Oncology

Mast cell tumors (MCT) are the most frequently encountered dermal/subcutaneous neoplasm in dogs representing 7% to 21% of all skin tumors in this species. Most MCT develop in older dogs and no sex predilection has been reported.

Most primary tumors are best treated by surgical excision. Most benign tumors, low grade cutaneous mast cell tumors, odontogenic tumors, or solitary mammary tumors are perhaps best treated by wide surgical excision.

Nasal and paranasal sinus tumors represent only 1-2% of all tumors but 60-80% of all canine respiratory tract tumors, and are even less frequent in cats. Nasal tumors occur most commonly in the nasal cavity with secondary extension into the frontal and other paranasal sinuses.

The process of radiation oncology from the time of patient identification to completion of radiation therapy is undoubtedly a complex one and requires significant communication between all services from the moment a potential radiation patient is seen and certainly prior to any surgical intervention. Listed below is an outline of the radiation process and treatment considerations at each step.

Tyrosine kinases are proteins that phosphorylate other proteins on tyrosine residues thereby regulating cell growth and differentiation. They bind ATP and use this to add phosphate groups to key residues on themselves (termed autophosphorylation) and on other molecules, resulting in intracellular signaling and alterations in gene transcription that affect cell proliferation and survival.

In a recent study, researchers evaluated the use of indwelling, double-pigtail ureteral stents in dogs with ureteral obstruction secondary to trigonal malignancy.

Dr. Matthew Beal discusses this promising noninvasive alternative to cystostomy tubes.

Why it's important to stage cancer in dogs and cats before pursuing therapy.

Clinicopathologic features of these infrequently described tumors in dogs.

Surgeon Dr. Jenifer Newton discusses whether this is a good step to take before attempting removal.

Radiation was first used on horses in 1906. Today, finer, more sophisticated therapeutic techniques, procedures and equipment can be used to treat the relatively uncommon tumors in horses.

Identifying characteristics of esophageal leiomyoma.

Learn about the potential anticancer effects of piroxicam.

After decades of significant increase, delay adjusted rates stabilized in 1995 and fell since 1999.

Dr. Timothy Fan discussses the use of Neoplasene in cancer therapy.

While cytology does not give the practitioner the same amount of information as histopathology does, it can provide important information that is rapidly available, inexpensive, and minimally invasive. Cytology can provide important information that can change how subsequent treatment and diagnostics take place.

Soft tissue sarcomas (STS) – hemangiopericytoma, fibrosarcoma, neurofibrosarcoma, Schwannoma, peripheral nerve sheath tumor, malignant fibrous histiocytoma, liposarcoma, myxosarcoma, myxofibrosarcoma, spindle cell sarcoma, anaplastic/undifferentiated sarcoma – exhibit similar biological behavior, and hence can be dealt with in most cases with a similar therapeutic approach.

Cancer is a disease characterized by dysregulated growth, abridged cell death, and enhanced cell migration, invasion and angiogenesis. While the molecular mechanisms responsible for this phenotype are very diverse, one class of molecule that has been receiving a great deal of recent attention as a target for therapy are the receptor tyrosine kinases (RTKs).

The majority of cytotoxic chemotherapy protocols in common veterinary use are designed to have a low risk of adverse effects. In general, less than 1 in 4 animals will have unpleasant adverse effects and only approximately 5% will have a serious adverse event, leading to hospitalization.

The past 5 years have brought about some noteworthy and exciting changes in veterinary oncology, many of which are available to the practitioner or the client willing to consider referral. A brief discussion of these advances, their applications, and potential for the future, may be helpful in informing the clinician and the dedicated client. Some of these may be covered in greater detail in other lectures in this series.

The last few years have brought some interesting and novel discoveries with regard to the diagnosis and therapy of lymphoma in pets.

Canine hemangiosarcoma (HSA), a malignant tumor of blood vessel endothelial cells, is a relatively common malignancy in dogs compared with other species. In fact, owing to its rareness in humans, we do not have abundant human literature from which to extrapolate when making treatment decisions. Certain breeds (e.g. German shepherds, golden retrievers) appear to be at increased risk for the development of HSA, suggesting a possible genetic predisposition.

Osteosarcoma (OSA) represents the most common bony tumor of dogs and cats. Although information regarding etiopathogenesis is lacking, OSA of the long bones (appendicular OSA) is far more common in large and giant breed dogs than in smaller dogs. Rare causes of OSA include those associated with metallic implants, those formed after radiation therapy, and some feline vaccine-associated sarcomas.

Often, the primary clinician may be the veterinarian making a diagnosis of cancer in a pet and performing the initial client education regarding their pet's disease. Critically important, life-or death decisions regarding euthanasia, treatment, choice to pursue referral, etc. may be made based on information that the owner gets from their primary veterinarian.

Our knowledge of the brain on the neurochemical, genetic and molecular level is increasing steadily each year. Despite this, little is definitively known about the neurochemical correlates of various disease processes. Much of our knowledge concerning the etiology of mental illness comes from response to pharmacological intervention.