Veterinary Society of
Surgical Oncology

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

ORAL SQUAMOUS CELL CARCINOMA

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