Polymerase chain reaction analysis of the surgical margins of equine sarcoids for bovine papilloma virus DNA

Objective-To examine apparently normal skin around equine sarcoids for evid ence of bovine papilloma virus (BPV) DNA, and to relate this finding to the observed recurrence after surgery. Study Design-Prospective study. Animals or Sample Population-Forty-one equine sarcoids from 19 horses. Materials and Methods-The tumors were surgically excised at a measured dist ance of 8, 12, or 16 mm. Samples from the tumor and of the entire surroundi ng skin were taken at 4, 8, 12, and 16 mm from the tumor border and analyze d for the presence of BPV DNA using polymerase chain reaction (PCR) amplifi cation. The samples were grouped per examined sarcoid, and a tumor was cons idered positive at a certain distance as soon as at least one of the sample s at that distance was positive. The clinical outcome was recorded for each sarcoid after a minimal follow-up of 6 months. Results-All sarcoids were positive for BPV1 or BPV2 The tumor margin was po sitive at 4, 8, 12, and 16 mm in, respectively, 95%, 73%, 39%, and 33% of t he examined sarcoids. Local recurrence was observed in 3 sarcoids on 3 diff erent horses. From survival analysis, there was a greater likelihood for lo cal recurrence when sarcoids had a surgical margin that was positive for BP V DNA. Conclusions and Clinical Relevance-BPV DNA is often detected in visibly nor mal skin around sarcoids, and there is a significantly greater probability for local recurrence when the surgical margins are positive for the presenc e of BPV DNA. (C) Copyright 2001 by The American College of Veterinary Surg eons.