Comparison of two different doses of bleomycin in electrochemotherapy protocols for feline cutaneous squamous cell carcinoma nonsegregated from ultraviolet light exposure

Denner S Dos Anjos,Oscar R Sierra,Carlos E Fonseca-Alves,Andrigo B De Nardi,Enrico P Spugnini

doi:10.1038/s41598-020-75472-0

Denner S Dos Anjos, Oscar R Sierra + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-75472-0

Copy DOI

Abstract

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin tumors in cats due to chronic exposure to ultraviolet light. Local treatments such as electrochemotherapy (ECT) promote disease control or even complete remission. We hypothesize that cats could benefit from treatments using bleomycin at reduced dosages. A prospective nonrandomized single-blind study evaluated the clinical parameters, site lesion, staging, disease-free interval (DFI) and survival time by comparing the standard dose of bleomycin (15,000 UI/m2) (n = 22) with a reduced dose (10,000 UI/m2) (n = 34) in cats with cSCC that underwent ECT as the sole treatment modality. No statistically significant difference in DFI or overall survival was observed between the 2 groups. A higher DFI was found in cats with a small tumor size (less than 0.33 cm3) compared with that for cats with a large tumor size (P = 0.045). Furthermore, a reduced overall survival time for cats with a higher stage in the standard group SG (T3 and T4) (P = 0.004) was observed when compared to that for cats with a lower stage (T1 and T2). In conclusion, ECT using both doses of bleomycin may achieve the same response rate in terms of the overall response, DFI, and overall survival.

Highlights

Cutaneous squamous cell carcinoma is one of the most common skin tumors in cats due to chronic exposure to ultraviolet light
In the standard group (SG), 12 cats had Cutaneous squamous cell carcinoma (cSCC) located on the nasal planum, but only two received tube feeding for 7–14 days post-ECT for nutritional support due to nasal edema/obstruction generating anosmia
This study demonstrated a similar efficacy between the SG and reduced group (RG) in terms of bleomycin treatment in cats with cSCC that underwent ECT without differences in disease-free interval (DFI) and overall survival

Summary

Introduction

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin tumors in cats due to chronic exposure to ultraviolet light Local treatments such as electrochemotherapy (ECT) promote disease control or even complete remission. A prospective nonrandomized single-blind study evaluated the clinical parameters, site lesion, staging, disease-free interval (DFI) and survival time by comparing the standard dose of bleomycin (15,000 UI/m2) (n = 22) with a reduced dose (10,000 UI/m2) (n = 34) in cats with cSCC that underwent ECT as the sole treatment modality. Since fur is a physical barrier to UV radiation, the most commonly areas affected by cSCC are the ears, eyelids, nasal planum, lips and temporal a reas[4,5,6] Most of these tumors have an insidious progression characterized by nonhealing scabbing lesions that tend to progress over time to ulcers. In the veterinary oncology field, it can be used as palliative, adjuvant, or neoadjuvant treatment or administered at the time of surgery (intraoperative ECT)[11]

Objectives

Results

Conclusion