Page 1874 - Cote clinical veterinary advisor dogs and cats 4th

Squamous Cell Carcinoma 941

cats), and curettage with thermocautery accelerated radiation therapy protocol ○ Cats sublingual: poor response to therapy;
can be effective for small superficial provided a median survival of 163 days, survival time < 3 months
VetBooks.ir • Aural: total ear canal ablation with bulla Chronic Treatment PEARLS & CONSIDERATIONS Diseases and Disorders
lesions, with decreasing effectiveness for
with long-term survivors (>2 years) noted
larger lesions.
with tonsil or cheek locations.
osteotomy provides best survival times. In
cats, the tumors can invade aggressively into • Cyclooxygenase 2 (COX2) expression was Comments
• Planum: cosmesis and quality of life after a
the skull bones, precluding surgical excision. shown in 40 of 40 canine SCC cases, and nosectomy are generally good to excellent,
• Digital therapy with piroxicam or other nonsteroidal with high owner satisfaction. Early treat-
○ Dog: digital amputation; adjuvant antiinflammatory drugs (NSAIDs) may be ment when the lesion is small enough for a
therapy usually unnecessary; can discuss of benefit. surgical cure is strongly recommended when
chemotherapy as below • COX2 expression also has been detected in possible.
○ Cats: therapy unrewarding if metastatic 27/27 cats with cutaneous SCC and 4/9 cats • Aural
lesion; if thoracic films are normal and with actinic keratosis. ○ Canal: complete ear ablation is needed;
only one digit is involved, amputation simple debulking is inadequate because
of the digit is recommended. PROGNOSIS & OUTCOME the tumor will continue to invade inward,
• Bowen’s disease making a surgical cure impossible later.
○ Daily topical imiquimod has shown • Planum: excellent prognosis for cure if ○ Pinna: preneoplastic changes can extend
some efficacy in cats: median survival complete surgical resection. Median survival along the entire edge of the pinna;
time > 3 years in series of 12 cats. This of cats with planum and/or pinna SCC: 673 complete pinnectomy may be required
imidazoquinoline works by binding to days with surgery alone for cure. If lesion is very small, simple
surface toll-like receptors 7 and 8 on • Aural, canal: excellent prognosis for cure removal of the affected tip of the ear can
macrophages, which leads to innate and if treated early; unfortunately, tumors in be considered, with a later decision made
cell-mediated immune responses result- cats have often progressed massively before according to need for further excision
ing in tissue-specific apoptosis. Systemic identification, leading to a median survival based on histopathologic exam results.
therapy was not shown to be of benefit. time of only 3.8 months. • Digital
• Oral • Digital ○ Dog: tumors often go undiagnosed
○ Gingival: aggressive resection, including ○ Dog: good prognosis, with 95% 1-year and for extensive amounts of time due to
partial mandibulectomy or maxillectomy. 75% 2-year survival rates. Median survival treatment for a nail bed infection. Any
Definitive radiation for residual micro- not reached in recent study (>1700 days) questionable, non–antibiotic-responsive
scopic disease if surgery does not provide ○ Cat: for metastatic lesion, digital amputa- digital swelling must be biopsied.
tumor-free margins tion median survival is only 1-2 months; for ○ Cat: primary digit tumors are rare; three-
○ Tongue, dog: if rostral to midlingual, primary digital SCC, reported survival time view thoracic radiographs are essential
surgical resection (40%-60% of the tongue with surgery varies (3 weeks to 2 years). before surgery because digital tumors
can be removed with good function • Oral are usually secondary.
remaining, possibly more). Dogs with ○ Dogs with rostral SCC: wide surgical • Oral
tumors < 2 cm live significantly longer. resection can be curative. ○ Mandibular, maxillary, and lingual SCC
○ Tonsillar: usually poor treatment options ○ Dogs with mandibular or maxillary non- in rostral locations in dogs can be cured
due to invasiveness and metastatic resectable SCC: radiation therapy. Median with aggressive resection.
behavior; multimodality therapy includes survival time is 450 days. Control time ○ SCC in cats and in other locations in the
surgical debulking, if possible, of primary for dogs with tumors greater than 4 cm mouth in dogs is difficult to address due
mass and involved lymph nodes, followed in diameter is generally shorter. to invasiveness and/or metastasis.
by chemotherapy and radiation therapy; ○ Histologic grade may be predictive for ○ Multimodality therapy may extend survival
may extend survival times survival, with significantly worse survival times, but quality of life can be an issue
○ Sublingual and gingival, cat: very poor for dogs with grade 3 tumors. with the treatments.
treatment options. Surgical excision is ○ Dogs with tonsillar SCC: surgery and ■ Dogs with tonsillar SCC can have
usually not feasible. Radiation therapy and radiation therapy. Median survival is pronounced dysphagia and discomfort;
photodynamic therapy have been tried 100 days. With surgery, irradiation, and surgical debulking may not alleviate
with limited success. Gemcitabine as a chemotherapy (doxorubicin and cisplatin), clinical signs, and radiation therapy
radiation sensitizer with palliative radiation median survival is 270 days. If only one can contribute to local discomfort for
has significant hematologic and normal tonsil is affected and no metastasis, surgery several weeks.
tissue toxicosis and therefore cannot be and chemotherapy may provide prolonged ■ Cats with mandibular or maxillary
recommended. survival (median, 637 days in one small SCC can have temporary responses to
Chemotherapy: study). chemotherapy and radiation therapy,
• Piroxicam 0.3 mg/kg PO q 24h (caution ○ Dogs with lingual SCC: rostral to midlin- but side effects may necessitate place-
regarding gastric ulcerative effects); has gual masses can be cured with wide resec- ment of a feeding tube. The occasional
some effect against gross SCC in dogs (18% tion if < 2 cm. Dogs with nonresectable cat with a small lesion may have a
complete and partial remission, 29% stable lingual SCC can be treated with radiation greatly extended survival time with
disease). therapy, but survival is generally short surgery.
• Cisplatin + piroxicam: ≈40% renal toxicoses, (median, 4 months), with dogs euthanized ■ Case selection for multimodality
so the combination is not recommended due to local proliferation. treatment is important for dogs and
• Carboplatin ± piroxicam has been reported in ○ Cats with mandibular SCC: radiation cats, and owners need to have realistic
several small case series to have effect against therapy and mitoxantrone or carboplatin; expectations for the success of the
canine SCC in a variety of primary sites. without surgery, generally poor response; therapy.
• Docetaxel with cyclosporine gavage in dogs median survival of 180 days. Mandibu-
with oral SCC: 50% (6/12) response rate lectomy and irradiation: median survival Prevention
• In 31 cats with SCC in a variety of oral of 14 months; euthanasia usually due to Planum and pinna: limit sun exposure in
locations, carboplatin combined with an local recurrence. light-coated cats.

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