The Big “C” - Part 1 - Fibrosarcoma (Soft Tissue Sarcomas)
Fibrosarcoma, also known as soft tissue sarcomas, are malignant (harmful or dangerous) tumors that form in connective tissue such as fat, blood vessels, lymph nodes, smooth muscles, skeletal muscles, etc. Although fibrosarcomas can re-appear locally, they are known for spreading to other parts of the body (metastasize.) This metastasis can occur weeks or even months after the fibrosarcoma have been removed. For this reason, part of the treatment may include chemotherapy and / or radiation.
To diagnosis fibrosarcoma, a technique called Fine Needle Aspirate is used in which the veterinarian will collect a few cells from the animal using a needle and syringe. However, this may not be enough to reach a definite diagnosis, in which case a biopsy may have to be performed. This, along with blood tests and x-rays will assist the veterinarian or oncologist in making a diagnosis. In dogs, fibrosarcomas are normally found in the trunk and limbs. In cats, it could be caused by virus-induced or vaccine induced (usually by the feline Leukemia virus) inoculations. Older cats can also get solitary fibrosarcomas along the trunk, limbs, toes and ears.
Deep and wide removal of the tumor is usually the best surgical option for fibrosarcomas, because unless the entire tumor is removed, the chance of it coming back within a year is over 70 . Radiation can help to prevent the tumor from re-occurring at the original site. Chemotherapy can be used for tumors that cannot be removed or to help prevent the cancer cells from making new tumors at other areas of the pets’ body.
As pain is very common in pets that have cancer, untreated pain will decrease the animal’s quality of life. Untreated pain will also prolong the recovery and / or treatment process. It is vital that the vet assistant helps the owner to recognize pain in their pets and the best way to manage it. Usually the best treatment is to stop it before it starts and administer pain medication before any procedures are started.
Weight loss is often observed in pets that have cancer not only due to loss of appetite, but also because of an altered metabolism and the side effect of the radiation and / or chemotherapy. The prognosis for fibrosarcoma is actually good. However, the recurrence of the tumor coming back depends upon how much of the tumor that could be removed along with post –surgical options such as radiation and/ or chemotherapy. The management of soft tissue reoccurrence is more difficult to handle than the original tumor. It is important for your pets to have long term follow up vet visits.
Any new or previously unseen lump or bump should be checked out by your local veterinarian. If they suspect fibrosarcoma, they may refer you to an oncologist for further diagnostic testing. If you have any questions, contact the veterinary assistant at your pets veterinary office.