Real-world effectiveness and safety of bleomycin in patients with keloids and hypertrophic scars: a systematic review and meta-analysis

Pathological scars are classified into hypertrophic scars and keloids, and currently have poor treatment outcomes and high recurrence rates. Bleomycin has received widespread attention in scar treatment in recent years, but there is currently no exploration on its real-world data. PubMed, Embase, and Cochrane databases were searched, and eight retrospective studies on the use of bleomycin for treatment were included, covering a total of 562 patients with keloids and hypertrophic scars. The meta-analysis results revealed that 90% of patients had significant flattening of scars after treatment with bleomycin, 5% had moderate flattening, and 4% had mild flattening. The recurrence rate after treatment was only 3%. The major adverse reaction was hyperpigmentation, with an incidence rate of 8%, and no significant ulcers or skin atrophy were reported. Subgroup analysis showed that the significant flattening rate treated with bleomycin alone was 91%, which was significantly different from the 79% treated with bleomycin in combined with triamcinolone acetonide, but the difference was not statistically significant. In addition, the significant flattening rate was 99% in Western patients and 57% in Asian patients, reflecting the impact of racial differences on treatment outcomes. There was no statistically significant difference in curative effects between males and females (RR: 0.95; P = 0.77). Overall, bleomycin has good curative effect in treating scars and has high safety, especially showing more significant effects in Western populations. However, racial differences, treatment plans, and other factors may affect the therapeutic effect of bleomycin. Future research can further explore the mechanisms of these factors and provide more personalized treatment plans for patients with scar.