TP53 mutations and the association with platinum resistance in high grade serous ovarian carcinoma

OBJECTIVES

Alterations in the tumor suppressor TP53 gene are the most common mutations in high grade serous ovarian carcinoma. The impact of TP53 mutations on clinical outcomes and platinum resistance is controversial. We sought to evaluate the genomic profile of high grade serous ovarian carcinoma and explore the association of TP53 mutations with platinum resistance.

METHODS

Next generation sequencing data was obtained from our institutional database for patients with high grade serous ovarian carcinoma undergoing primary treatment. Sequencing data, demographic, and clinical information was reviewed. The primary outcome analyzed was time to recurrence or refractory diagnosis. Associations between the primary outcome and different classification schemes for TP53 mutations (structural, functional, hot spot, pathogenicity scores, immunohistochemical staining patterns) were performed.

RESULTS

209 patients met inclusion criteria. TP53 mutations were the most common mutation. There were no differences in platinum response with TP53 hotspot mutations or high pathogenicity scores. Presence of TP53 gain-of-function mutations or measure of TP53 gain-of function activity were not associated with platinum resistance. Immunohistochemical staining patterns correlated with expected TP53 protein function and were not associated with platinum resistance.

CONCLUSIONS

TP53 hotspot mutations or high pathogenicity scores were not associated with platinum resistance or refractory disease. Contrary to prior studies, TP53 gain-of-function mutations were not associated with platinum resistance. Estimation of TP53 gain-of-function effect using missense mutation phenotype scores was not associated with platinum resistance. The polymorphic nature of TP53 mutations may be too complex to demonstrate effect using simple models, or response to platinum therapy may be independent of initiating TP53 mutation.

Loss of mitochondrial pyruvate carrier 1 supports proline-dependent proliferation and collagen biosynthesis in ovarian cancer

The pyruvate transporter MPC1 (mitochondrial pyruvate carrier 1) acts as a tumour-suppressor, loss of which correlates with a pro-tumorigenic phenotype and poor survival in several tumour types. In high-grade serous ovarian cancers (HGSOC), patients display copy number loss of MPC1 in around 78% of cases and reduced MPC1 mRNA expression. To explore the metabolic effect of reduced expression, we demonstrate that depleting MPC1 in HGSOC cell lines drives expression of key proline biosynthetic genes; PYCR1, PYCR2 and PYCR3, and biosynthesis of proline. We show that altered proline metabolism underpins cancer cell proliferation, reactive oxygen species (ROS) production, and type I and type VI collagen formation in ovarian cancer cells. Furthermore, exploring The Cancer Genome Atlas, we discovered the PYCR3 isozyme to be highly expressed in a third of HGSOC patients, which was associated with more aggressive disease and diagnosis at a younger age. Taken together, our study highlights that targeting proline metabolism is a potential therapeutic avenue for the treatment of HGSOC.

The impact of an educational and information systems initiative on somatic BRCA testing rates in patients with high grade serous tubo-ovarian cancer in Western Australia

Objective

Poly-ADP ribose polymerase inhibitors (PARPi) have expanded the management armamentarium against high grade serous tubo-ovarian cancer (HGSOC) in patients with germline and somatic BRCA pathogenic variants (PVs). Germline testing has been available in Western Australia (WA) since July 2015, whilst somatic BRCA testing was previously only available through interstate laboratories. We hypothesized that due to complexity of referral, testing rates for somatic BRCA would be low. We aimed to demonstrate that improving education and information systems would improve testing rates in our service.

Methods

Retrospective data were collected for all patients with HGSOC reviewed between June - November 2021. BRCA testing for this period was discussed at multi-disciplinary tumor board. Patients eligible to commence PARPi that had not received somatic testing were referred. Changes were implemented to patient outcome reports, the results application was adjusted to flag clinicians, departmental guidelines were developed, and teaching sessions conducted. Testing rates from March - August 2022 were compared.

Results

From June - November 2021, 98% of patients had germline BRCA testing performed. PVs in BRCA1/2 were detected in 18% of patients. Of those without germline PVs, further somatic BRCA testing was referred in 42% of patients. One somatic PV was detected. From March - August 2022, 99% of patients had germline BRCA testing and 17% had PVs detected. Further somatic BRCA testing was referred in 72% of patients. No somatic PVs were detected.

Conclusion

Testing rates for germline BRCA variants in patients with HGSOC in WA are high. Focused education and information systems improved somatic BRCA testing rates.

Multiplex serum immune profiling reveals circulating LAG-3 is associated with improved patient survival in high grade serous ovarian cancer

OBJECTIVE

High grade serous ovarian cancer (HGSOC) exhibits low response rates to clinically available immunotherapies. Nevertheless, emerging research has demonstrated that certain immune factors are predictive for HGSOC patient clinical outcomes, with our own groups previous work demonstrating that intratumoral levels of the immune checkpoint receptor LAG-3 is associated with improved patient survival. In this current study we sought to uncover non-invasive circulating immune prognostic and predictive signatures in HGSOC.

METHODS

A multiplex approach was employed that examined circulating levels of immune checkpoint receptors LAG-3 and PD-1 along with 48 common cytokine and chemokines in a cohort of 75 HGSOC treatment naïve patient serum samples.

RESULTS

Elevated serum LAG-3 was significantly associated with improved progression-free survival (PFS) and overall survival (OS) in HGSOC, while circulating PD-1 levels were largely unrelated with patient clinical outcomes. Cytokine and chemokine analysis revealed lower IL-15 expression correlated with improved PFS and OS, while increased IL-1α, IL-1Ra, IL-6, IL8 and VEGF were significantly associated with preoperative CA-125 levels. ROC analysis demonstrated that serum LAG-3 levels exhibited consistent reasonable predictability as a single agent.

CONCLUSIONS

Serum-derived LAG-3 was identified out of a diverse array of chemokine and cytokines as the immune-based factor most significantly associated with improved HGSOC survival. These findings suggest that LAG-3 could be implemented as a non-invasive patient predictive marker for improved HGSOC clinical outcomes.

Molecular characteristics and clinical behaviour of epithelial ovarian cancers

Ovarian carcinoma (OC) is an umbrella term for multiple distinct diseases (histotypes), each with their own developmental origins, clinical behaviour and molecular profile. Accordingly, OC management is progressing away from a one-size-fits all approach, toward more molecularly-driven, histotype-specific management strategies. Our knowledge of driver events in high grade serous OC, the most common histotype, has led to major advances in treatments, including PARP inhibitor use. However, these agents are not suitable for all patients, most notably for many of those with rare OC histotypes. Identification of additional targeted therapeutic strategies will require a detailed understanding of the molecular landscape in each OC histotype. Until recently, tumour profiling studies in rare histotypes were sparse; however, significant advances have been made over the last decade. In particular, reports of genomic characterisation in endometrioid, clear cell, mucinous and low grade serous OC have significantly expanded our understanding of mutational events in these tumour types. Nonetheless, substantial knowledge gaps remain. This review summarises our current understanding of each histotype, highlighting recent advances in these unique diseases and outlining immediate research priorities for accelerating progress toward improving patient outcomes.

Frequency of serous tubal intraepithelial carcinoma (STIC) in patients with high grade serous ovarian cancer

OBJECTIVE

Serous tubal intraepithelial carcinoma (STIC) is a known precursor of high-grade serous ovarian cancer (HGSOC). This study aimed to evaluate the proportion of STIC in patients with HGSOC and analyze the STIC-related prognosis in patients with HGSOC.

MATERIALS AND METHODS

All pathology reports at our institution that included bilateral salpingectomies of patients with HGSOC from January 2013 to December 2018 were reviewed by two experienced pathologists. The specimens from the ovaries and the salpinx including fimbria were examined. We analyzed the correlation between STIC and HGSOC and compared the clinical characteristics and STIC-related prognostic outcomes in patients with HGSOC.

RESULTS

Eleven of the 76 cases were STIC. BRCA mutations were found in 16.9% of patients with HGSOC. STIC was observed in 30.0% of patients with BRCA mutations and in 14.3% of patients without BRCA mutations. The incidence of STIC in patients with BRCA mutations was approximately twice that in patients without BRCA mutations; however, the difference was not statistically significant (P = 0.231). Further, the 5-year survival rate of patients without STIC appeared to be high; nevertheless, the difference was not statistically significant (59.7% vs. 47.4%, P = 0.633). Moreover, there was no significant difference in disease-free survival rate according to STIC (36.4% vs. 33.1%, P = 0.956).

CONCLUSION

STIC was identified in patients with HGSOC, and STIC incidence was prominent in HGSOC related to BRCA mutation. Although low frequency, STIC was detected in patients without BRCA mutation. Therefore, prophylactic salpingectomy may be useful for prevention of HGSOC.

A novel cell line panel reveals non-genetic mediators of platinum resistance and phenotypic diversity in high grade serous ovarian cancer

OBJECTIVES

Resistance to cancer therapy is an enduring challenge and accurate and reliable preclinical models are lacking. We interrogated this unmet need using high grade serous ovarian cancer (HGSC) as a disease model.

METHODS

We created five in vitro and two in vivo platinum-resistant HGSC models and characterised the entire cell panel via whole genome sequencing, RNASeq and creation of intraperitoneal models.

RESULTS

Mutational signature analysis indicated that platinum-resistant cell lines evolved from a pre-existing ancestral clone but a unifying mutational cause for drug resistance was not identified. However, cisplatin-resistant and carboplatin-resistant cells evolved recurrent changes in gene expression that significantly overlapped with independent samples obtained from multiple patients with relapsed HGSC. Gene Ontology Biological Pathways (GOBP) related to the tumour microenvironment, particularly the extracellular matrix, were repeatedly enriched in cisplatin-resistant cells, carboplatin-resistant cells and also in human resistant/refractory samples. The majority of significantly over-represented GOBP however, evolved uniquely in either cisplatin- or carboplatin-resistant cell lines resulting in diverse intraperitoneal behaviours that reflect different clinical manifestations of relapsed human HGSC.

CONCLUSIONS

Our clinically relevant and usable models reveal a key role for non-genetic factors in the evolution of chemotherapy resistance. Biological pathways relevant to the extracellular matrix were repeatedly expressed by resistant cancer cells in multiple settings. This suggests that recurrent gene expression changes provide a fitness advantage during platinum therapy and also that cancer cell-intrinsic mechanisms influence the tumour microenvironment during the evolution of drug resistance. Candidate genes and pathways identified here could reveal therapeutic opportunities in platinum-resistant HGSC.

Can TP53 variant negative be high-grade serous ovarian carcinoma? A case series

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TP53 variant negative high-grade serous ovarian cancer is rare and can still show p53 abnormal immunohistochemistry.

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Diagnostic and therapeutic considerations include pathologic, molecular and clinical domains.

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Genetic reassessment through more comprehensive assays should be considered to ensure no missed rare or complex variants.

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Presence of BRCA mutations can occur in TP53 variant high-grade serous ovarian cancer.

Integrated bioinformatic analysis identifies UBE2Q1 as a potential prognostic marker for high grade serous ovarian cancer

Background

High grade serous ovarian cancer (HGSOC) accounts for nearly 60% of total cases of epithelial ovarian cancer. It is the most aggressive subtype, which shows poor prognosis and low patient survival. For better management of HGSOC patients, new prognostic biomarkers are required to facilitate improved treatment strategies and ensure suitable healthcare decisions.

Methods

We performed genome wide expression analysis of HGSOC patient samples to identify differentially expressed genes (DEGs) using R based Limma package, Clust and other statistical tools. The identified DEGs were subjected to weighted gene co-expression network analysis (WGCNA) to identify co-expression patterns of relevant genes. Module trait and gene ontology analyses were performed to establish important gene co-expression networks and their biological functions. Overlapping the most relevant DEG cluster 4 with prominent WGCNA cyan module identified strongest correlation of UBE2Q1 with ovarian cancer and its prognostic significance on survival probability of ovarian cancer patients was investigated. The predictive value of UBE2Q1 as a potential biomarker was analysed by correlating its expression with 12-months relapse free survival of patients in response to platin/taxane, the standard first-line chemotherapy for ovarian cancer, and analysing area under the ROC curve.

Results

An integrated gene expression analysis and WGCNA, identified UBE2Q1 as a potential prognostic marker associated with poor relapse-free survival and response outcome to platin/taxane treatment of patients with high grade serous ovarian cancer.

Conclusions

Our study identifies a potential UBE2Q1 – B4GALT3 functional axis in ovarian cancer, where only the E2 conjugating enzyme showed a poor prognostic impact on the disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07928-z.

The BRCA1 c.788G > T (NM_007294.4) variant in a high grade serous ovarian cancer (HGSOC) patient: foods for thought

In this report we described the case of a BRCA1/2 (BRCA) molecular testing performed on tumor sample in a High Grade Serous Ovarian Cancer (HGSOC) patient with two different Next Generation Tumor Sequencing (NGTS) pipelines. The two clinical reports leaded to apparently different BRCA status, providing important foods for thought. After NGTS, the gene sequencing information (i.e., reads) are aligned to the reference gene sequences obtained from public databases, in order to provide an uniform nomenclature for unambiguous variant designation. However, the criteria adopted for variant reporting in tissue test are not always univocal. Particularly, this is the case of rare and unclassified BRCA variants for which the molecular evaluation may be a relevant challenge. Here we described a BRCA1 unclassified variant that may be re-evaluated in the context of alternative BRCA1 transcripts due to its different biological effect. We underlined that an in-depth knowledge of BRCA testing is mandatory for its appropriate use.

Tumor-intrinsic and -extrinsic (immune) gene signatures robustly predict overall survival and treatment response in high grade serous ovarian cancer patients

In the present study, we developed a transcriptomic signature capable of predicting prognosis and response to primary therapy in high grade serous ovarian cancer (HGSOC). Proportional hazard analysis was performed on individual genes in the TCGA RNAseq data set containing 229 HGSOC patients. Ridge regression analysis was performed to select genes and develop multigenic models. Survival analysis identified 120 genes whose expression levels were associated with overall survival (OS) (HR = 1.49-2.46 or HR = 0.48-0.63). Ridge regression modeling selected 38 of the 120 genes for development of the final Ridge regression models. The consensus model based on plurality voting by 68 individual Ridge regression models classified 102 (45%) as low, 23 (10%) as moderate and 104 patients (45%) as high risk. The median OS was 31 months (HR = 7.63, 95% CI = 4.85-12.0, P < 1.0-10) and 77 months (HR = ref) in the high and low risk groups, respectively. The gene signature had two components: intrinsic (proliferation, metastasis, autophagy) and extrinsic (immune evasion). Moderate/high risk patients had more partial and non-responses to primary therapy than low risk patients (odds ratio = 4.54, P < 0.001). We concluded that the overall survival and response to primary therapy in ovarian cancer is best assessed using a combination of gene signatures. A combination of genes which combines both tumor intrinsic and extrinsic functions has the best prediction. Validation studies are warranted in the future.

Evaluating the current status of protein kinase C (PKC)-protein kinase D (PKD) signalling axis as a novel therapeutic target in ovarian cancer

Ovarian cancer, especially high grade serous ovarian cancer is one of the most lethal gynaecological malignancies with high relapse rate and patient death. Notwithstanding development of several targeted treatment and immunotherapeutic approaches, researchers fail to turn ovarian cancer into a manageable disease. Protein kinase C (PKC) and protein kinase D (PKD) are families of evolutionarily conserved serine/threonine kinases that can be activated by a plethora of extracellular stimuli such as hormones, growth factors and G-protein coupled receptor agonists. Recent literature suggests that a signalling cascade initiated by these two protein kinases regulates a battery of cellular and physiological processes involved in tumorigenesis including cell proliferation, migration, invasion and angiogenesis. In an urgent need to discover novel therapeutic interventions against a deadly pathology like ovarian cancer, we have discussed the status quo of PKC/PKD signalling axis in context of this disease. Additionally, apart from discussing the structural properties and activation mechanisms of PKC/PKD, we have provided a comprehensive review of the recent reports on tumor promoting functions of PKC isoforms and discussed the potential of PKC/PKD signalling axis as a novel target in this lethal pathology. Furthermore, in this review, we have discussed the significance of several recent clinical trials and development of small molecule inhibitors that target PKC/PKD signalling axis in ovarian cancer.

Clinical and pathological significance of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer

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PD-L1 expression in HGSOC requires further study with modern antibody reagents and platforms.

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The association of PD-L1 positive cases with CD8+ immune cells is more prominent.

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The checkpoint value in HGSOC is not yet clear, but there is an importance meaningful when the threshold is ≥5%.

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PD-L1 expression shows two immunohistochemical staining patterns, patchy/diffuse and patchy/focal.

We investigated programmed cell death 1 (PD-1) / programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer (HGSOC) and its relationship to tumor infiltrating lymphocytes (TIL) and prognosis. Formalin fixed paraffin embedded (FFPE) samples of 94 HGSOC cases were included in the study. Immunohistochemical analysis (CD3, CD4, CD8, PD-1 and PD-L1) was performed. Samples were analyzed for expression of immune proteins in the peritumoral stromal and intratumoral areas, scored, and expression was correlated with overall survival, stage, and age. PD-L1 staining ratio with a score greater than 0 was found to have lower survival. There were two positive staining patterns, patchy/diffuse and patchy/focal patterns, in 24 (25.5%) cases. Considering the threshold value ≥5%, we demonstrated that the PD-L1 positive cancer cell membrane immunoreactivity rate and patchy/diffuse PD-L1 expression were 9.6% (n = 9). There was statistically significant relationship between high PD-1 scores and PD-L1 cases of ≥ 5%. A statistically significant difference was found between PD-L1 staining and survival in patients with a threshold ≥ 5%. However an appropriate rate for treatment was determined in 9.6% cases. There was a statistically significant correlation between PD-1 positive TIL score and intratumoral CD3, peritumoral stromal CD3, intratumoral CD4 and intratumoral CD8 positive cells. Survival was lower in cases with higher PD-L1 positive stromal TIL score.

Droplet digital PCR for large genomic rearrangements detection: A promising strategy in tissue BRCA1 testing

BACKGROUND AND AIMS

With the introduction of Olaparib as target therapy for High Grade Serous Ovarian Cancer (HGSOC) patients with germline and somatic BRCA1/2 mutations, the genetic test performed on tumor tissue has become important like the germline test. In somatic testing the evaluation of Large Genomic Rearrangements (LGRs) represents the main challenge. We describe a droplet digital PCR (ddPCR) assay for the evaluation of target BRCA1 LGRs on blood and formalin-fixed paraffin-embedded (FFPE)/Fresh Frozen Tissue (FFT) samples.

MATERIALS AND METHODS

We analyzed blood, FFPE and FFT samples in a validation setting of n = 78 HGSOC patients. We applied the ddPCR to BRCA1 exons 2, 20 and 21 as some of the most common BRCA1 exons involved in LGRs in our cohort of patients.

RESULTS

The ddPCR custom assays allowed the identification of LGRs in all sample types, including FFPE specimens. Moreover, we were able to clearly detect LGRs accounted as somatic event.

CONCLUSION

The introduction of ddPCR in a comprehensive workflow, encompassing both germline and somatic tests, represents an improvement in BRCA1/2 testing. ddPCR can overcome challenges related to BRCA testing, especially on FFPE analysis. Finally, ddPCR represents a promising alternative strategy to the established standard methods currently used in clinical setting.

The prognostic value of ITGA and ITGB superfamily members in patients with high grade serous ovarian cancer

Background

Deregulation of integrins signaling had been documented to participate in multiple fundamental biological processes, and the aberrant expression of integrin family members were linked to the prognosis of various cancers. However, the role of integrins in predicting progression and prognosis of ovarian cancer patients are still largely elusive. This study is aimed to explore the prognostic values of ITGA and ITGB superfamily members in high grade serous ovarian cancers (HGSOC).

Methods

GSE26712 dataset was used to determine the differential expression of ITGA and ITGB superfamily member between HGSOC and normal counterparts. The Cancer Genome Altas (TGGA) and GSE9891 datasets were used to determine the prognostic values of ITGA and ITGB superfamily members in HGSOC, followed by the development of nomograms predictive of recurrence free survival (RFS) and overall survival (OS).

Results

ITGA6 and ITGB5 expression were significantly downregulated in HGSOC compared with that in normal counterparts. In contrast, ITGA2, ITGA5, ITGA7, ITGA8, ITGA9, ITGA10, ITGB3, ITGB4, ITGB6, and ITGB8 were all significantly upregulated in HGSOC compared with that in normal counterparts. Both univariable and multivariable analysis indicated that ITGB1 was associated with extended RFS. The ITGB1-related nomogram indicated that ITGB1 had the largest contribution to RFS, followed by FIGO stage and debulking status. The C-index for predicting RFS was 0.55 (95% CI 0.50–0.59) in TCGA dataset (training dataset) and 0.65 (95% CI 0.59–0.72) in GSE9891 dataset (validation dataset), respectively. Regarding OS, ITGB8 was associated with reduced survival suggested by both univariable and multivariable analysis. ITGA7 appeared to be associated with improved survival though without reaching statistical significance. The ITGA7/ITGB8-based nomogram showed that age at initial diagnosis had the largest contribution to OS, followed by ITGB8 and ITGA7 expression. The C-index for predicting OS was 0.65 (95% CI 0.60–0.69) in TCGA dataset (training dataset) and 0.59 (95% CI 0.51–0.66) in GSE9891 dataset (validation dataset), respectively.

Conclusion

In conclusion, ITGB1, ITGA7 and ITGB8 added prognostic value to the traditional clinical risk factors used to assess the clinical outcomes of HGSOC.

High resolution melting profiles (HRMPs) obtained by magnetic induction cycler (MIC) have been used to monitor the BRCA2 status highlighted by next generation tumor sequencing (NGTS): a combined approach in a diagnostic environment

Resistance can be the result of secondary tissue variants (STVs), which restore the open reading frame of the germline BRCA allele, producing functional BRCA protein in germline BRCA1/2 (BRCA) pathogenic variant (PV) carriers, treated with platinum-based chemotherapy or poly-(ADP-ribose) polymerase inhibitors (PARP-1). We reported recently a BRCA2 mutant high grade serous ovarian cancer (HGSOC) patient with acquired resistance to the PARP-1 olaparib due to a STV detected by next generation tumor sequencing (NGTS). The aim of this study was to evaluate the versatility of the high-resolution melting analysis (HRMA) obtained by magnetic induction cycler (MIC) to monitor the BRCA2 status in formalin-fixed paraffin-embedded (FFPE) tissue samples of this patient and to compare the results obtained by NGTS. HRMA highlighted the BRCA2 STV previously detected in the IIIrd HGSOC recurrence following the tissue BRCA2 tissue status comparing the high resolution melting profiles (HRMPs). HRMPs differentiate not only BRCA2 alleles, but also their different allele abundance. We underline that (1) the MIC uses a latest generation technology guaranteeing temperature uniformity and maintenance in each well allowing high and accurate performance to obtain reported results and (2) the HRMA maintains a high sensitivity and specificity when it is performed on FFPE samples. Finally, this study represents an additional use of the HRMA, confirming its extreme versatility in the diagnostic environment.

Elevated GALNT10 expression identifies immunosuppressive microenvironment and dismal prognosis of patients with high grade serous ovarian cancer

High grade ovarian serous cancer (HGSC) is a malignant disease with high mortality. Glycosylation plays important roles in tumor invasion and immune evasion, but its effect on the immune microenvironment of HGSC remains unclear. This study examined the association of glycosyltransferase expression with HGSC prognosis and explored the underlying mechanism using clinical specimens and integrated bioinformatic analyses. We identified a cluster of 15 glycogenes associated with reduced overall survival, and GALNT10 was found to be an independent predictor of HGSC prognosis. The high GALNT10 expression was associated with increased regulatory CD4+ T cells infiltration and decreased granzyme B expression in CD8+ T cells. The expression of GALNT10 and its product, Tn antigen, in HGSC specimens was associated with the increased infiltration of M2 macrophages and neutrophils, and the decreased infiltration of CD3+ T cells, NK cells, and B cells. Taken collectively, high GALNT10 expression confers with immunosuppressive microenvironment to promote tumor progression and predicts poor clinical outcomes in HGSC patients.

Tumour immune cell infiltration and survival after platinum-based chemotherapy in high-grade serous ovarian cancer subtypes: A gene expression-based computational study

Background

Increasing evidence supports that the immune infiltration of tumours is associated with prognosis. Here, we sought to assess the relevance of the cellular composition of the immune infiltrate to survival after platinum-based chemotherapy amongst patients with high-grade serous ovarian cancer and evaluate these effects by molecular subtype.

Methods

We searched publicly available databases and identified 13 studies with more than 2000 patients. We estimated the proportions of 22 immune cell subsets by using a computational approach (CIBERSORT). Then, we investigated the associations between each immune cell subset and progression-free survival (PFS) and overall survival (OS), with cellular proportions modelled as quartiles.

Findings

A high fraction of M1 [hazard ratio (HR) = 0.92, 95% confidence interval (CI) = 0.86–0.99] and M0 (HR = 0.93, 95% CI = 0.87–0.99) macrophages emerged as the most closely associated with favourable OS. Neutrophils were associated with poor OS (HR = 1.06, 95% CI = 1.00–1.13) and PFS (HR = 1.10, 95% CI = 1.02–1.13). Amongst the immunoreactive tumours, the M0 macrophages and the CD8+ T cells were associated with improved OS, whereas the M2 macrophages conferred worse OS. Interestingly, PD-1 was associated with good OS (HR=0.89, 95% CI = 0.80–1.00) and PFS (HR=0.89, 95% CI = 0.79–1.01) in this subtype. Four subgroups of tumours with distinct survival patterns were identified using immune cell proportions with unsupervised clustering.

Interpretation

Further investigations of the quantitative cellular immune infiltrations in tumours may contribute to therapeutic advances.

Paraneoplastic opsoclonus-myoclonus syndrome as a presentation of high grade serous ovarian cancer

Opsoclonus-myoclonus syndrome (OMS) is a rare paraneoplastic disorder that is most often seen in association with pediatric neuroblastoma, breast cancer, small cell lung cancer, and prostate cancer. There are only three previously documented cases relating paraneoplastic OMS to ovarian cancer. We present a unique case of OMS related to a stage IIIC high grade serous ovarian carcinoma in a patient with germline BRCA2 mutation, with ten years of clinical follow up. This case report is presented to document the rare association of OMS with epithelial ovarian cancer. Additionally, in this case, OMS and epithelial cancer were successfully treated with medical therapy alone. This is the first report to our knowledge to document ten years of clinical follow up in this context, and to report that the association may not be evident at the time of ovarian cancer recurrence.

Prognostic significance of TEM7 and nestin expression in women with advanced high grade serous ovarian cancer

OBJECTIVES

Tumor endothelial marker 7 (TEM7) and nestin have been proposed to be new candidates for neoangiogenesis assessment. Nestin is also cancer stem cells marker in various malignant tumors.

AIMS

To investigate the expression of TEM7, nestin and nestin-related microvessel density (MVD) in high-grade serous ovarian cancer samples and to study their correlation with overall survival (OS) and disease-free survival (DFS) times.

MATERIAL AND METHODS

Tumor samples obtained from 70 women with FIGO IIIc/IV ovarian serous cancer were studied with immunohistochemistry.

RESULTS

Patients median age was 54 yrs (range: 29-72 years), 86% died of the disease with median OS = 28.5 months and median DFS = 10 months (3 years DFS = 19%; 5 years. DFS = 13.8%). High nestin expression was found in 16 (23%) patients with 3 years and 5 years OS of 14% and 0%. In low-nestin expression group OS and DFS were 42% and 25%, respectively. Median nestin-MVD (16, range:12-23) was not correlated with cancer cells nestin expression and with both DFS and OS. High TEM7 expression was found in 29 women (41%) of whom 21 (72%) died of the disease. A 5-year OS in these women was 27% as compared to 8% in low TEM7 expression group, but TEM7 presence had no association with nestin, nestin-MVD and both OS and DFS.

CONCLUSIONS

Nestin as a marker of cancer stem cells may assist in the prediction of OS and DFS in women with high grade serous ovarian cancer. Nestin may also be considered a novel therapeutic target for antiangiogenic agents.

Prognostic value of tumor PD-L1 expression combined with CD8+ tumor infiltrating lymphocytes in high grade serous ovarian cancer

Expression of programmed cell death-ligand 1 (PD-L1) is known to be a mechanism whereby cancer can escape immune surveillance, but the relationship between tumor PD-L1 expression and tumor-infiltrating lymphocytes (TILs), and their association with clinical outcomes in patients with high grade serous ovarian cancer (HGSOC) remain ambiguous. We detected the expression of PD-L1 and CD3⁺, CD4⁺, CD8⁺ TILs in 107 patients with HGSOC by immunohistochemical analysis. Using a 5% threshold, 24.30% and 15.89% cases were found with positive expression of PD-L1 in the membrane of tumor cells and TILs respectively. Carcinoma PD-L1 expression mainly localized to the tumor invasive front and was associated with advanced FIGO stage (p=0.023) and abundant stromal CD8⁺ TILs infiltration (p=0.020). Tumors containing PD-L1⁺ TILs were more likely to have PD-L1 expression by the carcinoma cells (p<0.001). Univariate and multivariate analyses demonstrated that a higher number of intraepithelial CD3⁺ or CD8⁺ TILs was an independent prognostic factor for longer overall survival (OS), whereas tumor PD-L1 expression was a predictive factor for poorer OS only in univariate analysis. PD-L1 expression in TILs was not a prognostic factor in univariate analysis. The Kaplan-Meier curves of the four sub-groups and log-rank test showed that patients with negative tumor PD-L1 expression/higher numbers of intraepithelial CD8⁺ TILs had the longest median OS, while those with positive tumor PD-L1 expression/lower numbers of intraepithelial CD8⁺ TILs had the shortest median OS (p<0.001). Our results indicate that tumor PD-L1 expression in combination with intraepithelial CD8⁺ TILs infiltration has prognostic impact in patients with HGSOC. These biomarkers may be useful for the stratification of patients. Further evaluation of PD-1/PD-L1 as therapeutic targets for HGSOC is warranted.

Tumor-associated macrophage expression of PD-L1 in implants of high grade serous ovarian carcinoma: A comparison of matched primary and metastatic tumors

OBJECTIVE

Data on PD-L1 expression in high grade serous ovarian carcinoma (HGSOC) is mixed. Some studies report robust tumor staining and others identify expression limited to tumor-associated macrophages (TAM). TAM PD-L1 expression is induced in HGSOC metastatic implants from patients who have undergone chemotherapy. However, it is unclear whether TAM acquisition of PD-L1 plays a role in treatment naïve tumors. We investigated PD-L1 expression in primary ovarian tumors and matched metastatic implants from predominantly treatment-naïve HGSOC.

METHODS

Sixty one primary HGSOC were evaluated with PD-L1 and CD68 IHC: 40 on TMA and 21 on whole section. Whole section cases were matched to a metastatic implant. TAM were delineated by CD68. Membranous PD-L1 staining was scored separately for tumor cells and TAM.

RESULTS

Eight percent of primary HGSOC demonstrated PD-L1 expression. In contrast, 74% showed PD-L1+ TAM. In the 16 treatment naïve cases, 13 (81.3%) demonstrated fidelity in intratumoral PD-L1 expression between the primary and metastatic site. Of the 21 matched pairs, only one case (4.8%) did not exhibit PD-L1 positive TAM in the metastatic implant and 19 (90.5%) showed fidelity across both locations. Intratumoral and immune infiltrate PD-L1 expression was not different in cases who received neoadjuvant chemotherapy compared to treatment naïve cases.

CONCLUSIONS

PD-L1+ TAM are common in both primary and metastatic HGSOC however tumoral PD-L1 staining is rare. There was high fidelity of PD-L1 expression when comparing primary tumors and metastatic implants in treatment naïve specimens. Clinical trials are needed to determine whether tumor-associated staining correlates with clinical response to PD-1/PD-L1 inhibition.

Ascites regression following neoadjuvant chemotherapy in prediction of treatment outcome among stage IIIc to IV high-grade serous ovarian cancer

Background

No consensus exists on the outcome-related factors of interval debulking surgery (IDS) in patients with advanced high-grade serous ovarian cancer (HG-SOC) who underwent neoadjuvant chemotherapy (NAC). This study aimed to explore the optimal timing for IDS and the prognosis-associated factors of International Federation of Gynecology and Obstetrics stage IIIc to IV HG-SOC patients.

Methods

A total of 160 IIIc to IV stage HG-SOC patients were retrospectively analyzed. Patients with large volume ascites underwent NAC and subsequent IDS from the Jiangsu Institute of Cancer Research between 1993 and 2013. The outcome of IDS-associated factors was explored by logistic regression. To predict IDS outcome, the potential values of serum CA-125 levels and CA-125 decreasing kinetics were determined by the receiver operating characteristic curve. The associations between survival durations and covariates were assessed by Cox proportional hazards model and log-rank test.

Results

Optimal IDS was achieved in 80.6% of HG-SOC patients who underwent NAC. Multivariate analyses revealed that ascites regression (p = 0.01), serum CA-125 level (p = 0.02), and CA-125 decreasing kinetics (p = 0.01) were independent optimal IDS predictors. CA-125 decreasing kinetics, IDS outcome, and ascites volume were independently associated with overall survival (OS) (p = 0.04, p < 0.01, p = 0.03, respectively) and progression-free survival (PFS) (p < 0.01, p < 0.01, p = 0.02, respectively). Patients who exhibited disappearance of ascites (<500 ml) had longer PFS (19.7 months vs.14.9 months) and OS (32.1 months vs. 26.0 months) than patients who exhibited residual ascites (≥500 ml). Subsets with higher CA-125 decreasing kinetics (≥2.2) had longer PFS (21.4 months vs.13.1 months) and OS (29.6 months vs.26.8 months) than counterparts (kinetics < 2.2).

Conclusions

Ascites regression and CA-125 decreasing kinetics were independently associated with surgical outcome and prognosis in advanced HG-SOC patients who underwent NAC.

The pro-inflammatory effect of obesity on high grade serous ovarian cancer

INTRODUCTION

Obesity is a known generator of chronic inflammation but has an uncertain role in ovarian carcinogenesis and survival. Pro-inflammatory cytokines have previously been associated with poor outcomes. Given the established links, we sought to determine whether obesity and pro-inflammatory cytokines affect platinum sensitivity.

METHODS

A retrospective review was performed of patients undergoing primary debulking surgery (PDS) for high grade serous ovarian cancer (HGSC) who had available pre-operative serum. Oncologic and treatment characteristics were recorded and analyzed using SAS version 9.3. Bioplex reagent kit was used to measure serum cytokine concentrations.

RESULTS

86 patients met study criteria. Most were Caucasian (88%) and non-diabetic (92%). All patients had advanced stage (III/IV) disease and received chemotherapy after PDS. In univariate analysis, lower VEGF (p=0.013) was associated with longer overall survival (OS). Low IL-8 level (p=0.053) was marginally associated with platinum resistant disease. After adjusting for covariates including residual disease and maintenance therapy, IL-8 was no longer associated with platinum sensitive status (p=0.13), VEGF remained associated with OS (low vs. high HR 0.3, 95% CI 0.1-0.8, p=0.018), and higher IL-12 was associated with longer PFS (HR 0.4, 95% CI 0.2-0.9, p=0.031).

CONCLUSION

In HGSC, pro-inflammatory cytokines are influenced by obesity, as differing inter-cytokine correlations were observed based on BMI, possibly due to dysregulation between cytokines in the setting of obesity. Differences in survival and platinum sensitivity were not noted. Future studies are warranted to determine whether obesity may be a modifiable risk factor for poorer outcomes due to differing immune response.

In vivo tumor growth of high-grade serous ovarian cancer cell lines

OBJECTIVE

Genomic studies of ovarian cancer (OC) cell lines frequently used in research revealed that these cells do not fully represent high-grade serous ovarian cancer (HGSOC), the most common OC histologic type. However, OC lines that appear to genomically resemble HGSOC have not been extensively used and their growth characteristics in murine xenografts are essentially unknown.

METHODS

To better understand growth patterns and characteristics of HGSOC cell lines in vivo, CAOV3, COV362, KURAMOCHI, NIH-OVCAR3, OVCAR4, OVCAR5, OVCAR8, OVSAHO, OVKATE, SNU119 and UWB1.289 cells were assessed for tumor formation in nude mice. Cells were injected intraperitoneally (i.p.) or subcutaneously (s.c.) in female athymic nude mice and allowed to grow (maximum of 90 days) and tumor formation was analyzed. All tumors were sectioned and assessed using H&E staining and immunohistochemistry for p53, PAX8 and WT1 expression.

RESULTS

Six lines (OVCAR3, OVCAR4, OVCAR5, OVCAR8, CAOV3, and OVSAHO) formed i.p xenografts with HGSOC histology. OVKATE and COV362 formed s.c. tumors only. Rapid tumor formation was observed for OVCAR3, OVCAR5 and OVCAR8, but only OVCAR8 reliably formed ascites. Tumors derived from OVCAR3, OVCAR4, and OVKATE displayed papillary features. Of the 11 lines examined, three (Kuramochi, SNU119 and UWB1.289) were non-tumorigenic.

CONCLUSIONS

Our findings help further define which HGSOC cell models reliably generate tumors and/or ascites, critical information for preclinical drug development, validating in vitro findings, imaging and prevention studies by the OC research community.

BRCA1 gene promoter methylation status in high-grade serous ovarian cancer patients--a study of the tumour Bank ovarian cancer (TOC) and ovarian cancer diagnosis consortium (OVCAD)

BACKGROUND

Mutations in BRCA1/2 genes are involved in the pathogenesis of breast and ovarian cancer. Inactivation of these genes can also be mediated by hypermethylation of CpGs in the promoter regions. Aim of this study was to analyse the clinical impact of BRCA1 promoter gene methylation status in a homogenous cohort of high-grade serous ovarian cancer (HGSOC) patients.

METHODS

The cohort included 257 primary HGSOC patients treated by cytoreduction and platinum-based chemotherapy. DNA was extracted from fresh frozen tissue samples. BRCA1 gene promoter methylation rate was assessed using polymerase chain reaction (PCR).

RESULTS

14.8% of patients presented hypermethylation within a selected region of the BRCA1 promoter. The rate of hypermethylation was significantly higher in younger patients (20.8% hypermethylation in the age group ⩽ 58 years versus 8.7% hypermethylation in the age group >58 years; p = 0.008). Optimal tumour debulking could be reached in 63% of patients, without significant differences in the extent of residual disease with respect to the methylation status. No impact of BRCA1 gene promoter methylation status on progression free- and overall-survival rates was found. No significant differences within BRCA1 promoter methylation status between primary and metastatic tissue could be observed. These results on BRCA1 promoter methylation status were also confirmed in a subgroup of 107 patients found negative for BRCA1 exon 11 mutations.

CONCLUSIONS

Our data suggest that BRCA1 methylation determines the earlier onset of HGSOC. Furthermore our study supports the idea that BRCAness is not only due to mutations but also to epigenetic changes in BRCA1 promoter gene.