Glossary

ADJUVANT: An ingredient used in some vaccines that helps create a stronger immune response in those receiving the vaccine. Common adjuvants in feline rabies or leukemia vaccines are aluminum compounds and killed viruses. It is suspected that the increased immune response increases inflammation, thereby increasing the risk of FISS.

BIOPSY: A procedure to remove a piece of tissue or a sample of cells from your body so that it can be tested in a laboratory.

BENIGN: A condition, tumor, or growth that is not cancerous.

BRACHYTHERAPY: Brachytherapy is a form of radiation therapy where a sealed radiation source is placed inside or next to the area requiring treatment. This is not commonly used to treat FISS.

CANCER: A disease in which abnormal cells divide uncontrollably and destroy body tissue.

CHEMOTHERAPY: A drug treatment that uses powerful chemicals to kill fast-growing cells in the body. Not known to be an effective stand-alone treatment for FISS.

CLEAN MARGINS: Along with the tumor, healthy tissue that surrounds the tumor is removed during surgery for the best chance at removing all the cancer. Clean margins indicates the tumor was completely removed and 3 to 5cm of healthy, cancer-free tissue surrounding the tumor was also removed. Clean margins are the best predictor for achieving a low recurrence rate.

CLEAN BUT CLOSE MARGINS: The tumor was completely removed, but only a narrow margin (within millimeters) of healthy tissue was removed around the tumor.

COARSE-FRACTIONED RADIOTHERAPY: Sometimes also referred to as “palliative radiotherapy,” coarse-fractionated radiation therapy uses larger doses per fraction across fewer fractions. The overall radiation dose delivered is lower and the number of treatment sessions required is significantly less than definitive radiotherapy. Fractions are usually administered once per week for several weeks.

COMPUTED TOMOGRAPHY (CT) SCAN: A medical imaging technique used to obtain detailed internal images of the body. These help the doctors picture the size, shape, and location of the tumor and may aid in surgery or radiotherapy planning.

CURATIVE: Curative treatment options are those that intend to cure or completely eliminate the disease.

CYTOLOGY: The exam of a single cell type, as often found in fluid specimens. It's mainly used to diagnose or screen for cancer following a fine-needle aspiration.

DEFINITIVE RADIOTHERAPY: Also referred to as “full-course radiotherapy” or “fine-fractioned radiotherapy,” definitive radiation therapy uses smaller doses per fraction across more fractions. The overall radiation dose delivered is higher, and this treatment is typically considered curative. Fractions are usually administered daily for several weeks.

DIRTY MARGINS: Cancer cells were detected along the edge of the healthy tissue excised during tumor removal surgery, indicating the tumor was not fully removed.

DISEASE-FREE INTERVAL: The time between completion of treatment (surgery, radiotherapy, etc.) and the progression or recurrence of disease. Sometimes also referred to as “progression-free interval.”

DOCOSAHEXAENOIC ACID (DHA): An omega-3 fatty acid found in cold-water, fatty fish, such as salmon. Studies claim it may have anti-tumor/anti-cancer properties.

DOXORUBICIN: A type of chemotherapy drug called an anthracycline. It slows or stops the growth of cancer cells by blocking an enzyme called topo isomerase 2. This is the most common chemotherapy drug used for FISS.

EICOSAPENTAENOIC ACID (EPA): An omega-3 fatty acid found in cold-water, fatty fish, such as salmon. Studies claim it may have anti-tumor/anti-cancer properties.

EXCISION: Also known as an excisional biopsy, surgical excision is a procedure that removes cells or samples of skin from the surface of the body.

FELINE INJECTION SITE SARCOMA (FISS): Feline injection site sarcomas (FISS) are cancerous tumors that can arise following injections.

FIBROSARCOMA: The most common type of tumor seen with FISS, fibrosarcomas are a malignant (cancerous) tumor that originates in the connective fibrous tissue found at the ends of bones of the arm or legs, and then spreads to other surrounding soft tissues.

FINE-NEEDLE ASPIRATION (FNA): A small amount of tissue or fluid is removed from a suspicious area with a thin, hollow needle and checked for cancer cells. This test may help rule out other causes for abnormal growths, but usually is not successful in diagnosing FISS.

FRACTION: Radiotherapy is split into a number of treatments called fractions that are given over several weeks. Delivering a small fraction of the total radiation dose allows time for normal cells to repair themselves between treatments, thereby reducing side effects.

IMMUNOTHERAPY: A type of cancer treatment that uses substances made by the body or in a laboratory to boost the immune system and help the body find and destroy cancer cells. Effective when used in conjunction with surgery and/or radiotherapy.

INTERLEUKIN-2 (IL-2): An important T cell stimulatory cytokine approved as an exogenous anti-tumor agent. This is used in the ALVAC IL-2/Oncept IL-2 vaccines to stimulate the immune system.

LOCAL RECURRENCE: The cancer has regrown in the same place as the original cancer or very close to it.

MACROSCOPIC DISEASE: Cancer that is visible to the normal human eye, usually in the form of a tumor.

MALIGNANT: Cancerous tumors with cells that grow uncontrollably and spread locally and/or to distant sites.

MESENCHYME: A type of loosely organized animal embryonic connective tissue of undifferentiated cells that give rise to most tissues. FISS is a malignant skin tumos of mesenchymal origin.

METASTASIS: A pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body.

MICROSCOPIC DISEASE: Microscopic cancer cells that have escaped from the original tumor. These cells can be too small to see on imaging tests. Microscopic disease is common in FISS due to its microscopic tendrils which extend from the tumor.

MONOMODAL TREATMENT: A treatment plan consisting of only one treatment option (i.e. surgery, radiotherapy, chemotherapy, or immunotherapy).

MULTIMODAL TREATMENT: A treatment plan consisting of multiple treatment options together. Multimodal plans commonly include surgery, chemotherapy, radiation and/or immunotherapy. Multimodal treatment plans produce significantly better outcomes as compared to monomodal plans.

NECROSIS: The death of body tissue. It occurs when too little blood flows to the tissue. Tissue with FISS tumors may necrose as the tumor grows in size. Increased necrosis has a negative correlation with prognosis.

NEOPLASM: An abnormal growth of tissue that can be benign (noncancerous) or malignant (cancerous).

ONCEPT IL-2: A veterinary medicine that contains the active substance feline interleukin-2 recombinant canarypox virus. Oncept IL-2 is used to treat cats with fibrosarcoma, a type of aggressive tumor that affects the soft tissues. It is used in combination with surgery and radiotherapy to reduce the risk of and delay the tumor coming back.

PALLIATIVE: Specialized medical care that focuses on providing relief from pain and other symptoms of a serious illness.

PROGNOSIS: The likelihood or expected development of a disease, including whether the signs and symptoms will improve or worsen or remain stable over time.

RADIOTHERAPY: A type of cancer treatment that uses beams of intense energy to kill cancer cells.

SARCOMA: Rare cancers that develop in the bones and soft tissues, including fat, muscles, blood vessels, nerves, deep skin tissues and fibrous tissues.

STEREOTACTIC RADIOTHERAPY (SRT): Delivers a curative dose of radiation from numerous different angles to focus the radiation while sparing the surrounding normal tissue from damage. The large number of beams allows for highly conformal target treatment with a steep dose gradient, while the nonintersecting arcs minimize exposure of normal overlying tissue, allowing a larger single treatment dose and, therefore, a lower total dose to be applied. SRT involves fewer treatments, typically 1 to 3, called “fractions,” with a larger amount of radiation applied at each administration as compared to the traditional or conventional radiotherapy.