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.
Conjugated equine estrogen and medroxyprogesterone acetate are associated with decreased risk of breast cancer relative to bioidentical hormone therapy and controls. By the 1990s it became popular for women to use hormone therapy (HT) to ease menopause symptoms. Bioidentical estrogen and progesterone are supplements whose molecular structures are identical to what is made in the human body, while synthetic supplements are ones whose structures are not. After the Women's Health Initiative found that the combined use of the synthetics conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) increased breast cancer risk, prescriptions for synthetic HT declined considerably. Since then there has been an increased interest in bioidentical HT; toda...
Mechanisms of cancer resistance in long-lived mammals. Cancer researchers have traditionally used the mouse and the rat as staple model organisms. These animals are very short-lived, reproduce rapidly and are highly prone to cancer. They have been very useful for modelling some human cancer types and testing experimental treatments; however, these cancer-prone species offer little for understanding the mechanisms of cancer resistance. Recent technological advances have expanded bestiary research to non-standard model organisms that possess unique traits of very high value to humans, such as cancer resistance and longevity. In recent years, several...
Equine renal hemangiosarcoma: clinical presentation, pathologic features, and pSTAT3 expression. Hemangiosarcoma is an uncommon tumor in horses. We characterized 3 cases of equine renal hemangiosarcoma, focusing on clinical and pathologic features, and describe occurrence of the epithelioid variant of hemangiosarcoma in one of these cases. Nuclear expression of phosphorylated STAT3 (pSTAT3) was assessed to analyze potential inappropriate STAT3 activation as a component of tumor pathogenesis. Clinical signs in the 3 horses included insidious weight loss, followed in one case by serosanguineous nasal discharge and terminal epistaxis, and nonspecific signs of abdominal pain. Two of the heman...
[A case of leptomeningeal melanomatosis with acute paraplegia and multiple cranial nerve palsies]. A 62-year-old man with acute paraplegia was transferred to our hospital. He had flaccid paraplegia and multiple cranial nerve palsies, such as mydriasis of the left pupil, abduction palsy of the left eye, hoarseness and dysphagia, but no meningeal irritation signs. MRI of the spinal canal showed swellings of the conus medullaris and the cauda equine, and also contrast enhancement of the spinal meninges. The cerebrospinal fluid (CSF) showed pleocytosis and protein increment. The lymph node was swollen in his right axilla. The biopsy specimen from the right axillary lymph node revealed metastasi...
Ocular and periocular hemangiosarcoma in six horses. To determine the characteristics of and prognosis for ocular and periocular hemangiosarcoma in horses. Methods: Six horses treated for ocular or periocular hemangiosarcoma. Methods: A retrospective review of medical records from 2007 to 2015 was performed to identify horses with a histologic diagnosis of ocular or periocular hemangiosarcoma. Signalment (age, sex, breed), duration of clinical signs, prior treatment, tumor size and location, medical and surgical treatment including postoperative chemotherapy, follow-up time, and outcome were obtained from medical records. Histopathology was revi...
Renal neoplasia in horses – a retrospective study. Being confronted with a case series of renal neoplasia in several horses which was in striking divergence to literature data, we recognized the need of a retrospective study to assess the presence of renal neoplasms in horses. Methods: Anamnestic animal data, necropsy findings and results of histological and immunohistochemical examinations from 2010 through 2015 were collected and evaluated regarding renal neoplasia. Results: Data from postmortem examinations of 1069 horses revealed 20 horses with renal tumors constituting a prevalence of 1.87 %. Primary renal neoplasms built the majority o...
H2S Activated Drug Release from Protein Cages. We took advantage of gasotransmitter HS as a chemical reaction-based trigger for controlled release of doxorubicin which is precoordinated by copper ions and enclosed in horse spleen apoferritin. The nanocomposite is stable at physiological pH and temperature before HS activation. The drug release process avoids disassembly of protein shells and is controllable by the strong affinity of sulfide with copper ions. The in vitro cytotoxicity assay indicates the antitumor effect of doxorubicin toward tumor cells could be achievable by HS activation.
Genomic landscape of copy number variation and copy neutral loss of heterozygosity events in equine sarcoids reveals increased instability of the sarcoid genome. Although they are the most common neoplasms in equids, sarcoids are not fully characterized at the molecular level. Therefore, the objective of this study was to characterize the landscape of structural rearrangements, such as copy number variation (CNV) and copy neutral loss of heterozygosity (cnLOH), in the genomes of sarcoid tumor cells. This information will not only broaden our understanding of the characteristics of this genome but will also improve the general knowledge of this tumor and the mechanisms involved in its generation. To this end, Equine SNP64K Illumina microarrays were appl...
Isolated limb perfusion electrochemotherapy for the treatment of an advanced squamous cell carcinoma of the hoof in a mare. A twenty-year-old female saddle horse was referred for evaluation of a seven month, non-healing erosive lesion of the right hind hoof with proliferation and bleeding of the underlying soft tissues. This lesion had been twice surgically treated as a canker but rapidly recurred. Histological examination of the second excision revealed a well-differentiated squamous cell carcinoma. At presentation, the horse was mildly depressed, lame and partially non-weight-bearing on the right hind leg, which exhibited a 10 x 10 cm erosive and proliferative lesion remodeling the hoof. After completing staging ...
Papillomavirus infection and squamous cell carcinoma in horses. Squamous cell carcinoma (SCC) is a common disease that seriously impairs the health and welfare of affected horses and other equids. In humans, almost all cervical carcinomas, a high percentage of anogenital SCCs and a subset of SCCs of the head and neck are caused by high-risk human papillomavirus (hrHPV) infection. Since hrHPV-induced human cancers and equine SCC have similar cytological and histopathological features, it has been hypothesised that equine SCCs could also be induced by papillomaviruses. This review provides an overview of the current evidence for an aetiological association b...
Recent clinical trials of cancer immunogene therapy in companion animals. This mini-review presents the results of veterinary clinical trials on immunogene therapy published from 2014 to 2016. A variety of tumors, among them melanoma (canine and equine), mastocytoma (canine), mammary adenocarcinoma (canine) and fibrosarcoma (feline) were treated by using diverse strategies. Non-viral vectors were usually employed to transfer genes of cytokines, suicide enzymes and/or tumor associated antigens. In general terms, minor or no adverse collateral effects were related to these procedures, and treated patients frequently improved their conditions (better quality of life, d...
A missense mutation in damage-specific DNA binding protein 2 is a genetic risk factor for limbal squamous cell carcinoma in horses. Squamous cell carcinoma (SCC) is the most common cancer of the equine eye, frequently originating at the limbus, with the potential to invade the cornea, cause visual impairment, and result in loss of the eye. Several breeds of horses have a high occurrence of limbal SCC implicating a genetic basis for limbal SCC predisposition. Pedigree analysis in the Haflinger breed supports a simple recessive mode of inheritance and a genome-wide association study (N = 23) identified a 1.5 Mb locus on ECA12 significantly associated with limbal SCC (Pcorrected = 0.04). Sequencing the most physiologicall...
Equine papillomavirus type 2: An equine equivalent to human papillomavirus 16? In horses, squamous cell carcinomas (SCC) commonly affect the external genitals. There is growing evidence that equine papillomavirus type 2 (EcPV2) infection promotes disease development. To assess the possible association of EcPV2 with equine SCCs of the head (HSCC), 15 HSCC DNA samples were screened by E6/E7, E2, and LCR PCR and amplicons were analysed for sequence variations. The physical form of EcPV2 in HSCC, genital lesions, and smegma from horses with SCC was then addressed using EcPV2 immunocapture PCR (IC/PCR) for detection of virion, and E6 vs. E2 qPCR to investigate possible integr...
Comprehensive characteristics of microRNA expression profile of equine sarcoids. Equine sarcoids are the most common neoplasms occurring in horses. Despite frequent occurrence, they are still not well described at the molecular level. Thus, in the present study, we performed a comprehensive comparative analysis of sarcoid miRNAome profile to identify aberrantly expressed microRNAs, along with their structural variants, potentially useful as biomarkers and, in a wider perspective, broaden the knowledge about this tumor and underlying mechanisms. To this end, we conducted next generation sequencing and as a result we identified both known and potentially novel miRNAs. Differ...
Gingival Fibrosarcoma in a Horse. A 4-year-old thoroughbred cross mare was referred to the University of Edinburgh Veterinary School Equine Hospital for treatment of a soft tissue tumor on the buccal gingival margin of the rostral right maxillary cheek teeth. The lesion was initially surgically excised and diagnosed as a fibrosarcoma via histopathology. Adjunctive treatment with intralesional cisplatin chemotherapy was begun. The tumor recurred and was repeatedly treated with intralesional cisplatin injections and additional surgical resection over the course of 14 weeks. Despite the initial poor response to treatment, no furt...
Comparative analysis of DNA methylation patterns of equine sarcoid and healthy skin samples. In this study, for the first time we report the genome-wide DNA methylation profile of skin tumour in horses and describe differentially methylated genomic regions (DMRs) with respect to healthy skin. Methods: The comparative analysis of DNA methylation patterns detected using Reduced Representation Bisulfite Sequencing (RRBS) technique, allowed identification of 136 regions showing differential methylation between sarcoid and normal skin tissue. Results: Most of the identified DMRs were short fragments, less than 1 kb in size, located in the intergenic regions. Among identified DMRs there wer...
Glycolysis inhibition improves photodynamic therapy response rates for equine sarcoids. Photodynamic therapy (PDT) holds great promise in treating veterinary and human dermatological neoplasms, including equine sarcoids, but is currently hindered by the amount of photosensitiser and light that can be delivered to lesions thicker than around 2 mm, and by the intrinsic antioxidant defences of tumour cells. We have developed a new PDT technique that combines an efficient transdermal penetration enhancer solution, for topical delivery of 5-aminolevulinic acid (ALA) photosensitiser, with acute topical post-PDT application of the glycolysis inhibitor lonidamine. We show that the new ...
Hypertrophic osteopathy secondary to metastatic ovarian adenocarcinoma in a mare. A 10-year-old Andalusian mare was presented for evaluation of weight loss, increasing periods of recumbency, and swelling of the lower limbs. Radiographs revealed severe palisading to solid periosteal new bone formation in numerous locations. Necropsy revealed a metastatic malignant adenocarcinoma of ovarian origin with secondary hypertrophic osteopathy. Une jument d’Andalousie âgée de 10 ans a été présentée pour évaluation à la suite d’une perte de poids, de périodes croissantes de décubitus et d’enflure dans les membres inférieurs. Les radiographies ont révélé des lésio...
Transcriptome analysis of equine sarcoids. Equine sarcoids are the most commonly detected skin tumours in Equidae. In the present research, a comparative transcriptomic analysis was performed which aimed at looking inside a tumour biology and identification of the expression profile as a potential source of cancer specific genes useful as biomarkers. We have used Horse Gene Expression Microarray data from matched equine sarcoids and tumour-distant skin samples. In total, 901 significantly differentially expressed genes (DEGs) between lesional and healthy skin samples have been identified (fold change ≥ 2; P < 0.05). The la...
Electrochemotherapy as a single or adjuvant treatment to surgery of cutaneous sarcoid tumours in horses: a 31-case retrospective study. The aim of our study was to evaluate the efficacy of electrochemotherapy (ECT) with cisplatin as a single or adjuvant treatment for sarcoids in equids. Different treatment options with different success rates were proposed. Thirty-one horses and one donkey with different clinical type, size and location of tumours were treated with ECT as a single treatment (18 animals with 52 tumour nodules) or as adjuvant treatment with marginal surgical excision (14 animals with 18 tumour nodules). In animals treated only with ECT with cisplatin, complete response was obtained in 48/52 (92.3 per cent) nodul...
Neoplasia in 125 donkeys (Equus asinus): literature review and a survey of five veterinary schools in the United States and Canada. A diagnosis of neoplasia was noted in 125 of 357 donkeys (35%) in our review of medical records from 5 veterinary schools in the United States and Canada. Equine sarcoid was the most common tumor in our study, accounting for 72% of all tumors and 82% of cutaneous tumors. Soft-tissue sarcomas were the second most common skin tumors. All other types of neoplasia were rare. Important differences in the occurrence of neoplasia in donkeys compared to horses included the rarity or absence of squamous cell carcinoma in any organ system and gray horse melanoma. Lymphosarcoma, the most common malignant...
Bovine Papillomavirus DNA and S100 Profiles in Sarcoids and Other Cutaneous Spindle Cell Tumors in Horses. Histopathologic differentiation between deep dermal or subcuticular equine sarcoids (ie, nodular sarcoids) and other spindle cell tumors in the dermis and subcutis such as peripheral nerve sheath tumors (PNSTs) can be challenging based on morphologic criteria alone. It has been proposed that polymerase chain reaction (PCR) for bovine papillomavirus (BPV) DNA and S100 immunohistochemistry be used as diagnostic tests to separate equine sarcoids from PNSTs. We reviewed 197 skin-associated spindle cell tumors (ie, soft tissue sarcomas), including PNSTs and sarcoids, received at the University of F...
A case of giant cell tumor of soft parts in a horse. A 12-year-old British Warmblood mare was examined by the referring veterinarian for evaluation of a cutaneous lesion on the dorsal thorax to the right of the midline. Cytologic examination of fine-needle aspirates from the mass was supportive of a giant cell tumor of soft parts (GCTSP). Laser surgical excision and postoperative methyl aminolevulinate (MAL) photodynamic therapy (PDT) were performed. Histologic examination of the mass confirmed the cytologic diagnosis. At 8 months from surgery, no evidence of recurrence has been observed. Giant cell tumors of soft parts are rare cutaneous neopla...
Enhanced cytotoxicity of bleomycin, cisplatin, and carboplatin on equine sarcoid cells following electroporation-mediated delivery in vitro. Electroporation is a method used to deliver poorly permeant chemotherapeutic drugs to tumor cells, potentiating the cytotoxic effects of drugs and overall clinical response. Despite existing evidence of the potential benefits of electroporation to enhance the antitumoral effects of drugs, there is a lack of understanding about the effects of electroporation on equine tumor cells. This study investigated the combined effects of electroporation and bleomycin, cisplatin, and carboplatin on an equine sarcoid cell line (EqS04b). The use of electroporation increases the cytotoxic effects of bleomyci...
Both tumour cells and infiltrating T-cells in equine sarcoids express FOXP3 associated with an immune-supressed cytokine microenvironment. Bovine papillomavirus (BPV) infections of equine species have a central role in the aetiology of equine sarcoids; a common benign skin tumour of horses, zebras and donkeys. Within the lesions, all of the early papillomavirus genes are expressed and promote the excessive replication of fibroblasts which characterise these tumours. Equine sarcoids differ from BPV induced fibro-papillomas of cattle (the natural host of BPV), in that they do not produce high amounts of virus particles, do not usually regress spontaneously and do not sero-convert to BPV; features which suggest that affected horses ...
CD47 expression in cryopreserved equine cutaneous masses and normal skin. We investigated CD47 expression in cryopreserved sections of equine cutaneous masses and normal skin. CD47 is a cell surface protein expressed on many cell types and overexpressed in some tumors. Interaction of CD47 and signal regulatory protein-alpha (SIRPα) inhibits phagocytosis by macrophages. Formalin-fixed tissues from horses prospectively enrolled in the study were used to establish a histologic diagnosis. Immunohistochemical assays were performed on cryopreserved tissues using anti-CD47 antibodies or IgG control antibodies. CD47 was not expressed on equine normal skin but positivity to...
Malignant Glomus Tumour (Glomangiosarcoma) with Additional Neuroendocrine Differentiation in a Horse. A 13-year-old Icelandic crossbred horse was presented with headshaking and progressive impairment of chewing. A slowly growing mass was identified in the anterior maxilla. This was associated with lysis of the alveolar bone and the roots of the incisors and there were nodular proliferations affecting the nasal septum and conchae. There was no response to chemotherapy and so the horse was humanely destroyed. Based on morphological, immunohistochemical and ultrastructural findings the mass was classified as a malignant glomus tumour with multifocal vascular spaces and additional neuroendocrine d...