Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma

Zeynep Nurselin Kot; Zülal Feyza Eker; Ümit Özcan

doi:10.33988/auvfd.1985403

Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma

Abstract

Urothelial carcinoma is an aggressive malignancy of the canine lower urinary tract that is frequently associated with urethral obstruction and limited therapeutic options after chemotherapy failure. We describe the clinical course and serial ultrasonographic responses to lapatinib–piroxicam rescue therapy in a 15-year-old spayed female French Bulldog with trigonal urothelial carcinoma, following an initial partial response to vinblastine and subsequent disease progression. Initial treatment with vinblastine, administered every two weeks for a total of eight doses, achieved partial response. However, the recurrence of hematuria and complete urethral obstruction prompted second-line treatment. Combination therapy with lapatinib (25 mg/kg/day) and piroxicam (0.3 mg/kg/day) induced rapid tumor regression, with a partial response documented by ultrasonography on Day 14 and a complete response of the primary urinary bladder target lesion on Day 30 according to cRECIST criteria. Adverse events observed during treatment included increased alkaline phosphatase activity, anorexia, vomiting, and diarrhea. Although the primary urinary bladder target lesion remained in complete response, a new intra-abdominal mass cytologically consistent with urothelial carcinoma was detected on Day 60, constituting overall progressive disease according to cRECIST, and the patient died two days later. This case demonstrates that lapatinib–piroxicam rescue therapy was associated with a rapid complete ultrasonographic response of the primary urinary bladder lesion following an initial partial response to vinblastine and subsequent disease progression; however, this local response was followed shortly thereafter by extravesical disease progression. Serial ultrasonographic assessment according to cRECIST provided an objective and practical method for monitoring treatment response throughout the course of therapy.

Keywords

References

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Details

Primary Language

English

Subjects

Veterinary Medicine, Veterinary Diagnosis and Diagnostics, Veterinary Urology

Journal Section

Case Report

Authors

Zeynep Nurselin Kot ^*
0000-0002-0631-5471
Türkiye

Zülal Feyza Eker
0009-0000-4801-8240
Türkiye

Ümit Özcan
0000-0002-0868-6399
Türkiye

Early Pub Date

October 22, 2026

Publication Date

-

Submission Date

July 2, 2026

Acceptance Date

September 11, 2026

Published in Issue

Year 2026 Number: Advanced Online Publication

DOI

https://doi.org/10.33988/auvfd.1985403

IZ

https://izlik.org/JA97DW98DF

Cite

RIS / Bibtex

APA

Kot, Z. N., Eker, Z. F., & Özcan, Ü. (2026). Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma. Ankara Üniversitesi Veteriner Fakültesi Dergisi, Advanced Online Publication. https://doi.org/10.33988/auvfd.1985403

AMA

1.Kot ZN, Eker ZF, Özcan Ü. Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma. Ankara Univ Vet Fak Derg. 2026;(Advanced Online Publication). doi:10.33988/auvfd.1985403

Chicago

Kot, Zeynep Nurselin, Zülal Feyza Eker, and Ümit Özcan. 2026. “Complete Ultrasonographic Response of a Primary Bladder Lesion Followed by Extra-Vesical Progression After Lapatinib–piroxicam Rescue Therapy in a Dog With Urothelial Carcinoma”. Ankara Üniversitesi Veteriner Fakültesi Dergisi, no. Advanced Online Publication. https://doi.org/10.33988/auvfd.1985403.

EndNote

Kot ZN, Eker ZF, Özcan Ü (October 1, 2026) Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma. Ankara Üniversitesi Veteriner Fakültesi Dergisi Advanced Online Publication

IEEE

[1]Z. N. Kot, Z. F. Eker, and Ü. Özcan, “Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma”, Ankara Univ Vet Fak Derg, no. Advanced Online Publication, Oct. 2026, doi: 10.33988/auvfd.1985403.

ISNAD

Kot, Zeynep Nurselin - Eker, Zülal Feyza - Özcan, Ümit. “Complete Ultrasonographic Response of a Primary Bladder Lesion Followed by Extra-Vesical Progression After Lapatinib–piroxicam Rescue Therapy in a Dog With Urothelial Carcinoma”. Ankara Üniversitesi Veteriner Fakültesi Dergisi. Advanced Online Publication (October 1, 2026). https://doi.org/10.33988/auvfd.1985403.

JAMA

1.Kot ZN, Eker ZF, Özcan Ü. Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma. Ankara Univ Vet Fak Derg. 2026. doi:10.33988/auvfd.1985403.

MLA

Kot, Zeynep Nurselin, et al. “Complete Ultrasonographic Response of a Primary Bladder Lesion Followed by Extra-Vesical Progression After Lapatinib–piroxicam Rescue Therapy in a Dog With Urothelial Carcinoma”. Ankara Üniversitesi Veteriner Fakültesi Dergisi, no. Advanced Online Publication, Oct. 2026, doi:10.33988/auvfd.1985403.

Vancouver

1.Zeynep Nurselin Kot, Zülal Feyza Eker, Ümit Özcan. Complete ultrasonographic response of a primary bladder lesion followed by extra-vesical progression after lapatinib–piroxicam rescue therapy in a dog with urothelial carcinoma. Ankara Univ Vet Fak Derg. 2026 Oct. 1;(Advanced Online Publication). doi:10.33988/auvfd.1985403