Page 515 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

CHAPTER 24 Tumors of the Respiratory System 493

VetBooks.ir

A B

C D

• Fig. 24.1 (A) Preoperative image of nasal planum squamous cell carcinoma in a 10-year-old Labrador
retriever. (B) Immediately after nasal planectomy; (C) 9 days postoperatively; and (D) 6 weeks postopera-
tively.

3
surgery alone. The median survival times (MSTs) for surgically
treated cats in this study were 673 days and 530 days for cats
with isolated nasal planum SCC and SCC in multiple locations,
respectively. 3
Conservative surgical approaches are not typically recom-
mended as most nasal planum tumors are invasive and recurrence
rates are high when an aggressive surgical approach is not utilized.
However, surgical curettage and diathermy has been described
in 34 cats with nasal planum tumors, including nine cats with
carcinoma in situ and seven cats with SCC. This technique
11
resulted in better cosmesis and good local tumor control with a
local tumor recurrence rate of 6% after a median follow-up time
11
of 18 months.
External Beam Radiation Therapy
External beam RT has been described for the treatment of nasal
planum SCC in both dogs and cats, either for primary treatment
or in the adjuvant setting. The results have been discouraging in
dogs with local recurrence reported in virtually all patients with
median times to recurrence of 2 to 3 months. 4,5
RT has been described for the treatment of cats using either
• Fig. 24.2 Recurrence of a nasal planum squamous cell carcinoma (SCC) 7 3,12
in a 13-year-old domestic shorthair cat 3 months after nasal planum resec- orthovoltage, megavoltage, or an accelerated protocol using
13
tion. Recurrence of the tumor can be seen in the ventral aspect of the left protons. For cats treated with orthovoltage, the 1-year progres-
neo-nare (arrow). sion-free survival (PFS) rate was 60%, and prognostic factors