Minimally invasive ethyl cellulose ethanol ablation in domesticated cats with naturally occurring head and neck cancers: Six cats

Vet Comp Oncol. 2021 Sep;19(3):492-500. doi: 10.1111/vco.12687. Epub 2021 Feb 23.


It is difficult to retain tumoricidal doses of ethanol in large or unencapsulated tumours without causing intoxication or damaging surrounding tissue. Ethyl cellulose-ethanol ablation (ECEA) overcomes this limitation by trapping ethanol intratumorally. To evaluate the safety of ECEA and to develop a clinically feasible workflow, a single-arm pilot study was performed in cats with lingual/sublingual squamous cell carcinoma (SCC). Six cats underwent intratumoral injection of 6% ethyl cellulose in ethanol. Subjects were observed overnight. There was mild bleeding and transient hyperthermia, and injection site pain and swelling that improved with anti-inflammatory drugs. Serum ethanol was minimally elevated; the mean concentration peaked 1 hour after injection (129 +/- 15.1 nM). Cats were rechecked at weeks 1 and 2; booster treatments were given in cats (n = 3) with stable quality of life and partial response to therapy. Recheck examinations were then performed monthly. The longest tumour dimension increased in each animal (progressive disease via cRECIST); however, estimated tumour volume was reduced in 3 of 6 cats, within 1 week of ECEA. All cats were euthanized (median survival time 70 days) because of local tumour progression and/or lingual dysfunction that was likely hastened by ECEA. ECEA is not a viable treatment for feline lingual/sublingual SCC; tumour volume was effectively reduced in some cats, but the simultaneous loss of lingual function was poorly tolerated. Further optimization may make ECEA a useful option for SCC at other oral sites in the cat, and for head and neck malignancies in other species.

Keywords: head and neck cancer; intratumoral injection; minimally invasive procedure; palliative; surgical alternative.

MeSH terms

  • Animals
  • Carcinoma, Squamous Cell* / drug therapy
  • Carcinoma, Squamous Cell* / veterinary
  • Cat Diseases* / drug therapy
  • Cats
  • Cellulose / analogs & derivatives*
  • Cellulose / therapeutic use
  • Ethanol
  • Head and Neck Neoplasms* / drug therapy
  • Head and Neck Neoplasms* / veterinary
  • Pilot Projects
  • Quality of Life


  • Ethanol
  • ethyl cellulose
  • Cellulose