Squamous cell carcinoma is the second most common form of skin cancer in cats. It's highly treatable if found early, but it is deadly if left untreated. Excessive exposure to sunlight is the most common cause of squamous cell carcinoma. White cats are most susceptible to this cancer, but dark-coated cats are not immune.
SCC lesions usually appear on areas of cats that are hairless or sparsely covered, such as the temples, nose, ears, lips and eyelids. Such lesions have an irregular, hardened border and might be ulcerated, or open, and oozing fluid. They generally look very similar in appearance to small scabs or scratch wounds. As SCC tumors develop, the area around lesions will swell and the ulceration will worsen.
SCC can occur in the mouths of cats. It is the most common oral cancer in cats. Symptoms of oral SCC include drooling or excessive salivating, swelling of the jaw, bad breath, weight loss and a diminished appetite.
After a biopsy confirms the presence of SCC on the cat’s skin, there are several options for removal of the lesion. The first option is surgical removal of the affected skin. If the lesion occurs on the cat’s nose or ears, portions of those areas might require removal. Cryotherapy, destroying a lesion by freezing it, is another option. Radiation is useful in treating facial lesions that are less than 2 millimeters deep. Direct injection into the lesion with chemotherapeutic substances is effective in some cases. Treatment for oral SCC involves using a combination of surgery and radiation therapy.
For tumors that go undetected until they are at a more advanced stage, a full course of radiation, lasting over three weeks, may be required in an attempt to curb the tumor’s progression. However, if a tumor has already spread internally, the likelihood of successful treatment diminishes significantly.
Early detection and treatment of SCC is critical for a positive long-term prognosis. A thorough examination of the cat and a watchful eye for the appearance of any sores or symptoms is the best way to catch the emergence of SCC at a stage when treatment is most effective. Annual veterinary examinations are also beneficial to address any areas of concern.