The effects of a single dose of 5-fluorouracil on keloid scars: A clinicaltrial of timed wound irrigation after extralesional excision

The possibility of altering the pathophysiology of keloid scars was investi gated in 11 patients, using a single application of 5-fluorouracil solution for 5 minutes after extralesional excision was performed. Similar excision al wounds treated with phosphate-buffered saline for 5 minutes served as sy nchronous controls. An objective scoring system and subjective assessment w ere made to assay the change in the quality of the wound-healing and scar t issue produced by this treatment. A keloid scar score was used at regular t ime intervals after treatment to assess the quality of scar produced, there by enabling the treated and control scars to be clinically compared. Biopsies were taken of the control and treated scars 1 month after treatmen t; the biopsy specimens were then subjected to immunohistochemical analysis as well as a functional assessment of cultured keloid fibroblasts. The imm unohistochemical antigens assayed were Ki-67 (also called MIB-1; a marker o f cell proliferation); vascular cell adhesion molecule-1 (a marker of infla mmation), transforming growth factor beta-1 (a factor involved in scarring) and CD-68 (a macrophage-specific marker). Fibroblast-populated collagen la ttices provided a functional assessment of fibroblast contraction. All treated and control wounds healed without any dehiscence or infection. The keloid scar score revealed that there was a perceived improvement in co ndition for those treated with 5-fluorouracil, compared with the control sp ecimens, during the 6-month follow-up period in the five patients who atten ded all their clinic appointments; data on later recurrence are not complet e as yet. The wounds treated with 5-fluorouracil produced scars that had a significant (p < 0.01) reduction in all the markers assayed, apart from CD- 68. Functionally, the keloid fibroblasts from three of five of the treated patients showed reduced contractile capacity. This pilot study demonstrates that a "single-touch" technique with 5-fluoro uracil can produce a change in the characteristics of the healing keloid wo und after extralesional excision. Long-term studies are required to elucida te the correct dosage and time of exposure to improve the efficacy of this potential treatment.