Keywords
Canine mammary tumor · Mistletoe therapy · Viscum album · Adjuvant treatment · Veterinary medicine · Quality of life · Oncology
Summary
Postsurgical Adjuvant Treatment with Mistletoe Extract (Viscum album ssp. album) in Canine Mammary TumorsBackground: The high incidence rate and malignancy of canine mammary tumors (CMTs) and their treatment pose a challenge in veterinary practice. Postsurgical therapy is required. Currently, there is no established standardized postsurgical adjuvant therapy and such a therapy is not expected for the near future. Maintaining or increasing the dogs' quality of life (QL) and their tolerance of the treatment are of importance to the pet owner. Cancer treatment by using extracts of European mistletoe (Viscum album L.; VAE) is well introduced in human medicine. Besides tumor baseline therapy using radiation or chemotherapy, treatment with VAE is one of the most common adjuvant methods among complementary and alternative therapies. Also in veterinary oncology, Viscum preparations have been used successfully for many years in various species. A number of studies underlined the positive effects of mistletoe treatment in animals. Methods: In the present study, the effects and benefits of postsurgical adjuvant therapy with VAE in canine mammary adenocarcinomas were investigated. Additionally, effects on QL were analyzed. For this purpose, a total of 56 female dogs were enrolled in the study. Of these, 33 dogs served as retrospective control group whereas 23 dogs were assigned as prospective VAE treatment group. The latter started VAE after surgical tumor excision. Results: The median survival time (MST) for all involved dogs (n = 56) was 32 months (interquartile range 13-51 months). For the control group, Kaplan-Meier analysis showed survival of 24 (73%), 20 (61%), 15 (45%), and 5 dogs (12%) after 12, 24, 36, and 48 months, respectively. In the Viscum group, survival was 19 (83%), 14 (61%), 11 (48%), and 1 dog (4%), respectively. Multivariate Cox proportional hazard analysis resulted in a lower death risk after VAE treatment (hazard ratio (HR) 0.53, 95% confidence interval (CI) 0.22-1.26), which was not significantly different between the two groups (p = 0.151). An also not significant tendency of decrease in tumor-related death risk to 25% (HR 0.251, 95% CI 0.056-1.122; p = 0.07) was observed for the treatment group. Conclusions: The results indicate a tendency of lower tumor-related death risk after postsurgical adjuvant VAE therapy in female dogs suffering from CMTs. The QL was stable during the entire observation period and the therapy was well tolerated by the patients. (HR 0,251,122). Schlussfolgerungen: Es kann eine Tendenz zur Senkung des tumorbedingten Sterberisikos der VAEGruppe bei guter Verträglichkeit der Therapie angenommen werden. Die LQ der Tiere blieb über die gesamte Beobachtungszeit auf hohem Niveau stabil.