Effect of mitomycin C on keloid fibroblasts: An in vitro study

Keloids are the result of aberrant wound healing of human skin after dermal injury. Therapeutic options include excision followed by radiation therapy, steroid injection, and compression with silicone sheets among others. Local invasion and recurrence after excision has provoked interest in treating keloids as neoplasms. The purpose of this study was to determine the effect of mitomycin C (MMC) on keloid fibroblasts. Keloid fibroblasts obtained from five different patients were exposed to MMC. A control group of normal and keloid cells was treated with phosphate buffered saline only. Contrast microscopy showed a decrease of fibroblast density during the 3 weeks after exposure for normal and keloid fibroblasts relative to untreated fibroblasts. This was confirmed by total cell counts (p = 0.1) and measurement of DNA synthesis. By the third week, there was a recovery in DNA synthesis and increased cell count for some of the treated fibroblasts. We concluded that at an appropriate concentration, MMC shows proliferation of keloid fibroblasts in vitro for a period of 3 weeks. This agent may be considered in clinical trials after surgical excision of keloids.