DOI
https://doi.org/10.18849/ve.v11i3.750Abstract
PICO Question
In dogs diagnosed with canine transmissible venereal tumour (CTVT), does treatment with vincristine combined with ivermectin, compared to treatment with vincristine alone, lead to improved clinical outcomes?
Clinical bottom line
Category of research
Treatment.
Number and type of study designs reviewed
Two randomised controlled trials.
Strength of evidence
Weak.
Outcomes reported
The studies collectively indicate that the combination of vincristine and ivermectin may be an effective and well-tolerated treatment for CTVT, with potential advantages over vincristine alone. One study demonstrated a statistically significant reduction in the number of treatment sessions for tumour remission, although methodological limitations and the absence of long-term follow-up limit the evidence. The other study observed comparable treatment efficacy across groups and a trend toward improved tolerability, despite the presence of cytomorphologically resistant types in the combination group; however, these differences were not statistically significant.
Conclusion
Ivermectin, a synthetic avermectin, may augment the action of vincristine when used for the treatment of CTVT. This may reduce the duration of therapy, lessen side effects, minimise recurrence and in turn reduce the animal’s suffering. Overall, the evidence to support this is assessed as weak.
References
Abeka, Y.T. (2019). Review on Canine Transmissible Venereal Tumour (CTVT). Cancer Therapy and Oncology International Journal. 14(4), 555895. DOI: http://dx.doi.org/10.19080/CTOIJ.2019.14.555895
Bulhosa, L.F., Estrela-Lima, A., da Silva Solcà, M., Gonçalves, G.S.D., Larangeira, D.F., de Pinho, F.A. & Barrouin-Melo, S.M. (2020). Vincristine and ivermectin combination chemotherapy in dogs with natural transmissible venereal tumour of different cyto-morphological patterns: A prospective outcome evaluation. Animal Reproduction Science. 216, 106358. DOI: https://doi.org/10.1016/j.anireprosci.2020.106358
Didier, A. & Loor, F. (1996). The abamectin derivative ivermectin is a potent P-glycoprotein inhibitor. Anti-Cancer Drugs. 7(7), 745–751. DOI: https://doi.org/10.1097/00001813-199609000-00005
Drinyaev, V.A., Mosin, V.A., Kruglyak, E.B., Novik, T.S., Sterlina, T.S., Ermakova, N.V., Kublik, L.N., Levitman, M. Kh., Shaposhnikova, V.V. & Korystov, Y.N. (2004). Antitumour effect of avermectins. European Journal of Pharmacology. 501(1–3), 19–23. DOI: https://doi.org/10.1016/j.ejphar.2004.08.009
Gaspar, L.F.J., Ferreira, I., Colodel, M.M., Brandão, C.V.S. & Rocha, N.S. (2010). Spontaneous canine transmissible venereal tumour: cell morphology and influence on P-glycoprotein expression. Turkish Journal of Veterinary and Animal Sciences. 34(5), 447–454. DOI: https://doi.org/10.3906/vet-0911-198
Jiang, L., Wang, P., Sun, Y.J. & Wu, Y.J. (2019). Ivermectin reverses the drug resistance in cancer cells through EGFR/ERK/Akt/NF-κB pathway. Journal of Experimental and Clinical Cancer Research. 38, 265. DOI: https://doi.org/10.1186/s13046-019-1251-7
Korystov, Y.N., Ermakova, N.V., Kublik, L.N., Levitman, M.K., Shaposhnikova, V.V., Mosin, V.A., Drinyaev, V.A., Kruglyak, E.B., Novik, T.S. & Sterlina, T.S. (2004). Avermectins inhibit multidrug resistance of tumour cells. European Journal of Pharmacology. 493(1–3), 57–64. DOI: https://doi.org/10.1016/j.ejphar.2004.03.067
Lapa, F.A.S., Andrade, S.F., Gervazoni, E.R., Kaneko, V.M., Sanches, O.C. & Gabriel Filho, L.R.A. (2012). Histopathological and cytological analysis of transmissible venereal tumour in dogs after two treatment protocols. Colloquium Agrariae. 8(1), 36–45. Available from: https://journal.unoeste.br/index.php/ca/article/view/657 (Accessed date: 20 February 2025).
Purohit, G.N. (2009). Canine Transmissible Venereal Tumour: A Review. The Internet Journal of Veterinary Medicine. 6(1).
Sewoyo, P.S. & Kardena, I.M. (2022). Canine transmissible venereal tumour: treatment review and updates. Revista Electrónica de Veterinaria. 23(1) 01–07. DOI: https://doi.org/10.5281/zenodo.15281327
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