Use of carbon dioxide laser vaporization for the treatment of feline cutaneous squamous-cell carcinoma

Squamous-cell carcinoma (scc) has a slow malignant progression and a locally invasive behaviour. Treatment options include cryotherapy, photodynamic therapy, chemotherapy and radical surgery, depending on the extent of the tumour and the degree of dermal infiltration. Objective To determine the long-term effectiveness of carbon-dioxide (CO2) laser vaporization of scc in cats. Methods Cats with clinical signs and histopathological lesions consistent with in situ, superficially and deeply infiltrative scc, underwent the CO2 laser vaporization (10 Watt of power, continuous wave mode for 3-5 min.). The irradiated area was larger than the lesion in order to prevent relapses. Debris of carbonization was removed and the part refreshed and cleaned with a sterile saline solution. A topic chlorexidine 0,5% solution (Clorexiderm®, ICF srl, Palazzo Pignano, CR, Italy) and robenacoxib 1 mg/kg per os (Onsior®, Elanco, Sesto Fiorentino, FI, Italy) were prescribed once daily for a week. Clinical controls were scheduled after 4, 6 and 12 months. Results Fifteen white-coated cats, medium age 10 year-old (range 8-15) were treated: 2/15 had in situ scc, 11/15 had superficially infiltrative scc, 2/15 had poorly differentiated deeply infiltrative scc. After 4 months, cats in the latest group had only a partial response and needed surgical ablation. 13/15 cats had a complete response at a follow up of six months (6/15) and one year (4/15). No side effects were noticed. Conclusion CO2 laser vaporization is a good and safe option to treat in situ and superficially infiltrative scc in cats allowing a complete resolution, while it is ineffective in the long term for deeply infiltrative scc.