longer OS in HGSC, but with poorer prognosis in endometrioid ovarian carcinoma. Patients with HGSC harboring both RB1 loss and pathogenic germline BRCA variants had superior OS compared to patients with either alteration alone, and their median OS was three times longer than those without pathogenic BRCA variants and retained RB1 expression (9.3 vs. 3.1 years). Enhanced sensitivity to cisplatin and paclitaxel was seen in BRCA1-altered cells with RB1 knockout. Combined RB1 loss and BRCA-deficiency correlated with transcriptional markers of enhanced interferon response, cell-cycle deregulation, and reduced epithelial-mesenchymal transition. CD8+ lymphocytes were most prevalent in BRCA-deficient HGSC with co-loss of RB1. Co-occurrence of RB1 loss and BRCA-deficiency was associated with exceptionally long survival in patients with HGSC, potentially due to better treatment response and immune stimulation.

Genomic Catastrophe (Chromothripsis and Polyploidy) Correlates With Tumor Distribution in Extrauterine High-grade Serous Carcinoma.

Most extrauterine high-grade serous carcinomas (HGSCs) are thought to develop first in the distal fallopian tube. Most models of HGSC assume origin from relatively stable, noninvasive serous tubal intraepithelial carcinomas. However, widespread tumor involvement in the absence of a serous tubal intraepithelial carcinoma could occur after catastrophic genomic events (CGEs; such as chromothripsis or polyploidy). Twenty-six HGSCs assigned to fallopian tube (n = 9, group 1) and/or ovary (n = 9, group 2), and primary peritoneal (n = 8, group 3) were assessed by microarray (Oncoscan). CGEs were identified in 15/26 (57.7%); chromothripsis-like pattern in 13/26 (50.0%) and polyploidy in 6/26 (23.1%). CGE was seen in 4/9 (44.4%), 9/9 (100%), and 2/8 (25%) cases in groups 1. 2, and 3, respectively. Overall, CGEs were seen in 9/9 (100%) cases with grossly evident ovarian parenchymal involvement versus 6/17 (35.3%) without (P = 0.0024). Ovarian size (measured on the long axis) correlated with CGE positivity (P = 0.016). CGEs are significantly more common in HGSCs with ovarian parenchymal involvement compared with those limited to the fallopian tube and/or extraovarian tissues. These associations suggest geographically different tumor growth patterns and support the subdivision of HGSCs according to not only the stage but also tumor distribution. They have implications for clinical and pathologic presentation, trajectory of tumor evolution, and in the case of primary peritoneal HGSCs, potentially unique precursors to tumor transitions that could inform or influence cancer prevention efforts.

Podocalyxin promotes the formation of compact and chemoresistant cancer spheroids in high grade serous carcinoma

High grade serous carcinoma (HGSC) metastasises primarily intraperitoneally via cancer spheroids. Podocalyxin (PODXL), an anti-adhesive transmembrane protein, has been reported to promote cancer survival against chemotherapy, however its role in HGSC chemoresistance is unclear. This study investigated whether PODXL plays a role in promoting chemoresistance of HGSC spheroids. We first showed that PODXL was expressed variably in HGSC patient tissues (n = 17) as well as in ovarian cancer cell lines (n = 28) that are more likely categorised as HGSC. We next demonstrated that PODXL-knockout (KO) cells proliferated more slowly, formed less compact spheroids and were more fragile than control cells. Furthermore, when treated with carboplatin and examined for post-treatment recovery, PODXL-KO spheroids showed significantly poorer cell viability, lower number of live cells, and less Ki-67 staining than controls. A similar trend was also observed in ascites-derived primary HGSC cells (n = 6)—spheroids expressing lower PODXL formed looser spheroids, were more vulnerable to fragmentation and more sensitive to carboplatin than spheroids with higher PODXL. Our studies thus suggests that PODXL plays an important role in promoting the formation of compact/hardy HGSC spheroids which are more resilient to chemotherapy drugs; these characteristics may contribute to the chemoresistant nature of HGSC.

The prognostic significance of tumor-immune microenvironment in ascites of patients with high-grade serous carcinoma.

High-grade serous carcinoma (HGSC) is often associated with ascites at presentation. Our objective was to quantify immune cells (ICs) in ascites prior to any treatment was given and evaluate their impact on progression-free survival (PFS) and overall survival (OS). Forty-seven patients with primary HGSC and ascites were included. Flow-cytometric analysis was performed to detect percentages of CD3+ T cells (CD4+, CD8+, Tregs, and NKT cells), B cells, NK cells (CD56brightCD16- and CD56dimCD16+ subsets), macrophages and dendritic cells (DCs). Furthermore, CD103 expression was analyzed on T cells and their subsets, while PD-1 and PD-L1 expression on all ICs. Cut-off of low and high percentages of ICs was determined by the median of variables, and correlation with PFS and OS was calculated. CD3+ cells were the predominant ICs (median 51%), while the presence of other ICs was much lower (median ≤10%). CD103+ expression was mostly present on CD8+, and not CD4+ cells. PD-1 was mainly expressed on CD3+ T cells (median 20%), lower expression was observed on other ICs (median ≤10%). PD-L1 expression was not detected. High percentages of CD103+CD3+ T cells, PD-1+ Tregs, CD56brightCD16- NK cells, and DCs correlated with prolonged PFS and OS, while high percentages of CD8+ cells, macrophages, and PD-1+CD56brightCD16- NK cells, along with low percentages of CD4+ cells, correlated with better OS only. DCs were the only independent prognostic marker among all ICs. Our results highlight the potential of ascites tumor-immune microenvironment to provide additional prognostic information for HGSC patients. However, a larger patient cohort and longer follow-up are needed to confirm our findings.

Morphological and Immunocytochemical Characterization of Tumor Spheroids in Ascites from High-Grade Serous Carcinoma.

Tumor spheroids in the ascites of high-grade serous carcinoma (HGSC) are poorly described. Our objective was to describe their morphological features, cellular composition, PD-1 and PD-L1 expression, and survival correlation of these parameters. The density and size of spheroids were assessed in Giemsa-stained smears; the cell composition of spheroids, including tumor cells, immune cells, capillaries, and myofibroblasts, as well as PD-1 and PD-L1 expression on tumor and immune cells was assessed in immunocytochemically stained cell block sections. Forty-seven patients with primary HGSC and malignant ascites were included. A cut-off value for a spheroid density of 10% was established, which significantly predicted overall survival. However, spheroid size did not correlate with survival outcomes. Spheroids were primarily composed of tumor cells, but the presence of lymphocytes and macrophages was also confirmed. Moreover, capillaries were present in the spheroids of three patients, but the presence of myofibroblasts was not confirmed. PD-1 was expressed on lymphocytes but not on tumor cells. PD-L1 expression was seen on both tumor and immune cells, assessed by 22C3 and SP263 antibody clones but not by the SP142 clone. Our results highlight the potential of routine cytopathological techniques to analyze spheroids in HGSC ascites as a valuable tool to investigate their potential as prognostic markers.

LRP1B—a prognostic marker in tubo-ovarian high-grade serous carcinoma

Low-density lipoprotein (LDL) receptor-related protein 1B (LRP1B) is a member of the LDLreceptor family and has often been discussed as a tumor suppressor gene, as its down-regulation is correlated with a poor prognosis in multiple carcinoma entities. Due to the high metastasis rate into the fatty peritoneal cavity and current research findings showing a dysregulation of lipid metabolism in tubo-ovarian high-grade serous carcinoma (HGSC), we questioned the prognostic impact of the LRP1B protein expression. We examined a well-characterized large cohort of 571 patients with primary HGSC and analyzed the LRP1B protein expression via immunohistochemical staining (both in tumor and stroma cells separately), performed precise bioimage analysis with QuPath, and calculated the prognostic impact using SPSS. Our results demonstrate that LRP1B functions as a significant prognostic marker for overall survival (OS) and progression-free survival (PFS) in HGSC on the protein level. High cytoplasmic expression of LRP1B in tumor, stroma, and combined tumor and stroma cells has a significantly positive association with a mean prolongation of the OS by 42 months (P=.005), 29 months (P=.005), and 25 months (P=.001), respectively. Additionally, the mean PFS was 18 months longer in tumor (P=.002), 19 months in stroma (P=.004), and 19 months in both cell types combined (P=.01). Our results remained significant in multivariate analysis. We envision LRP1B as a potential prognostic tool that could help us understand the functional role of lipid metabolism in advanced HGSC, especially regarding liposomal medications.

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.

A rare case of primary high-grade serous carcinoma arising in left fallopian tube

Primary fallopian tube carcinoma is a rare gynaecological tumour that has an incidence of 3.6 per million women per annum.1 There is likely an underestimation of true incidence due to late stage presentations and the histopathologic similarity to epithelial ovarian cancer.2

Cytopathological assessment is an accurate method for identifying immunophenotypic features and BRCA1/2 mutations of high-grade serous carcinoma from ascites.

High-grade serous carcinoma (HGSC) is the most common and aggressive type of ovarian cancer, and it is often associated with ascites at presentation. The objective of this study was to evaluate the accuracy of cytopathology to identify immunophenotypic features of HGSC and BRCA1/2 mutations from ascites. The study included 45 patients with histologically confirmed primary HGSC and malignant ascites. Immunocytochemistry (ICC) staining for PAX8, WT1, P53, P16, and Ki-67 was performed on cytospins and cytoblocks prepared from ascites. Next-generation sequencing (NGS) was used to detect germline/somatic BRCA1/2 mutations in the ascites. Both ICC and NGS results were compared with immunohistochemistry (IHC) and NGS results from tissue blocks of primary tumor. Cronbach α and χ2 statistics, respectively, were used. ICC/IHC results for PAX8, WT1, P53, and P16 showed good reliability between cytospins, cytoblocks, and tissue blocks (α>0.75), whereas poor reliability and significant differences were observed for Ki-67 between ascites and tissue blocks (α<0.26; p < .001 [Kruskal-Wallis]). For germline BRCA1/2 mutations, 100% concordance was confirmed, but only 14% concordance was confirmed for somatic mutations. These results demonstrate that cytopathology is an accurate method for identifying immunophenotypic features of HGSC and detecting germline BRCA1/2 mutations from ascites. However, further investigation is required for assessing the proliferation activity of HGSC in ascites and for detecting somatic BRCA1/2 mutations.

High ratio of pCXCR4/CXCR4 tumor infiltrating immune cells in primary high grade ovarian cancer is indicative for response to chemotherapy

BackgroundOvarian cancer (OC) is the fifth most common malignant female cancer with a high mortality, mainly because of aggressive high-grade serous carcinomas (HGSOC), but also due to absence of specific early symptoms and effective detection strategies. The CXCL12-CXCR4 axis is considered to have a prognostic impact and to serve as potential therapeutic target. Therefore we investigated the role of pCXCR4 and CXCR4 expression of the tumor cells and of tumor infiltrating immune cells (TIC) in high-grade serous OC and their association with the recurrence-free (RFS) and overall survival (OS).MethodsA tissue microarray of 47 primary high grade ovarian serous carcinomas and their recurrences was stained with primary antibodies directed against CXCR4 and pCXCR4. Beside the evaluation of the absolute tumor as well as TIC expression in primary and recurrent cancer biopsies the corresponding ratios for pCXCR4 and CXCR4 were generated and analyzed. The clinical endpoints were response to chemotherapy, OS as well as RFS.ResultsPatients with a high pCXCR4/CXCR4 TIC ratio in primary cancer biopsies showed a significant longer RFS during the first two years (p = 0.025). However, this effect was lost in the long-term analysis including a follow-up period of 5 years (p = 0.128). Interestingly, the Multivariate Cox regression analysis showed that a high pCXCR4/CXCR4 TIC ratio in primary cancer independently predicts longer RFS (HR 0.33; 95CI 0.13 - 0.81; p = 0.015). Furthermore a high dichotomized distribution of CXCR4 positive tumor expression in recurrent cancer biopsies showed a significantly longer 6-month RFS rate (p = 0.018) in comparison to patients with low CXCR4 positive tumor expression. However, this effect was not independent of known risk factors in a Multivariate Cox regression (HR 0.57; 95CI 0.24 - 1.33; p = 0.193).ConclusionsTo the best of our knowledge we show for the first time that a high pCXCR4/CXCR4 TIC ratio in primary HGSOC biopsies is indicative for better RFS and response to chemotherapy.Highlights• We observed a significant association between high pCXCR4/CXCR4 TIC ratio and better RFS in primary cancer biopsies, especially during the early postoperative follow-up and independent of known risk factors for recurrence.• High CXCR4 tumor expression in recurrent HGSOC biopsies might be indicative for sensitivity to chemotherapy. We found evidence that at the beginning of the disease (early follow-up) the role of the immune response seems to be the most crucial factor for progression. On the other hand in recurrent/progressive disease the biology of the tumor itself becomes more important for prognosis.• We explored for the first time the predictive and prognostic role of pCXCR4/CXCR4 TIC ratio in high-grade serous ovarian cancer.

Complete metabolic response after carboplatin desensitization in Peritoneal Carcinomatosis

High-grade serous primary peritoneal cancer is highly sensitive to platinum-based chemotherapy with response rates above 80%. Incidence of immediate hypersensitivity reactions to carboplatin is estimated to be between 15% and 20%, usually seen after a mean of 6-8 infusions, with patients developing moderate to severe reactions. A 62-year-old female patient with stage IIIC primary high-grade serous carcinoma of the peritoneum was diagnosed and chemotherapy with carboplatin and Paclitaxel was indicated by the oncology service and patient shows response. At 6 months the patient returns, a new PET/CT reports progression of the disease. Carboplatin/paclitaxel cycles are restarted and in the eight cycle of carboplatin within 40 min of administration, she presented severe anaphylaxis with skin, pulmonary, cardiac and atypical symptoms. Infusion is suspended and intramuscular epinephrine with hydrocortisone and chlorphenamine are administered resolving symptoms. Intradermal skin test with carboplatin at the concentration of 10 mg / ml (dilution 1: 100) was positive. Due to the symptoms presented and to continue the safe reintroduction to carboplatin, a 4 bag 16-step drug desensitization protocol was carried out at a total dose of 620 mg with no hypersensitivity reactions. Prolonged carboplatin use is associated with an increased incidence of carboplatin-related hypersensitivity reactions. And in patients that present hypersensitivity reactions, a safe and effective carboplatin desensitization protocol can be carried out to reach the administration of a full dose. Desensitization protocol induces tolerance to a drug temporarily and is dependent on continuous exposure.

Mesothelin Expression Is Not Associated with the Presence of Cancer Stem Cell Markers SOX2 and ALDH1 in Ovarian Cancer.

Mesothelin (MSLN) overexpression (OE) is a frequent finding in ovarian carcinomas and increases cell survival and tumor aggressiveness. Since cancer stem cells (CSCs) contribute to pathogenesis, chemoresistance and malignant behavior in ovarian cancer (OC), we hypothesized that MSLN expression could be creating a favorable environment that nurtures CSCs. In this study, we analyzed the expression of MSLN and CSC markers SOX2 and ALDH1 by immunohistochemistry (IHC) in different model systems: primary high-grade serous carcinomas (HGSCs) and OC cell lines, including cell lines that were genetically engineered for MSLN expression by either CRISPR-Cas9-mediated knockout (Δ) or lentivirus-mediated OE. Cell lines, wild type and genetically engineered, were evaluated in 2D and 3D culture conditions and xenografted in nude mice. We observed that MSLN was widely expressed in HGSC, and restricted expression was observed in OC cell lines. In contrast, SOX2 and ALDH1 expression was limited in all tissue and cell models. Most importantly, the expression of CSC markers was independent of MSLN expression, and manipulation of MSLN expression did not affect CSC markers. In conclusion, MSLN expression is not involved in driving the CSC phenotype.

Primary High-grade Serous Carcinoma of the Fallopian Tube as an Incidental Intraoperative Finding: A Case Report

: Primary carcinoma of the fallopian tube is a rare, but fatal gynecologic cancer. The preoperative diagnosis of this carcinoma is challenging due to the absence of specific symptoms and signs, and in most patients, it is an intraoperative finding. A 55-year-old patient (G3Ab1P2) was referred to the urogynecology clinic of our hospital with the chief complaints of heavy, prolonged menstrual bleeding and a persistently abnormal yellow discharge, which could not be distinguished by the patient from urinary leaks. After a complete diagnostic work-up, the patient was identified as a candidate for hysterectomy due to abnormal vaginal bleeding resistant to megestrol acetate, family history of malignancy, and abnormal vaginal discharge. Laparotomy revealed unusual left fallopian tube features (large, bulky, and vegetative), suggesting malignancy. The intraoperative frozen-section analysis of the left fallopian tube and the ovarian specimens indicated the mass as a high-grade serous carcinoma of the fallopian tube. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, and partial omentectomy were performed for the patient. The definitive histopathological diagnosis was high-grade serous carcinoma of the left fallopian tube (stage 2b) with omental involvement, without any evidence of lymphovascular invasion. High-grade serous carcinoma of the fallopian tube is likely to have non-specific symptoms, causing a significant delay in diagnosis and treatment, which negatively affects the prognosis and survival of these patients.

The Claudin-Low Subtype of High-Grade Serous Ovarian Carcinoma Exhibits Stem Cell Features.

Simple SummaryHere, we identified and characterized a claudin-low subtype of high-grade serous ovarian cancer. This rare variant of undifferentiated neoplasm shares transcriptional features with the homonym subtype of breast cancer, including low epithelial differentiation, high mesenchymal signature, and enrichment for stem cell features. Since the claudin-low transcriptional signature is associated with poor prognosis, we believe that the identification of the claudin-low molecular profile may have important clinical implications, paving the way for personalized medicine in ovarian cancer patients.Claudin-low cancer (CL) represents a rare and biologically aggressive variant of epithelial tumor. Here, we identified a claudin-low molecular profile of ovarian high-grade serous carcinoma (HGSOC), which exhibits the main characteristics of the homonym breast cancer subtype, including low epithelial differentiation and high mesenchymal signature. Hierarchical clustering and a centroid based algorithm applied to cell line collection expression dataset labeled 6 HGSOC cell lines as CL. These have a high energy metabolism and are enriched in CD44+/CD24− mesenchymal stem-like cells expressing low levels of cell-cell adhesion molecules (claudins and E-Cadherin) and high levels of epithelial-to-mesenchymal transition (EMT) induction transcription factors (Zeb1, Snai2, Twist1 and Twist2). Accordingly, the centroid base algorithm applied to large retrospective collections of primary HGSOC samples reveals a tumor subgroup with transcriptional features consistent with the CL profile, and reaffirms EMT as the dominant biological pathway functioning in CL-HGSOC. HGSOC patients carrying CL profiles have a worse overall survival when compared to others, likely to be attributed to its undifferentiated/stem component. These observations highlight the lack of a molecular diagnostic in the management of HGSOC and suggest a potential prognostic utility of this molecular subtyping.

Primary High Grade Serous Carcinoma of the Fallopian Tube: A Case Report

A 49-year-old, perimenopausal nulliparous woman with lower abdominal pain and abnormal uterine bleeding. Clinical and radiological findings suggested a right adnexal tumor. CA-125 level was moderately elevated. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was done. Peroperative findings revealed a soft to friable growth arising from right fallopian tube with no involvement of ovaries. Histopathologic examination confirmed it to be a high grade serous carcinoma, FIGO stage IA. The histomorphology resembled high grade serous carcinoma of ovary, however ovaries on both sides appeared unremarkable. Surgery was uneventful and the patient was discharged after seven days of hospital stay. She did not receive postoperative chemotherapy or radiotherapy and is under follow-up. The case is reported for its occurrence in an uncommon anatomic site and preoperative dilemma with relevant review of literature.

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...

Are Epithelial Ovarian Cancers of the Mesenchymal Subtype Actually Intraperitoneal Metastases to the Ovary?

Primary ovarian high-grade serous carcinoma (HGSC) has been classified into 4 molecular subtypes: Immunoreactive, Proliferative, Differentiated, and Mesenchymal (Mes), of which the Mes subtype (Mes-HGSC) is associated with the worst clinical outcomes. We propose that Mes-HGSC comprise clusters of cancer and associated stromal cells that detached from tumors in the upper abdomen/omentum and disseminated in the peritoneal cavity, including to the ovary. Using comparative analyses of multiple transcriptomic data sets, we provide the following evidence that the phenotype of Mes-HGSC matches the phenotype of tumors in the upper abdomen/omentum: (1) irrespective of the primary ovarian HGSC molecular subtype, matched upper abdominal/omental metastases were typically of the Mes subtype, (2) the Mes subtype was present at the ovarian site only in patients with concurrent upper abdominal/omental metastases and not in those with HGSC confined to the ovary, and (3) ovarian Mes-HGSC had an expression profile characteristic of stromal cells in the upper abdominal/omental metastases. We suggest that ovarian Mes-HGSC signifies advanced intraperitoneal tumor dissemination to the ovary rather than a subtype of primary ovarian HGSC. This is consistent with the presence of upper abdominal/omental disease, suboptimal debulking, and worst survival previously reported in patients with ovarian Mes-HGSC compared to other molecular subtypes.

Magnetic resonance imaging findings of extrauterine high-grade serous carcinoma based on new pathologic criteria for primary site assignment.

There has been no study that has reported magnetic resonance imaging (MRI) findings of extrauterine high-grade serous carcinomas (HGSCs) that have been histologically determined by the new criteria. To assess MRI findings of extrauterine HGSCs based on new pathologic criteria. Fifty patients with histopathologically proven extrauterine HGSCs, who underwent pretreatment gadolinium-enhanced MRI, were included in this study. After surgery, the primary sites were histopathologically determined based on new criteria for primary site assignment in extrauterine HGSCs as follows: fallopian tube (n = 34); ovary (n = 9); primary peritoneal HGSC (n = 1); and tubo-ovarian (n = 6). We retrospectively reviewed MR images and compared the MR findings between tubal and ovarian primaries. MRI patterns with tubal primaries were classified as ovarian cancer (62%), peritoneal cancer (35%), and fallopian tube cancer (3%). MRI patterns with ovarian primaries were classified as ovarian cancer (78%) and peritoneal cancer (22%). The frequency of the involvement of the fallopian tube, ovary, peritoneum, uterus, and lymph node was not significantly different between the two pathologies. There was no significant difference in the abnormal amount of ascites, hemorrhagic ascites, or characteristics of the ovarian lesions between the two pathologies. On MR images, tubal primaries almost always exhibited ovarian or peritoneal cancer pattern, but rarely exhibited fallopian tube cancer pattern. MR findings could not accurately differentiate between tubal and ovarian primaries; therefore, histopathologic investigation is essential for determination of the primary site of extrauterine HGSCs.

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.

Abstract AP07: PROTEIN AND IMAGING MARKERS FOR EARLY DETECTION OF EPITHELIAL OVARIAN CANCER

Abstract A central problem in ovarian cancer is late diagnosis, where the 5-year survival rate plummets well below 50%. It is now believed that a significant fraction of ovarian high grade serous carcinoma (HGSC) may actually start in the fallopian tubes (FTs), and that precancerous changes are detectable before metastasis to the ovary and peritoneal cavity occurs. A recently published molecular evolutionary analysis identifies a window of 7 years between development of a serous tubal intraepithelial carcinoma (STIC) and initiation of ovarian carcinoma, with metastases following rapidly thereafter. The authors are working to address the unmet clinical need for a minimally invasive test for early (pre-metastatic) ovarian cancer. Existing whole-body imaging techniques and transvaginal ultrasound have thus far displayed inadequate resolution and sensitivity, however optical imaging methods could fulfill the criteria for detection of primary HGSC when it is still located in the FTs and before it has spread to the ovaries. We have shown that two optical imaging modalities, optical coherence tomography (OCT) and multispectral fluorescence imaging (MFI) have great promise for detection of ovarian and FT abnormalities. In a small ex-vivo study, we found that 5 MFI measurements were sufficient to distinguish between normal, cancerous, and benign FT and ovary tissue with 100% sensitivity and specificity. We used laparoscopic OCT in an in-vivo study of 17 women and revealed distinct image features for normal, cancerous, and benign abnormalities of the ovary. For minimally invasive imaging of the fallopian tubes, a sub-millimeter diameter, flexible, steerable endoscope is necessary in order to navigate through the natural orifice of the ostium in the uterus. We have recently prototyped the smallest (0.8 mm diameter) OCT/MFI imaging endoscope with a forward-viewing imaging channel. The system as tested has approximately 70 degree full field of view, a working distance from 1 mm to infinity, and resolution that varies from 35 µm at 1 mm to 180 µm at 10 mm working distance. Such an imaging test is minimally invasive however not appropriate for wholesale screening of the general population. Therefore, we propose to utilize it as an adjunct confirmatory test after an initial positive or suspicious blood test. Our preliminary data indicate that there are significant changes in serum protein biomarkers in HGSC cases more than 18 months before diagnosis. We have identified FBG and PF4 as pre-diagnostic biomarkers of HGSC with 18-84 months lead time, and have generated and validated a 3-biomarker panel (FBG, PF4, and CA125) that classifies HGSC with &amp;gt;80% sensitivity/&amp;gt;70% specificity and 18-84 months lead time. We have identified overexpression of several glycolytic enzymes in STIC lesions and in human pre-diagnostic serum samples, indicating potential usefulness of these proteins as screening biomarkers and potential utility of glycolysis as imaging biomarker of STIC lesion. Our continuing work is focused on refining the serum protein biomarker sensitivity and specificity, creating a second-generation falloposcope for a first-in-women feasibility study, and creating an integrated model that incorporates both sets of data into an early EOC detection method. Citation Format: Jennifer K. Barton, Anna E. Lokshin, David A. Fishman, John F. Black. PROTEIN AND IMAGING MARKERS FOR EARLY DETECTION OF EPITHELIAL 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 AP07.