Curettage and diathermy: a treatment for feline nasal planum actinic dysplasia and superficial squamous cell carcinoma

Prognostic factors for cats with squamous cell carcinoma of the nasal planum following high-dose rate brachytherapy

OBJECTIVES

The aim of the study was to investigate retrospectively the prognostic impact of variables such as sex, neuter status, breed, age, number of lesions, location and size of the tumour, tumour extension beyond the nasal planum, ulceration and lymph node status, among others, in a population of cats treated with high-dose rate brachytherapy.

METHODS

This study reviews the outcome of 58 cats with cytologically and/or histologically confirmed squamous cell carcinoma of the nasal planum, treated at the Clinic Alliance (Bordeaux, France) with high-dose rate brachytherapy from 2010-2016. The total radiation dose delivered was 30 Gy, administered in two different schedules: five fractions of 6 Gy for a period of 4 days (Tuesday-Friday) or four fractions of 7.5 Gy for a period of 3 days (Tuesday- Thursday). Data were collected from cats' clinical records.

RESULTS

Complete response was achieved in 72% (n = 36) of the cats, partial response in 24% (n = 13) and 2% (n = 1) did not respond. Median progression-free survival and overall survival times were 316 and 835 days, respectively.

CONCLUSIONS AND RELEVANCE

Results indicated that sex (P = 0.045), extension of the tumour from the nasal planum to the upper lip (P = 0.015), tumour size (P = 0.015; P = 0.001), the existence of a previous treatment (P = 0.043) and the tumour response to high-dose rate brachytherapy (P = 0.038; P <0.001) are prognostic factors for cats with squamous cell carcinoma of the nasal planum following high-dose rate brachytherapy.

Lip-to-nose flap for reconstruction of the nasal planum after curative intent excision of squamous cell carcinoma in cats: Description of technique and outcome in seven cases

OBJECTIVE

To describe the surgical technique for nasal planum reconstruction with a lip-to-nose flap after curative intent surgical excision of squamous cell carcinoma (SCC) in cats and to report the surgical outcomes.

STUDY DESIGN

Short case series.

ANIMALS

Seven cats with SCC of the lateral (n = 6) or dorsal (n = 1) aspect of the nasal planum.

METHODS

After tumor excision, a mucocutaneous lip-to-nose flap was harvested from the upper lip and transposed to reconstruct the nasal planum. Variables recorded included surgical time, surgical complications, healing complications, flap success rate, and cosmetic and long-term functional outcomes.

RESULTS

Median surgical time was 67.5 minutes (range 49-80), and no intraoperative complications occurred. Postoperatively, six cats developed self-limiting edema of the muzzle, and one cat had nasal discharge for 2 days. No major complications occurred during the healing process, and all cats went on to achieve successful healing of their flap. A small area of partial-thickness necrosis developed at the cranial edge of the flap in three cats and healed spontaneously in all cases within a few days. According to owner satisfaction and periodic clinical assessment, cosmetic and long-term functional of outcomes were considered good in all cats.

CONCLUSION

The lip-to-nose flap allowed for aesthetic and functional reconstruction of the nasal planum after curative intent surgical excision of feline SCC.

CLINICAL SIGNIFICANCE

The lip-to-nose flap is an option for a single-stage reconstruction of the nasal planum following partial nasal planectomy in cats.

Felis catus papillomavirus type 2 virus-like particle vaccine is safe and immunogenic but does not reduce FcaPV-2 viral loads in adult cats

Felis catus papillomavirus type 2 (FcaPV-2) commonly infects the skin of domestic cats and has been associated with the development of skin cancer. In the present study, a FcaPV-2 virus-like particle (VLP) vaccine was produced and assessed for vaccine safety, immunogenicity, and impact on FcaPV-2 viral load. This is the first report of the use of a papillomavirus VLP vaccine in domestic cats. The FcaPV-2 VLP vaccine was given to ten adult cats that were naturally infected with FcaPV-2, and a further ten naturally infected cats were sham vaccinated as a control group. The rationale for vaccinating cats already infected with the virus was to induce neutralizing antibody titers that could prevent reinfection of new areas of skin and reduce the overall viral load, as has been demonstrated in other species. Reducing the overall FcaPV-2 viral load could reduce the risk for subsequent PV-associated cancer. The vaccine in this study was well-tolerated, as none of the cats developed any signs of local reaction or systemic illness. In the treatment group, the geometric mean anti-papillomavirus endpoint antibody titers increased significantly following vaccination from 606 (95% CI 192-1913) to 4223 (2023-8814), a 7.0-fold increase, although the individual antibody response varied depending on the level of pre-existing antibodies. Despite the immunogenicity of the vaccine, there was no significant change in FcaPV-2 viral load in the treatment group compared to the control group, over the 24 week follow-up period. A possible reason is that FcaPV-2 was already widespread in the basal skin layer of these adult cats and so preventing further cells from becoming infected had no impact on the overall viral load. Therefore, these results do not support the use of a FcaPV-2 VLP vaccine to reduce the risk for PV-associated cancer in cats in which FcaPV-2 infection is already well established. However, these results justify future studies in which the vaccine is administered to younger cats prior to FcaPV-2 infection becoming fully established.

Retrospective clinical study on outcome in cats with nasal planum squamous cell carcinoma treated with an accelerated radiation protocol

BACKGROUND

Cutaneous squamous cell carcinoma of the nasal planum in cats is a common indication for antitumor treatment such as external beam radiation therapy. Curative-intent radiation therapy has been described as a valuable treatment option, resulting in long and stable tumor control in these patients. The aim of the current study was to evaluate outcome and toxicity, as well as possible prognostic factors using an accelerated hypofractionated radiation therapy protocol. Cats with squamous cell carcinoma of the nasal planum treated with an accelerated radiation protocol (10 × 4.8 Gy, over one week) were retrospectively evaluated. Tumor- and treatment-associated variables were evaluated in respect to local control and survival.

RESULTS

Forty-four cats met the inclusion criteria for this study. All cats showed complete response to therapy. Median disease-free interval (DFI) for all cases was 916 days (95% CI: 456-1377). One- and two-year DFIs were 71% (95% CI: 56-86%) and 60% (95% CI: 43-77%). Of the tested variables, only tumor volume showed a tendency to influence DFI, with larger tumors having a 5.4 times greater risk of recurrence than the smaller ones (HR 1.33 (95% CI: 0.99-1.79), p = 0.054). Median overall survival (OS) was 902 days (95% CI: 862-942). One- and 2-year OSs were 79.3% (95% CI: 67.3-91.3) and 58.4% (95% CI: 42.8-74). Of the tested variables, again, only tumor volume influenced OS with larger tumors having a 6.3 times greater risk of dying than the smaller ones (HR 1.36 (95% CI: 1.07-1.73), p = 0.010). The acute and late toxicity profile was low and hence clinically acceptable.

CONCLUSIONS

Curative-intent radiation therapy with an accelerated fractionation schedule can be considered a safe, cosmetically superior treatment option for cutaneous squamous cell carcinomas of the nasal planum in cats, resulting in long and stable tumor control.