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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.
Importance of sphingolipids and inhibitors of sphingolipid metabolism as components of animal diets. Sphingolipids are highly bioactive compounds that participate in the regulation of cell growth, differentiation, diverse cell functions, and apoptosis. They are present in both plant and animal foods in appreciable amounts, but little is known about their nutritional significance. Recent studies have shown that feeding sphingomyelin to female CF1 mice treated with a colon carcinogen (1,2-dimethylhydrazine) reduced the number of aberrant colonic crypt foci; longer-term feeding also affected the appearance of colonic adenocarcinomas. Therefore, dietary sphingolipids should be considered in studi...
Comparison of intratumoral administration of cisplatin versus bleomycin for treatment of periocular squamous cell carcinomas in horses. To compare therapeutic benefits of intratumoral administration of cisplatin and bleomycin for squamous cell carcinoma of the eyelids in horses. Methods: 25 horses with 27 T2-stage periocular squamous cell carcinomas. Methods: Horses were treated 4 times at 2-week intervals with a slow-release formulation of cisplatin (1 mg/cm3 of tissue) or bleomycin (1 IU/cm3 of tissue). A two-stage design was used to minimize the sample size in each treatment arm. Results: The local control rate at 1 year for lesions treated with cisplatin was 93 +/- 6%, and with bleomycin was 78 +/- 10%. Difference in local...
[A case of cutaneous epitheliotropic malignant lymphoma (mycosis fungoides) in a horse]. This article describes an eleven year old mare with apathy, fever, enlarged mandibular lymph nodes, skin lesions on the upper lip and edematous, grey-red mucous membranes in the nose, mouth and vulva. Histopathology revealed infiltrates with atypical lymphocytes forming Pautrier's microabscesses. The neoplastic cells had large, often indented nuclei. Immunohistology showed that some cells were CD3-positive (Pan T-cell-marker). The diagnosis of cutaneous epitheliotropic malignant lymphoma (Mycosis fungoides) was made. The etiology in the horse is unknown.
Analysis of the equine tumor suppressor gene p53 in the normal horse and in eight cutaneous squamous cell carcinomas. Wild type equine p53 was amplified between exons 2 and 9 by the polymerase chain reaction using primers designed from conserved regions in other species. An 828 base pair region, corresponding to codons 25-313 of human p53, was sequenced in both directions. Human and equine amino acid sequences were 87% homologous in this region and 96% homologous in conserved domains II-V. Of eight equine cutaneous or mucocutaneous squamous cell carcinomas directly sequenced from exons 5-8, two had p53 point mutations resulting in single amino acid substitutions.
Tumour suppressor gene p53 in the horse: identification, cloning, sequencing and a possible role in the pathogenesis of equine sarcoid. The tumour suppressor protein p53 enhances the genetic stability of the cell and plays a critical role in tumour suppression. Equine p53 was analysed by sequencing exons 5 to 9, a region which includes most known mutations and all the mutational hotspots in the species that have been investigated. The fragment was amplified, cloned and sequenced from genomic and complementary DNA. A comparison of the predicted amino acid sequences between the horse and other species resulted in identities between 66 per cent with the clawed frog and 92 per cent with the cat. Using the single strand conformatio...
Generation of in vitro natural cytotoxicity of horse lymphocytes against sarcoid-derived tumor cells not expressing major histocompatibility complex antigens. To analyze in vitro lymphocyte-mediated immune responses of horses with sarcoids against allogeneic sarcoid cells containing endogenous retrovirus but not expressing major histocompatibility complex antigens. Methods: Lymphocyte-mediated immune reactions were assessed by means of proliferative responses in mixed lymphocyte tumor cell culture (MLTC) assay and lymphocyte-mediated cytotoxicity against various equine target cells. Methods: 12 horses with sarcoid tumors and 15 control horses. Methods: Blood lymphocytes were cocultured in MLTC with allogeneic sarcoid cells (Mc-1, BayMc-1), equine te...
Penetrating keratoplasty for treatment of recurrent squamous cell carcinoma of the cornea in a horse. Squamous cell carcinoma involving the cornea and conjunctiva of the left eye in a 14-year-old horse was treated by superficial keratectomy in combination with beta-radiation and radiofrequency hyperthermia. The tumor recurred 4 months later in the central cornea at the edge of the previous keratectomy site. Penetrating keratoplasty was performed in an effort to remove the tumor and retain a visual eye. The eye was visual 13 months after surgery. Mild fibrosis and vascularization were observed in the area of the penetrating keratoplasty.
Triphasic nephroblastoma in a horse. A large abdominal mass in a 3-year-old filly was discovered clinically and removed and examined after the horse had been humanely killed. Histologically, three different tissue types were noted, occurring in equal amounts: epithelium largely in the form of well-differentiated tubules, multifocally distributed cell-dense foci of blastema, and myxoid to fibrous stroma. A diagnosis of triphasic nephroblastoma, a rare tumour in the horse, was made on the basis of microscopical findings. The finding of numerous glomeruloid structures confirmed the diagnosis and assisted in distinguishing the tumour...
Immunohistochemical detection of P53 overexpression in paraffin wax-embedded squamous cell carcinomas of cattle, horses, cats and dogs. One hundred and six squamous cell carcinomas (SCCs) of cattle, horses, cats and dogs were analysed immunohistochemically for overexpression of p53 protein. The monoclonal antibody pAb 240, which recognizes only mutant p53, was used. Of 41 bovine ocular SCCs, 26 (63.4%) showed p53 nuclear reactivity. All of six (100%) equine ocular SCCs and seven of nine (77.7%) SCCs of the equine penis or vulva gave positive reactions. In nine of 11 (81.8%) feline SCCs of the ear and in seven of 14 (50%) feline SCCs of other locations, p53 immunoreactivity was detected. Only seven of 25 (29.5%) canine cutaneou...
Three cases of carcinoid in the equine nasal cavity and maxillary sinuses: histologic and immunohistochemical features. Three cases of carcinoid tumor in horses are described. The tumors originated from the maxillary sinuses and the retrobulbar region and caused exophthalmos. Histologically, they had a characteristic endocrine pattern and were argyrophilic with the Grimelius stain. All tumors contained reactivity for neuron-specific enolase and synaptophysin. Two of three tumors were reactive for both bovine and porcine chromogranin A. These immunohistochemical results confirm the neuroendocrine nature of these tumors. Neuroendocrine cells could not be detected in the nasal mucosa and maxillary sinuses of a nor...
Nucleotide sequence of exons 5 to 9 of the p53 tumour-suppressor gene of the horse (Equus caballus). An evolutionary conserved 1.3 kb fragment corresponding to the horse p53 tumour suppressor gene was PCR amplified, cloned and the nucleotide sequence determined. The p53 fragment encoded exons 5 to 9 and the intervening introns. The nucleotide sequence and the predicted aminoacid sequence showed a high level of homology with human and donkey p53 sequences.
Fumonisins, mycotoxins of increasing importance: their nature and their effects. The fumonisins (FBs) are a group of closely related mycotoxins that are prevalent in maize. They were isolated from strains of Fusarium moniliforme (Sheldon), which were implicated in the aetiology of human oesophageal cancer in the Transkei, South Africa. Their discovery explained the cause of equine encephalomalacia, or "hole in the head" syndrome, when it was found by feeding trials in horses that they elicited the disease. Subsequently, they were found to cause hepatic cancer in rats and pulmonary oedema in pigs, with most animal species tested showing liver and kidney damage. FB1 is the m...
Equine melanocytic tumors: a retrospective study of 53 horses (1988 to 1991). A study of 57 cutaneous melanocytic tumors from 53 horses revealed 4 distinct clinical syndromes: melanocytic nevus, dermal melanoma, dermal melanomatosis, and anaplastic malignant melanoma. Melanocytic nevus and anaplastic melanoma each had histopathologic features that distinguished them from dermal melanoma and dermal melanomatosis. Dermal melanoma and dermal melanomatosis were histologically similar but could be differentiated by their clinical features. Melanocytic nevi were diagnosed in 29 horses with an average age of 5 years; they were solitary, superficial masses that occurred in both...
Cutaneous amyloidosis in a horse with lymphoma. A horse with malignant lymphoma (histiolymphocytic) and cutaneous amyloidosis is described. The lymphoma involved the dura mater of the spinal cord and some of the peripheral lymph nodes. Multifocal amyloid deposits were present in the skin and subcutis of the ventral abdomen but not within the lymphoma cell infiltrates or in the viscera.
Septic cholangiohepatitis and cholangiocarcinoma in a horse. Septic cholangiohepatitis was diagnosed in an 11-year-old Warmblood gelding with a history of intermittent colic and fever. Klebsiella pneumoniae, susceptible to gentamicin, was cultured from the biopsy specimen. However, treatment with gentamicin was unsuccessful, and histologic examination and bacteriologic culture of a biopsy specimen obtained 3 weeks later revealed progression of the hepatic inflammation and yielded growth of gentamicin-resistant K pneumoniae. At this time, several discrete hyperechoic structures, suggestive of biliary calculi, were seen ultrasonographically. A change in a...
Iridium-192 interstitial brachytherapy for equine periocular tumours: treatment results and prognostic factors in 115 horses. One hundred and fifteen horses with periocular tumours were treated with iridium-192 interstitial brachytherapy. Tumours included squamous cell carcinomas (n = 52) and sarcoids (n = 63). All horses were scheduled to receive 60 Gy (minimal tumour dose) given at a low dose rate (0.034 +/- 0.010 Gy/h). The mean and median follow-up times to last contact or death were 24 and 16 months, respectively. Chronic radiation reactions included palpebral fibrosis (10.4%), cataract (7.8%), keratitis and corneal ulceration (6.9%). Cosmetic changes included permanent epilation (21.7%) and hair dyspigmentation...
Spontaneous equine pulmonary granular cell tumors: morphologic, histochemical, and immunohistochemical characterization. Spontaneous equine pulmonary granular cell tumors were diagnosed in six mature horses at slaughter. These tumors were grossly recognized as multiple (5/6) or single (1/6) creamy white, firm nodules. The tumors, located adjacent to bronchi and bronchioles, often invaded airways, resulting in partial to complete occlusion of the lumina. Neoplastic cells were rounded to polyhedral with numerous eosinophilic cytoplasmic granules that reacted uniformly positive with S-100 and neuron-specific enolase antibodies and multifocally with glial fibrillary acidic protein antibodies. These cells were negati...
Fumonisins: their implications for human and animal health. Fusarium moniliforme is one of the predominant fungi associated with corn intended for human and animal consumption world-wide. Fumonisins, food-borne carcinogens that occur naturally in corn, were first isolated and chemically characterized in South Africa in 1988. The major metabolite, fumonisin B1 (FB1), was subsequently shown to cause leukoencephalomalacia (LEM) in horses, pulmonary edema syndrome (PES) in pigs, and liver cancer in rats. FB1 is also a cancer promoter and initiator in rat liver; hepatotoxic to horses, pigs, rats, and vervet monkeys; cytotoxic to mammalian cell cultures; and...
Experimental treatment of equine sarcoid using a xanthate compound and recombinant human tumour necrosis factor alpha. A xanthate compound with antiviral and antitumoural activities, tricyclodecan-9-yl-xanthogenate (D609) in combination with the potassium salt of the lauric acid (KC12) and, in a further investigation, the above-mentioned substances together with recombinant human TNF alpha (rh-TNF alpha), were tested on equine sarcoid tumours for therapeutic efficacy. A pilot investigation on 5 healthy horses showed that the compounds were well-tolerated; apart from a local, temporary oedema at the injection site, no other clinical symptoms were observed after subcutaneous administration of volumes from 0.1 to...
An immunohistochemical study of an equine B-cell lymphoma. The tissues of an 8-year-old thoroughbred castrated male horse with equine lymphoma were examined immunohistochemically. Neoplastic masses were observed in the mediastinum, mesenteric lymph nodes, gastric mucosa and serosa, liver capsule, and spleen capsule with associated lymph nodes. Histopathologically, the neoplastic cells were seen to consist predominantly of a mixture of well differentiated small and large types. Immunohistochemically, the small lymphoid cells were MHC class IIlow+ and PanT- and the large lymphoid cells were MHC class IIhigh+ and PanT-. These findings revealed that the n...
Topical use of 5-fluorouracil for treatment of squamous cell carcinoma of the external genitalia of horses: 11 cases (1988-1992). Ten horses with histologically confirmed squamous cell carcinoma (SCC) and 1 horse with presumptive SCC of the external genitalia were treated with a combination of surgical debridement and topical administration of 5-fluorouracil, or with topical treatment alone. Tumor remission was obtained in all horses except 1 in which owner compliance was deficient, and no recurrences have been reported. Topical use of 5-fluorouracil as a chemotherapeutic agent for treatment of genital lesions of SCC in horses should be considered as a viable alternative to radical surgical excision.
