Retrospective study: Laser excision versus combined laser, cryosurgery and intralesional 5‐fluorouracil in the treatment of equine sarcoids

Summary Background Laser excision is used routinely in the treatment of sarcoids but may be ineffective in cases where complete excision cannot be achieved. A multimodal approach is warranted in these cases. 5‐FU may improve the lethal effect of cryosurgery as an adjunct to laser excision. Objectives To compare two treatment protocols for equine sarcoids, laser excision alone versus a combination protocol of laser excision, cryosurgery and 5‐FU chemotherapy. Factors associated with sarcoid recurrence are also investigated. Study design Retrospective case controlled study. Results Eighty‐four horses with 168 histologically confirmed sarcoids were included, with a median follow‐up time of 39 months (IQR 21–62 months). Sarcoid recurrence at the treated site was reported in 38% of cases and in 23% of any individual sarcoid. No significant difference was demonstrated between treatment categories in either rate of sarcoid recurrence ( p  = 0.45 for any treated horse, p  = 0.63 for individual sarcoid) or time to sarcoid recurrence ( p  = 0.73). Sarcoid recurrence was higher in horses with a greater number of sarcoids (OR 1.2 (1.0–1.5), p  = 0.03); when treatment had been received prior to admission (OR 7.6 (2.0–33), p  = 0.004). Horses with urogenital sarcoids or >1 mixed sarcoid experienced more rapid recurrence (HR 3.6 (1.3–10), p  = 0.02 and HR 9.9 (3.3–30), p  < 0.001) and recurrence was less rapid following the treatment of a horse's first sarcoid (HR 0.3 (0.1–0.7), p  = 0.009). Main limitations Significant differences in case populations in each treatment category. Treatment selection was neither blinded nor randomised and missing data and recall bias limit the study's power. Sarcoid recurrence was owner reported. Conclusions When assessing the likelihood of sarcoid recurrence, characteristics of both the individual patient and sarcoid phenotype must be considered carefully when selecting a specific treatment protocol.