Avaliação da cardiotoxicidade da doxorrubicina em cães – estudo piloto

Resumo

Doxorubicin is a potent antineoplastic agent, belonging to one of the major classes of chemotherapeutic drugs used in oncology, the anthracyclines. Doxorubicin exerts antitumor activity against a wide variety of neoplasms, such as lymphoma, sarcomas and carcinomas, however, its use is conditioned by the possible occurrence of cardiotoxicity. The cardiotoxic mechanism of doxorubicin is still controversial, however, it is thought to be related to an increase in oxidative stress in the myocardium, mainly due to the generation of reactive oxygen species and lipid peroxidation, in cardiac cells. The cardiotoxicity induced by doxorubicin manifests itself in a similar way to dilated cardiomyopathy, in a process that depends on the cumulative total dosage administered. In this study, I intended to evaluate the presence of cardiotoxicity in dogs with different neoplasms, undergoing doxorubicin chemotherapy protocols. For this purpose, controls of echocardiographic parameters and cardiac biomarkers were performed during 5 stages of doxorubicin administration. Results of this study were not suggestive of cardiotoxicity, however, a consistent increase in plasma cardiac troponin I, with greater relevance at the end of the protocol, suggested some contribution of doxorubicin in myocardial injury. Because of the constraint associated with loss to follow-up, often implied in medical oncology, it was not possible to obtain an ideal sample size, so the conclusions drawn from this study are limiting. With this study, I pretend to alert to the importance of frequent prevention and control of cardiac function, in animals treated with this cardiotoxic drug. Although cardiotoxicity is not so frequent in dogs, due to the lower aggressiveness of chemotherapy protocols and a greater control of the cumulative doses, I believe that it is fundamental to focus on prevention in order to ensure an early diagnosis of cardiotoxicity, or even occult cardiac pathologies or cardiac involvement of neoplastic origin, which can contribute to a worsening of the health of each patient.

Data do prémio	2017
Idioma original	Português
Supervisor	Luís Pedro Rodrigues de Lima Lobo (Orientador) & JOAQUIM JOSÉ GARCIA PEREIRA HENRIQUES (Orientador)