[Diagnosis of uterine sarcomas and rare uterine mesenchymal tumours with malignant potential. Guidelines of the French Sarcoma Group and Rare Gynaecological Tumours]

The landscape of uterine sarcomas is becoming more complex with the description of new entities associated with recurrent driver molecular alterations. Uterine sarcomas, in analogy with soft tissue sarcomas, are distinguished into complex genomic and simple genomic sarcomas. Leiomyosarcomas and undifferentiated uterine sarcomas belong to complex genomic sarcomas group. Low-grade and high-grade endometrial stromal sarcomas, other rare tumors associated with fusion transcripts (such as NTRK, PDGFB, ALK, RET ROS1) and SMARCA4-deficient uterine sarcoma are considered simple genomic sarcomas. The most common uterine sarcoma are first leiomyosarcoma and secondly endometrial stromal sarcomas. Three different histological subtypes of leiomyosarcoma (fusiform, myxoid, epithelioid) are identified, myxoid and epithelioid leiomyosarcoma being more aggressive than fusiform leiomyosarcoma. The distinction between low-grade and high-grade endometrial stromal sarcoma is primarily morphological and immunohistochemical and the detection of fusion transcripts can help the diagnosis. Uterine PEComa is a rare tumor, which is distinguished into borderline and malignant, according to a risk assessment algorithm. Embryonal rhabdomyosarcoma of the uterine cervix is more common in children but can also occur in adult women. Embryonal rhabdomyosarcoma of the uterine cervix is almost always DICER1 mutated, unlike that of the vagina which is wild-type DICER1, and adenosarcoma which can be DICER1 mutated but with less frequency. Among the emerging entities, sarcomas associated with fusion transcripts involving the NTRK, ALK, PDGFB genes benefit from targeted therapy. The integration of molecular data with histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Deep Learning for Detecting BRCA Mutations in High-Grade Ovarian Cancer Based on an Innovative Tumor Segmentation Method From Whole Slide Images

BRCA1 and BRCA2 genes play a crucial role in repairing DNA double-strand breaks through homologous recombination. Their mutations represent a significant proportion of homologous recombination deficiency and are a reliable effective predictor of sensitivity of high-grade ovarian cancer (HGOC) to poly(ADP-ribose) polymerase inhibitors. However, their testing by next-generation sequencing is costly and time-consuming and can be affected by various preanalytical factors. In this study, we present a deep learning classifier for BRCA mutational status prediction from hematoxylin-eosin-safran-stained whole slide images (WSI) of HGOC. We constituted the OvarIA cohort composed of 867 patients with HGOC with known BRCA somatic mutational status from 2 different pathology departments. We first developed a tumor segmentation model according to dynamic sampling and then trained a visual representation encoder with momentum contrastive learning on the predicted tumor tiles. We finally trained a BRCA classifier on more than a million tumor tiles in multiple instance learning with an attention-based mechanism. The tumor segmentation model trained on 8 WSI obtained a dice score of 0.915 and an intersection-over-union score of 0.847 on a test set of 50 WSI, while the BRCA classifier achieved the state-of-the-art area under the receiver operating characteristic curve of 0.739 in 5-fold cross-validation and 0.681 on the testing set. An additional multiscale approach indicates that the relevant information for predicting BRCA mutations is located more in the tumor context than in the cell morphology. Our results suggest that BRCA somatic mutations have a discernible phenotypic effect that could be detected by deep learning and could be used as a prescreening tool in the future.

Association between post-operative hPG80 (circulating progastrin) detectable level and worse prognosis in glioblastoma

BACKGROUND

Patients with glioblastomas have a dismal prognosis, and there is no circulating predictive or prognostic biomarker. Circulating progastrin, hPG80, is a tumor-promoting peptide present in the blood of patients with various cancers that has been shown to have prognostic value. We evaluated the prognostic value of plasma hPG80 in patients with isocitrate dehydrogenase-wild type glioblastoma after surgery.

PATIENTS AND METHODS

A multicentric retrospective study in glioblastoma patients treated with standard radio-chemotherapy was conducted. The hPG80 levels were measured in plasma EDTA samples collected after surgery with an ELISA DxPG80.lab kit (Biodena Care, Montpellier, France), which has a detection threshold of 1.2 pM. The relationship between post-operative hPG80 plasma levels, in combination with other known prognostic factors, and patients' progression-free survival (PFS) and overall survival (OS) was evaluated.

RESULTS

Sixty-nine patients were assessable. Plasma samples were collected after tumor biopsy (B), partial resection (PR), and complete resection (CR) for 22, 25, and 22 patients, respectively. At a median concentration of 5.37 pM (interquartile range 0.00-13.90 pM), hPG80 was detected in 48 (70%) patients (hPG80+). CR was associated with significant lower values of hPG80 levels: the median value was 0.7 versus 9.1 pM for PR (P = 0.02) and 8.3 pM for B (P = 0.004). The hPG80 detection rate was also significantly lower: 50% (CR) versus 72% (PR) versus 86% (B) (P = 0.005). The median follow-up was 39 months [22.4 months-not reached]. hPG80 post-operative detection was associated with numerically shorter PFS (6.4 versus 9.4 months, P = 0.13) and OS (14.5 versus 20.9 months, P = 0.11). In multivariate analysis, hPG80 was a prognostic factor for OS (P = 0.034).

CONCLUSIONS

Circulating hPG80 could serve as a new prognostic biomarker after surgery in patients with glioblastoma treated with radio-chemotherapy.

Deep Learning Methodologies Applied to Digital Pathology in Prostate Cancer: A Systematic Review

Deep learning (DL), often called artificial intelligence (AI), has been increasingly used in Pathology thanks to the use of scanners to digitize slides which allow us to visualize them on monitors and process them with AI algorithms. Many articles have focused on DL applied to prostate cancer (PCa). This systematic review explains the DL applications and their performances for PCa in digital pathology. Article research was performed using PubMed and Embase to collect relevant articles. A Risk of Bias (RoB) was assessed with an adaptation of the QUADAS-2 tool. Out of the 77 included studies, eight focused on pre-processing tasks such as quality assessment or staining normalization. Most articles (n = 53) focused on diagnosis tasks like cancer detection or Gleason grading. Fifteen articles focused on prediction tasks, such as recurrence prediction or genomic correlations. Best performances were reached for cancer detection with an Area Under the Curve (AUC) up to 0.99 with algorithms already available for routine diagnosis. A few biases outlined by the RoB analysis are often found in these articles, such as the lack of external validation. This review was registered on PROSPERO under CRD42023418661.

Spatial Distribution of Immune Cells in Primary and Recurrent Glioblastoma: A Small Case Study

Only a minority of patients with glioblastoma (GBM) respond to immunotherapy, and always only partially. There is a lack of knowledge on immune distribution in GBM and in its tumor microenvironment (TME). To address the question, we used paired primary and recurrent tumors from GBM patients to study the composition and the evolution of the immune landscape upon treatment. We studied the expression of a handful of immune markers (CD3, CD8, CD68, PD-L1 and PD-1) in GBM tissues in 15 paired primary and recurrent GBM. In five selected patients, we used Nanostring Digital Spatial Profiling (DSP) to obtain simultaneous assessments of multiple biomarkers both within the tumor and the microenvironment in paired primary and recurrent GBM. Our results suggest that the evolution of the immune landscape between paired primary and recurrent GBM tumors is highly heterogeneous. However, our study identifies B3-H7 and HLA-DR as potential targets in primary and recurrent GBM. Spatial profiling of immune markers from matched primary and recurrent GBM shows a nonlinear complex evolution during the progression of cancer. Nonetheless, our study demonstrated a global increase in macrophages, and revealed differential localization of some markers, such as B7-H3 and HLA-DR, between GBM and its TME.

A Multigene Signature Associated with Progression-Free Survival after Treatment for IDH Mutant and 1p/19q Codeleted Oligodendrogliomas

BACKGROUND

IDH mutant and 1p/19q codeleted oligodendrogliomas are the gliomas associated with the best prognosis. However, despite their sensitivity to treatment, patient survival remains heterogeneous. We aimed to identify gene expressions associated with response to treatment from a national cohort of patients with oligodendrogliomas, all treated with radiotherapy +/- chemotherapy.

METHODS

We extracted total RNA from frozen tumor samples and investigated enriched pathways using KEGG and Reactome databases. We applied a stability selection approach based on subsampling combined with the lasso-pcvl algorithm to identify genes associated with progression-free survival and calculate a risk score.

RESULTS

We included 68 patients with oligodendrogliomas treated with radiotherapy +/- chemotherapy. After filtering, 1697 genes were obtained, including 134 associated with progression-free survival: 35 with a better prognosis and 99 with a poorer one. Eight genes (ST3GAL6, QPCT, NQO1, EPHX1, CST3, S100A8, CHI3L1, and OSBPL3) whose risk score remained statistically significant after adjustment for prognostic factors in multivariate analysis were selected in more than 60% of cases were associated with shorter progression-free survival.

CONCLUSIONS

We found an eight-gene signature associated with a higher risk of rapid relapse after treatment in patients with oligodendrogliomas. This finding could help clinicians identify patients who need more intensive treatment.

Uterine sarcomas and rare uterine mesenchymal tumors with malignant potential. Diagnostic guidelines of the French Sarcoma Group and the Rare Gynecological Tumors Group

The landscape of uterine sarcomas is becoming increasingly complex with the description of new entities associated with recurrent molecular alterations. Uterine sarcomas, as well as soft tissue sarcomas, can be distinguished into complex genomic sarcomas and simple genomic sarcomas. Leiomyosarcoma and pleomorphic type undifferentiated uterine sarcoma belong to the first group. Low-grade and high-grade endometrial stromal sarcomas, NTRK, COL1A1::PDGFB, ALK, RET, ROS1 associated sarcomas, and SMARCA4 deficient uterine sarcoma belong to the second group. Leiomyosarcoma is the most common uterine sarcoma followed by endometrial stromal sarcomas. Three different histologic subtypes of leiomyosarcomas are recognized with distinct diagnostic criteria and different clinical outcomes, the myxoid and epithelioid leiomyosarcomas being even more aggressive than the fusiform type. The distinction between low-grade and high-grade endometrial stromal sarcoma is based first on morphology and immunohistochemistry. The detection of fusion transcripts helps in the diagnosis. Definitely recognized as a separate entity, uterine PEComa is a rare tumor whose diagnostic criteria are being recently defined. Uterine PEComa has a specific algorithm stratifying the tumors into uncertain malignant potential and malignant tumors. Embryonal rhabdomyosarcomas of the uterine cervix are not restricted to children but can also be observed in adult women and are almost always DICER1 mutated, unlike embryonal rhabdomyosarcoma of the vagina which are DICER1wild-type, and adenosarcoma which can be DICER1 mutated but with less frequency. As sarcomas associated with fusion transcripts involving the NTRK, ALK, COL1A1::PDGFB genes can benefit from targeted therapy, systematic detection are now relevant especially for patients with high risk of relapse or in recurrent setting. The integration of molecular data with dedicated expert pathology review for histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Prognostic value of hPG80 (circulating progastrin) in IDH-wild type glioblastoma treated with radio-chemotherapy

2049

Background: hPG80 (circulating progastrin) is a protein secreted by many cancer types, playing a role in tumorigenesis by regulating cancer stem cells, angiogenesis, proliferation/differentiation and decreasing apoptosis. hPG80 is detectable in plasma of cancer patients and previous studies have shown its prognostic role in various cancers. Given the lack of circulating biomarker in glioblastoma, we evaluated the prognostic value of plasma hPG80 in patients with IDH wild type glioblastoma Methods: This multicentric retrospective study included IDHwt glioblastoma patients treated with standard radio-chemotherapy. The ELISA DxPG80.lab kit (Biodena Care, Lausanne, Switzerland) was used to measure hPG80 levels after surgery with a detection threshold of 1 pM in all plasma EDTA samples according to the manufacturer’s instruction. The prognostic impact of hPG80 was evaluated on patient’s progression-free survival (PFS) and overall survival (OS). Results: We included 70 patients (38 males /32 women) with a median age of 64 years (Range 19 - 84). Karnofsky index was > 70% in 52 (91%) of 57 evaluable patients. Tumor biopsy (B), partial resection (PR), complete resection (CR) were performed in 22, 25 and 23 patients respectively. MGMT promotor was methylated in 22 (40%) of the 55 evaluable patients. After surgery, hPG80 was detected in 48 (69%) patients (hPG80+) with a median concentration of 9.52 pM (IQR 5.21 - 21.20). Complete surgery was associated with undetectable levels of hPG80 (52% (CR) vs 28% (PR) vs 14% (B), p = 0.006) and lower concentration if hPG80+ (CR: 5.8 pM [IQR 1.92 - 11.38] vs PR: 12.84 pM [IQR 8.09 - 37.09]; p = 0.04 vs B: 9.86 pM [IQR 4.66 - 21.63]; p = 0.16). With a median follow-up of 39 months (22.4-NR), 86% of patients had progressed and 70% had died. In univariate analysis, hPG80 positivity was associated with PFS (5.6m vs 8.5m, p = 0.053) and OS (14.5 vs 22m, p = 0.04) in hPG80+ vs hPG80- patients respectively. hPG80+ patients with complete surgery had worse median OS than hPG80- patients (14.5 vs 22.0 m; p = 0.051 respectively. Cox proportional hazards model did not fit for covariate analysis. Conclusions: Our findings show that hPG80 could serve as a new circulating prognostic biomarker in IDHwt glioblastoma patients treated with radio-chemotherapy. Further explorations are ongoing in larger cohorts including longitudinal evaluation during the course of the disease.

A phase II randomised study of preoperative trastuzumab alone or combined with everolimus in patients with early HER2-positive breast cancer and predictive biomarkers (RADHER trial)

INTRODUCTION

Resistance to trastuzumab in breast cancer is an ongoing challenge. Clinical and biological effects of co-targeting HER2 and mammalian target of rapamycin (mTOR) in patients with HER2-positive early operable breast cancer via the addition of everolimus to preoperative trastuzumab were evaluated in a phase II randomised study.

METHODS

Patients were randomised 1:1 to receive trastuzumab (4 mg/kg initial dose then 2 mg/kg weekly for 5 weeks) alone or combined with everolimus (10 mg/day for 6 weeks) and then underwent surgery. Tumours were assessed by clinical examination and echography at the baseline and on treatment. The primary end-point was the clinical response rate at 6 weeks. Pathological response and safety were also evaluated. Baseline and surgery tumour samples were assessed by immunohistochemistry and multiplex immunoanalysis for predictive downstream effectors of the PI3K/AKT/mTOR and MAP kinase (MAPK) pathways.

RESULTS

Eighty-two patients were enrolled, 41 per arm. The clinical response rates were 34.1% and 43.9% with trastuzumab alone and combined with everolimus, respectively. Pathological response rates were 43.6% and 47.5%, respectively. Addition of everolimus increased toxicity, notably mucositis (82.5% versus 5.0%) and rash (57.5% versus 10.0%), but grade III/IV events were rare. No correlation between response to treatments and baseline candidate biomarkers was identified, except for PIK3CA mutations which were found to predict trastuzumab resistance. Significant changes were seen in several MAPK pathway effectors after combination therapy.

CONCLUSIONS

The addition of everolimus did not improve the efficacy, but induced MAPK signalling. Combination therapy to overcome pathway cross-talk should be considered to maximise the effectiveness of trastuzumab in this setting. ClinicalTrial.gov Identifier NCT00674414.

Phenotypic discordance between primary and metastatic breast cancer in the large-scale real-life multicenter French ESME cohort

Expression of hormone receptor (HR) for estrogens (ER) and progesterone (PR) and HER2 remains the cornerstone to define the therapeutic strategy for breast cancer patients. We aimed to compare phenotypic profiles between matched primary and metastatic breast cancer (MBC) in the ESME database, a National real-life multicenter cohort of MBC patients. Patients with results available on both primary tumour and metastatic disease within 6 months of MBC diagnosis and before any tumour progression were eligible for the main analysis. Among the 16,703 patients included in the database, 1677 (10.0%) had available biopsy results at MBC diagnosis and on matched primary tumour. The change rate of either HR or HER2 was 27.0%. Global HR status changed (from positive = either ER or PR positive, to negative = both negative; and reverse) in 14.2% of the cases (expression loss in 72.5% and gain in 27.5%). HER2 status changed in 7.8% (amplification loss in 45.2%). The discordance rate appeared similar across different biopsy sites. Metastasis to bone, HER2+ and RH+/HER2- subtypes and previous adjuvant endocrine therapy, but not relapse interval were associated with an HR discordance in multivariable analysis. Loss of HR status was significantly associated with a risk of death (HR adjusted = 1.51, p = 0.002) while gain of HR and HER2 discordance was not. In conclusion, discordance of HR and HER2 expression between primary and metastatic breast cancer cannot be neglected. In addition, HR loss is associated with worse survival. Sampling metastatic sites is essential for treatment adjustment.

Meningiomas and cyproterone acetate: a retrospective, monocentric cohort of 388 patients treated by surgery or radiotherapy for intracranial meningioma

PURPOSE

Meningiomas are the most common intracranial tumors, accounting for 20-30% of central nervous system tumors. Recently, the European Medicines Agency issued an alert on cyproterone acetate (CPA) based on the results of a study that found an increased risk of meningioma 7 to 20 times higher when a patient is on CPA. The primary objective of this study was to determine the prevalence of CPA exposure in patients who had one or more intracranial meningiomas treated surgically or with radiation therapy. The secondary objectives were to establish a description of the patients who had intracranial meningioma in Nantes and to establish whether there was a difference in the intrinsic and tumoral characteristics of patients exposed to CPA compared with patients who had no hormonal exposure and patients who had been exposed to other hormones.

METHODS

Monocentric, retrospective study including all patients treated by surgery or radiotherapy for intracranial meningioma from 2014 to 2017 excluding those with a history of exposure to ionizing radiation or neurofibromatosis type 2.

RESULTS

388 patients were included, 277 were treated by surgery and 111 by radiotherapy. 3.9% of the patients had a history or current use of CPA, 16.2% were taking other hormonal treatment. Compared with the group without hormonal exposure, the CPA-exposed group had significantly an earlier onset of meningiomas at 48.9 vs. 61.9 years (p = 0.0005) and had more multiple meningiomas, 26.7% vs. 6.1% (p = 0.0115).

CONCLUSIONS

In our study, patients with a history or current use of CPA had significantly more meningiomas and were significantly younger at the onset.

[Inflammatory cardiomyopathies: Diagnosis, correlations with imaging, interest of myocardial biopsy and place of molecular biology]

Inflammatory cardiomyopathies, also known as "myocarditis" are inflammatory pathologies affecting the myocardium and characterized by vast etiological and clinical heterogeneity. They can be asymptomatic, particularly in viral forms, or be responsible for sudden death, particularly in subjects under 35 years olds. Due to insufficient sensitivity and specificity of imaging and biology, the gold standard is histopathological and is performed on an endomyocardial biopsy or on explanted heart samples in a transplant context. Their classification has considerably evolved and is now based on the identification of a predominant cell pattern such as lymphocytic, neutrophilic or eosinophilic polynuclear, giant cell or granulomatous myocarditis. These different patterns will guide the etiological diagnosis, prognosis and the therapies to be implemented. Due to the importance of viral etiologies, this morphological analysis must be complemented by a virological analysis based on PCR with viral load quantification. In addition, some authors have been able to demonstrate the occurrence of myocarditis in patients with arrhythmogenic cardiomyopathy of genetic origin. The aim of this chapter is to review the current state of knowledge on inflammatory cardiomyopathies and their management.

One-year conditional survival of dogs and cats with invasive mammary carcinomas: A concept inspired from human breast cancer

Numerous studies have described the prognostic factors of canine and feline mammary carcinomas (MCs), that is, variables that predict patient survival after diagnosis. But how does survival estimation evolve in patients that escaped early death from their cancer? In human oncology, conditional survival (CS), the probability of surviving X further years when cancer patients have already survived Y years, is used to analyse cancer outcomes in a long‐term perspective. In this cohort of 344 dogs and 342 cats with surgically removed stage I to III invasive MCs, with a minimal follow‐up of 2 years, we calculated the 1‐year CS, that is, the probability for patients that have survived 1 year, to survive or to die from cancer during the subsequent year. The 1‐year conditional specific survival probabilities were 59% and 48% at diagnosis of invasive MC respectively in dogs and cats, and 80% and 52% in 1‐year surviving dogs and cats respectively, suggesting that 1‐year surviving dogs were relatively protected from cancer‐related death, whereas feline MCs remained life‐threatening cancers for longer periods of time. Among the most significant parameters associated with CS in surviving dogs and cats were the nodal stage and lymphovascular invasion, as well as patient age, cancer stage and margin status in surviving dogs. By comparison, tumour size and the histological grade did not significantly alter CS probabilities in surviving dogs and cats. Conditional survival may be considered a very interesting tool for veterinary practitioners to estimate the likely outcome of cancer survivors.

[Magnetic Resonance Imaging for local preoperative staging in endometrial cancer: Nantes local experience]

OBJECTIVES

To determine the diagnostic accuracy of magnetic resonance imaging (MRI) for local preoperative staging in endometrial cancer in our center (Centre Hospitalier Universitaire de Nantes: CHU), since the French National Cancer Institute's surgery recommendations publication in 2010, especially for the prediction of myometrial and cervical stromal invasion.

METHODS

Retrospective monocentric study of consecutive women operated of endometrial cancer in gynecology department of CHU de Nantes, who underwent preoperative pelvic MRI in our Radiology department from November 2010 to November 2016. MRI data collected from initial report and compared to surgical histological findings as gold standard.

RESULTS

Sixty-four patients were included. Deep myometrial invasion was present in 35 patients in MRI versus 34 patients on postoperative histology (5 false positives, 4 false negatives). Cervical stromal invasion was present in 9 patients in MRI versus 19 patients on postoperative histology (2 false positives, 12 false negatives). The sensitivity and the specificity were respectively 88.23% (95% confidence intervals (CI) [0.71-0.96]) and 83.33% (CI [0.64-0.93]) for the deep myometrial invasion; 36.84% (CI [0.17-0.61]) and 95.55% (CI [0.83-0.99]) for the cervical stromal invasion.

CONCLUSION

Our results were comparable to the literature data, with a low sensitivity for the cervical stromal invasion detection, driving us to change our MRI protocol with optional high-resolution T2 sequences perpendicular to the cervical canal if necessary.

Pineoblastoma segregates into molecular sub-groups with distinct clinico-pathologic features: a Rare Brain Tumor Consortium registry study

Pineoblastomas (PBs) are rare, aggressive pediatric brain tumors of the pineal gland with modest overall survival despite intensive therapy. We sought to define the clinical and molecular spectra of PB to inform new treatment approaches for this orphan cancer. Tumor, blood, and clinical data from 91 patients with PB or supratentorial primitive neuroectodermal tumor (sPNETs/CNS-PNETs), and 2 pineal parenchymal tumors of intermediate differentiation (PPTIDs) were collected from 29 centres in the Rare Brain Tumor Consortium. We used global DNA methylation profiling to define a core group of PB from 72/93 cases, which were delineated into five molecular sub-groups. Copy number, whole exome and targeted sequencing, and miRNA expression analyses were used to evaluate the clinico-pathologic significance of each sub-group. Tumors designated as group 1 and 2 almost exclusively exhibited deleterious homozygous loss-of-function alterations in miRNA biogenesis genes (DICER1, DROSHA, and DGCR8) in 62 and 100% of group 1 and 2 tumors, respectively. Recurrent alterations of the oncogenic MYC-miR-17/92-RB1 pathway were observed in the RB and MYC sub-group, respectively, characterized by RB1 loss with gain of miR-17/92, and recurrent gain or amplification of MYC. PB sub-groups exhibited distinct clinical features: group 1-3 arose in older children (median ages 5.2-14.0 years) and had intermediate to excellent survival (5-year OS of 68.0-100%), while Group RB and MYC PB patients were much younger (median age 1.3-1.4 years) with dismal survival (5-year OS 37.5% and 28.6%, respectively). We identified age < 3 years at diagnosis, metastatic disease, omission of upfront radiation, and chr 16q loss as significant negative prognostic factors across all PBs. Our findings demonstrate that PB exhibits substantial molecular heterogeneity with sub-group-associated clinical phenotypes and survival. In addition to revealing novel biology and therapeutics, molecular sub-grouping of PB can be exploited to reduce treatment intensity for patients with favorable biology tumors.

Identification of an immune-suppressed subtype of feline triple-negative basal-like invasive mammary carcinomas, spontaneous models of breast cancer

Feline invasive mammary carcinomas are characterized by their high clinical aggressiveness, rare expression of hormone receptors, and pathological resemblance to human breast cancer, especially triple-negative breast cancer (negative to estrogen receptor, progesterone receptor, and epidermal growth factor receptor type 2). Recent gene expression studies of triple-negative breast cancers have highlighted their heterogeneity and the importance of immune responses in their biology and prognostic assessment. Indeed, regulatory T cells may play a crucial role in producing an immune-suppressed microenvironment, notably in triple-negative breast cancers. Feline invasive mammary carcinomas arise spontaneously in immune-competent animals, in which we hypothesized that the immune tumor microenvironment also plays a role. The aims of this study were to determine the quantity and prognostic value of forkhead box protein P3-positive peritumoral and intratumoral regulatory T cells in feline invasive mammary carcinomas, and to identify an immune-suppressed subgroup of triple-negative basal-like feline invasive mammary carcinomas. One hundred and eighty female cats with feline invasive mammary carcinomas, treated by surgery only, with 2-year follow-up post-mastectomy, were included in this study. Forkhead box protein P3, estrogen receptor, progesterone receptor, Ki-67, epidermal growth factor receptor type 2, and cytokeratin 14 expression were assessed by automated immunohistochemistry. Peritumoral regulatory T cells were over 300 times more abundant than intratumoral regulatory T cells in feline invasive mammary carcinomas. Peritumoral and intratumoral regulatory T cells were associated with shorter disease-free interval and overall survival in both triple-negative (ER-, PR-, HER2-, N = 123 out of 180) and luminal (ER+ and/or PR+, N = 57) feline invasive mammary carcinomas. In feline triple-negative basal-like (CK14+) mammary carcinomas, a regulatory T-cell-enriched subgroup was associated with significantly poorer disease-free interval, overall survival, and cancer-specific survival than regulatory T-cell-poor triple-negative basal-like feline invasive mammary carcinomas. High regulatory T-cell numbers had strong and negative prognostic value in feline invasive mammary carcinomas, especially in the triple-negative basal-like subgroup, which might contain a "basal-like immune-suppressed" subtype, as described in triple-negative breast cancer. Cats with feline invasive mammary carcinomas may thus be interesting spontaneous animal models to investigate new strategies of cancer immunotherapy in an immune-suppressed tumor microenvironment.

STING-dependent paracriny shapes apoptotic priming of breast tumors in response to anti-mitotic treatment

A fascinating but uncharacterized action of antimitotic chemotherapy is to collectively prime cancer cells to apoptotic mitochondrial outer membrane permeabilization (MOMP), while impacting only on cycling cell subsets. Here, we show that a proapoptotic secretory phenotype is induced by activation of cGAS/STING in cancer cells that are hit by antimitotic treatment, accumulate micronuclei and maintain mitochondrial integrity despite intrinsic apoptotic pressure. Organotypic cultures of primary human breast tumors and patient-derived xenografts sensitive to paclitaxel exhibit gene expression signatures typical of type I IFN and TNFα exposure. These cytokines induced by cGAS/STING activation trigger NOXA expression in neighboring cells and render them acutely sensitive to BCL-xL inhibition. cGAS/STING-dependent apoptotic effects are required for paclitaxel response in vivo, and they are amplified by sequential, but not synchronous, administration of BH3 mimetics. Thus anti-mitotic agents propagate apoptotic priming across heterogeneously sensitive cancer cells through cytosolic DNA sensing pathway-dependent extracellular signals, exploitable by delayed MOMP targeting.

CD8+ T cell-mediated endotheliopathy is a targetable mechanism of neuro-inflammation in Susac syndrome

Neuroinflammation is often associated with blood-brain-barrier dysfunction, which contributes to neurological tissue damage. Here, we reveal the pathophysiology of Susac syndrome (SuS), an enigmatic neuroinflammatory disease with central nervous system (CNS) endotheliopathy. By investigating immune cells from the blood, cerebrospinal fluid, and CNS of SuS patients, we demonstrate oligoclonal expansion of terminally differentiated activated cytotoxic CD8+ T cells (CTLs). Neuropathological data derived from both SuS patients and a newly-developed transgenic mouse model recapitulating the disease indicate that CTLs adhere to CNS microvessels in distinct areas and polarize granzyme B, which most likely results in the observed endothelial cell injury and microhemorrhages. Blocking T-cell adhesion by anti-α4 integrin-intervention ameliorates the disease in the preclinical model. Similarly, disease severity decreases in four SuS patients treated with natalizumab along with other therapy. Our study identifies CD8+ T-cell-mediated endotheliopathy as a key disease mechanism in SuS and highlights therapeutic opportunities.

PDTM-24. PINEOBLASTOMA SEGREGATES INTO MOLECULAR SUBTYPES WITH DISTINCT CLINICOPATHOLOGIC FEATURES: REPORT FROM THE RARE BRAIN TUMOUR CONSORTIUM

BACKGROUND

Pineoblastoma (PB) is a rare but aggressive pediatric brain tumour arising from the pineal gland. Overall survival rates are estimated at 50–70%, with younger patients (< 5 years old) faring much worse (15–40%) despite intensive treatment regimens. Although germline RB1 and DICER1 alterations have been reported in a small proportion of PB, the clinical significance of such alterations and the biology of sporadic cases remains unknown.

METHODS

We collected tumor tissue from 93 PB cases diagnosed at their referring centres. We undertook global DNA methylation profiling and performed multiple orthogonal consensus clustering analyses to elucidate PB subgroups. Chromosomal copy number alterations were determined using Conumee and GISTIC2, and whole exome or targeted sequencing was completed. Clinical data was analyzed with correlative statistical methods and outcomes were measured by Kaplan-Meier survival estimates.

RESULTS

PB comprise five epigenetic groups, designated 1, 2, 3, 4A, and 4B. Deleterious, mutually exclusive alterations affecting miRNA biogenesis pathway members (DICER1, DROSHA, and DGCR8) were observed in 12/21 group 1 and 11/11 group 2 samples. Group 4A was characterized by recurrent RB1 loss and gain of the oncogenic miR-17/92, and group 4B by recurrent gain or amplification of MYC. These groups also exhibit distinct clinical features. PB groups 1–3 arose in older children (median ages 5.2–14.0 years) and had intermediate to excellent outcome (5-year OS of 71.9–100%). Group 4A and 4B were restricted to much younger children (median age 1.3–1.4 years) and had dismal prognoses (5-year OS 37.5% and 28.6%, respectively).

CONCLUSIONS

PB divides into five groups with distinct genetic and clinical profiles. These findings will have important implications for precise patient stratification and form the foundation for preclinical studies of biology-informed therapies.

Proposal for a Histological Staging System of Mammary Carcinomas in Dogs and Cats. Part 1: Canine Mammary Carcinomas

Background: Staging of mammary carcinomas of dogs and cats is not only important for prognostic purposes, but also to guide therapy, in particular regarding adjuvant chemotherapy. The classical staging system relies on T, the clinical tumor size, N, the clinical nodal stage, and M, distant metastasis, evaluated by the clinician. However, a more precise and reliable staging system is applied to human stage I–III breast cancer, i.e., without distant metastasis, in which T is replaced by the pathologic tumor size (pT), and N is replaced by the pathologic nodal stage (pN), both evaluated by the pathologist. This staging system is strongly associated with patient outcomes, and is used to select treatment options. The purpose of this study was to design a histologic staging system for Canine Mammary Carcinomas (CMCs, part 1 of this article), and Feline Mammary Carcinomas (part 2), inspired from human oncology, and to assess its association with patient outcomes.

Materials and Methods: This retrospective study included 433 female dogs with a surgically removed CMC. Patient outcomes were recorded over a 2-years follow up period. CMCs were staged according to pT (greatest diameter in millimeters on histological slides), lymphovascular invasion (LVI), and pN (confirmed by cytokeratin AE1/AE3 immunohistochemistry). The histological stages were defined as: Stage 0 (CMCs in situ, surrounded by a continuous layer of p63+ myoepithelial cells), Stage I (pT1 ≤ 20 mm, LVI–, pN0–pNX, where pNX refers to the absence of lymph node sample), Stage II (pT2 > 20 mm, LVI–, pN0–pNX), Stage IIIA (pT1, LVI+, and/or pN+), and Stage IIIB (pT2, LVI+, and/or pN+).

Results: Disease-free-interval, overall survival and specific survival significantly differed by histological stage. For specific survival, median survival times and hazard ratios (HR) by Cox proportional hazards regression (p < 0.0001) were: Stage 0 (median survival not reached; HR = 1.00; N = 89; 21% of the dogs), Stage I (1,720 days; HR = 3.05; p = 0.0018; N = 81; 19%), Stage II (1,181 days; HR = 4.39; p < 0.0001; N = 79; 18%), Stage IIIA (348 days; HR = 10.59; p < 0.0001; N = 79; 18%), and Stage IIIB (163 days; HR = 16.59; p < 0.0001; N = 105; 24%).

Conclusion: The proposed histological staging system (invasiveness, pT, LVI, pN) is a very strong prognostic factor for CMCs.

Proposal for a Histological Staging System of Mammary Carcinomas in Dogs and Cats. Part 2: Feline Mammary Carcinomas

Background: Feline mammary carcinomas (FMCs) are characterized by a high frequency of metastatic spread. The clinical TNM (Tumor, Node, Metastasis) system is used to describe local, regional, and distant tumor extent within the patient, but few publications confirmed its association with survival in cats with FMC. The purpose of this study was to determine if the histological staging system proposed for dogs in part 1 of this article had significant association with prognosis in cats.

Materials and Methods: This retrospective study included 395 female cats with a surgically removed mammary carcinoma, with a 2-year follow-up. Invasiveness (distinction between in situ and invasive FMCs), the pathologic tumor size (pT), lymphovascular invasion (LVI), and the pathologic nodal stage (pN) defined a 5-stage system: Stage 0 (FMCs in situ), Stage I (pT1, LVI–, pN0–pNX), Stage II (pT2, LVI–, pN0–pNX), Stage IIIA (pT1, LVI+ and/or pN+), and Stage IIIB (pT2, LVI+ and/or pN+), where pT1 was ≤20 mm, pT2 was >20 mm, and pNX corresponded to unsampled draining lymph node.

Results: Higher histological stages were associated with reduced disease-free interval, overall survival, and specific survival. For cancer-specific survival, by univariate analysis (p < 0.0001), median survival times and 1-year specific survival rates (1ySSR) were: stage 0 (1484 days; 1ySSR = 85%; N = 55; 14% of the cats), stage I (808 days; 1ySSR = 76%; N = 103; 26%), stage II (377 days; 1ySSR = 51%; N = 56; 14%), stage IIIA (448 days; 1ySSR = 60%; N = 83; 21%), and stage IIIB (207 days; 1ySSR = 29%; N = 98; 25%). The histological stages were also associated with specific survival by multivariate analysis (Hazard Ratio (HR) = 2.72 for stage IIIB, HR = 1.76 for stage IIIA, HR = 1.50 for stage II compared with stage I), independently of Progesterone Receptor expression (HR = 0.34 for PR+ compared with PR– FMCs) and tumor-associated inflammation (HR = 1.33 when moderate to severe compared with absent to mild).

Conclusion: A same histological staging system could be applied in dogs and cats with mammary carcinoma to refine prognosis assessment. In the near future, a preoperative complete tumor clinical staging and treatment based on the published standard of care should be performed in order to better validate the histological staging system here proposed.

P04.12 Characteristics of IDH-mutant gliomas with non-canonical IDH mutations

BACKGROUND

About 10% of IDH-mutant gliomas harbor non-canonical IDH mutations (non-R132H IDH1 and IDH2 mutations). The aim of the present study was to analyze the characteristics of these gliomas in comparison to those of IDH1 R132H mutant gliomas.

MATERIAL AND METHODS

We retrospectively analyzed the characteristics of a multicentric series of 161 gliomas with non-canonical IDH mutations and compared them to those of consecutive series of 109 IDH1 R132H mutant gliomas. Medical, radiological and pathological were reviewed.

RESULTS

Median age at diagnosis was 35 years in gliomas with a non-canonical IDH1 mutation, 42 years in those with an IDH2 mutation and 44 years in those with an IDH1R132H mutation. A familial history of cancer was more frequent in gliomas with a non-canonical IDH mutation than in those with an IDH1 R132H mutation (22,3% vs 5,5%, p<0.05). In both IDH1 R132H-mutant and non-canonical IDH-mutant gliomas the most frequent location was the frontal lobe. Yet, compared to IDH1R132H-mutant gliomas those with a non-canonical IDH mutation had more frequently an infratentorial location (5,5% vs 0% p<0,05) and were more frequently multicentric (4,9%, versus 0.9%, p<0.05). Compared to IDH1R132H-mutant gliomas, gliomas with a non-canonical IDH1 mutation were more frequently astrocytomas (65.7% vs 45%, p<0.05) while those with an IDH2 mutation were more frequently oligodendrogliomas (82% vs 55%, p<0.05). The median overall survival in IDH1 R132H-mutant and non-canonical IDH-mutant gliomas was similar (122 versus 120 months).

CONCLUSION

Gliomas with non-canonical IDH mutations are associated with distinct clinical, radiological and histological characteristics. Their prognosis, however, is similar to that of gliomas with canonical IDH mutations.

Combined chemotherapy and allogeneic human Vγ9Vδ2 T lymphocyte-immunotherapies efficiently control the development of human epithelial ovarian cancer cells in vivo

Epithelial ovarian cancer (EOC) represents 5% of human gynecologic cancers in the world, is heterogeneous and highly invasive with a dismal prognosis (5 year-survival rate <35%). Diagnosis of EOC is frequently made at advanced stages and, despite aggressive treatments combining surgery and chemotherapy, fatal relapse rapidly occurs and is accompanied by a peritoneal carcinosis. In this context, novel therapeutical advances are urgently required. Adoptive transfer(s) of immune effector cells, including allogeneic human Vγ9Vδ2 T lymphocytes, represent attractive targets for efficiently and safely tracking tissue-invading tumor cells and controlling tumor dissemination in the organism. Our study describes the establishment of robust and physiological orthotopic model of human EOC in mouse, that includes surgical resection (ovariectomy) and chemotherapy, which are ineluctably accompanied by a fatal peritoneal carcinosis recurrence. Through a complementary set of in vitro and in vivo experiments, we provide here a preclinical proof of interest of the antitumor efficiency of adoptive transfers of allogeneic human Vγ9Vδ2 T lymphocytes against EOC, in association with surgical debulking and standard chemotherapies (i.e., taxanes and platinum salts). Moreover, our results indicate that chemo- and immunotherapies can be combined to improve the antitumor efficiency of immunotherapeutic lines. Altogether, these results further pave the way for next-generation antitumor immunotherapies, based on local administrations of human allogeneic human Vγ9Vδ2 T lymphocytes, in association with standard treatments.

Feline Invasive Mammary Carcinomas: Prognostic Value of Histological Grading

Feline mammary carcinomas are highly malignant tumors usually associated with poor outcome. Nevertheless, survival times can differ significantly according to various prognostic factors. The Elston and Ellis (EE) histologic grading system, originally developed for human breast cancer, is commonly used to grade feline mammary carcinomas, although it is not really adapted for this species, hence the need of a more relevant grading system. Although few veterinary studies attempted to validate previously published results in an independent cohort, the aim of our study was to evaluate the prognostic value of different histologic grading systems in feline invasive mammary carcinomas, including the EE grading system applicable to human breast cancers and the modified and newly designed histologic grading systems recently proposed by Mills et al. Survey data and histologic features of 342 feline invasive mammary carcinomas were analyzed with respect to overall and cancer-specific survival. The histological grading system with best prognostic value was the mitotic-modified Elston and Ellis (MMEE) grading system: grade III carcinomas (P = .04, hazard ratio [HR] = 1.46, 95% CI, 1.01-2.11), grade II (P = .03, HR = 1.39, 95% CI, 1.03-1.88), and grade I carcinomas (HR = 1.00, reference), with decreasing hazard ratios significantly were associated with a worse overall survival, independently from the pathologic tumor size (pT ≥ 20 mm: P = .002, HR = 1.45, 95% CI, 1.15-1.83) and positive nodal stage (P = .001, HR = 1.51, 95% CI, 1.18-1.94). This retrospective study validates Mills et al's proposal to adapt the thresholds for mitotic counts to better assess the histological grade of the highly proliferative mammary carcinomas encountered in the cat.

Identification of three subtypes of triple-negative breast cancer with potential therapeutic implications

Background

Heterogeneity and lack of targeted therapies represent the two main impediments to precision treatment of triple-negative breast cancer (TNBC), and therefore, molecular subtyping and identification of therapeutic pathways are required to optimize medical care. The aim of the present study was to define robust TNBC subtypes with clinical relevance.

Methods

Gene expression profiling by means of DNA chips was conducted in an internal TNBC cohort composed of 238 patients. In addition, external data (n = 257), obtained by using the same DNA chip, were used for validation. Fuzzy clustering was followed by functional annotation of the clusters. Immunohistochemistry was used to confirm transcriptomics results: CD138 and CD20 were used to test for plasma cell and B lymphocyte infiltrations, respectively; MECA79 and CD31 for tertiary lymphoid structures; and UCHL1/PGP9.5 and S100 for neurogenesis.

Results

We identified three molecular clusters within TNBC: one molecular apocrine (C1) and two basal-like-enriched (C2 and C3). C2 presented pro-tumorigenic immune response (immune suppressive), high neurogenesis (nerve infiltration), and high biological aggressiveness. In contrast, C3 exhibited adaptive immune response associated with complete B cell differentiation that occurs in tertiary lymphoid structures, and immune checkpoint upregulation. External cohort subtyping by means of the same approach proved the robustness of these results. Furthermore, plasma cell and B lymphocyte infiltrates, tertiary lymphoid structures, and neurogenesis were validated at the protein levels by means of histological evaluation and immunohistochemistry.

Conclusion

Our work showed that TNBC can be subcategorized in three different subtypes characterized by marked biological features, some of which could be targeted by specific therapies.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1148-6) contains supplementary material, which is available to authorized users.

Bcl-2 expression and prognostic significance in feline invasive mammary carcinomas: a retrospective observational study

BACKGROUND

Cats spontaneously develop invasive mammary carcinomas with high clinical aggressiveness, and are considered relevant animal models for human breast cancer. Bcl-2 is an anti-apoptotic pro-survival protein, whose expression is associated with a favorable outcome in human breast cancer. The aim of our study was to determine the frequency of Bcl-2 expression in feline invasive mammary carcinomas (FMCs), its relationship with other clinicopathologic variables, and its prognostic value. This retrospective study included 180 FMCs, diagnosed in female cats treated by surgery only, with a 2-year follow-up post-mastectomy. Bcl-2, ER, PR, Ki-67, HER2, and CK5/6 expression were determined by automated immunohistochemistry. A receiver-operating-characteristic curve was used to set the threshold for Bcl-2 positivity.

RESULTS

The cohort comprises 32% (57/180) luminal FMCs defined by ER and/or PR positivity, and 68% (123/180) triple-negative FMCs (negative for ER, PR, and HER2). Bcl-2 expression was considered as positive when at least 65% of tumor cells were immunohistochemically stained. Thirty-one out of 180 FMCs (17%) were Bcl-2-positive. There was no significant association between Bcl-2 expression, and the tumor size, nodal stage, histological grade, or ER, PR, Ki-67, HER2, and CK5/6 expression. By multivariate survival analysis (Cox proportional-hazards regression), Bcl-2 positivity in FMCs was associated with longer disease-free interval (p = 0.005, HR = 0.38), overall survival (p = 0.028, HR = 0.61), and cancer-specific survival (p = 0.019, HR = 0.54) independently of other powerful prognostic factors such as pathologic tumor size, pathologic nodal stage, and distant metastasis. The positive prognostic value of Bcl-2 was confirmed in both luminal FMCs, of which 9/57 (16%) were Bcl-2-positive, and in basal-like triple-negative (ER-, PR-, HER2-, CK5/6+) FMCs, of which 14/76 (18%) were Bcl-2-positive.

CONCLUSIONS

Compared to human breast cancer, Bcl-2 positivity in feline invasive mammary carcinomas is also associated with better outcome, but is less common, and not associated with ER, PR, and HER2 expression. Cats with spontaneous Bcl-2-positive FMCs could be useful in preclinical trials evaluating anti-Bcl-2 strategies for chemoresistant luminal or triple-negative breast cancers.

Interactions between cancer-associated fibroblasts and tumor cells promote MCL-1 dependency in estrogen receptor-positive breast cancers

Selective inhibition of BCL-2 is expected to enhance therapeutic vulnerability in luminal estrogen receptor-positive breast cancers. We show here that the BCL-2 dependency of luminal tumor cells is nevertheless mitigated by breast cancer-associated fibroblasts (bCAFs) in a manner that defines MCL-1 as another critical therapeutic target. bCAFs favor MCL-1 expression and apoptotic resistance in luminal cancer cells in a IL-6 dependent manner while their own, robust, survival also relies on MCL-1. Studies based on ex vivo cultures of human luminal breast cancer tissues further argue that the contribution of stroma-derived signals to MCL-1 expression shapes BCL-2 dependency. Thus, MCL-1 inhibitors are beneficial for targeted apoptosis of breast tumor ecosystems, even in a subtype where MCL-1 dependency is not intrinsically driven by oncogenic pathways.

Canine invasive mammary carcinomas as models of human breast cancer. Part 2: immunophenotypes and prognostic significance

PURPOSE

Relevant animal models of human breast cancer are currently needed, especially for the aggressive triple-negative breast cancer subtype. Recent studies and our results (Part 1) indicate that spontaneous canine invasive mammary carcinomas (CMCs) resemble human breast cancer by clinics and pathology as well as behavior and prognostic indicators. We hypothesized that the current molecular classifications of human breast cancer, used for therapeutic decision, could be relevant to dogs.

METHODS

Three hundred and fifty female dogs with spontaneous CMC and a 2-year follow-up were retrospectively included. By immunohistochemistry, CMCs were classified according to Nielsen (Clin Cancer Res 10:5367-5374, 2004) and Blows (PlosOne doi: 10.1371/journal.pmed.1000279, 2010) into the subtypes of human breast cancer.

RESULTS

Four immunophenotypes were defined either according to Nielsen classification (luminal A 14.3%, luminal B 9.4%, triple-negative basal-like 58.6%, and triple-negative nonbasal-like 17.7% CMCs); or to Blows classification (luminal 1-: 11.4%, luminal 1+: 12.3%, Core basal phenotype: 58.6%, and five-negative phenotype: 17.7%). No HER2-overexpressing CMC as defined by a 3 + immunohistochemical score was observed in our cohort. By univariate and multivariate analyses, both immunophenotypical classifications applied to CMCs showed strong prognostic significance: luminal A or luminal 1+ CMCs showed a significantly longer disease-free interval (HR = 0.46), Overall (HR = 0.47), and Specific Survival (HR = 0.56) compared to triple-negative carcinomas, after adjustment for stage.

CONCLUSIONS

In our cohort, triple-negative CMCs largely predominated (76%), were much more prevalent than in human beings, and showed an aggressive natural behavior after mastectomy. Dogs are thus potent valuable spontaneous models to test new therapeutic strategies for this particular subtype of breast cancer.

Pharmacological targeting of apelin impairs glioblastoma growth

Glioblastoma are highly aggressive brain tumours that are associated with an extremely poor prognosis. Within these tumours exists a subpopulation of highly plastic self-renewing cancer cells that retain the ability to expand ex vivo as tumourspheres, induce tumour growth in mice, and have been implicated in radio- and chemo-resistance. Although their identity and fate are regulated by external cues emanating from endothelial cells, the nature of such signals remains unknown. Here, we used a mass spectrometry proteomic approach to characterize the factors released by brain endothelial cells. We report the identification of the vasoactive peptide apelin as a central regulator for endothelial-mediated maintenance of glioblastoma patient-derived cells with stem-like properties. Genetic and pharmacological targeting of apelin cognate receptor abrogates apelin- and endothelial-mediated expansion of glioblastoma patient-derived cells with stem-like properties in vitro and suppresses tumour growth in vivo. Functionally, selective competitive antagonists of apelin receptor were shown to be safe and effective in reducing tumour expansion and lengthening the survival of intracranially xenografted mice. Therefore, the apelin/apelin receptor signalling nexus may operate as a paracrine signal that sustains tumour cell expansion and progression, suggesting that apelin is a druggable factor in glioblastoma.

Canine invasive mammary carcinomas as models of human breast cancer. Part 1: natural history and prognostic factors

Purpose

Dogs have been proposed as spontaneous animal models of human breast cancer, based on clinicopathologic similarities between canine and human mammary carcinomas. We hypothesized that a better knowledge of the natural history and prognostic factors of canine invasive mammary carcinomas would favor the design of preclinical trials using dogs as models of breast cancer.

Methods

The 2-year outcome of 350 female dogs with spontaneous invasive mammary carcinoma was studied. The investigated prognostic factors included age at diagnosis, pathologic tumor size, pathologic nodal stage, lymphovascular invasion, histological grade, and expression of Estrogen Receptor alpha (ERα), Progesterone Receptor, Ki-67, Human Epidermal Growth Factor Receptor 2, basal cytokeratins 5/6, and Epidermal Growth Factor Receptor. Multivariate survival analyses were performed using the Cox proportional hazards model.

Results

The overall survival after mastectomy was 11 months. Within 1 year post mastectomy, 41.5% of dogs (145/350) died from their mammary carcinoma. By multivariate analysis, the significant prognostic factors for overall survival included a pathologic tumor size larger than 20 mm [HR 1.47 (95% confidence interval 1.15–1.89)], a positive nodal stage [pN+, HR 1.89 (1.43–2.48)], a histological grade III [HR 1.32 (1.02–1.69)], ERα negativity [HR 1.39 (1.01–1.89)], a high Ki-67 proliferation index [HR 1.32 (1.04–1.67)], and EGFR absence [HR 1.33 (1.04–1.69)].

Conclusion

The short natural history of spontaneous canine invasive mammary carcinomas and high rate of cancer-related death allow for rapid termination of preclinical investigations. The prognostic factors of invasive mammary carcinomas are remarkably similar in dogs and humans, highlighting the similarities in cancer biology between both species.

Efficient Mitochondrial Glutamine Targeting Prevails Over Glioblastoma Metabolic Plasticity

Purpose: Glioblastoma (GBM) is the most common and malignant form of primary human brain tumor in adults, with an average survival at diagnosis of 18 months. Metabolism is a new attractive therapeutic target in cancer; however, little is known about metabolic heterogeneity and plasticity within GBM tumors. We therefore aimed to investigate metabolic phenotyping of primary cultures in the context of molecular tumor heterogeneity to provide a proof of concept for personalized metabolic targeting of GBM.Experimental Design: We have analyzed extensively several primary GBM cultures using transcriptomics, metabolic phenotyping assays, and mitochondrial respirometry.Results: We found that metabolic phenotyping clearly identifies 2 clusters, GLN^High and GLN^Low, mainly based on metabolic plasticity and glutamine (GLN) utilization. Inhibition of glutamine metabolism slows the in vitro and in vivo growth of GLN^High GBM cultures despite metabolic adaptation to nutrient availability, in particular by increasing pyruvate shuttling into mitochondria. Furthermore, phenotypic and molecular analyses show that highly proliferative GLN^High cultures are CD133^neg and display a mesenchymal signature in contrast to CD133^pos GLN^Low GBM cells.Conclusions: Our results show that metabolic phenotyping identified an essential metabolic pathway in a GBM cell subtype, and provide a proof of concept for theranostic metabolic targeting. Clin Cancer Res; 23(20); 6292-304. ©2017 AACR.

Abstract 1137: ADAM8 drives aggressive phenotype of triple-negative inflammatory breast cancer & constitutes a novel therapeutic target

Inflammatory Breast Cancer (IBC) is a rare, highly aggressive form of cancer that is frequently locally advanced or metastasized at the time of diagnosis. The Triple-Negative subtype of IBC (TN-IBC), in particular, is characterized by very poor overall survival. TN-IBC lacks targeted therapies and is primarily treated with radiation or chemotherapy, which are inefficient. Recently, we identified the cell surface transmembrane ADAM8 (A Disintegrin and Metalloproteinase) protein as a driver of Triple-Negative Breast Cancer (TNBC) growth and metastasis via its Metalloproteinase (MP) and Disintegrin (DI) domains, respectively. In in vivo proof-of-concept experiments with a prototype reagent, we demonstrated that simultaneous, antibody-based, targeting of the ADAM8 MP and DI domains is an effective therapeutic approach for TNBC (Romagnoli et al., EMBO Mol. Med. 6:278, 2014).

The aggressive behavior of IBC cells has been attributed to a stem-like cancer cell compartment with high ALDH activity (ALDH+). Our studies of the green tea compound epigallocatechin-3 gallate (EGCG) revealed that it reduced growth of tumors derived from ALDH+ SUM-149 TN-IBC cells. We now report that EGCG concurrently decreases tumor levels of ADAM8 mRNA. This led us to assess the role of ADAM8 in TN-IBC. Tumor biopsies from 15 patients taken at the time of diagnosis and/or after neo-adjuvant treatment with chemotherapy, as well as paired lymph node and skin samples (when available) were analyzed by immunohistochemistry for ADAM8 expression. We report that 45.5% of primary TN-IBC patient tumors and 50.0% of metastases within the axillary lymph nodes express high levels of ADAM8 and its expression is largely unaffected by chemotherapy. In addition, ADAM8 expression was higher in the aggressive ALDH+ stem-like SUM-149 cell compartment. Consistently, knockdown of ADAM8 dramatically reduced the ability of SUM-149 cells to grow in an anchorage independent fashion and to migrate through Matrigel. A newly prepared anti-human ADAM8 mouse monoclonal antibody (ADP13) inhibited the MP and DI domains of ADAM8 on SUM-149 cells. ADP13 reduced orthotopic growth of tumors derived from SUM-149 cells by 40% in mice treated by i.p. injection 2 days a week with a dose of 4.5 mg/kg (n=7). Dose-response curves and survival experiments are in progress.

Conclusions: ADAM8 expression is present in almost half of TN-IBC patient tumors and their metastases, and promotes aggressive phenotype of TN-IBC cells in in vitro 3D-assays. A pre-clinical mouse model of TN-IBC validated ADAM8 as an accessible and promising new target for therapeutic intervention against this highly aggressive disease.

Citation Format: Mathilde Romagnoli, Stefania Pianetti, Sonia G. Das, Delphine Loussouarn, Carole Gourmelon, Mario Campone, Sophie Barillé-Nion, Giang T. Nguyen, Srimathi Srinivasan, Gail E. Sonenshein, Nora D. Mineva. ADAM8 drives aggressive phenotype of triple-negative inflammatory breast cancer & constitutes a novel therapeutic target [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1137. doi:10.1158/1538-7445.AM2017-1137

YM155 potently triggers cell death in breast cancer cells through an autophagy-NF-kB network

Specific overexpression in cancer cells and evidence of oncogenic functions make Survivin an attractive target in cancer tharapy. The small molecule compound YM155 has been described as the first “Survivin suppressant” but molecular mechanisms involved in its biological activity and its clinical potential remain obscure. We herein show that YM155 exerts single agent toxicity on primary breast cancer cells grown in an ex vivo assay preserving tumor microenvironment. In vitro assays indicate that YM155 more efficiently triggers cell death in breast cancer cells (including these with stem-cell like properties) than in non tumorigenic mammary cells. YM155-induced cell death is critically dependent on autophagy and NF-kB but independent of p53 and it coïncides with DNA damage an a DNA damage response in p53-proficient cells. Our results point out a crosstalk between NF-KB and autophagy controlling YM155-induced death in breast cancer cells and argue for the potential use of YM155 as a genotoxic agent in breast cancer therapy.

The dog as a naturally-occurring model for insulin-like growth factor type 1 receptor-overexpressing breast cancer: an observational cohort study

BACKGROUND

Dogs spontaneously develop invasive mammary carcinoma with a high prevalence of the triple-negative (TN) subtype (lack of ER-Estrogen Receptor and PR-Progesterone Receptor expression, lack of HER2-Human Epidermal Growth Factor Receptor 2 overexpression), making this animal model relevant for investigating new therapeutic pathways. Insulin-like growth factor Type-1 receptor (IGF1R) is frequently overexpressed in primary human breast cancers, with a growing role in the TN phenotype. The purpose of this study was to investigate the Dog as a candidate model for IGF1R-overexpressing mammary carcinoma.

METHODS

150 bitches with canine mammary carcinoma (CMC) and a known 2-year follow-up were retrospectively included. IGF1R expression was assessed by immunohistochemistry (IHC) using a similar scoring system as for HER2 in breast cancer. The prognostic value of the IGF1R expression was assessed in terms of overall and specific survival as well as disease-free interval (DFI).

RESULTS

47 CMC (31 %) were classified as luminal and 103 (69 %) as triple-negative (TN-CMC). 41 % of CMC overexpressed IGF1R (IHC score 3+) of which 76 % were TN-CMC and 62 % grade III. IGF1R overexpression was associated with aggressive features including lymphovascular invasion, histological grade III, low ER expression and the TN phenotype. Univariate and multivariate analyses revealed that IGF1R overexpression was associated with shorter overall and specific survivals and shorter DFI in TN-CMC.

CONCLUSIONS

IGF1R overexpression is common and related to a poor outcome in canine invasive mammary carcinoma, particularly in the triple negative subtype, as in human breast cancer. Preclinical studies using the Dog as a spontaneous animal model could be considered to investigate new therapies targeting IGF1R in triple-negative breast cancer.

Prediction of Recurrence and Survival for Triple-Negative Breast Cancer (TNBC) by a Protein Signature in Tissue Samples

To date, there is no available targeted therapy for patients who are diagnosed with triple-negative breast cancers (TNBC). The aim of this study was to identify a new specific target for specific treatments. Frozen primary tumors were collected from 83 adjuvant therapy-naive TNBC patients. These samples were used for global proteome profiling by iTRAQ-OFFGEL-LC-MS/MS approach in two series: a training cohort (n = 42) and a test set (n = 41). Patients who remains free of local or distant metastasis for a minimum of 5 years after surgery were classified in the no-relapse group; the others were in the relapse group. OPLS and Kaplan-Meier analyses were performed to select candidate markers, which were validated by immunohistochemistry. Three proteins were identified in the training set and validated in the test set by Kaplan-Meier method and immunohistochemistry (IHC): TrpRS as a good prognostic markers and DP and TSP1 as bad prognostic markers. We propose the establishment of an IHC test to calculate the score of TrpRS, DP, and TSP1 in TNBC tumors to evaluate the degree of aggressiveness of the tumors. Finally, we propose that DP and TSP1 could provide therapeutic targets for specific treatments.

Prognostic Relevance of Histomolecular Classification of Diffuse Adult High-Grade Gliomas with Necrosis

Diffuse adult high-grade gliomas (HGGs) with necrosis encompass anaplastic oligodendrogliomas (AOs) with necrosis (grade III), glioblastomas (GBM, grade IV) and glioblastomas with an oligodendroglial component (GBMO, grade IV). Here, we aimed to search for prognostic relevance of histological classification and molecular alterations of these tumors. About 210 patients were included (63 AO, 56 GBM and 91 GBMO). GBMO group was split into "anaplastic oligoastrocytoma (AOA) with necrosis grade IV/GBMO," restricted to tumors showing intermingled astrocytic and oligodendroglial component, and "GBM/GBMO" based on tumors presenting oligodendroglial foci and features of GBM. Genomic arrays, IDH1 R132H expression analyses and IDH direct sequencing were performed. 1p/19q co-deletion characterized AO, whereas no IDH1 R132H expression and intact 1p/19q characterized both GBM and GBM/GBMO. AOA with necrosis/GBMO mainly demonstrated IDH1 R132H expression and intact 1p/19q. Other IDH1 or IDH2 mutations were extremely rare. Both histological and molecular classifications were predictive of progression free survival (PFS) and overall survival (OS) (P < 10(-4) ). Diffuse adult HGGs with necrosis can be split into three histomolecular groups of prognostic relevance: 1p/19q co-deleted AO, IDH1 R132H-GBM and 1p/19q intact IDH1 R132H+ gliomas that might be classified as IDH1 R132H+ GBM. Because of histomolecular heterogeneity, we suggest to remove the name GBMO.

Abstract P3-06-07: Alterations of intratumoral signalling in breast cancer patients receiving pre-operative trastuzumab alone or combined with everolimus

Background: PI3K/AKT/mTOR and MAP kinase pathways are major signaling pathways involved in mammary tumorigenesis and are investigated as putative targets for therapy. Multiple cross-talks exists between these two pathways, allowing the regulation of one another by and inversely, depending on the cell conditions. It has been reported that trastuzumab acted differently when used pre-operatively or in neo-adjuvant setting with a lower implication of signaling blockade and a higher induction of ADCC when used alone in chemotherapy naive patients. Additionally, mTOR blockade has been experimentally reported to activate MAPK pathway through a feed-back loop effect. The purpose of this study was to retrospectively investigate the effect on MAPK signaling of adding everolimus to trastuzumab as preoperative therapy of HER-2 positive primary breast cancer amenable to surgery (Unicancer RADHER Phase II trial).

Patients and methods: Formalin-fixed paraffin embedded and frozen tumor samples of primary breast cancer (n=80), were obtained from 82 patients with infiltrating breast carcinoma randomized from July 2008 to April 2012 to receive ttrastuzumab alone (T arm) (loading dose 4mg/kg, then 2mg/kg/week), or combined with everolimus (T+E arm) (10 mg/day) for a 6 week pre-operative treatment. The median patient age at diagnosis (at the randomization) was 52.7 years. All patients had baseline biopsies taken before initiation of the treatment, at cycle 4 as an option and at surgery. FFPE samples were used for immunohistochemistry (pAKT, pS6K, eIF4E, LKB1), frozen samples were used for multiplex immunoanalysis of phosphorylated PI3K/AKT/mTOR and MAPKinase signaling proteins analysis (p-AKT, p-GSK3, p-P70S6K, p-MEK1, p-ERK1/2, p-P90RSK). Before being submitted to total protein extraction, all biopsies were controlled to ensure a tumor content &gt;50%. 40 pairs associating baseline + surgery tumor specimens or baseline + cycle 4 biopsies were eligible for protein extraction.

Results: No statistically significant relationship was observed between the expression level of any of the phosphoproteins in the initial biopsies and neither the clinical nor the pathological response, overall. After treatment, as compared to the level of expression measured in the initial biopsies, no significant variation of expression of either PI3 kinase or MAP kinase related phosphoprotein was observed in T arm. In T+E arm, significant inhibition of PI3 kinase/mTOR pathway was only observed downstream mTOR protein with decreased expression of p-P70S6 kinase and p-4EBP1 together with a significant activation of MAPK pathway was detected with increased expression of p-MEK1, p-ERK1/2 was observed in T+E arm.

Conclusion: These results confirm that when used alone in chemotherapy naive patients, trastuzumab could not mainly act through the blockade of signaling and therefore when combined with mTOR inhibitors could lead to the suppression of negative feedback regulation of MAP kinase pathway.

Citation Format: Jean-Louis Merlin, Maeva Lion, Jennifer Wong, Thomas Bachelot, Fabrice Andre, Isabelle Treilleux, Delphine Loussouarn, Jacques Bonneterre, Maria Rios, Véronique Dieras, Marta Jimenez, Agnès Leroux, Mario Campone. Alterations of intratumoral signalling in breast cancer patients receiving pre-operative trastuzumab alone or combined with everolimus [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-06-07.

Abstract P2-04-07: Gene-expression molecular subtyping of immunohistochemistry-typed triple-negative breast cancer tumours

BACKGROUND

Recently, it has been shown that annotation of triple-negative breast tumours (TNBC) by means of immunohistochemistry (IHC) or gene-expression signatures (GES) gave different results: 20 to 30% of these tumours were not basal-like, but luminal A, B or HER2-E. In this study, we aimed at identifying gene-expression molecular subclassification of IHC-TNBC.

MATERIALS AND METHODS

Patients

Studied bi-centric cohort retrospectively included 107 randomly selected women whose primary breast tumours lacked IHC expression of estrogen receptor, progesterone receptor and HER2. Patients were diagnosed and treated primarily between 1998 and 2007 at the ICO-Gauducheau (n=65) and the ICO-Papin (n=42).

Gene expression profiling

Gene expression analysis was performed using Affymetrix Human Genome U133 Plus 2.0 Arrays that correspond to approximately 20,000 genes.

Statistical analysis

Unsupervised analysis was performed by means of fuzzy clustering. Independent IHC-TNBC cohort (GSE21653; n=87) was used for external validation.

"Fuzzy cluster" functional annotation

To annotate "fuzzy-clusters", we used clinicopathologic characteristics, gene-expression signatures (GES) (PAM50, Proliferation score, TNBCtype, Immune response, Claudin-low), Gene Ontology enrichment and IHC (CK5, CK5/6, HER1, AR, Ki-67, FOXA1).

RESULTS

Fuzzy clustering partition individualized 3 clusters in our cohort: C1, C2 and C3. "Fuzzy cluster" functional annotation results are displayed in Table 1. C1 was composed of a mixture of non-basal-like subtypes. C2 and C3 were basal-like and IHC-TNBC. Except an adenoid cystic case, C2 was exclusively composed of basal-like subtypes. C3 was essentially characterized by immune response and included 26% of claudin-low subtypes. For this reason, C3 should rather be named "immune response cluster". External validation confirmed our results.

Table1. "Fuzzy cluster" functional annotation results.N° "fuzzy cluster"C1 (n=24)C2 (n=48)C3 (n=35)P-valueClinicopathologic characteristicsAge (mean years)64.656.851.9&lt;0.05SBRLowHigh&lt;0.05NPILowHigh&lt;0.05Gene-expression signaturesPAM50Luminal B (61%), A (22%)Basal-like (98%)Basal-like (91%) Proliferation scoreLowHigh ++High +&lt;0.05TNBCtypeLuminal androgen receptorBasal-like 1, mesenchymalImmune response Immune responseSteroid hormone responseImmune responseImmune response Claudin-low0%Low frequency (2%)Higher frequency (26%) Gene Ontology enrichmentBiological processesEpithelial cell differentiation, hormone metabolic processCell adhesion, locomotion, chemotaxisImmune response ImmunohistochemistryCK5 and/or HER1 positive50%91%&lt;0.05AR positive73%5%&lt;0.05Ki-67 positive29%87%&lt;0.05FOXA1 positive83%9.6%&lt;0.05

CONCLUSION

Heterogeneity within basal-like and IHC-TNBC is still controversial and require further research to understand the complexity of the disease, and to identify molecular drivers that can be therapeutically targeted. Annotation discordances between IHC and GES clearly indicate that a robust molecular subtyping method must be found. Correct molecular assignment would permit to orientate 20 to 30% of IHC-TNBC patients towards targeted therapy (hormonotherapy or anti-HER2).

Citation Format: Mario Campone, Loïc Campion, Delphine Loussouarn, Isabelle Valo, Catherine Guérin-Charbonnel, Antoine Vanier, Wilfried Gouraud, Catherine Guette, Véronique Verrièle, Agnès Chassevent, Pascal Jézéquel. Gene-expression molecular subtyping of immunohistochemistry-typed triple-negative breast cancer tumours [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-04-07.