Biologic Behaviour

•SCC accounts for 75% of oral tumors in cats and is the most common feline oral tumor

•flea collars, high canned food, canned tuna fish ± cigarette smoke significantly increase the risk of oral SCC

•median age 12 years (range, 2.5-18.0 years)

•no sex predilection

•site predilection: tongue, pharynx, or tonsils (42%), mandible (27%), and maxilla (27%)

•bone involvement is common and extensive

•perineural infiltration by mandibular SCC may be responsible for tumor extension into the retrobulbar space

•regional lymph node and distant metastasis is rare

•however, local tumor control is often poor and long-term course is unknown

•paraneoplastic hypercalcemia has been reported

Treatment

Surgery

•surgical techniques: mandibulectomy and maxillectomy

Radiation Therapy

•radiation therapy improves survival rate when combined with either surgery or chemotherapy

•radiation therapy with 6 weekly fractions of 6 Gy and twice weekly low-dose gemcitabine (25 mg/m 2) as a radiation sensitizer results in an overall response rate of 75%, median duration of response of 42.5 days, and a MST 111.5 days

•palliative radiation therapy is not effective with radiation-induced complications or PD in 86% (6/7) cats

Chemotherapy

•no known effective chemotherapeutic agent for primary or metastatic SCC

•mitoxantrone, carboplatin (which has shown in vitro activity against feline SCC), and combination of doxorubicin and cyclophosphamide have been used either alone or in combination with radiation therapy with some effects

•liposome-encapsulated cisplatin is ineffective and causes acute toxic reactions

Prognosis

•prognosis is poor with 12-month survival rate usually < 10%

•MST 45 days with surgery alone

•MST 90 days with radiation therapy alone

•MST 14 months with hemimandibulectomy and radiation therapy

•MST 75-170 days with radiation therapy and chemotherapy (cisplatin, carboplatin, gemcitabine, or mitoxantrone)

•MST 75 days with radiation therapy and local hyperthermia