Cancer Risk in Vitiligo: No Evidence of Increased Prevalence-A Systematic Review and Meta-analysis.

Introduction: Vitiligo, a chronic depigmenting disorder affecting 1-2% of the global population, is caused by immune-mediated melanocyte destruction. While its pathogenesis is multifactorial, the relationship between vitiligo and malignancy risk remains controversial. Some studies suggest an increased cancer risk, while others propose a potential protective effect, particularly against skin cancers. This study provides a comprehensive evaluation of malignancy risks in patients with vitiligo.

Methods: This systematic review and meta-analysis followed PRISMA 2020 guidelines and was registered with PROSPERO (CRD42023483130). A comprehensive search was conducted across Medline, EMBASE, and Cochrane databases. Studies reporting hazard ratios for malignancy incidence in patients with vitiligo were included. Data extraction and risk of bias assessment were performed using the Cochrane ROBINS-E tool.

Results: Of 7753 records identified, 6378 remained after duplicates were removed, and 12 studies were included in the final review. Quantitative analysis was performed on six studies. The combined sample comprised 3,267,951 participants, including 289,322 patients with vitiligo. Three meta-analyses were conducted for melanoma, non-melanoma skin cancer, and lymphoma. The pooled hazard ratio (HR) for lymphoma was 1.00 (95% CI 0.40-2.53), for melanoma 0.80 (95% CI 0.27-2.34), and for non-melanoma skin cancer 0.38 (95% CI 0.00-732.76), suggesting no consistent associations.

Conclusion: This meta-analysis did not identify significant differences in cancer risk across the examined subgroups. While a protective effect of vitiligo against some malignancies cannot be excluded, substantial heterogeneity among studies warrants cautious interpretation. Further high-quality research is needed to clarify these associations.