Utvärtes behandling av sarkoider på häst med Aldara TM eller Xxterra TM : en jämförande pilotstudie

Abstract: Sarcoid is the most common tumor in horses all over the world. The sarcoid is a benign, locally invasive, usually fibroblastic proliferative skin neoplasm. Even if the etiology is not completley verified, the epidemiology and clinical behavior suggest a infectious intervention, probably BPV type 1 or type 2. However, it is known that the cause is multifactorial. A genetic prepdispositon has been identified associated to genes within the Major Histocompatibility Complex (MHC), but also to breed, age and perhaps gender. There is also a proved connection between skin-trauma and development of sarcoids. This type of neoplasm tend to develop in areas of thin skin, such as the face, distal limbs and ventral parts of thorax, abdomen and genital areas. There are six saroid types identified makroscopically; occult, nodular, verrucous, fibroblastic, mixed sarcoid and malevolent. However a biopsy for histopathology is needed to verify the diagnosis. There are several treatment options available (surgery, cryosurgery, hyperthermia, radiation, chemotherapy and immunotherapy), but their use may be limited depending on the type of sarcoid, size, area affected, localization, available equipment and environmental safety. Sarcoids are also known for a high reoccurence rate after treatment. This study compares and analysis the effects of Aldara™ and Xxterra™. Aldara™ is a verified immunotherapy, whereas the exact mechanism of action for Xxterra™ is not verified, though according to the producer Xxterra™ is also an immunotherapy. With this type of treatment the local immune system will be stimulated to reduce tumour cells and virus. The purpose of this study was to find a simple and effective treatment with a low rate of reoccurency. The study enrolled 19 horses with a total of 130 tumours. Of these tumors, 41 where treated and the rest were used as untreated controls. Seventeen horses with 30 tumours were treated with Aldara™ and 10 horses with 15 tumours were treated with Xxterra™. Eight of the horses with multiple sarcoids were treated with both ointments. Of the 30 tumors treated with Aldara™ 27 tumors (90%) has so far responded with size reduction or total regression. The 3 tumors that didn´t respond to treatment were all fibroblastic sarcoids localized to the distal limbs on one horse. Of the 15 tumors treated with Xxterra™ 14 tumors (93%) has so far responded with size reduction or total regression. The tumor that didn´t respond to treatment was an occult sarcoid localized to the shoulder. In all the tumors that didn´t respond to treatment a change of medicine was made, after a treatment free period of at least 12 weeks, which immedately lead to a reduction in size. All the tumors has so far responded to at least one of the treatments. The preliminary results of these two types of treatments are encouraging, though the number of horses included in the study is small. An extended study, comprising more horses and longer periods of follow-up, is required to be able to corroborate these conclusions.