Retrospective study: Laser excision versus combined laser, cryotherapy
and intralesional 5-fluorouracil in the treatment of equine sarcoids.
Abstract
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 cryotherapy 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, cryotherapy, 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 sarcoids. 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 sarcoids) 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); for
individual sarcoids ≥100mm in diameter (OR 5.6 (1.1-30), p=0.03); and
for treatment under general anaesthesia (OR 5.0 (1.4-19), p=0.01).
Horses with urogenital sarcoids and >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 the individual
patient and sarcoid(s) are likely to be more significant than selection
of any individual treatment protocol.