Topic:Cancer
Cancer in horses encompasses a range of neoplastic diseases that affect various tissues and organs in equine species. These conditions involve the uncontrolled growth of abnormal cells, which can form tumors and potentially spread to other parts of the body. Common types of cancer in horses include sarcoids, squamous cell carcinoma, and melanoma, each with distinct characteristics and clinical presentations. Diagnosis often involves a combination of physical examination, imaging techniques, and histopathological analysis. Treatment options vary based on the type and stage of cancer and may include surgical intervention, chemotherapy, and radiation therapy. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathophysiology, diagnostic methods, and treatment strategies for cancer in horses.
Evaluation of Hypoxia-Inducible Factor-1 Alpha (HIF-1α) in Equine Sarcoid: An Immunohistochemical and Biochemical Study. equine sarcoids are the most frequent skin tumors in equidae worldwide. It is well known that delta bovine papillomaviruses are their causative agents. We have recently shown the presence in equine sarcoids of abnormal vessel structures, which could cause a hypoxic condition. The aim of this study was to analyze the expression of hypoxia-inducible factor-1 alpha (HIF-1α) in a subset of BPV positive equine sarcoids and explore the relationship with vascular endothelial growth factor (VEGF) expression. Results: 80% of equine sarcoids showed strong cytoplasmic staining in >60% of neoplastic f...
Bleaching melanin in formalin-fixed and paraffin-embedded melanoma specimens using visible light: a pilot study. In fluorescence microscopy, light radiation can be used to bleach fluorescent molecules in formalin-fixed and paraffin-embedded (FFPE) samples, in order to increase the ratio between signal of interest and background autofluorescence. We tested if the same principle can be exploited in bright field microscopy to bleach pigmented melanoma FFPE sections together with cell morphology maintenance. After dewaxing and rehydration, serial FFPE sections of a feline diffuse iris melanoma, a canine dermal melanoma, a gray horse dermal melanoma and a swine cutaneous melanoma were irradiated with visible ...
Paving the way for more precise diagnosis of EcPV2-associated equine penile lesions. There is growing evidence that equine papillomavirus type 2 (EcPV2) infection is causally associated with the development of equine genital squamous cell carcinomas (SCCs). Early stages of disease present clinically as plaques or wart-like lesions which can gradually progress to tumoural lesions. Histologically these lesions are inconsistently described as benign hyperplasia, papilloma, penile intraepithelial neoplasia (PIN), carcinoma in situ (CIS) or SCC. Guidelines for histological classification of early SCC precursor lesions are not precisely defined, leading to potential misdiagnosis. Th...
Cauda equina syndrome in an ovarian malignant-mixed müllerian tumor with leptomeningeal spread. Leptomeningeal metastasis is extremely rare in patients with ovarian cancer, but should be considered in patients presenting with neurologic deficits such as cauda equine syndrome. Given its poor prognosis and lack of data currently on management, additional studies are needed to optimize treatment regimens and improve outcomes.
Epitope Analysis of an Antihorse Podoplanin Monoclonal Antibody PMab-219. Podoplanin (PDPN), which is a mucin-type membrane glycoprotein, is expressed on lymphatic endothelial cells and epithelial cells of many organs. PDPN is also overexpressed in several malignant cancers, and its expression is associated with cancer progression and poor prognosis. Human PDPN possesses three platelet aggregation-stimulating (PLAG) domains and the PLAG-like domain (PLD), which binds to C-type lectin-like receptor-2 (CLEC-2). Previously, we reported a novel antihorse PDPN (horPDPN) monoclonal antibody (mAb), PMab-219, using Cell-Based Immunization and Screening (CBIS) method. PMab-2...
Additional Evidence for DDB2 T338M as a Genetic Risk Factor for Ocular Squamous Cell Carcinoma in Horses. Squamous cell carcinoma (SCC) is the most common periocular cancer in horses and the second most common tumor of the horse overall. A missense mutation in damage-specific DNA-binding protein 2 (DDB2, c.1012 C>T, p.Thr338Met) was previously found to be strongly associated with ocular SCC in Haflinger and Belgian horses, explaining 76% of cases across both breeds. To determine if this same variant in DDB2 contributes to risk for ocular SCC in the Arabian, Appaloosa, and Percheron breeds and to determine if the variant contributes to risk for oral or urogenital SCC, histologically confirmed SCC c...
Occupational Exposures in an Equestrian Centre to Respirable Dust and Respirable Crystalline Silica. Sand-based products are regularly used as footing material on indoor equestrian arenas, creating a potential occupational exposure risk for respirable crystalline silica (RCS) for equestrian workers training and exercising horses in these environments. The objective of this study was to evaluate an equestrian worker's personal RCS and respirable dust (RD) exposure. Sixteen personal full-shift RD measurements were collected from an equestrian worker and analysed for RD, quartz and cristobalite. Geometric mean exposures of 0.12 mg m and 0.02 mg m were calculated for RD and RCS concentrations, re...
Treatment of Infiltrative Superficial Tumors in Awake Standing Horses Using Novel High-Frequency Pulsed Electrical Fields. Irreversible electroporation is a proven ablation modality for local ablation of soft tissue tumors in animals and humans. However, the strong muscle contractions associated with the electrical impulses (duration, 50-100 μs) requires the use of general anesthesia and, in most situations, application of neuromuscular blockade. As such, this technology is not used in an outpatient setting for ablating common cutaneous tumors (e.g., squamous cell carcinoma or melanoma) in humans or animals. Recently, high-frequency irreversible electroporation (H-FIRE) technology has been developed to enable ele...
Malignant Mesothelioma of the Vaginal Tunic and Peritoneum in a Young Stallion. Mesothelioma is a rare malignancy in horses. This report describes a case in which marked hemoperitoneum, moderate anemia, and moderate dependent edema were the presenting clinical signs in a 2-year-old Standardbred stallion with mesothelioma of the vaginal tunic. On necropsy, approximately 40 L of dark red fluid distended the abdomen. A dark red mass infiltrated and effaced the right pampiniform plexus, and red nodular masses were present multifocally on the parietal and visceral peritoneal surfaces. Histopathologically, the masses were composed of malignant spindle cells with a sarcomatoid ...
Treatment Options for Melanoma of Gray Horses. All gray horses inherited a single gene mutation, STX17G, that unbalances melanocyte behavior to cause graying and propensities to develop vitiligo and melanoma. The coat color genes ASIPa and MC1RE add risk such that relative likelihood of melanoma based on pregraying coat color is black > bay > chestnut. Melanomas begin at about 4 years. Locoregional control of melanoma masses depends on surgical removal and/or intralesional chemotherapy (possibly with adjunctive hyperthermia or electroporation). Systemic treatment is not evidence based but immunomodulators (cimetidine, levamisole) and ...
Bisphosphonate use in the horse: what is good and what is not? Bisphosphonates (BPs) are a family of molecules characterized by two key properties: their ability to bind strongly to bone mineral and their inhibitory effects on mature osteoclasts and thus bone resorption. Chemically two groups of BPs are recognized, non-nitrogen-containing and nitrogen-containing BPs. Non-nitrogen-containing BPs incorporate into the energy pathways of the osteoclast, resulting in disrupted cellular energy metabolism leading to cytotoxic effects and osteoclast apoptosis. Nitrogen-containing BPs primarily inhibit cholesterol biosynthesis resulting in the disruption of intrac...
Calcium electroporation: The bioelectrochemical treatment of spontaneous equine skin tumors results in a local necrosis. Electrochemotherapy (ECT) is an anticancer bioelectrochemical therapy where electrical field pulses (electropermeabilization) increase intracellular concentration of antitumor drugs. The procedure is very effective against skin tumors. The restrictive regulations concerning anticancer drugs in veterinary medicine limit use of ECT. Electroporation with calcium (Electroporation Calcium Therapy)(ECaT) was proved to be effective in vivo on induced tumors in laboratory animals. This study evaluated the effects of ECaT in equine sarcoids (spontaneous skin tumors) on an animal cohort. Pulse parameter...
Methylation Marks of Blood Leukocytes of Native Hucul Mares Differentiated in Age. Horses are one of the longest-living species of farm animals. Advanced age is often associated with a decrease in body condition, dysfunction of immune system, and late-onset disorders. Due to this, the search for new solutions in the prevention and treatment of pathological conditions of the advanced age of horses is desirable. That is why the identification of aging-related changes in the horse genome is interesting in this respect. In the recent years, the research on aging includes studies of age-related epigenetic effects observed on the DNA methylation level. We applied reduced represent...
Standing Hand-Assisted Laparoscopic Diagnosis and Treatment of a Rare Case of Uterine Adenocarcinoma in an 18-Year-Old Mare. An 18-year-old French Trotter mare was presented to the Clinique Equine, Ecole Nationale Vétérinaire d'Alfort, for exploration of a 3-month-duration vaginal bleeding. A transrectal ultrasound examination identified a mass within the right uterine horn wall, which had been suspected during transrectal palpation. It was described as a firm heterogeneous intramural mass (7 × 12 cm) in the right uterine horn, located few centimeters cranially to the bifurcation. Hysteroscopy confirmed the ulcerated and irregular shape of the mass. A standing hand-assisted flank laparoscopy was performed to ca...
RNA-seq analysis in equine papillomavirus type 2-positive carcinomas identifies affected pathways and potential cancer markers as well as viral gene expression and splicing events. Equine papillomavirus type 2 (EcPV2) was discovered only recently, but it is found consistently in the context of genital squamous cell carcinomas (SCCs). Since neither cell cultures nor animal models exist, the characterization of this potential disease agent relies on the analysis of patient materials. To analyse the host and viral transcriptome in EcPV2-affected horses, genital tissue samples were collected from horses with EcPV2-positive lesions as well as from healthy EcPV2-negative horses. It was determined by RNA-seq analysis that there were 1957 differentially expressed (DE) host genes...
A missense mutation in damage-specific DNA binding protein 2 is a genetic risk factor for ocular squamous cell carcinoma in Belgian horses. Belgian horses are commonly affected with ocular squamous cell carcinoma (SCC), the most common cancer of the equine eye. A missense mutation in damage-specific DNA binding protein 2 (DDB2 c.1013C>T, p.Thr338Met) has been established as a recessive genetic risk factor for ocular SCC in the Haflinger breed. A sample of Belgian horses with unknown SCC phenotype was shown to possess this variant at a similar frequency to the Haflinger breed. Retrospective studies indicate that chestnut coat colour may predispose to the development of SCC. Objective: To determine if DDB2 c.1013C>T is a risk ...
Mediastinal Ectopic Thyroid Carcinoma and Concurrent Multinodular Pulmonary Fibrosis in a Horse. A 30-year-old Standardbred gelding was referred for chronic pleural effusion. Thoracic ultrasound revealed marked bilateral pleural effusion and a large heterogeneous mass within the cranial mediastinum, which extended from the right 5th to the 11th intercostal space. Subsequently, on thoracic radiographs, the cranial mediastinal mass was confirmed, and a nodular interstitial pattern was identified in the lungs. Because of progressive clinical deterioration of the patient, the owners elected humane euthanasia and necropsy was performed. The mediastinal mass was consistent with an ectopic thyro...
An unusual case of giant cell tumor of soft parts in an American Warmblood horse. Fine needle aspiration and tissue biopsy samples were taken from a subcutaneous mass in the cranial stifle region of a 10-yr-old horse. Key cytologic features included numerous mildly to moderately pleomorphic histiocytic cells admixed with mononuclear inflammatory cells, occasional fibroblasts, multinucleated cells, and hemosiderin-laden macrophages. Based on these features, cytologic differentials included granulomatous inflammation with reactive fibroplasia, histiocytic sarcoma, giant cell tumor of soft parts (GCTSPs), and giant cell tumor of bone. The tissue biopsy supported a diagnosis of...
Differentially expressed microRNAs, including a large microRNA cluster on chromosome 24, are associated with equine sarcoid and squamous cell carcinoma. The aim of this study was to investigate microRNA (miRNA) differential expression in the two most common equine skin tumours, equine sarcoid (ES) and squamous cell carcinoma (SCC), and its potential influence on the tumour microenvironment at post-transcriptional level. We investigated miRNA fingerprints in four subgroups: mild (ESM) and aggressive (ESA) ES and ocular SCC (oSCC) and genital SCC (gSCC). Three tumours and three control samples were included in each of the four subgroups. Following next generation sequencing, miRNA differential expression analysis using DESeq2 was carried out. Pa...
Cross-species genomic landscape comparison of human mucosal melanoma with canine oral and equine melanoma. Mucosal melanoma is a rare and poorly characterized subtype of human melanoma. Here we perform a cross-species analysis by sequencing tumor-germline pairs from 46 primary human muscosal, 65 primary canine oral and 28 primary equine melanoma cases from mucosal sites. Analysis of these data reveals recurrently mutated driver genes shared between species such as NRAS, FAT4, PTPRJ, TP53 and PTEN, and pathogenic germline alleles of BRCA1, BRCA2 and TP53. We identify a UV mutation signature in a small number of samples, including human cases from the lip and nasal mucosa. A cross-species comparative...
Squamous cell carcinoma with clear cell differentiation in an equine eyelid. A 15-y-old Miniature horse mare had a 6-mo history of an ulcerated mass on the right lower eyelid. An incisional biopsy and a subsequent excisional biopsy were submitted to the Michigan State University Veterinary Diagnostic Laboratory for microscopic evaluation. Histologically, the incisional biopsy was composed of sheets of large neoplastic vacuolated polygonal cells. A few regions contained poorly differentiated neoplastic round-to-basaloid cells that rimmed the sheets of highly vacuolated polygonal cells. Both vacuolated and basaloid cells exhibited strong perimembranous and cytoplasmic im...
The use of a combined sliding skin graft and a free labial mucocutaneous graft for reconstruction of the equine upper eyelid after full-thickness excision of a melanoma. A melanoma of the upper eyelid was resected in a gray warmblood gelding. A full functional eyelid could be obtained by completion a sliding skin graft with a free labial mucocutaneous graft transplantation to restore the mucocutaneous junction and to decrease the risk of postoperative trichiasis.
Differences in miRNA differential expression in whole blood between horses with sarcoid regression and progression. Currently no methods are available to predict the clinical outcome of individual horses with equine sarcoid (ES) disease. Objective: To investigate if whole blood microRNA (miRNA) profiles can predict the long-term development of ES tumors. Methods: Five horses with regression and 5 with progression of ES lesions monitored over 5-7 years and 5 control horses free of ES for at least 5 years. Methods: For this cohort study, RNA extracted from whole blood samples from the regression, progression, and control groups was used for high throughput sequencing. Known and novel miRNAs were identified us...
MicroRNA fingerprints in serum and whole blood of sarcoid-affected horses as potential non-invasive diagnostic biomarkers. Serum and whole blood microRNA (miRNA) fingerprints have been proposed as a new class of non-invasive human cancer biomarkers. In this study, we compared equine sarcoid (ES) disease-specific serum and whole blood miRNA fingerprints and correlated them to miRNA expression in sarcoid tissue. After high throughput sequencing, miRNA differential expression analysis between six ES-affected and five control horses was carried out in serum and whole blood using a DESeq algorithm, accounting for the influence of hemolysis and the white blood cell count. Target gene, pathway prediction and enrichment a...
Limbal squamous cell carcinoma in a Rocky Mountain Horse: Case report and investigation of genetic contribution. To document a case of limbal squamous cell carcinoma (SCC) in a Rocky Mountain Horse stallion determined to be homozygous for the genetic risk factor (DDB2 c.1013C>T) strongly associated with the disease in Haflinger and Belgian horses, and to determine the frequency of this allele in a larger population of Rocky Mountain Horses. Methods: One privately owned Rocky Mountain Horse and 84 Rocky Mountain Horses screened for allelic frequency. Methods: A complete ophthalmic examination was performed on a Rocky Mountain Horse stallion for assessment of a mass affecting the right eye. A clinical diag...
Expression of vascular endothelial growth factor (VEGF) in equine sarcoid. Sarcoids are the mostcommon skin tumors in horses, characterized by rare regression, invasiveness and high recurrence following surgical intervention and Delta Papillomaviruses are widely recognized as the causative agents of the disease. In order to gain new insights into equine sarcoid development, we have evaluated, in 25 equine sarcoids, by immunohistochemistry and western blotting analysis, the expression levels of VEGF, Ki67 and bcl-2. Moreover, we have measured microvessel density and specific vessel parameters. Results: All sarcoid samples showed a strong and finely granular cytoplasma...
DNA methylation patterns of the S100A14, POU2F3 and SFN genes in equine sarcoid tissues. Genetic and epigenetic alterations in the equine sarcoid, a locally invasive skin tumour of equids, are still poorly characterized. Numerous studies have provided reliable evidence for the relationship between the development of cancer and the loss of function of a number of tumour suppressor genes. In the present study, we assessed methylation levels in the promoter region of SFN, S100A14 and POU2F3 genes in sarcoid samples to clarify whether DNA methylation may be associated with previously identified changes in the expression level of these genes during the course of tumour progression. Usi...
Genetic risk for squamous cell carcinoma of the nictitating membrane parallels that of the limbus in Haflinger horses. Squamous cell carcinoma (SCC) is the most common cancer affecting the equine eye, with a higher incidence documented in Haflinger horses. Recently, a missense variant in the gene damage specific DNA binding protein 2 (DDB2, p.Thr338Met) on ECA12 was identified as a risk factor for the development of limbal SCC in Haflinger horses. SCC also occurs on the nictitating membrane; therefore, investigating the role of this missense variant in nictitating membrane SCC is warranted. In this study, a common ancestor was identified among Haflinger horses affected with limbal SCC or with nictitating membr...
Histocytic-like Atypical Mast Cell Tumours in Horses. This report describes a series of four equine mast cell tumours (MCTs) with atypical morphological features. The tumours were 1-2 cm in diameter and mostly localized to the eyes (one eyelid, two conjunctiva). Histologically, they were composed of very large (up to 35 μm) round pleomorphic cells with a large central to paracentral nucleus and abundant granular cytoplasm. A large number of viable mature eosinophils were detected intermingled with the large round cells. Histochemical staining (toluidine blue and Perls' Prussian blue) and immunohistochemistry (KIT, mast cell tryptase, lysozyme ...